Elektrik - Best Electronic Projects Reviews

5 Volt DC Regulator to charge iphone and other phones from 12 or more DC voltage

noreply@blogger.com (dvbot) — Mon, 05 Jun 2017 20:50:00 +0000

5 Volt DC Regulator to charge mobile phones from variable DC voltage

Mobile phones commonly charge with 5 volt regulated DC supply, so essentially we are going to build a 5 volt regulated DC deliver from 35 - 7 volt DC.

This DC supply can be used to charge mobiles as well as the power supply for virtual circuits, breadboard circuits, ICs, microcontrollers and so on. For 12 volt or more you just need to set up a heat sink for better voltage and current.

This circuit in particular is composed a 5V voltage regulator IC (7805) and filter capacitors.

LM7805 Voltage Regulator

This incorporated circuit made by texas devices is very popular for regulating voltage as much as 35v down to 5v. It is recommended to use heatsink if the input voltage is above 12volt, so the heat dissipation is better and the output as well as the life of voltage regulator is not disturbed.

100uf Polorized Capacitor

This capacitor is polorized because of this it may most effective be positioned in only one direction. the gray stripe on one side with the arrows dictates the negative side of the capacitor.

Application

Can be used to convert 12 volts from a car battery or a cigarette lighter into a universal 5 volt phone charger, which can later on connected to USB female.

Can convert fluctuating DC volts from source to stable and filtered 5 volt DC.

Protects your gadgets from draining over voltage than it's limit.

Connecting 5 Volt DC to USB female

Connect the negative from the above circuit to the black wire of USB wire and positive to red wire of USB. Connect the white and green wire together so phone is tricked into thinking it is connected to charger and can accept full ampere provided from the circuit, which can be around 1000mA.

This kind of wiring will work with most phones like iPhones and common android phones.

How to easily repair Momentary Switches used in boats

noreply@blogger.com (dvbot) — Wed, 17 Aug 2016 12:53:00 +0000

Momentary switches make generators and motors begin at the push of a catch. In any case, when they don't begin, consider the switch as opposed to the segment itself.

If your horn won't blow, or blows erratically, it's probably the switch that is causing the problem

A momentary switch can come in various structures. You are presumably most acquainted with the little push button on your panel or board in charge. How about we take the button for horn for instance. You push it in and the horn blows. You take your finger off, it pops pull out, and the horn quits blowing. Assume the horn doesn't blow, or blows whimsically, when you push the button in. The issue might be eroded connections at the switch terminals or somewhere else. This is anything but difficult to fix so check connections at the switch, horn, and power sources, before going any further. On the off chance that you see erosion or different weaknesses, for example, a loose connection, settle that first. This might be as basic as fixing a screw or detaching the connection, cleaning it with a abrasive, including a squirt of moisture disbursing oil, and reassembling. In the event that you don't see an issue with the wiring and connection, suspect the switch.

Finding the root of problem

The basics of a momentary switch are genuinely basic. The button is basically a plunger held in the out position inside its casing by a spring. At the flip side of the plunger (inside the switch lodging) is a contact surface. This is a metal channel joined to the plunger, or pushed by the plunger, with the goal that it contacts (jumps) and consequently connects the back ends of the two wire terminals. The circuit is completed and the horn blows. When you remove your finger, the spring pushes the plunger back out and the contact is broken.

Momentary switch from a horn - the wires attach to the terminals at the base.

Carefully opening switch by bending back tabs.

Removing terminal plate from switch box.

You can usually determine quickly if the switch itself is the offender via deliberately hopping the wires, which are connected to the terminals behind the switch. Essentially remove one wire from its terminal and touch it to the next. This normally causes a spark, and sparks cause blasts and fire unless the territory where you are working is totally free of combustibles, including gasses. You can likewise get a little stun in case you're not cautious. A few mechanics utilize an improvised jumper wire, which is a short bit of well insulated wire with terminals at every end and a positive on/off switch in the center. You turn the wire switch off, interface the wire ends to the momentary switch terminals, turn the wire switch on, and this more securely jump the terminals. This wire and its on/off switch must be heavy duty enough to securely conduct the current involved. (On the off chance that you have any uncertainty, get a qualified professional to do this straightforward check.) If the horn blows when you jump the wires, your issue is likely in the switch.

You can likewise test the switch, in principle, by removing both wires and utilizing a volt-ohm meter to test for continuity by touching the probes to the switch terminals. There ought to be absolute continuity when you push the button. On the off chance that there is no continuity, or if it is intermittent, you have found the issue. Be that as it may, volt-ohm meters are at times hard to interpret unless you're acquainted with them. (Notice I utilize words, for example, "presumably" and "generally" a lot of times. This is on the grounds that, with boat work, even straightforward boat work, couple of things are certain and it's essential to dependably expect the unforeseen.)

In deep working of the switch

Given how basic momentary switches are, what can turn out badly?

Generally the contact points get to be hollowed or eroded to the degree that they pass either no current or current deficient to carry out the work well. The fix might be to just sand or file the contacts. You should disconnect the wiring and remove the switch from the panel board first and open the lodging at that end of the switch. This might be simple or not worth the exertion, depending upon the switch, but rather in a crisis circumstance you might be happy you know how to take care of the issue at least temporarily.

With the terminal plate removed and the switch depressed, you can see the two humps on the jumper bar at the base of the switch, which make contact with the contact pads on the terminal plate to close the circuit.

In this switch, the contact pads have become corroded and pitted, and the jumper bar is askew.

After partial filing and cleaning, most of the corrosion on the contact pads has been removed, but the depression on the left-hand pad from arcing may interfere with a good contact.

Another sort of issue is that the contact part moves or becomes dislodged from its assembly and in this way doesn't solidly seat against the rear of the wire terminals when you push the button. This is normally brought on by age and wear, and is from time to time worth fixing. (A well-made switch will regularly keep going quite a while before this happens.)

A third issue can happen if there is obstacle between the plunger and the shaft walls in which it moves. This could happen from issues, for example, a lot of oil or lubricant that has solidified from dirt, or from corrosion. Contingent upon the build of your switch, this might be simple or hard to get to, and clean utilizing light emery polishing paper or maybe only a rough clean rag. It can be an especially troubling issue in light of the fact that frequently the plunger gets stuck in the down position, implying that the horn won't turn off. This issue is far more awful if the momentary switch is being utilized to begin the engine. It is common for these switches to stick down in this application, making the starter solenoid stay activated, and therefore keeping on running the starter even after the motor has fired off. This can rapidly ruin an extremely costly starter and related parts and is a justifiable reason to replace these moderately cheap switches frequently.

Simple 3 Watt and 5 Watt LED Driver Circuit Using IC 338

noreply@blogger.com (dvbot) — Wed, 30 Dec 2015 16:35:00 +0000

The IC LM338 as we probably are aware, is a profoundly adaptable gadget with regards to controlling voltages and current levels.
In the present outline, the gadget is designed in the programmed current control mode.

White LEDs particularly require a very much dimensioned info, actually the current to these LEDs must be entirely controlled.

By interfacing its ADJ pin with the OUTPUT ensures that the current at the OUTPUT is continually checked by the ADJ terminal and is never permitted to go past the foreordained level set by the resistor.

The gadget can bolster no less than 3 amps of current through it, in this manner effortlessly gets to be good to drive 1 to 5 quantities of 1 watt LEDs, each having their own particular current constraining resistors.

The present limiting resistors can be tried different things with, presumably lesser values may be tried for increasing the luminosity levels of the LEDs, however anything under 50 Ohms ought not be attempted, in light of the fact that it may bring about a perpetual harm to the LEDs.

The data to the LM 338 IC can be from a directed DC control supply, fit for supplying 12 volts at 3 amps or more.

The IC LM 338 ought to be mounted over a heatsink for better execution.

The data diode ought to be appraised at 3 amps, so a 1N5408 turns out to be OK for the application.

In the event that the circuit is expected for working outside, the data may be taken from a 12 v battery, as from a vehicles battery.

For L = 3 Watt LED:
R = 1.8 Ohms of 2 Watt

For L = 5 Watt LED:
R = 1.05 Ohms of 4 Watt

Remote control switch on or off for home appliances

noreply@blogger.com (dvbot) — Tue, 03 Nov 2015 19:24:00 +0000

Associate this circuit to any of your home apparatuses (light, fan, radio, and so on) to make the machine turn on/off from a TV, VCD or DVD remote control. The circuit can be activated from up to 10 meters.

The 38kHz infrared (IR) beams produced by the remote control are received by IR collector module TSOP1738 of the circuit.
Pin 1 of TSOP1738 is associated with ground, pin 2 is joined with the power supply through resistor R5 and the output is taken from pin 3. The output signal is increased by transistor T1 (BC558).

