Electronics Circuit Application

LT3760 8-channel LED driver circuit.

noreply@blogger.com (Anonymous) — Sat, 07 Sep 2013 11:12:00 +0000

This Led driver circuit schematic is based on the LT3760 8-channel LED driver circuit which is a step-up DC/DC controller capable of driving up to 45V of LEDs.
Each channel of LT3760 contains an accurate current sink with ±2% current matching. Output current for each channel can be programmed from 20mA to 100mA per string but for higher output LED current the channels can be paralleled .

The PWM dimming allowed by LT3760 is up to 3000:1 and an analog dimming range up to 25:1. The operating frequency can be programmed from 100kHz up to 1MHz using a resistor or an external clock .
The LT3760 LED driver circuit schematic is very simple and require few external components offering high efficiency and other many features like : 8-Channel LED Driver , wide input range : 6V to 40V , ±2% LED Current Matching at 40mA , up to 3000:1 True Color PWM™ Dimming Range , single Resistor Sets LED Current (20mA to 100mA) , protection for LED Pin to VOUT short , Parallel Channels for Higher LED Current , programmable LED current derating vs temperature , programmable frequency (100kHz to 1MHz) , synchronizable to an external clock .
The LT3760 can be used in many applications where is needed a high efficiency LED driver.
As you can see in the schematic circuit bellow is presented a 13W Driver 1MHz SEPIC, 8 Strings, 100mA Per String . If you want to use LT3760 please read the manufacturer datasheet .Electronics Circuit Application

Micropower DC-DC Converter circuits LT1073

noreply@blogger.com (Anonymous) — Tue, 03 Sep 2013 15:20:00 +0000

Features

No Design Required
Operates at Supply Voltages From 1.0V to 30V
Consumes Only 95µA Supply Current
Works in Step-Up or Step-Down Mode
Only Three External Off-the-Shelf Components Required
Low-Battery Detector Comparator On-Chip
User-Adjustable Current Limit
Internal 1A Power Switch
Fixed or Adjustable Output Voltage Versions
Space-Saving 8-Pin MiniDIP or SO8 Packag

Typical Application

Description

The LT1073 is a versatile micropower DC/DC converter. The device requires only three external components to deliver a fixed output of 5V or 12V. The very low minimum supply voltage of 1V allows the use of the LT1073 in applications where the primary power source is a single cell. An on-chip auxiliary gain block can function as a low-battery detector or linear post-regulator. Average current drain of the LT1073-5 used as shown in the Typical Application circuit below is just 135µA unloaded, making it ideal for applications where long battery life is important. The circuit shown can deliver 5V at 40mA from an input as low as 1.25V and 5V at 10mA from a 1V input.
The device can easily be configured as a step-up or step-down converter, although for most step-down applications or input sources greater than 3V, the LT1173 is recommended. Switch current limiting is user-adjustable by adding a single external resistor. Unique reverse-battery protection circuitry limits reverse current to safe, nondestructive levels at reverse supply voltages up to 1.6V.

Applications

Pagers
Cameras
Single-Cell to 5V Converters
Battery Backup Supplies
Laptop and Palmtop Computers
Cellular Telephones
Portable Instruments
4mA-20mA Loop Powered Instruments
Hand-Held Inventory Computers
Battery-Powered Alpha, Beta and Gamma Particle Detectors

Electronics Circuit Application

3Vdc to 12Vdc step up DC converte circuits.

noreply@blogger.com (Anonymous) — Mon, 02 Sep 2013 13:56:00 +0000

The 3Vdc to 12Vdc step up DC converter by IC LT1073-12,

When we have a battery of two cell 1.5V AA batteries or 3 voltage input source, but want size of voltage 12VDC. This circuit can be done, but when we use the battery voltage size of 2 V will be has a current is about 35mA only, That’s something we accept, In some work we use low power interface, such as : an op-amp circuits, digital CMOS circuits and others.

In addition to I have the boost up DC volt, more 3 circuits, with the same circuit is a little device, information about the device. You can see it in circuit Electronics Circuit Application

2X50 W TDA1562 stereo AMP circuits

noreply@blogger.com (Anonymous) — Mon, 26 Aug 2013 16:37:00 +0000

4AA Battery Powered 12V LED Spotlight - 12V Power Supply circuits

noreply@blogger.com (Anonymous) — Sat, 24 Aug 2013 15:54:00 +0000

Most of the electronic projects and electronic devices are required 12V power source; typically a 12V sealed lead acid battery or AC powered power supply. These are typically large, heavy, difficult to handle, and expensive; portability is less. The best solution is to use a DC-DC Step up converter. These types of convertors are inexpensive, light weight and easy to use. Also provides power management and easy to work with renewable energy sources.

