Simple Schematic Collection

Battery Charger for NiCad Batt

noreply@blogger.com (nano) — Fri, 18 May 2012 20:59:00 +0000

This battery charger circuit is designed for recharging NiCad batteries based on an AC-powered current source method.

It can crank out as much as 1 amp and can be modified to go even higher by choosing different devices for Q1.

Since this circuit uses AC line voltages and currents, please exercise extreme caution during assembly, turn-on, and test.

Solar Battery Charger Circuit Schematic

noreply@blogger.com (nano) — Thu, 17 May 2012 20:34:00 +0000

Here is a solar charger circuit that is used to charge Lead Acid or Ni-Cd batteries using the solar energy power.

The circuit harvests solar energy to charge a 6 volt 4.5 Ah rechargeable battery for various applications.

The charger has Voltage and Current regulation and Over voltage cut off facilities.

Battery Charger for 12v

noreply@blogger.com (nano) — Thu, 17 May 2012 20:22:00 +0000

This is a design of the circuit diagram of a simple and straight forward battery charger that can be used to charge all type of 12V rechargeable batteries including car batteries.

This circuit is completed with ammeter VU for displaying the current. This is the figure of the circuit.

Lithium Poly Charger

noreply@blogger.com (nano) — Sun, 13 May 2012 18:21:00 +0000

The above circuit will charge any 2-cell * Li-Ion battery pack.

Maximum current is about 650 milliamps.

The circuit is designed for batteries of 900mah or higher. Note this circuit is NOT for Li-Metal batts (i.e. Duralites).

Power source can be a 12v Gell cell (Power panel), or can be powered by a car’s cigarette lighter.

I use an old 12v DC wall transformer (800ma or more.) Radio shack sells a 12v/1amp wall DC adapter #273-1776 that will work.

Supply does not need to be regulated. In fact my cheap supply outputs 17 volts with no load.

Source: http://www.shdesigns.org

Transistor Checker

noreply@blogger.com (nano) — Thu, 10 May 2012 16:34:00 +0000

This simple circuit can check transistors, in the circuit, down to 40 ohms across the collector-base or base-emitter junctions.

It can also check the output power transistors on amplifier circuits.

Circuit operation is as follows. The 555 timer ( IC1 ) is set up as a 12hz multi vibrator.

The output on pin 3 drives the 4027 flip-flop ( IC2). This flip-flop divides the input frequency by two and delivers complementary voltage outputs to pin 15 and 14.

VHF Antenna Amplifier

noreply@blogger.com (nano) — Thu, 10 May 2012 16:29:00 +0000

A very simple antenna amplifier electronic circuit project can be designed using this circuit diagram .

This antenna amplifier electronic circuit can be used for a frequency range between 1 and 300MHz .

This circuit antenna amplifier can be used for high frequency and VHF band ( for radio and TV) and will provide a 22 dB gain .

This antenna amplifier electronic project has a very low noise , under 1.6dB .

This VHF, FM amplifier circuit is constructed based on the BFT66 transistor connected in common emitter connection.

Intercom Circuit with Transistors

noreply@blogger.com (nano) — Thu, 10 May 2012 16:16:00 +0000

This is a 2-station simple intercom circuit build based on transistors part and using common 8R mini speakers.

The speaker works as microphone and generate sound, so there is no need microphone for this intercom.

The "press-to-talk" switches should have a spring-return so the intercom can never be left ON, push on switch can be used for this kind of task.
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D.I.Y Gold Detector Schematic

noreply@blogger.com (nano) — Tue, 08 May 2012 08:47:00 +0000

Here the very simple and easy build gold detector circuit.

The circuit capable to sense gold or metal or coins from a distance of about 20cm, depending on the size of the object to detect.

The circuit oscillates at about 140kHz and a harmonic of this frequency is detected by an AM radio.

You can simply tune the radio receiver until a squeal is detected.

Phone calling Detector

noreply@blogger.com (nano) — Sun, 06 May 2012 18:36:00 +0000

This circuit was designed to detect when a call is incoming in a cellular phone (even when the calling tone of the device is switched-off) by means of a flashing LED.

The device must be placed a few centimeters from the cellular phone, so its sensor coil L1 can detect the field emitted by the phone receiver during an incoming call.

Broadcast Transmitter Circuit Diagram

noreply@blogger.com (nano) — Sun, 06 May 2012 15:45:00 +0000

In this circuit, a 74HC14 hex Schmitt trigger inverter is used as a square wave oscillator to drive a small signal transistor in a class C amplifier configuration.

The oscillator frequency can be either fixed by a crystal or made adjustable (VFO) with a capacitor/resistor combination.

Radio Wave Alarm

noreply@blogger.com (nano) — Sun, 06 May 2012 15:30:00 +0000

This very simple alarm circuit is sure to have the police beating a path to your door - however, it has the added advantage of alerting you to their presence even before their footsteps fall on the doormat.

Amplifier Timer Schematic Diagram

noreply@blogger.com (nano) — Sun, 06 May 2012 09:11:00 +0000

This circuit turns-off an amplifier or any other device when a low level audio signal fed to its input is absent for 15 minutes at least.