The amplifier signal is given to clock pin 14 of decade counter IC CD4017 (IC1). Pin 8 of IC1 is grounded, pin 16 is joined with Vcc and pin 3 is associated with LED1 (red), which shines to demonstrate that the machine is "off."

The output of IC1 is taken from its pin 2. LED2 (green) associated with pin 2 is utilized to demonstrate the "on" condition of the apparatus. Transistor T2 (BC548) joined with pin 2 of IC1 drives hand-off RL1. Diode 1N4007 (D1) goes about as a freewheeling diode. The machine to be controlled is associated between the pole of the relay and neutral terminal of mains. It gets associated with live terminal of AC mains by means of normally opened (N/O) contact when the relay energizes.

Simple Car Audio Amplifier Circuit

noreply@blogger.com (dvbot) — Tue, 03 Nov 2015 19:14:00 +0000

A straightforward low power car stereo amplifier circuit taking into account TDA 2003 is showed here.

The circuit utilizes low cost, promptly accessible components and it is anything but difficult to develop.
TDA2003 is an integrated car radio amplifier from ST Micro electronics that has a ton of good elements like short circuit protection for all the pins, heat over range level low harmonic distortion, low traverse bending and so on.

In the circuit given here each TDA2003 is wired as a mono amplifier working from a 12V DC supply. Resistors R2 and R3 shapes a feedback system that sets the amplifier gain. C7 is the input DC de-coupling capacitor and C5 couples the speaker to the amplifiers yield. C4 is utilized for enhancing the swell dismissal or ripple rejection while C1 and C2 are utilized for power supply filteration. C3 and R1 are utilized for setting the upper frequency cut-off. Network containing C6 and R4 is utilized for frequency adjustment and to avoid oscillation.

Using Arduino as a simple Web Server along with Ethernet shield

noreply@blogger.com (dvbot) — Fri, 16 Oct 2015 10:00:00 +0000

Using an Ethernet shield along with Arduino board you can turn it into a simple web server which can be accessed by anyone on the internet, and by accessing that server with a browser running on any computer connected to the same network as the Arduino board, you can:

Control hardware from the webpage like fan or lights (using Javascript buttons).
Read the state of a switch which can be either ON or OFF (using simple HTML).
Read value of a sensors connected to Arduino board (using simple HTML).

Arduino Board

Ethernet Shield

Hardware needed:

To use an Arduino Board as a Simple Web server, you need the following:

   DC Voltage of 5V from Arduino - To power the Ethernet Shield
    Ethernet shield - To connect with LAN
    Connection speed: 10/100Mb - For optimum performance.
    Connection with Arduino on SPI port

The Ethernet shield will connect the Arduino board to the Web or Internet. Setup is very simple, Just plug the header pins of the shield into your Arduino, then connect an Ethernet cable to the shield. In the figure below, you can see an Arduino Mega with an Ethernet shield installed and connected with internet.

Now let's get to the working.

We will demonstrate how to use the Arduino as a Web server, in the further experiment we will find how Arduino can show the state of a switch through sending information as a web server. Giving it's output in html pages

Components required:

1 x Ethernet cable
1 x Wi-Fi Router (Optional)
1 x Arduino Mega2560 or Arduino UNO
1 x Ethernet Shield
1 x Breadboard or blank circuit board can do as well
3 x Jumper Wires
1 x 1k Resistor
2 x 9VDC Adaptor
1 x Push button

Schematic

Connect the components as shown in the figure above. Pin 8 of the Arduino is connected to the Push button. This pin is configured as an INPUT, and when the button is pushed, the Arduino will read a HIGH value on this pin because the current will start flowing in this part. The Arduino will then set the status of the OUTPUT to ON on the webpage it hosts. When it is released, the output will be set to OFF. The status of the switch will available to the Web server as we need it.

Ethernet design

To control the Ethernet shield, you utilize the Ethernet.h library.

The shield must be allocated a MAC and IP address utilizing the Ethernet.begin() function. For a specific gadget, a MAC address is an all around extraordinary identifier. Current Ethernet shields accompany a sticker showing the MAC address. For more seasoned shields, an arbitrary one ought to work, however one should not utilize the same MAC address for many Ethernet Shields. Legitimacy of IP address relies on upon the arrangement of one's network. In the event that DHCP is utilized, it might dynamically assign an IP to the shield.

IP ADDRESS

IP address (Internet Protocol address) is a numerical name allotted to every gadget participating in a PC system that uses the Internet Protocol for correspondence. To indicate the IP address which is done inside the system. It is basic:

byte ip[] = { 192, 168, 0, 112 } and change it to match one own setup. For instance, if the switch's IP location is 192.168.0.60, and the scanner has 192.168.0.40, So I will allot the IP of Ethernet shield to 192.168.0.50 with the assistance of taking after order:

byte ip[] = { 192, 168, 0, 50 };

The initial three bytes ought to be same and it should not have similar IP address as any of other devices connect in same LAN.

MAC ADDRESS

MAC address (media access control location) is an exceptional identifier doled out to every gadget taking an interest in a physical system. Every bit of systems administration gear has an one of a kind serial number to recognize itself over a system and this is typical hard-modified into the hardware's firmware. In any case, with Arduino, we can characterize the MAC address our self.

byte mac[] = { 0x90, 0xA2, 0xDA, 0x0D, 0x85, 0xD9 };

You can set the subnet and portal with the assistance of taking after charges:

byte subnet[] = { 255, 255, 255, 0 }; /allocating subnet veil

byte gateway[] = { 192, 168, 0, 1 }; /allocating entryway

Along these lines, to setup Ethernet Shield, the square of code is given below:

/********************ETHERNET SETTINGS ********************/

byte mac[] = { 0x90, 0xA2, 0xDA, 0x0D, 0x85, 0xD9 }; /allotting MAC address

byte ip[] = { 192, 168, 0, 112 }; /ip in lan

byte subnet[] = { 255, 255, 255, 0 }; /allotting subnet mask

byte gateway[] = { 192, 168, 0, 1 }; /allotting default gateway

The following is a picture of the connection, demonstrating how the Arduino board unites with the Wi-Fi switch. The Ethernet link associate shield with the switch and switch then join remotely with the portable workstation. Or you can just connect the Ethernet shield directly to your home router or switch.

Program
Below is the script that outputs HTML of a simple Web page.

client.println("<!DOCTYPE html>"); //web page is made using HTML

client.println("<html>");

client.println("<head>");

client.println("<title>Ethernet Tutorial</title>");

client.println("<meta http-equiv=\"refresh\" content=\"1\">");

client.println("</head>");

client.println("<body>");

client.println("<h1>A Webserver Tutorial </h1>");

client.println("<h2>Observing State Of Switch</h2>");

client.print("<h2>Switch is:  </2>");

if (digitalRead(8))

{

client.println("<h3>ON</h3>");

}

else

{

client.println("<h3>OFF</h3>");

}


client.println("</body>");

client.println("</html>");

This program will display a web page on a Web browser when the IP address assigned to the Arduino is accessed.
The line:

client.println("<http-equiv=\"refresh\" content=\"1\">");

Educates the browser to refresh the page. At the point when the page is accessed once again, the Arduino will again read the switch's status and present it in the output.
Recall that, you can simply see the source code of the displayed Web page. On pushing the push button, you can watch the changing condition of the switch in the webpage.
You can likewise set this up to keep running without the switch. To do this you have to:

Assign a manual IP address to the Arduino's Ethernet say 192.168.0.2 and Subnet mask 255.255.255.0 default Gateway empty.
Use a cross-over Ethernet cable to link the two (laptop and Arduino).
We should then be able to get your Arduino site up on http://192.168.0.2 from the laptop.