The input power source could be rechargeable AA batteries. Let’s make an environment friendly 12V/130mA power supply!

100uf Electrolytic Capacitor 16V C1,C2 -2
100Ohms Resistor 1/4W R1,R2 -2
1N5817 Schotkey Diode 1A D1- 1
150UH Radial Power Inductor 1A IND1- 1
LT1073CN8-12 IC DIP Package IC1 -1
IC Base 8 PIN -1
PCB to Wire Connector- 2
4AA Battery Holder- 1

The heart of this application is LT1073 IC. It is a power management IC which steps up low voltage into high voltage by switching.

First I etched four PCBs for the prototype using a PCB design software and some other tools. The PCBs are very small (4cmX2cm) because components need to be solder as close as to the IC; because of the performance issues. I made ground copper track as wide as possible.

Now my prototype works fine and I decided to make the PCB in large quantity. I did some changes and sent my PCB file to a local PCB production company and first I got 100 pieces of PCBs. The PCBs are in good quality with solder spots and copper shield; easy to solder

Ratings:
Operating Hours: 20,000 hours
Operating Voltage: 12V
Intensity: 55,000 mcd
Forward Current: 80 mA @ 12Vdc
Viewing Angle: 30 Degrees

Absolute Maximum Ratings:
Operating Voltage(V): 14 V
Operating Temperature (Topr): -25oC to +85oC
Storage Temperature (Ts): -35oC to +100oC

variable voltage adjustable power supply circuits

noreply@blogger.com (Anonymous) — Fri, 23 Aug 2013 00:25:00 +0000

Features:
Regulated Adjustable Voltage out 2-30VDC
High Current Output 5A (based on transformer selection).
Adjustable Current Limit
Can be used as a variable current supply.
Based on LM317 Voltage Regulator.
Built in protection diodes
Speed controlled fan connection (based on current draw).
Current meter connection (0.1V/1A).

Circuit Diagram

Features universal capcitor mounting/spacing to allow various capacitors to fit. Mounting pattern that fits TO-200 or TO-218/247 for pass transistor and transistor used for current limit circuit. Fan connection uses connection compatible with standard PC fan connection; allowing use of PC heatsink fan combination.

Circuit Board Layout
Electronics Circuit Application

MOBILE PHONE BATTERY CHARGER CIRCUITS.

noreply@blogger.com (Anonymous) — Thu, 22 Aug 2013 15:21:00 +0000

Mobile phone chargers available in the market are quite expensive. The circuit presented here comes as a low-cost alternative to charge mobile telephones/battery packs with a rating of 7.2 volts, such as Nokia 6110/6150.

The 220-240V AC mains supply is down converted to 9V AC by transformer X1. The transformer output is rectified by diodes D1 through D4 wired in bridge configuration and the positive DC supply is directly connected to the charger’s output contact, while the negative terminal is connected through current limiting resistor R2. LED2 works as a power indicator with resistor R1 serving as the current limiter and LED3 indicates the charging status. During the charging period, about 3 volts drop occurs across resistor R2, which turns on LED3 through resistor R3. An external DC supply source (for instance, from a vehicle battery) can also be used to energise the charger, where resistor R4, after polarity protection diode D5, limits the input current to a safe value. The 3-terminal positive voltage regulator LM7806 (IC1) provides a constant voltage output of 7.8V DC since LED1 connected between the common terminal (pin 2) and ground rail of IC1 raises the output voltage to 7.8V DC. LED1 also serves as a power indicator for the external DC supply..Electronics Circuit Application

12V to 220V inverte 500W Circuits

noreply@blogger.com (Anonymous) — Sun, 18 Aug 2013 13:29:00 +0000

Attention: This Circuit is using high voltage that is lethal. Please take appropriate precautions

Using this circuit you can convert the 12V dc in to the 220V Ac. In this circuit 4047 is use to generate the square wave of 50hz and amplify the current and then amplify the voltage by using the step transformer.