Pushing P1 the device is switched-on feeding any appliance connected to SK1. Input audio signal is boosted and squared by IC2A & IC2B and monitored by LED D4.

Mini Subwoofer Circuit - 22W

noreply@blogger.com (nano) — Sun, 06 May 2012 08:24:00 +0000

The subwoofer is a subwoofer or a speaker to reproduce low frequencies, devotee of 20 Hz to 150 Hz electronic circuit diagram below shows the details of a scheme of the main amplifier TDA1516 22 watt in 4 ohm car subwoofer driver.

This device is designed for an existing stereo amplifier, often requires adding another blow to the music of driving a subwoofer.

Wireless Transmitter for IR Headphone

noreply@blogger.com (nano) — Tue, 24 Apr 2012 19:41:00 +0000

This circuit shows a Wireless Transmitter for IR Headphone.

Step Down DC Converter

noreply@blogger.com (nano) — Mon, 23 Apr 2012 10:23:00 +0000

This is a ADP1821 Step Down DC-to-DC Converter circuit.

This circuit uses ADP1821 that is synchronous pulse-width-modulated (PWM), step-down controller, inexpensive and versatile.

It can drive all N-channel power stage to regulate an output voltage as low as 0.6 V.

Converter circuit 12Vdc to 24Vdc

noreply@blogger.com (nano) — Mon, 23 Apr 2012 07:18:00 +0000

This converter circuit shows a DC-DC converter that converting up 12Vdc source to a 24Vdc.

It can be used to run radios, small lights, relays, horns and other 24V accessories from a 12V vehicle with a maximum draw of about 800mA.

Doubler Voltage with ne555 schematic

noreply@blogger.com (nano) — Mon, 23 Apr 2012 06:50:00 +0000

This circuit shows a doubler voltage with ne555 schematic.

This be Simple Doubler Voltage circuit, from voltage 12VDC to be 24VDC.

By use Timer IC highly popular the number NE555 and other equipment a little again.

It can give current get about 50mA convenient for the circuit, that use low current the small-sized.

Stepper Motor Driver Circuit Diagram

noreply@blogger.com (nano) — Sun, 22 Apr 2012 11:09:00 +0000

Using L297-L298 integrated circuits manufactured by SGS Thomson (ST) can be made a control circuit for a stepper motor with two phase bipolar or unipolar four-phase (maximum current allowed on stage is 2 A).

This integrated motor driver generates control signals for the double stator and allows selection of travel direction and execution of a full step or half step, through proper planning its inputs, TTL compatible.

Electronic Timer with display circuit

noreply@blogger.com (nano) — Sun, 22 Apr 2012 10:56:00 +0000

Using this electronic scheme can be built an electronic timer which can be set to measure a maximum of 60 hours.

The electronic timer allows the fixation of some intermediate time. On reaching this point, a buzzer will sound.

The circuit is built using ICM7217 integrated circuit, manufactured by Intersil, which contains a CMOS counter up / down, with 4 digits and display properly.

Audio Stereo Power Amp Circuit

noreply@blogger.com (nano) — Sat, 21 Apr 2012 06:37:00 +0000

This is a 50 Watt Audio power amplifier circuit based single IC STK4036II. Use heatsink to prevent overheating on the IC.

The amplifier circuit will give you good quality of sound unexpensive and have low price.

It is easy we make a power amplifier using only few external components.

The STK4036II amplifier are will find in enough eponymous stereo amplifiers , but also in enough activety loudspeakers.

FM Antenna Booster Circuit Diagram

noreply@blogger.com (nano) — Sat, 21 Apr 2012 05:58:00 +0000

This is a low cost fm antenna booster that can be used to listen to programmes from distant FM stations clearly.

The antenna fm booster circuit comprises a common-emitter tuned RF preamplifier wired around VHF/UHF transistor 2SC2570 (C2570).

Battery Indicator schematic diagram

noreply@blogger.com (nano) — Fri, 20 Apr 2012 18:55:00 +0000

This circuit diagramc shows a simple battery level indicator.

In general, in mobile phones, the battery levels is displayed in dot or bar style.

This helps you to effortlessly acknowledge the battery level.

Power Supply for regulated current and voltage

noreply@blogger.com (nano) — Mon, 16 Apr 2012 10:02:00 +0000

Click to enlarge

This is also another useful project for anyone working in electronics.

Both Current and Voltage Regulation is Extremely Important to Help Prevent Damage to Circuit, Especially Experimental Circuits.

This circuit used a Rotary Switch to select Various Current ranges as a Potentiometer is not very practical for the lower resistance/High Current Ranges.

Stabilized Power Supply Circuit 3-30V

noreply@blogger.com (nano) — Sun, 15 Apr 2012 08:37:00 +0000

This is a very useful project for anyone working in electronics.

It is a versatile power supply that will solve most of the supply problems arising in the everyday work of any electronics work shop.

Adjustable Lab Power Supply

noreply@blogger.com (nano) — Sun, 15 Apr 2012 07:07:00 +0000

Make your own lab power supply complete with adjustable voltage and constant current source. Using single IC (LM324)