Below is the code that you would load into the Arduino to connect it directly to the PC without the router:

#include <SPI.h>
#include <Ethernet.h>


/******************** ETHERNET SETTINGS ********************/

byte mac[] = { 0x90, 0xA2, 0xDA, 0x0D, 0x85, 0xD9 };  //physical mac address
byte ip[] = { 192, 168, 0, 112 };                   // ip in lan
byte subnet[] = { 255, 255, 255, 0 };              //subnet mask
byte gateway[] = { 192, 168, 0, 1 };              // default gateway
EthernetServer server(80);                       //server port


void setup()
{
Ethernet.begin(mac,ip,gateway,subnet);     // initialize Ethernet device
server.begin();                             // start to listen for clients
pinMode(8, INPUT);                         // input pin for switch
}

void loop()
{
EthernetClient client = server.available();   // look for the client

// send a standard http response header

client.println("HTTP/1.1 200 OK");
client.println("Content-Type: text/html");
client.println("Connnection: close");
client.println();

/* 
This portion is the webpage which will be
sent to client web browser one can use html , javascript
and another web markup language to make particular layout 
*/

client.println("<!DOCTYPE html>");    //web page is made using html
client.println("<html>");
client.println("<head>");
client.println("<title>Ethernet Tutorial</title>");
client.println("<meta http-equiv=\"refresh\" content=\"1\">");

/*
The above line is used to refresh the page in every 1 second
This will be sent to the browser as the following HTML code:
<meta http-equiv="refresh" content="1">
content = 1 sec i.e assign time for refresh 
*/

client.println("</head>");
client.println("<body>");
client.println("<h1>A Webserver Tutorial </h1>");
client.println("<h2>Observing State Of Switch</h2>");

client.print("<h2>Switch is:  </2>");

if (digitalRead(8))
{
client.println("<h3>ON</h3>");
}
else
{
client.println("<h3>OFF</h3>");
}

client.println("</body>");
client.println("</html>");

delay(1);      // giving time to receive the data

/*
The following line is important because it will stop the client
and look for the new connection in the next iteration i.e
EthernetClient client = server.available();
*/
client.stop();

}

Hope you liked this project. For more projects related to Arduino or any other electronic please message me or write them in the comments.

Simple +-400Watt Amplifier using TDA7294 or TDA7293 + Power Transistors 2SC5200 and 2SA1943

noreply@blogger.com (dvbot) — Thu, 08 Oct 2015 07:47:00 +0000

This additional part can be added to the traditional chip amp made using TDA7294 or TDA7293 to gain extra power in output.
The traditional chip amp produces about 40-50watt rms output which isn't any less but by adding these power transistors it can maximize the output to extreme.

This is the classic TDA7294 AMP with LOTS more Power then normal, this is with using Power Transistors at the output stage, it is a simple Addon to make, it just requires a SYNC resistor and the feedback to be moved to the output after the Power Transistors.

So to make this AMP you can just start with the TDA7294 with one change, just need to "move" the feedback so you can connect it to the Output after the Power Transistors, in all the AMPS that have been made with the TDA7294 the 6.8Ohm has been spot on when using the 2SC5200 & 2SA1943, if you use other transistors you may need to experiment with another value for the SYNC resistor.

Things to do when SYNC it is to listen to it, things to listen to are from very low volume (FROM a clean source) and go slowely up in volume, the POINT here is that it should just get louder like a normal amplifier would, if the SYNC is off then a normal thing will be that at audio peaks (like drums & bass) it will sound like someone is kicking your speakers because the Transistors kick in at a wrong volume then the amp is playing, believe me you will hear it, this needs to be corrected by changing the resistor else you will have an amp that only sounds good at very low volume and medium to high volume.

Component list: (1x AMP)
1x 680 (680R) Resistor
1x 10K Resistor
3x 22K Resistor
1x 6.8 (6R8) 5W Resistor
2x 0.15 (0R15) 5W Resistor
2x 10uF 50V Capacitor
2x 22uF 50V Capacitor
1x 1uF 63V MKT/BiPolar Capacitor
1x TDA7294 Chip AMP
1x 2SA1943 PNP Transistor
1x 2SC5200 NPN Transistor

Output Power: The output is at 400W+ (MAX) and this is based on that the TDA itself adds ONLY 20-40W (because of the much higher driving Ohm), but the 5200/1943 are some GOOD POWERFULL transistors and going through the datasheet it will deliver peeks over 600W (short pulse pr Transistor), they supply 100W but this is FULL DC and there are no audio tracks to my knowledge that has that kind of "sound"
Driving Impedance: We have been using it for 2-8Ohm speakers, the lowest we have driven was 1.3Ohm but as with all AMPS if you know your Transistors you know how many watts you can pull out, this AMP will drive what ever you hook it up to, JUST one thing, when we were using my 1.3Ohm set it did introduce some "noise" (sounded like 80' AMP hiss), and at this point the SYNC resistor properly needs to be changed, we did not do this, we took the lazy way out and put some 1.8Ohm POWER Resistors in line with the speakers instead.

We have been using this AMP for +3 years, it is good for driving 2-8Ohm speakers with current config (6.8Ohm RES & 5200/1943)

Stun Gun Circuit Diagram using 555 timer IC

noreply@blogger.com (dvbot) — Tue, 29 Sep 2015 19:30:00 +0000

CAUTION: Before going to explain about this circuit, we are going to strictly suggest that DO NOT TRY TO IMPLEMENT IT PRACTICALLY AS IT PRODUCES VERY HIGH VOLTAGE.
DO IT ONLY UNDER A PROFESSIONAL'S GUIDANCE!

A stun gun is usually a device used to produce a very high voltage, low current signal and is used mostly as a weapon to stun or send shock waves to the target with the intention to weaken or paralyze the target.

However moving towards to design the circuit, it should be kept in mind that in some countries, stun gun is banned so this project is only for educational purpose.
Because, this is actually a lethal weapon which can render a person mentally and physically paralyzed. It is usually powered by a 12 Volt battery or by a 12Volt DC adapter.
The stun gun circuit uses a 555 Timer to produce a current fluctuating signal and a voltage multiplier using a transformer and a multiple stage (8) arrangement of voltage doublers using capacitors and diodes.

You can use a Mosfet in place of BD679. For eg: IRF220

As soon as the switch is pressed, the operation of 555 Timer starts. A pulsating electric signal of low current is produced because of supply, which is stepped up using a step up transformer, to a voltage of around 1000V. The signal from the Timer is fed through the transistor switch.

All this results in the output of around a thousand volt which is enough to stun the target for some minutes.

A simple 12V battery charger schematic using LM317

noreply@blogger.com (dvbot) — Tue, 29 Sep 2015 11:16:00 +0000

This is a simple 12Volt Battery Charger Circuit which can be made using less components.

This circuit can be modified using the formulas given on it. Using the formulas the components can be changed to work with your battery.

It provides a fuse, as the positive and negative charge reversal protection, output short circuit protection, also protects if the output voltage exceeds 2V, it can also limit the current output.

An Ampere Meter can be used in series with the battery to check the output current to battery. Usually the output current should be below 10-15 Ampere.

500 Watt Inverter using Transistor 2N3055 along with Transformer ratings

noreply@blogger.com (dvbot) — Wed, 19 Aug 2015 11:11:00 +0000

This Circuit has been corrected while it had minor issues in the past, the circuit has been fully debugged for any problems and made 100% working now.

Utilizing this circuit you can change over the 12V DC into the 220V AC. In this circuit 4047 is utilized to create the square wave of 50hz and increase the current and afterward amplify the voltage by utilizing the step up transformer.

To calculate the Transformer rating for this circuit:

The basic formula is P=VI and between input output of the transformer you have

Power input = Power output

For example if you want a 220W output at 220V then we need 1A at the output. Then at the input you must have at least 18.3V at 12V because: 12V*18.3 = 220v*1

So you have to wind the step up transformer 12v to 220v but input winding must be capable to handle strong power of 20A.

Making your own 10,000 to 25,000 volt capacitor

noreply@blogger.com (dvbot) — Mon, 10 Aug 2015 21:05:00 +0000

We are going to make a big High Voltage Capacitor, so please do not try this unless you are an expert in handling high voltage equipments.

In our above HV Capacitor design, we used a clear plastic make up container that we purchased from a local market. We then purchased 5” x 50 foot aluminum sheeting from a hardware store, you will need 2 rolls. We then cut the aluminum in small pieces of 5” x 6” sheets. Once you are done with cutting both rolls up. Then you will need to make your bolt holes on the ends of your positive and your negative plates. You will need a good 3-M spray adhesive, which must spray a fine spray, you can Purchase this at any Hardware or Art Store. Now you will need to cut 6” x 6” plastic Mylar pieces for your die electric.

You will need to bond them to the aluminum plates. Use a 3 mill or a 4 mill plastic, this should hold up under 10,000 vdc.

Cut a small piece of ½”plywood to 5” x 6” then drill your bolt holes using the + and negative plate as a template, Now you will need a small drill press, set up a wood jig with register marks so you can drill holes in all the other aluminum plates in the exact same spot. Holes should be a little bigger than
the bolt. Even out 2 stacks of 5” x 6” aluminum plates, start off drilling the one stake first and mark each one as +.

This will help you later and you will thank me for it. Then do the Neg plates the same way. Make sure you drill holes in the exact same place, so all bolt holes will line up correctly when you push the holding bolts through. When you are finished drilling holes, place 4 guide bolts through the bottom of your plywood base. Using these bolts as guides.