How to calculate transformer rating
The basic formula is P=VI and between input output of the transformer we have Power input = Power output
For example if we want a 220W output at 220V then we need 1A at the output. Then at the input we 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 bear 20A.

author: Ashad Mustufa
e-mail: mustufa66@hotmail.com
web site: http://www.electronics-lab.com

AC Powered LED.

noreply@blogger.com (Anonymous) — Sat, 17 Aug 2013 15:03:00 +0000

A long time ago I found a little schematic on internet on how to power a LED from an AC Line.
I tested and modified it a little so now it works great.
You could use it as an power-on indicator for your waterpump or so. Also it can be used with whatever LED-color you like.

I included the schematics for US or canadian 110-120V 60Hz AC lines, as well as european or australian 230-240V 50Hz AC lines.

The capacitor is used to drop the voltage and the resistor to limit the inrush current.
Since the capacitor passes the current in both directions, a small diode is connected in parallel with the LED to provide a path for the negative half cycle and to limit the reverse voltage across the LED. The resistor value was chosen to limit the worst case inrush current to about 150mA which will drop to less than 30mA in a millisec as the capacitor charges.
The 0.47uF capacitor has an impedance of 5600 Ohms at 60Hz so the LED current is about 20mA half wave, or 10mA average (for the 230V version the impedance of the 0.33uF capacitor is 9600 Ohms at 50Hz which gives you also a LED current of about 10mA average)

Z = 1 / 2*Pi*f*C

Z = Impedance in Ohms

Pi = 3.14

f = frequency in Hertz

C = capacity in Farads)

A larger capacitor will increase the current and a smaller one will reduce it.
The capacitor must be a non-polarized type with a voltage rating of at least 250VDC or preferably more for 110V AC-lines, or at least 400VDC or preferably more for 230V AC-lines.
Resistor R1 discharges capacitor C1 in a few seconds after AC-line is disconnected. Remember that R1 must be able to withstand the full half wave peak AC-line voltage.
IMPORTANT: The circuit is powered from the AC line, so I will not be held responsible in any way for burned fingers, or melted fuses in your house. Isolate all connections with heat shrink.
Electronics Circuit Application

FM Transmitter Circuits - 4Transistors..

noreply@blogger.com (Anonymous) — Wed, 14 Aug 2013 00:22:00 +0000

This circuit provides an FM modulated signal with an output power of around 500mW. The input microphone pre-amp is built around a couple of 2N3904 transistors (Q1/Q2), and audio gain is limited by the 5k preset trim potentiometer. The oscillator is a colpitt stage, frequency of oscillation governed by the tank circuit made from two 5pF ceramic capacitors and the L2 inductor. The output stage operates as a 'Class D' amplifier, no direct bias is applied but the RF signal developed across the 3.9uH inductor is sufficient to drive this stage. The emitter resistor and 1k base resistor prevent instability and thermal runaway in this stage.Electronics Circuit Application

TV Transmitter Circuit ..

noreply@blogger.com (Anonymous) — Tue, 13 Aug 2013 13:51:00 +0000

This is a small TV transmitter circuit which transmits in VHF band, negative sound modulation and PAL video modulation. It is suitable in countries where the B and G system is used. Electronics Circuit Application

High Gain Yagi Wi-Fi Antenna

noreply@blogger.com (Anonymous) — Mon, 12 Aug 2013 01:27:00 +0000

Build this wi-fi antenna to build when you want results FAST and have just a few inexpensive tools and supplies available. It will greatly extend your wi-fi range - well beyond the limits of the dipoles that accompany most routers and some wireless adapters. When connected to a USB wireless adapter the performance is excellent. When connected to a high powered wi-fi adapter, the performance is astounding! Forget about building those overly hyped wi-fi cantennas - they don't perform anywhere close to the yagi antennas depicted here.
Sometimes the perfect wi-fi antenna is the one that can be made in an hour's time, from inexpensive parts, and yet enables connections over moderate to long distances. The yagi wi-fi antenna design depicted here is exactly that! It is computer designed, made of wood and wire, and provides high gain and directivity. It is directional - favoring wi-fi signals in one direction and rejecting interference from the sides or behind the antenna. The 15 element wi-fi antenna provides over 15 dB of gain (multiplying your effective radiated power by 31), while the larger 20 element wi-fi antenna provides over 17 dB of gain (multiplying your effective radiated power power by 51). Front to back ratio for both antennas is about 22 dB.
Yagi wi-fi antennas can be rather difficult to make - elements must be precisely cutto the proper length, and spaced at the correct distance from otherelements, or the antenna doesn't work. Before good computer tools were available, a designer used various charts and tables to determine antenna dimensions. These days, however, much of the mind numbing calculation can be carried out in a split second. One excellent tool for crunching design numbers is the yagi antenna modeler, created by Kevin Schmidt (W9CF) and Michael Lee.