Now spray the top of the plywood with adhesive. Now place your first 5” x 6” + plate on it, press down firmly. Now spray your mylar plastic on a sheet of cardboard away from your project, spraying only one side, you want to keep the spray away from your project or it will build up on your bolts. Now place the mylar to the right side of the holes, press firmly, now spray one side of your Neg. Plate and insert over the right side bolts. The left bolts are for your + plates and the Right side is for your Negative plates. Now repeat this over and over again.

Be careful and not to forget to place Mylar plastic in-between each + and Negative plate. Or they will short out.

It will take you about 16 hrs of work to finish, once you are done place 2 bolts on the top of your plastic lid. Connect the left one to the left bolts using 8 gauge wire or wire rated for the amount of voltage and amperage you are going to use capacitor for, do the same for the right.

Doing a Country Style track lighting.

noreply@blogger.com (dvbot) — Sat, 08 Aug 2015 20:58:00 +0000

Track lighting is another expansion in enriching our homes environment. It gives an extremely lovely lightning effect. One can change its brightening through a control unit in regards to the amount of light is needed.

They can be introduced in the kitchens and most perfect spot would be the lounge and rooms relying on their shape and the way of the client or occupant. These lights can be set near the windows, flower pots, book retires, and chimneys.

Track lights don't give brilliant light, yet the general impact is simply enhancing and gives a mood to the room. Specially framed and different shaped lights are accessible for the billiard table, kitchen table and some even molded as country utensils and western legacy ornamental styles. It is most suitable to utilize them where the roof tallness is adequate and the pendant can hand freely. These are found in distinctive shades, for example, nickel, bronze, metal, dark, chestnut, gold, copper, chrome, rust, silver and so on.

Arrangement should be possible in any structure, as a group forming a triangle, or inline or circle.

These lights must be mounted with the minimum height of 24 to 30 inches over the floor. On the off chance that more than two lights are utilized, customizable bars can be used.

Pure typical country track lights are the, cart wheel, milk jug in copper and brass, spur, lantern, chime, clock and numerous others. Each style likewise speaks to the culture of the district and acts and bringing close the people. They deliver the impact of warmth and convenience which other bright lights and modern lights don't. The costs range from 50 US$ to some even 1000 US$. Organizations into business are additionally offering altered style too.

Other suitable spots for these lights are on top of the windows, flower pots, fish aquarium, and corners of the dinning room, sitting lounge or family room. You can put them on entryways, stair lobbies where they can be utilized as a part of a solitary line. Lights fit as a fiddle of bell, or cart wheel, or lantern give a delicate look when utilized as a part of the dinning region making the room in all more pleasing and inviting.

Installation
If you already acquire a ceiling light fixture, track lights are anything but difficult to introduce. Basically remove the old apparatus, screw the track into the roof utilizing toggle botls or other fitting grapples, connect the new track to the electrical box, snap your lights set up and appreciate the enjoyment of moving them around to get the lighting in your room precisely the way you need it!

You can discover boundless approaches to put the track lights in and around your home. The idea is basically to give light and improve style and magnificence of your home with a low power bill. With LED track lighting framework you can make sure of sparing a considerable measure on your energy cost as these don't consume much power.

While innovation is at it's peak are you still wondering how solar panels work?

noreply@blogger.com (dvbot) — Mon, 03 Aug 2015 11:00:00 +0000

Solar Panels are turning out to be more well known today as a distinct option for conventional power era systems. By utilizing Solar Panels, we can outfit the Heat and Light energy gave by the sun and create power for anything from an icebox to a car. Have you ever seen Solar Panel secured rooftops or school zone signs with Solar Panels on and thought about how these Solar Panels work and what's going ahead "behind the boards?" "How do solar panels work?"

Lets take a gander at what Solar Panels are involved of and how solar panel innovation functions.

Solar Panel innovation is taking into account 2 sorts of sunlight based warmth accumulation: Solar power collectors and solar cells. Since for all intents and purposes of making solar cells are based on Solar panels, we'll concentrate on the Solar panel innovation. Solar cells, otherwise called photovoltaic cells, is the thing that makes up a photovoltaic board, or all the more regularly known as a Solar Panel. Try not to let the word photovoltaic threaten you. Lets break the word separately: photograph = light and voltaic = power (consider volt or voltage).

Basically it's speaking to the thought of changing over light into power. These photovoltaic cells are basically embody a semi-conductor, most generally silicon. I'm certain you have found out about silicon, and are really utilizing the innovation at this moment... in your Personal Computer, Silicon is utilized as a part of microchips, is is also utilized in every electronic semiconductor around the globe, is an exceptionally well known semi-conduit. At the point when light hits these silicon filled PV cells, the sunlight based vitality is consumed and a current is delivered inside the cell. By hanging together these Photovoltaic cells into a Solar panels, and putting contacts on the outside of this board, we have the capacity to take advantage of this electrical current.

Now that you know how Solar Panels work, what happens next?

When we have the Solar Panels wired and cooperating, they should be deliberately put in request to ensure they are presented to most extreme daylight. On account of utilizing solar panels at home, the rooftop would be the perfect place for the Solar Panels. It is essential to give careful consideration to the edge and situation of the boards to guarantee that Solar Panels work at their most elevated effectiveness. On the off chance that even one of the sun based cells is not completely presented to daylight, it can incredibly decrease the effectiveness of the whole board. It is likewise truly basic to change the edge of the boards through out the year so as to keep the solar panels presented to daylight amid the distinctive seasons. This may or may not be vital for you relying upon your individual design.

Right now we have created power, however the procedure is not complete yet. So as to have the capacity to utilize this vitality inside your home, we have to first change over the current from an Direct Current (DC) to an Alternate current (AC). To do this, we can utilize an inverter, which changes over this power into an AC current that family machines utilize. For example, an icebox or ventilation system have the capacity to utilize AC voltage. Another great step is to verify you store this vitality for times when either there is practically no daylight, for example, during the evening. This should be possible by putting away this power in batteries.

Deep cycling Batteries permit you to completely charge and revive using the current obtained from Solar Panels, keeping in mind the end goal to draw small amount of current over quite a long time. This is completely different from a car battery, where you require a bigger power boost for a brief time, i.e. when you ignite your car.

Next time you see Solar Panels at work, you'll see that it is a combination of Solar cells. On the off chance that you look carefully enough, you can see the individual Photovoltaic cells that make up each solar panels. Additionally, observe the boards position. Hope to perceive how others have expanded the boards presentation to the sun, by the stature, point, and situation of the board keeping in mind the end goal to permit the Solar Panels to work most productively.

Audio Clipping Peak Indicator using IC TL062

noreply@blogger.com (dvbot) — Fri, 31 Jul 2015 18:25:00 +0000

This Simple Audio Clipping Peak Indicator circuit was expected to distinguish clipping in preamp stages, mixers, equalizer, amplifiers and so on. It can be utilized as a different, convenient unit, to signal by using some LEDs when the output wave form a specific sound stage is "cutting" i.e. is coming to the onset of its maximum permitted peak voltage value before an over-load is happening. This will help the operator in avoiding extreme twisting or distortion in the audio to be created through the sound hardware chain, as if it were shielding your amplifier equipments and speakers from over-loading.

This unit is particularly useful in signaling overload of the input stages in mixers, PA or musical instruments amplification chains, but is also suited to power amplifiers. A careful setting of Trimmer R5 will allow triggering of the LED with a wide range of peak-to-peak input voltages, in order to suit different requirements.

Unfortunately, an oscilloscope and a sine wave frequency generator are required to accurately setup this circuit. Obviously, the unit can be embedded into an existing mixer, preamp or power amplifier, and powered by the internal supply rails in the 9 – 30V range. The power supply can also be obtained from higher voltage rails provided suitable R/C cells are inserted. SW1 and B1 must obviously be omitted.

Circuit Operation
The heart of the audio clipping circuit is a window comparator formed by two op-amps packaged into IC1. This technique allows to detect precisely and symmetrically either the positive or negative peak value reached by the monitored signal. The op-amps outputs are mixed by D1 and D2, smoothed by C4, R7 and R8, and feed the LED driver Q1 with a positive pulse. C5 adds a small output delay in order to allow detection of very short peaks.

Notes:

With the values shown, the circuit can be easily set up to detect sine wave clipping from less than 1V to 30V peak-to-peak (i.e. 15W into 8 Ohms). If you need to detect higher output peak-to-peak voltages, R1 value must be raised. On the contrary, if the circuit will be used to detect only very low peak-to-peak voltages, it is convenient to lower R1 value to, say, 220K omitting C2. In this way, the adjustment of R5 will be made easier.
Using a TL062 chip at 9V supply, stand-by current drawing is about 1.5mA and less than 10mA when the LED illuminates. With TL072 or TL082 chips, current drawing is about 4.5mA and 13mA respectively.
When using power supplies higher than 12V, the value of R10 must be raised accordingly.
When using power supplies higher than 25V, the working voltage value of C5 must be raised to 35 or 50V.