The on-line antenna modeler initially starts with several examples tailored for operation in the amateur radio bands. One of the best designs is the classic K1FO yagi. By following a few steps, the antenna can be scaled for the 2.4 Ghz wi-fi 802.11 b/g/n frequencies:

Start with the 15 or 20 element K1FO 70cm example.
In the "units" menu, select "Radians."
In the "conductivity" menu, select "Copper"
In the "frequency" field, enter 2450 (MHz) for the center of the wi-fi networking band.
For "Element Diameter", enter 0.08729 (radians).
Click the "calculate" button.
In the "units" menu, select "millimeters."
Note that the element diameter perfectly matches 14 gauge wire!
In the file menu, select "list elements."

The elements list will show each element, from the reflector (element 1, position zero mm), to the last director. Any changes in element diameter, metal type, or design frequency will need recalculation and the new elements list checked. These dimensions work quite well:

**Element data for the 15 Element Yagi Wi-Fi Antenna.**
Element	Length (mm)	Position (mm)
1 (Reflector)	59.61	0.00
2 (Driven Element)	58.55	18.34
3 (Director)	55.20	25.75
4 (Director)	53.62	39.51
5 (Director)	52.38	58.55
6 (Director)	51.68	82.19
7 (Director)	50.97	109.70
8 (Director)	50.62	140.74
9 (Director)	50.26	174.60
10 (Director)	49.91	210.94
11 (Director)	49.56	249.38
12 (Director)	49.21	289.60
13 (Director)	48.85	331.39
14 (Director)	48.68	374.25
15 (Director)	48.50	418.52

**Element data for the 20 Element Yagi Wi-Fi Antenna.**
Element	Length (mm)	Position (mm)
1 (Reflector)	59.96	0.00
2 (Driven Element)	58.91	18.34
3 (Director)	55.56	25.75
4 (Director)	53.97	39.51
5 (Director)	52.73	58.55
6 (Director)	52.03	82.19
7 (Director)	51.32	109.70
8 (Director)	50.97	140.74
9 (Director)	50.61	174.60
10 (Director)	50.26	210.94
11 (Director)	49.91	249.38
12 (Director)	49.56	289.60
13 (Director)	49.21	331.39
14 (Director)	49.03	374.25
15 (Director)	48.85	418.52
16 (Director)	48.68	463.67
17 (Director)	48.50	509.70
18 (Director)	48.32	556.26
19 (Director)	48.15	603.53
20 (Director)	47.97	651.32

Below is a graphic, meticulously adapted by AB9IL from the modeler, which shows element lengths and positions along the boom, measured from the reflector (location zero millimeters). Note that the driven element is depicted in green, and for the wi-fi yagi project, will be a folded dipole. Why a folded dipole? It provides a good impedance match to coaxial cable when used as the yagi wi-fi antenna's driven element. In free space, a folded dipole has a 300 ohm impedance at resonance, but the impedance drops drastically when parasitic elements are brought into close proximity.

This high gain wi-fi antenna can be constructed in a couple of hours and requires some measuring, cutting, bending, and bolting of metal. Use caution around the sharp edges. When finished, put it up and enjoy a very durable antenna that provides outstanding wi-fi performance.
There are crap copies of this antenna, pimped on crap peddling websites, which fail to perform. Use the instructions given here and avoid those cheap imitations!

YAGI Wi-Fi ANTENNA PARTS LIST:

A 1.2 meter length of 14 AWG bare, solid copper wire.
One wooden square, 1 cm per side, 50 cm long (70 cm for the 20 element antenna).
Wire cutters.
Metric ruler.
Drill, with 1.6 mm (1/16") bit.
Printed or written template with antenna dimensions.
Ball point pen or fine felt tipped marker.