Parts
R1 – 1M 1/4W Resistor (See Notes)
R2,R3,R8 – 100K 1/4W Resistors
R4,R6 – 10K 1/4W Resistors
R5 – 5K 1/2W Trimmer Cermet or Carbon
R7 – 2K2 1/4W Resistor
R9 – 22K 1/4W Resistor
R10 – 1K 1/4W Resistor (See Notes)
C1,C4 – 220nF 63V Polyester Capacitors
C2 – 4p7 63V Ceramic Capacitor (See Notes)
C3 – 220µF 25V Electrolytic Capacitor
C5 – 10µF 25V Electrolytic Capacitor (See Notes)
D1,D2 – N4148 75V 150mA Diodes
D3 – LED (Any dimension, shape and color)
Q1 – BC547 45V 100mA NPN Transistor
IC1 – TL062 Dual Low current BIFET Op-Amp (or TL072, TL082)
SW1 – SPST Toggle or Slide Switch or Any other switch
B1 – 9V PP3 Battery or a 9V DC power source. Should read at least 1 Ampere.

How to make a 2 Watt audio amplifier from discrete components

noreply@blogger.com (dvbot) — Fri, 24 Jul 2015 14:25:00 +0000

A 2 Watt audio amplifier made from discrete components.

A simple 2 Watt RMS Audio Amplifier which can be made from limited components.

Notes
This was one of the earliest circuits that I ever designed and built, in Spring 1982. At that time I had only an analogue meter and a calculator to work with. Although not perfect, this amplifier does have a wide frequency response, low harmonic distortion about 3%, and is capable of driving an 8 ohm speaker to output levels of around 5 watts with slightly higher distortion. Any power supply in the range 12 to 18 Volts DC may be used.

Circuit
The amplifier operates in Class AB mode; the single 470R preset resistor, PR1 controls the quiescent current flowing through the BD139/140 complimentary output transistors. Adjustment here, is a trade-off between low distortion and low quiescent current. Typically, under quiescent conditions, current is about 15 mA rising to 150 mA with a 50 mV input signal. The frequency response is shown below and is flat from 20Hz to 100kHz:

Bode Plot

The circuit is DC biased so that the emitters of the BD139 and BD140 are at approximately half supply voltage, to allow for a maximum output voltage swing. R9 and R10 provide a degree of temperature stabilization which works as follows. If the output transistors are warm, the emitter currents will increase. This causes a greater voltage drop across R9 and R10 reducing the available bias current. All four transistors are direct coupled which ensures:-

(i) A good low frequency response
(ii) Temperature and bias change stability.

DC Voltages of Prototype
The following voltage checks were made on my prototype. All voltage are made with respect to (wrt) 0 Volt and shown in the table below.

The BC109C and 2N3906 operate in common emitter. This alone will provide a very high open loop gain. The output BD139/140 pair operate in emitter follower, allowing the amplifier to drive low impedance speakers. The signal to noise ration is shown below:

Signal to Noise Ratio:

This amplifier has a S/n ratio of 115dB at 1kHz. Overall gain is provided by the ratio of the 22k and 1k resistor. A heat sink on the BD139/140 pair is recommended but not essential, though the transistors will run "hot" to the touch.

Fourier Analysis
A quick measure of the distortion of this amplifier was performed. Operating on a 15V DC power supply with an input sinusoidal waveform of 100mV peak to peak at 1KHz produced the following results in Tina.

Fourier Coefficients

The number of samples was set to 4096 and Fourier coefficients up to the 16^th harmonic were calculated. The sum of the all harmonics up to 16KHz amounted to just under 2.9% total harmonic distortion, the results are plotted below.

Harmonic Distortion

The second and third harmonic are the biggest contribution to overall distortion. Choosing a different amplifier design, a different visaing scheme or more evenly match components can reduce distortion accordingly. At the time this amplifier was made, I only had an analogue multimeter, so all things considered, it was not too bad an effort.

Picture of my Prototype
Finally an image of the original which has stood the test of time. The BD139,140 power transistors can be seen on the left hand side, the preset near top center, the BC109C center right and 2N3906 is buried under a miniature screened audio cable, center bottom.

Cheap 12V Battery for the project above

How to make your own simple 5pf Capacitor

noreply@blogger.com (dvbot) — Fri, 24 Jul 2015 14:19:00 +0000

It is surely possible to make your own capacitors.At least those with small values, like up to 5-100pF

PARTS:

– Insulated wire (24-gauge, stranded or unstranded)

That’s it! Simply twist the two wires together – six or seven times will do the trick – and voila!, you have entered the dark art of making your own capacitors!

All you need is an inchworm of wire.

Two examples of 5pf capacitors. They kind of look like the Einsturzede Neubauten dude…

Wanna check to see if you’re little twisting shenanigans have capacitance? Bring on the multimeter, an essential tool on your work bench. Adjust your multimeter to read ohms, making sure that it also displays your output in farads.

Essentially, a capacitor only consists of two metal plates separated by an insulator. The insulation of our 24-gauge wire acts as a buffer between two pieces of copper from making a completely closed connection from the shortest path.

Simple 150 Watt amplifier circuit using transistors

noreply@blogger.com (dvbot) — Wed, 15 Jul 2015 11:53:00 +0000

This is the cheapest 150 Watt amplifier circuit you can make,I think.Based on two Darlington power transistors TIP 142 and TIP 147 ,this circuit can deliver a blasting 150 W Rms to a 4 Ohm speaker.Enough for you to get rocked?;then try out this.

TIP 147 and 142 are complementary Darlington pair transistors which can handle 5 A current and 100V ,famous for their ruggedness. Here two BC 558 transistors Q5 and Q4 are wired as pre amplifier and TIP 142 ,TIP 147 together with TIP41 (Q1,Q2,Q3) is used for driving the speaker.This circuit is designed so rugged that this can be assembled even on a perf board or even by pin to pin soldering.The circuit can be powered from a +/-45V, 5A dual power supply.You must try this circuit.Its working great!

The preamplifier section of this circuit is based around Q4 and Q5 which forms a differential amplifier. The use of a differential amplifier in the input stage reduces noise and also provides a means for applying negative feedback. Thus overall performance of the amplifier is improved. Input signal is applied to the base of Q5 through the DC decoupling capacitor C2. Feedback voltage is applied to the base of Q4 from the junction of 0.33 ohm resistors through the 22K resistor.

A complementary Class AB push-pull stage is built around the transistors Q1 and Q2 for driving the loud speaker. Diodes D1 and D2 biases the complementary pair and ensures Class AB operation. Transistor Q3 drives the push-pull pair and its base is directly coupled to the collector of Q5.

Circuit Diagram & Parts List .

Notes.

Remember TIP 142 and 147 are Darlington pairs .They are shown as conventional transistors in figure for ease.So don’t get confused.Even though each of them have 2 transistors ,2 resistors and 1 diode inside ,only three pins ,base emitter and collector are coming out.Rest are connected internally.So its quite OK to assume each of them as transistor for ease.
Use a well regulated and filtered power supply.
Connect a 10K POT in series with the input as volume control if you need.Not shown in circuit diagram.
All electrolytic capacitors must be rated at least 50volts.

Power supply for this circuit.

A +40/-40 unregulated dual supply for powering this amplifier project is shown below. This power supply is only enough for powering one channel and for stereo applications double the current ratings of the transformer, diodes and fuses.

TIP 142 & 147 Internal diagram and pin out.

TIP 142-TIP 147 Pin Out Diagram with Schematics

A Simple Day Light Sensor Circuit using cheap components like LDR and UM66 IC

noreply@blogger.com (dvbot) — Mon, 13 Jul 2015 19:35:00 +0000

This circuit will help you to make a Light Sensitive Morning Alarm circuit using limited components.

The morning light or other light is sensed by an LDR (Light Dependent Resistor) or Photoresistor and it triggers the alarming section. The circuit generates a melodious alarming tone when light falls on it.

Wire-up the circuit as shown in schematic diagram and place the LDR next to the window pane closer to your bed. Since the LDR is more sensitive to light, so make sure it will not be false triggered.

The electronic components used in this circuit is cheap, so you can make this at your own home at very low cost and it consumes very less power, hence it ensures long working life.

The entire circuit can be classified into two sections

a. Light Sensing Section

b. Alarming Section

The light sensing part consists of a Light Dependent Resistor (LDR) or a photoresistor, which is a two terminal device having the capability to detect light (Photons).