YAGI Wi-Fi ANTENNA CONSTRUCTION:

Assemble the yagi wi-fi antenna following the steps below, starting with preparation of the boom, followed by mounting the elements. After the elements are mounted, a suitable connector is added, and the antenna is tested over-the-air. Keep in mind that it can be connected to most usb wireless adapters by cutting the circuit board antenna trace and patching in a pigtail feeding the antenna.

Draw a line as accurately as possible down the center of one side of the wooden boom.
Mark the boom centerline 5 cm from one end. This is the "zero location," where the director element will be mounted.
Continue down the boom, carefully marking the locations of each element on the centerline.
Carefully drill through the boom at each element's location. Make sure to drill straight through the boom, emerging on the other side still centered and perpendicular.
Cut one element at a time, carefully measuring each element before and after cutting, trimming as necessary for proper length. File the wire ends and make sure the lengths are as accurate as possible!
Press elements through the boom, centering each before moving to the next element.

Element positions marked
on the yagi wi-fi antenna boom.

The reflector element
after mounting.

For the driven element, cut a 130 mm length of wire, and make a 180 degree bend 30 mm from one end. Mount in boom, then make a bend 30 mm from other end. Adjust as necessary to create a folded dipole just under 59 mm in length with 5 mm spacing.
Double check all elements, making sure all are centered and parallel.
Attach a pigtail (or connector) to open ends of folded dipole.

Folded dipole prior
to mounting in antenna boom.

The driven element
before the last bend.

Two yagi wi-fi antenna
elements mounted in boom.

After all of the elements are measured, cut, and mounted, the antenna should resemble the finished yagi pictured below. Connect the pigtail or connector to the driven element. Then connect the wi-fi adapter or wireless router to the antenna and start checking over-the-air signal strengths. Note that the antenna may be sensitive to polarization: when the antenna seems to bring in the best signal, rotate it to find the best polarization. Mounting the antenna is possible using commonly available hardware, such as 90 degree angle brackets, U bolts, or even velcro.

Closeup of the wi-fi yagi feedpoint.
Keep the leads short!

The completed wi-fi yagi antenna.

Best Transformer less Power Supply Circuit Using IC LR645.

noreply@blogger.com (Anonymous) — Sat, 10 Aug 2013 14:34:00 +0000

A very interesting yet super simple transformer less power supply circuit has been discussed here. In one of my earlier posts I provided a similar circuit but it utilized a high voltage capacitor for dropping the mains voltage to lower usable levels. Here we study how the mains voltage is controlled to 12 volts and 5 volts using just a single IC LR645G and some other supportive ordinary active semiconductors.

In short the circuit diagram may be understood in the following manner:

The high voltage AC mains is rectified by the bridge configuration using four diodes at the input.
The rectified voltage is smoothed by the filter capacitor introduced just after the bridge network.
The rectified, filtered high voltage is fed to the IC LR645LG, which effectively reduces the voltage to 15 volts at 3 mA.
The FET pulls the 3 mA current output to 150 mA and feds it to the next stage which incorporates the 5 volt regulator stage.

However one big drawback of eliminating the use of a transformer is the DANGER of high voltage shock that actively hangs with all the naked points of the circuit. Therefore extreme caution must be exercised while building and testing this circuit and other attached circuits.

Parts List

Diodes - 1N4007

Input Capacitor - 4.7uF/400V,

Output Capacitors are 1uF/25V

ICs are LR645LG and 7805,

FET - DN2540N5

Electronics Circuit Application

50 Watt Amplifie small subwoofer Circuits..

noreply@blogger.com (Anonymous) — Wed, 07 Aug 2013 15:43:00 +0000

This is a handy, easy to build general purpose 50 watt amp. The amp has an input for a radio, TV, stereo or other line level device. It also has a phono input for a record player, guitar, microphone or other un-amplified source. With the addition of a low pass filter at the input, it makes a great amp for a small subwoofer.

parts List
R1 200 Ohm 1/4 W Resistor
R2 200K 1/4 W Resistor
R3 30K 1/4 W Resistor
R5 1K 1/4 W Resistor
R6 5K 1/4 W Resistor
R7,R10 1 Meg (5%) 1/2 W Resistor
R8,R9 0.4 Ohm 5 W Resistor
R11 10K Pot
R12,R13 51K 1/4 W Resistor
R14 47K 1/4 W Resistor
C1 100uF 35V Electrolytic Capacitor
C2 0.011uF Capacitor
C3 3750pF Capacitor
C4,C6 1000pF Capacitor
C5,C7,C8 0.001uF Capacitor
C9 50pF Capacitor
C10 0.3uF Capacitor
C11,C12 10,000uF 50V Electrolytic Capacitor
U1,U2 741 Op Amp
U3 ICL8063 Audio Amp Transister Driver thingy
Q1 2N3055 NPN Power Transistor
Q2 2N3791 PNP Power Transistor
notes
1. I know I skipped R4. That is not a problem :-)
2. Distortion is less than 0.1% up to 100HZ and increases to about 1% at 20kHz.
3. I haven't been able to find anyone who sells a suitable T1. You can always use two 24V 5A units in series. If you are building two amps (for stereo), then I would suggest using an old microwave transformer and rewinding it.
4. Q1 and Q2 will require heatsinks.
5. You may have trouble finding U3 because it is discontinued. Please don't email me about sources...I can't find it either Electronics Circuit Application

Cell Phone and iPod Battery Charger Circuit..

noreply@blogger.com (Anonymous) — Tue, 06 Aug 2013 15:06:00 +0000

Using the USB port on your computer to charge your player’s batteries is not always practical. What if you do not have a computer available at the time or if you do not want to power up a computer just for charging? Or what if you are traveling? Chargers for Mobile Phones iPods and MP3 players are available but they are expensive and you need separate models for charging at home and in the car.
This charger can be used virtually anywhere. While we call the unit a charger, it really is nothing more than a 5V supply that has a USB outlet. The actual charging circuit is incorporated within the iPOD or MP3 player itself, which only requires a 5V supply. As well as charging, this supply can run USB-powered accessories such as reading lights, fans and chargers, particularly for mobile phones.
The supply is housed in a small plastic case with a DC input socket at one end and a USB type "A" outlet at the other end, for connecting to Mobile Phone, an iPod or MP3 player when charging. A LED shows when power is available at the USB socket.

Parts:

    P1 = 1K
    R1 = 1R-0.5W
    R2 = 1R-0.5W
    R3 = 1R-0.5W
    R4 = 1K
    R5 = 560R
    R6 = 10R-0.5W
    R7 = 470R
    C1 = 470uF-25V
    C2 = 100nF-63V
    C3 = 470pF
    C4 = 100uF-25V
    D1 = 1N5404
    D2 = 1N4001
    D3 = 1N5819
    D4 = 5.1V-1W Zener Diode
    D5 = 5mm. Red LED
    L1 = 220uH
    S1 = USB 'A' Type Socket
    SW1 = On/Off Switch
    IC1 = MC34063A

Specifications:

    Output voltage ----------------------5V
    Output current ---------------------660mA maximum for 5V out
    Input voltage range ------------------9.5V to 15V DC
    Input current requirement ----------500mA for 9V in, 350mA for >12V input
    Input current with output shorted--- 120mA at 9V in, 80mA at 15V in
    Output ripple ------------------------14mV (from no load to 660mA)
    Load regulation ----------------------25mV (from no load to 660mA)
    Line regulation ----------------------20mV change at full load from 9 to 18V input
    No load input current ----------------20m

(The specification for the computer USB 2.0 port requires the USB port to deliver up to 500mA at an output voltage between 5.25V and 4.375V).

The circuit is based around an MC34063 switch mode regulator. This has high efficiency so that there is very little heat produced inside the box, even when delivering its maximum output current. The circuit is more complicated than if we used a 7805 3-terminal regulator but since the input voltage could be 15V DC or more, the voltage dissipation in such a regulator could be 5W or more at 500mA. and 5W is far too much for a 7805, even with quite a large heatsink. Credit for this circuit goes to SiliconChip, A wonderful electronics magazine .   Electronics Circuit Application

5 band graphic equalizer Circuits

noreply@blogger.com (Anonymous) — Tue, 06 Aug 2013 14:53:00 +0000

This circuit uses a single chip, IC BA3812L for realizing a 5 band graphic equalizer for use in hi-fi audio systems.The BA3812L is a five-point graphic equalizer that has all the required functions integrated onto one IC. The IC is comprised of the five tone control circuits and input and output buffer amplifiers. The BA3812L features low distortion, low noise, and wide dynamic range, and is an ideal choice for Hi-Fi stereo applica-tions. It also has a wide operating voltage range (3.5V to 16V), which means that it can be adapted for use with most types of stereo equipment.