The LDR decreases its resistance when suitable amount of light falls on it. The working principle of this circuit is based on the switching action of an npn transitor (SL 100). As i mentioned above, the LDR conducts current (Lowers its resistivity), when light falls on it and make the transistor switched ON.

The alarming section of the circuit consists of a Melody Generator IC (UM66), an NPN transistor (BC 548) and a Speaker. The output voltage from the Light Sensor Section is used to drive the alarm. The tone generated by UM66 is fed to the base of an NPN transistor, inorder to amplify the signal enough to drive the Loud-Speaker.

The whole circuit is powered by a Single 6V battery.

Cheapest High power LED driver circuit schematic

noreply@blogger.com (dvbot) — Mon, 13 Jul 2015 19:29:00 +0000

There are many other articles on internet with simpler circuits but none of them are cost effective or as cheap as this one.
Using some easy to get cheap components you can make a much better LED driver than you would have thought of.

In market, we can get 1Watt and 3Watt LED easily. And the ratings of those 1Watt LEds are Forward Voltage 3.2V – 3.6V, Forward Current 300mA and for the 3Watt ones,m the ratings are Forward Voltage: VF3.4V , Forward Current :700mA .

So we consider 3.4volts as optimal voltage, and thus the 1watt LED is giving 3.4×0.3=1.02Watt and for 3watt it is, 2.38Watts.

So here’s the simplest circuit that can be used.

Here, for a fixed reference supply, LM7805 regulator I.C which can deliver upto 1Amps of current, and in our cases the max required current is 700ma or 0.7Amps, so no problem there. And since the resistor “R” will be eating the extra 1.6 volts(5.0-3.4). So what would be the value of R?

For 1 watt model, there’s current of 300mA, so the value of the resistor should be 5.3 Ohms(appx) and wattage should be 0.48. So a 5.6ohms 1/2watt general purpose resistor will do the job perfectly. And similarly, for the 3Watt model, the value of R would be 2.2Ohm 1.25Watt(or 2Watt).

We can feed any voltage greater than 5.5 volts, so we can run this circuit in 6Volts supply or in 12 volts supply.

Simple and Cheap 100W Inverter Circuit

noreply@blogger.com (dvbot) — Tue, 07 Jul 2015 07:29:00 +0000

Inverter is a small circuit which will convert the direct current (DC) to alternating current (AC). The power of a battery is converted in to’ main voltages’ or AC power. This power can be used for electronic appliances like television, mobile phones, computer etc. the main function of the inverter is to convert DC to AC and step-up transformer is used to create main voltages from resulting AC.

In the block diagram battery supply is given to the MOSFET driver where it will convert DC to AC and the resulting AC is given to the step up transformer from the step up transformer we will the get the original voltage.

Main Components:

CD4047: CD4047 is a multi vibrator with very low power consumption designed by TEXAS INSTRUMENTS.it can operate in monostable multivibrator and also astable multivibrator.in the astable multivibrator mode it can operate in free running or gatable modes and also provides good astable frequency stability. It can generate 50% duty cycle which will create a pulse, which can be applied for inverter circuit. This is mainly used in frequency discriminators, timing circuits frequency divisions etc.

IRF540: IRF540 is a N-channel enhanced mode silicon gate field effect transistor (MOSFET).they are mainly used in switching regulators, switching converters relay drivers etc. the reason for using them in the INVERTER circuit is the because it is a high switching transistor , can work in very low gate drive power and have high input impedance.

IRF540 Symbol:

Simple 100W Inverter Circuit Diagram:

Explanation:

In the circuit diagram we can observe that 12V battery is connecter to the diode LED and also connected to the pin8 of the IC 4047 which is VCC or power supply pin and also to pin 4 and 5 which are astable and complement astable of the IC. Diode in the circuit will help not give any reverse current, LED will work as a indicator to the battery is working or not.
IC CD4047 will work in the astable multivibrator mode. To work it in astable multivibrator mode we need an external capacitor which should be connected between the pin1 and pin3. Pin2 is connected by the resistor and a variable resistor to change the change the output frequency of the IC. Remaining pins are grounded .The pins 10 and 11 are connected to the gate of the mosfets IRF540. The pin 10 and 11 are Q and ~Q from these pins the output frequencies is generated with 50% duty cycle.
The output frequency is connected to the mosfets through resistor which will help to prevent to the loading of the mosfets. The main AC current is generated by the two mosfets which will act as a two electronic switches. The battery current is made to flow upper half or positive half of the primary coil of transformer through Q1 this is done when the pin 10 becomes high and lower half or negative half is done by opposite current flow through the primary coil of transformer, this is done when pin 11 is high. By switching the two mosfets current is generated.
This AC is given to the step up transformer of the secondary coil from this coil only we will get the increased AC voltage , this AC voltage is so high; from step up transformer we will get the max voltage. Zenor diode will help avoid the reverse current.

NOTE: The generated AC is not equal to the normal AC mains or house hold current. You cannot use this voltage for pure electric appliances like heater, electric cooker etc. Because of the fast switching of mosfets heat is dissipated which will effect the efficiency, use heat sink to remove this problem. The transformer can be bought through transformer manufacturer in your city or town.

Lead Acid Battery Charger Circuit

noreply@blogger.com (dvbot) — Tue, 07 Jul 2015 07:25:00 +0000

To successfully charge a battery, it should be supplied with DC current and not AC. This circuit shows how you can use DC voltage to regulate and finally charge the battery.
Now if you have AC voltage, you can convert it using a rectifier bridge and pass it through filter to obtain DC voltage which can then be used in this circuit to charge the Lead Acid Battery. Car also consists a lead acid battery.

As seen in the DC voltage is given to the DC voltage regulator here we use LM317 which is a DC voltage regulator. The regulated DC out voltage is given to battery. There is also a trickle charge mode circuitry which will help to reduce the current when the battery is fully charged.

Components of Lead Acid Battery Charger Circuit:

LM317: LM317 is voltage regulator invented by Robert C. Dobkin and Robert J. Widlar in 1970.the main function of this voltage regulator is to regulate the voltage and give the constant voltage without any noise disturbance; for example if we have 42v and we want only 10v so to get this output we will give 42v to a voltage regulator and uninterrupted 10v. For LM317 there is no maximum voltage unless the difference between the input and output voltage should not exceed maximum differential voltage. The maximum differential voltage is around 40V and also it give exceed output current of 1.5A for 1.2v to 37V .it has three pins input, output and adjustable pin. In the adjustable we can adjust the difference between the input and output voltages. Minimum voltage should be 18V which is given as input voltage to the regulator.

Lead Battery: Lead Battery is a rechargeable battery in the 1857 by gaston plante. The main advantages of Lead battery is it will dissipate very little energy (if energy dissipation is less it can work for long time with high efficiency),it has very low energy to weight ratio, it can deliver high current’s and very low cost.

Lead Acid Battery Charger Circuit Diagram:

The circuit diagram can be seen below:

Circuit Explanation:

The DC voltage is connected to the Vin of the LM317 in between we have connected the capacitors will be opened but if it had any AC noise it will remove it.
The Vout of the LM317 is given to the battery which is to be charged, pin1Adjustment pin of the LM317 is connected to the transistor Q1, Resistor R1, R2, R5 which will help to adjust the regulator.
The output of regulated voltage and current is controlled by the transistor Q1, resistor R1 and R2 and potentiometer R5.potentiometer which is used to set the charging current. Resistor R2 will have more current when the battery is getting charged. This will help to conduct the transistor Q1. The conduction of Q1 will help to adjust the voltage of LM317.
TRICKLE CHARGE MODE: in this mode if the battery is charged the reverse current will flow. If the LED has glown then we can say that battery is charged. The diode D2 will protect the LM317 from the reverse current. When the battery is fully charged it will reduce the charge current. If the charge current the transistor will get off so the voltage regulator cannot be adjusted.

NOTE:

The battery should be charged with 1/10^th it’s charging current.so the voltage regulator must generate 1/10^th of the charging current produced by the battery
Heat sink should be attached to the LM317 to the get the better efficiency.

Bipolar LED Driver Circuit

noreply@blogger.com (dvbot) — Tue, 07 Jul 2015 07:22:00 +0000

A Bi color LED is a special type of LED consists of two diodes connected in inverse direction to each other inside a package. A bi color LED generally consists of three terminals- a common pin and two separate pins.

The common pin can be connected to ground if it is a common anode LED or connected to +5V supply, if it is a common cathode. However there is another type of bi color LED with two terminals. The device functions as per the positive signal given to one of the terminals. For instance for a green and red bi color LED, a positive signal at the green terminal and negative signal at red terminal ensures the green LED to be forward biased and red LED to be reverse biased. This causes the green light to flash. Same is the case for the red LED. However if both the terminals are given negative signals, neither of the diodes would conduct and the device would remain off. If positive signal is applied to both the terminals, a different color, based on the combination of the LED colors, would flash.

Here, we are designing a simple bi color LED driver circuit using a Microcontroller. The LED used here has a forward voltage drop of 2.2V and hence can be biased using a 5V supply. The control is done by the microcontroller program, based on the inputs given from two push buttons.

Principle Behind Bi-Polar LED Driver Circuit:

The circuit uses a microcontroller to drive the bipolar LED. The input command is given from the three push buttons and based on the inputs; the microcontroller is accordingly programmed to send appropriate signals to the two output pins. These output pins are connected to the terminals of the bi-polar LED.

Bipolar LED Driver Circuit Diagram:

Bipolar LED Driver Circuit Design:

It is a simple circuit and the design mainly involves designing the interfacing of Microcontroller, designing the oscillator and reset circuits for the microcontroller and selection of the LED resistor.

The microcontroller interfacing is accomplished by connecting two push button switches to port P1 and connecting the two terminals of bi color LED to port P2.

The oscillator design is done by selecting two 10pF ceramic capacitors in order to provide stability. The clock signal is generated using an 11MHz Crystal Oscillator. The reset circuit is designed by selecting an electrolyte capacitor of 10uF and a resistor of 10K to achieve a reset pulse width of 100ms. The voltage drop across the resistor is kept around 1.2V.

The first part of design involves writing the code for the microcontroller. This involves the following steps.

Create a new project in the Keil window.
Select the target device for the project. Here we select AT89C51 from Atmel.
Create a new file such that a blank text field appears.
Write the code. The code is written, keeping in mind the following algorithm,
Assign a variable to the input and output port.
Check if one of the inputs is active low.
In case one of the inputs is at logic low, assign a logic high signal to one of the LED terminals.
In case none are at logic low, make sure the LED is switched off.
Save the code with .c extension.
Add the code to the source folder under target folder.
Create a Hex file by clicking the ‘Configure Flash Tools’ under ‘Flash’ menu.

The second part involves drawing the circuit on simulation software. Here we use Proteus. The circuit is drawn based on the design method described above.

The third part involves simulating the circuit. This is done by first adding the hex file to the microcontroller and then clicking on the run button.

Working of Bipolar LED Driver Circuit

Once the circuit is switched on, the microcontroller continuously scans the input pins at port P1. Suppose the first button is pressed, the microcontroller receives a low logic signal at the corresponding input pin and accordingly the compiler assigns a high logic signal to pin P0.0 and low logic signal to pin P0.1. This causes the red light of the LED to glow.

Now when the second button is pressed, the compiler will accordingly assign a low logic signal to the pin P0.0 and a high logic signal to pin P0.1. This causes the green light to glow. On pressing the third button, low logic signals will be assigned to both the output pins and the LED will be switched off. In the meanwhile a low logic signal is always given to the common pin.

Bipolar LED Driver Applications:

This circuit can be used for indication purposes.
This circuit can be used at applications where flashing of light is required, as in beacon flashing.

Limitations of Bipolar LED Driver Circuit:

This is a theoretical circuit and may require changes for practical implementations.
Most of the bi color LEDs requires higher supply voltage than 5V because of their higher forward voltage rate and this circuit only provides 5V supply voltage to the LED.
The LED resistor provides a voltage drop which decreases the biasing voltage of the LED.

Simple audio amplifier using LM386.

noreply@blogger.com (dvbot) — Sun, 05 Jul 2015 10:06:00 +0000

The LM386 is an audio amplifier designed for use in low voltage consumer applications. The gain is internally set to 20 to keep external part count low, but the addition of an external resistor and capacitor between pins 1 and 8 will increase the gain to any value from 20 to 200.

Parts will be assembled and connected according to the following schematic:

This project uses an integrated circuit with capacity of 10 transistors to amplify much better with much less power drain on the batteries than our simple amplifier.

Following parts are required:

A LM386 integrated circuit amplifier chip
This is the main working part of the amplifier.
A small speaker
Some jumper wires
9 volt DC adapter of 2 Amps or more or 9 volt battery clip and 9 volt battery

The Three Penny Radio normally has a piezoelectric earphone attached at points J-20 and E-22. We replace the earphone with our amplifier.
Below is a closeup of the amplifier section:

Here you can see that we have connected the Three Penny Radio output at J-20 to the ground rail below the blue line. This rail has all of its holes connected together. We connect the black (negative) wire from the battery to the ground rail. We connect the red (positive) wire from the battery to the power rail, just above the red line at the top of the photo. Having the power and ground connected to these rails makes it easier to connect the other parts, and makes it easier to see where all the connections are.

You can connect your audio source instead of radio.

The other output from the Three Penny Radio us plugged into E-22.
Using the labeled grid as before, the parts are connected this way:

LM386 amplifier chip at E-24, E-25, E-26, E-27 and F-24, F-25, F-26, and F-27.
Jumper wire: F-20 to ground rail.
Jumper wire: C-22 to C-26.
Jumper wire: A-25 to ground rail.
Jumper wire: A-27 to ground rail.
Jumper wire: J-26 to power rail.
Speaker: red wire to H-27 and black wire to ground rail.
Negative 9 volt battery wire (black): ground rail.
Positive 9 volt battery wire (red): power rail.

When all the wires are connected properly, you should be able to hear radio stations coming from the speaker. They will not be particularly loud, but we can increase the volume 10-fold with a simple adjustment.

We put a 10 microfarad capacitor connecting pins 1 and 8 of the integrated circuit (put the negative capacitor lead into hole D-24 and the positive capacitor lead into hole G-24).

This bypasses a resistor inside the integrated circuit, boosting the gain from 20 to 200.

One problem with the circuit so far is that the speaker will get warm and the battery will not last long. This is because a certain amount of DC current is going through the speaker. Direct current (DC) does not make sounds, and so this current is a complete waste of battery power, and simply warms up the speaker coil.

We fix this problem by putting a 220 microfarad capacitor between the integrated circuit output pin (pin 5, in hole F-27) and the red speaker wire. The positive capacitor lead is put into hole J-27, and the negative capacitor lead is put into hole J-29. The red speaker wire is moved to hole G-29.

To prevent the capacitor from changing the sound, we add two more components to create a "filter" that lets only audio frequencies get to the speaker.

Here we have moved the negative lead of the 220 microfarad capacitor to hole J-28, and moved the red wire of the speaker to H-28. We put a 10 ohm resistor into holes G-27 and G-30. A 0.047 microfarad capacitor goes into hole F-30 and the ground rail.

Our amplifier is working pretty well now. But our little speaker has a high tinny voice, because of its size. It would be nice if it had a little more power on the lower frequencies, what we call "bass response".

We can arrange to amplify the lower frequencies more than the high ones. We make another filter from a 0.033 microfarad capacitor and a 10,000 ohm resistor, and connect that between the output pin and pin 1 of the integrated circuit. This will feed some of the low frequencies back into the amplifier to be amplified again.

We put the 10,000 ohm resistor in holes C-24 and F-29. We put the 0.033 microfarad capacitor in holes I-27 and I-29.

The amplifier is now ready with much better sound.

Arduino: an Introduction

noreply@blogger.com (dvbot) — Mon, 29 Jun 2015 13:12:00 +0000

Arduino is an open-source platform used for building electronics projects. Arduino consists of both a physical programmable circuit board (often referred to as a microcontroller) and a piece of software, or IDE (Integrated Development Environment) that runs on your computer, used to write and upload computer code to the physical board.

The Arduino platform has become quite popular with people just starting out with electronics, and for good reason. Unlike most previous programmable circuit boards, the Arduino does not need a separate piece of hardware (called a programmer) in order to load new code onto the board – you can simply use a USB cable. Additionally, the Arduino IDE uses a simplified version of C++, making it easier to learn to program. Finally, Arduino provides a standard form factor that breaks out the functions of the micro-controller into a more accessible package.

This is an Arduino Uno

The Uno is one of the more popular boards in the Arduino family and a great choice for beginners. We’ll talk about what’s on it and what it can do later in the tutorial.

This is a screenshot of the Arduino IDE.

Believe it or not, those 10 lines of code are all you need to blink the on-board LED on your Arduino. The code might not make perfect sense right now, but, after reading this tutorial and the many more Arduino tutorials waiting for you on our site, we’ll get you up to speed in no time!

The Arduino hardware and software was designed for artists, designers, hobbyists, hackers, newbies, and anyone interested in creating interactive objects or environments. Arduino can interact with buttons, LEDs, motors, speakers, GPS units, cameras, the internet, and even your smart-phone or your TV! This flexibility combined with the fact that the Arduino software is free, the hardware boards are pretty cheap, and both the software and hardware are easy to learn has led to a large community of users who have contributed code and released instructions for a huge variety of Arduino-based projects.