The five center frequencies are independently set using external capacitors, and as the output stage buffer amplifier and tone control section are independent circuits, fine control over a part of the frequency bandwidth is possible, By using two BA3812Ls, it is possible to construct a 10-point graphic equalizer. The amount of boost and cut can be set by external components.

The recommended power supply is 8V, but the circuit should work for a supply of 9V also. The maximum voltage limit is 16V.

The circuit given in the diagram operates around the five frequency bands:

100Hz

300Hz

1kHz

3kHz

10kHz

Electronics Circuit Application

Galaxy S3 Audio Problem and solution..

noreply@blogger.com (Anonymous) — Mon, 05 Aug 2013 14:56:00 +0000

Samsung Galaxy series is known to be one of the finest smart phone ranges that exist today, and this is mainly because its features have surely beaten a good number of industry giants. But nothing is flawless, no matter how better the technology is, as after some time it is going to start having some issues in it due to any of the reasons.

Case 1 – Noise in the speaker
    Case 2 – No Sound at all (During Dialing or Receiving calls)
    Case 3 – Low sound

Resolving Case 1 Issue

Case-1 issue normally occurs due to dust on speakers of your Samsung Galaxy S3 which covers Speaker Diaphragm. In order to resolve Case 1, all you have to do is to:

    Open cover of your Samsung Galaxy S3 (front end) and clean the speaker area with the help of a cotton bud or any cotton cloth, if it’s too much dusty than it is a good idea to replace it rather than cleaning it.

Resolving Case 2 Issue

Case–2 issue can be resolved by:

    Restarting your Samsung Galaxy S3.
    Overview Volume settings.

Resolving Case 3 Issue
Case-3 issue can only be resolved by replacing your Samsung Galaxy S3 speaker, and this problem occurs due to faulty speakers. There is no specific reason for a speaker to be faulty.
If your issue isn’t resolved with all that, than all you have to do is to move towards Hardware solution
After separating your Samsung Galaxy S3 audio chip with phone, than all you have to do is to:

Check volume level first.
Verify whether your strip or connector of Samsung Galaxy S3 had any kind of damage (Physical or Water)
In case it is damaged then replace it with a new strip or connector.
Now figure out either Capacitor or Codec is faulty, if any one of them is, replace it. (Red Marked areas notifies terminals of connector and Audio Codec). Electronics Circuit Application

Nokia 6270 PCB board layout.

noreply@blogger.com (Anonymous) — Sun, 04 Aug 2013 09:46:00 +0000

Nokia 6270 PCB board layout
The front and back side layout of components on Nokia 6270 main PCB board. to be used as mobile phone repair manual on Nokia 6270.

SIMPLE 230V LED DRIVER Circuits ..

noreply@blogger.com (Anonymous) — Sun, 04 Aug 2013 02:22:00 +0000

Led's commonly works only in DC, so we have to convert the alternating current to direct current and step down to a safe value before applying to the led sequence.

The circuit mainly consisting of 5 led bulbs, a bridge rectifier and a filtering network with voltage regulator.

The bridge rectifier is used to convert alternating current (AC) to pulsating DC. It is made possible by means of rectifying diodes (D1 to D4 1N4007)

The filtering is made possible by means of a capacitor (47uF). It is used to eliminate the ripples coming from rectifier circuit.

After regulating the filtered voltage using a zener diode, we get an almost direct current suitable for LED's.

230V LED Driver circuit without transformer. Here i am using 5 led's you can increase the count at your convineance. Due to the absence of Transformers we can reduce the cost and size of the circuit considerably. As we all know LED's are Cheap, efficient and cool device with low power consumption. So we can reduce our electricity bills to a great extent.

The circuit is powered by 230V 50Hz ac supply, so be careful while troubleshooting this project.

Led's commonly works only in DC, so we have to convert the alternating current to direct current and step down to a safe value before applying to the led sequence.

The circuit mainly consisting of 5 led bulbs, a bridge rectifier and a filtering network with voltage regulator.

The bridge rectifier is used to convert alternating current (AC) to pulsating DC. It is made possible by means of rectifying diodes (D1 to D4 1N4007)

The filtering is made possible by means of a capacitor (47uF). It is used to eliminate the ripples coming from rectifier circuit.