For everything from robots and a heating pad hand warming blanket to honest fortune-telling machines, and even a Dungeons and Dragons dice-throwing gauntlet, the Arduino can be used as the brains behind almost any electronics project.

Arduino Specification:

There are many varieties of Arduino boards that can be used for different purposes. Some boards look a bit different from the one below, but most Arduinos have the majority of these components in common:

Power (USB / Barrel Jack)

Every Arduino board needs a way to be connected to a power source. The Arduino UNO can be powered from a USB cable coming from your computer or a wall power supply that is terminated in a barrel jack. In the picture above the USB connection is labeled (1) and the barrel jack is labeled (2).
The USB connection is also how you will load code onto your Arduino board. More on how to program with Arduino can be found in our Installing and Programming Arduino tutorial.
NOTE: Do NOT use a power supply greater than 20 Volts as you will overpower (and thereby destroy) your Arduino. The recommended voltage for most Arduino models is between 6 and 12 Volts.

Pins (5V, 3.3V, GND, Analog, Digital, PWM, AREF)

The pins on your Arduino are the places where you connect wires to construct a circuit (probably in conjuction with a breadboard and some wire. They usually have black plastic ‘headers’ that allow you to just plug a wire right into the board. The Arduino has several different kinds of pins, each of which is labeled on the board and used for different functions.

GND (3): Short for ‘Ground’. There are several GND pins on the Arduino, any of which can be used to ground your circuit.
5V (4) & 3.3V (5): As you might guess, the 5V pin supplies 5 volts of power, and the 3.3V pin supplies 3.3 volts of power. Most of the simple components used with the Arduino run happily off of 5 or 3.3 volts.
Analog (6): The area of pins under the ‘Analog In’ label (A0 through A5 on the UNO) are Analog In pins. These pins can read the signal from an analog sensor (like a temperature sensor) and convert it into a digital value that we can read.
Digital (7): Across from the analog pins are the digital pins (0 through 13 on the UNO). These pins can be used for both digital input (like telling if a button is pushed) and digital output (like powering an LED).
PWM (8): You may have noticed the tilde (~) next to some of the digital pins (3, 5, 6, 9, 10, and 11 on the UNO). These pins act as normal digital pins, but can also be used for something called Pulse-Width Modulation (PWM). We have a tutorial on PWM, but for now, think of these pins as being able to simulate analog output (like fading an LED in and out).
AREF (9): Stands for Analog Reference. Most of the time you can leave this pin alone. It is sometimes used to set an external reference voltage (between 0 and 5 Volts) as the upper limit for the analog input pins.

Reset Button

Just like the original Nintendo, the Arduino has a reset button (10). Pushing it will temporarily connect the reset pin to ground and restart any code that is loaded on the Arduino. This can be very useful if your code doesn’t repeat, but you want to test it multiple times. Unlike the original Nintendo however, blowing on the Arduino doesn’t usually fix any problems.

Power LED Indicator

Just beneath and to the right of the word “UNO” on your circuit board, there’s a tiny LED next to the word ‘ON’ (11). This LED should light up whenever you plug your Arduino into a power source. If this light doesn’t turn on, there’s a good chance something is wrong. Time to re-check your circuit!

TX RX LEDs

TX is short for transmit, RX is short for receive. These markings appear quite a bit in electronics to indicate the pins responsible for serial communication. In our case, there are two places on the Arduino UNO where TX and RX appear – once by digital pins 0 and 1, and a second time next to the TX and RX indicator LEDs (12). These LEDs will give us some nice visual indications whenever our Arduino is receiving or transmitting data (like when we’re loading a new program onto the board).

Main IC

The black thing with all the metal legs is an IC, or Integrated Circuit (13). Think of it as the brains of our Arduino. The main IC on the Arduino is slightly different from board type to board type, but is usually from the ATmega line of IC’s from the ATMEL company. This can be important, as you may need to know the IC type (along with your board type) before loading up a new program from the Arduino software. This information can usually be found in writing on the top side of the IC. If you want to know more about the difference between various IC’s, reading the datasheets is often a good idea.

Voltage Regulator

The voltage regulator (14) is not actually something you can (or should) interact with on the Arduino. But it is potentially useful to know that it is there and what it’s for. The voltage regulator does exactly what it says – it controls the amount of voltage that is let into the Arduino board. Think of it as a kind of gatekeeper; it will turn away an extra voltage that might harm the circuit. Of course, it has its limits, so don’t hook up your Arduino to anything greater than 20 volts.

The Arduino Family

Arduino makes several different boards, each with different capabilities. In addition, part of being open source hardware means that others can modify and produce derivatives of Arduino boards that provide even more form factors and functionality. If you’re not sure which one is right for your project. Here are a few options that are well-suited to someone new to the world of Arduino:

Arduino Uno (R3)

The Uno is a great choice for your first Arduino. It’s got everything you need to get started, and nothing you don’t. It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a USB connection, a power jack, a reset button and more. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with a AC-to-DC adapter or battery to get started.

A simple fix for mouse click issues.

noreply@blogger.com (dvbot) — Mon, 29 Jun 2015 13:03:00 +0000

After a month of non-use, you might notice that your mouse clicks are not working as they used to. Many times because of lack of use of right clicks buttons, the buttons stops working. This can be fixed easily!

WARNING: DO THIS AT YOUR OWN RISK! UNPLUG YOUR MOUSE AND DO THIS SOMEWHERE YOU CAN FIND THE SMALL PIECES YOU ARE SURE TO DROP!

STEP 1:

Unplug the mouse and get out a small screwdriver. Every mouse I’ve seen has small Phillips head screws holding the pieces together, so if you don’t have one, get one, it’ll come in handy on more projects than just this one.

STEP 2:

Time to remove the screws from the bottom of the mouse and put them CLOSE BY so that you don’t lose them. I have marked the locations of the screws of my mouse in the picture.
Below is my mouse after separating the two.

STEP 3:

Since your mouse is already open, take the time to remove any hair, dust, or other matter inside. Once cleaned, it’s time to have a look at the micro-switches that register your clicks.

The switches will be small rectangular boxes with a small plastic piece that, when pushed, will emit a clicking sound. After you’ve found the switches, click both the right and left mouse buttons and notice how big of a difference in the sound they make. My left mouse button barely made an audible click before I fixed it.

STEP 4:

Once you’ve located the offending micro switch, it’s time to pop it open. Since my left mouse button was the culprit, I gently used a small flat-head screwdriver to lift up one corner of the switch cover. Be gentle here as breaking the plasic cover would be a very bad thing.

Pry gently on one side, then pry gently on the other side. When you succeed, you’ve be left with an open switch, a black cover, and a small plastic insert. DO NOT LOSE THIS! I’ve laid out the parts below so that you can get an idea of what things look like.

Notice the location of the small copper contact in the picture above. MEMORIZE HOW THIS FITS ONTO THE CONTACTS IN YOUR SWITCH. Okay, with that said, here’s a picture of what we’ve been searching for:

STEP 5:

This piece is tiny to say the least. Notice the curved “spring” in the center. To remove this piece, gently push sideways on the movable end until it is free from its resting contact. Below is a blown up switch view:

After checking to make sure the entire copper piece is level, insert a small flat head screw driver and force the spring part away from the rest of the copper piece. The picture below is me bending the spring away:

Be careful when bending the spring, the copper is extremely thin, and it doesn’t take much to make your mouse clicks stiff again.

STEP 6:

When you’re satisfied you’ve put enough spring back into the copper, it’s time to remount it to the contacts inside the switch.

Set the fixed end of the copper in first, then gently slide the movable end underneath the resting contact. You will have to put the spring down into it’s location AFTER this has been done. It takes some patience, so don’t get discouraged. I spent 10 minutes figuring this out.

Once you have the copper back in place, it should move up and down, but not click. Make sure the copper moves correctly before moving on to the next step.

STEP 7:

Now take the small plastic insert and work it back into the switch cover. A small bit should stick out of the top of the cover, a good check to make sure you’ve put it back in correctly

.

STEP 8:

To reattach the switch cover to the switch, simply turn the mouse upside down, and attach the cover over the switch into its original position. Why upside down, you ask? Holding it upside down will keep that tiny little plastic insert from falling out of the switch as you try to put it back in.

Once the cover is back in place, try out your “new”switch. You should notice that it feels firmer than it did before and that it should make an audible clicking noise. If it doesn’t do this, take the switch apart again and start from STEP 4.

STEP 9:

Carefully replace the mouse cover, being careful not to catch any loose wires, and then re screw it to the base. Plug it in and enjoy.