After regulating the filtered voltage using a zener diode, we get an almost direct current suitable for LED's.
- See more at: http://www.mycircuits9.com/2012/08/230v-led-driver-circuit.html#sthash.zRwA5uPL.dpuf

FM-Transmitter Circuit.

noreply@blogger.com (Anonymous) — Thu, 06 Jun 2013 14:23:00 +0000

Nothing critical here. To get a bit of tuning out of the coil you could put a 4-40pF trimmer capacitor (optional) parallel over the 1 μH coil, L1. C1/C4 and C5/C6 are ceramic capacitors, preferably NPO (low noise) types. C2/C3 are electrolytic or can be tantalum types. The antenna is nothing more than a piece of 12" wire or a piece of piano wire from 6" to 12".

To find the signal on your receiver, make sure there is a signal coming into the microphone, otherwise the circuit won't work. I use an old mechanical alarm clock (you know, with those two large bells on it). I put this clock by the microphone which picks up the loud tick-tock. I'm sure you get the idea... Or you can just lightly tap the microphone while searching for the location of the signal on your receiver.

Parts List

R1,R3 = 100K

R2 = 10K

R4 = 470 ohm

C1,C4 = 470pF

C2,C3 = 4.7μF, 16V, electrolytic

C5,C6 = 4.7pF

C7 = 4-40pF trimmer cap (optional, see text)

L1 = 1μH

Q1,Q2 = 2N2222, NPN transistor

Mic = Electret Microphone

B1 = 9 Volt, Alkaline battery

Samsung T100/T108 mobile phone repairing guide

noreply@blogger.com (Anonymous) — Wed, 05 Jun 2013 14:41:00 +0000

Nokia X2-00 Charging Solution Guide

noreply@blogger.com (Anonymous) — Sat, 01 Jun 2013 14:14:00 +0000

Electronics Circuit Application

Nokia X2-00 Mic solution guide.

noreply@blogger.com (Anonymous) — Sat, 01 Jun 2013 14:04:00 +0000

10Watt Audio Amplifier with Bass boost circuit.

noreply@blogger.com (Anonymous) — Thu, 30 May 2013 14:58:00 +0000

Circuit diagram

parts list

P1_________________22K   Log.Potentiometer (Dual-gang for stereo)
P2________________100K   Log.Potentiometer (Dual-gang for stereo)
R1________________820R   1/4W Resistor
R2,R4,R8____________4K7 1/4W Resistors
R3________________500R   1/2W Trimmer Cermet
R5_________________82K   1/4W Resistor
R6,R7______________47K   1/4W Resistors
R9_________________10R   1/2W Resistor
R10__________________R22   4W Resistor (wirewound)

C1,C8_____________470nF   63V Polyester Capacitor
C2,C5_____________100µF   25V Electrolytic Capacitors
C3,C4_____________470µF   25V Electrolytic Capacitors
C6_________________47pF   63V Ceramic or Polystyrene Capacitor
C7_________________10nF   63V Polyester Capacitor
C9________________100nF   63V Polyester Capacitor

D1______________1N4148    75V 150mA Diode

IC1_____________NE5532    Low noise Dual Op-amp

Q1_______________BC547B   45V 100mA NPN Transistor
Q2_______________BC557B   45V 100mA PNP Transistor
Q3_______________TIP42A   60V 6A    PNP Transistor
Q4_______________TIP41A   60V 6A    NPN Transistor

J1__________________RCA audio input socket

Power supply circuit

Circuit diagram

Parts

R11_________________1K5 1/4W Resistor

C10,C11__________4700µF 25V Electrolytic Capacitors

D2________________100V 4A Diode bridge
D3________________5mm. Red LED

T1________________220V Primary, 12 + 12V Secondary 24-30VA Mains transformer

PL1_______________Male Mains plug

SW1_______________SPST Mains switch .Electronics Circuit Application

TV signal amplifier 470Mhz-860Mhz circuit

noreply@blogger.com (Anonymous) — Tue, 28 May 2013 15:41:00 +0000

This amplifier can amplify to 10dB the RF signal from antenna working as class A and is based on transistor BFQ34 of Philips. The transistor comes in case SOT122A. You may find the BFQ34T in market but better do not use it as it has different characteristics.Input signal should be about 10mW if we want 10dB output. So with 0.5mW we get 5dB. Do not overdrive the transistor because the signal will be distorted full of lines, without color etc. So use 12Volts with 1A stabilised power supply. The circuit should be enclosed in a small metal box. Electronics Circuit Application