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Voltage Doubler

This is a Simple Voltage Doubler to boost 3V battery voltage to power some low-power 5V circuits. In...
 

Function Generator using ICL8038

This is an Intersil ICL8038 based lab bench function generator circuit, this works well and is based...
 

Digital Potentiometer

In this Circuit, digital potentiometer, connect pushbutton switches to fast and slow with one end to...
 

High Resistance Meter

I don't remember if this circuit worked properly. But a few were made and i might not have shown the...
 

FET Current Source

This is a constant current source using a FET. This is the most simple replacement to series resisto...
 

Constant Current Source LED Drive

This is a Constant Current Source LED Driver, When the LED driver Upper-NPN is driven by a voltage t...
 

LM555 Voltage Doubler

This circuit shows the voltage doubler working with a 555. LM555 has good drive 200mA, both Vcc and ...
 

Diode Thermometer

Measurement Of Temperature - When power transistors are used, they may tend to over heat. Likewise r...
 

Voltage Level Indicator

This circuit is derived from a Siemens Application Note 1974. ...
 

Single Digit Voltmeter

I wanted to design a logic probe as a tutorial, but there were many good ones in the web so i have t...
 

Dual Power Supply

This supply gives both positive and negative outputs. Appropriate Fuses should be used to protect fr...
 

Battery Backup Supply

This is a 9V power supply which will work even on power failure. It uses a rechargeable battery and ...
 

Simple Mains Voltage monitor

This Circuit helps in the monitoring of mains supply voltage. It does not use a isolation step down ...
 

Mains Voltage monitor using LM3914

This Circuit helps in the monitoring of mains supply voltage. It does not use a isolation step down ...
 

Edison Bulb Life Extender

The Edsion Filament lamp may be less popular, but it is the most cost-effective light even today.
 

Passive volume control

Volume control circuit for speaker 4 ohm or 8 ohm located in the another room far away. by using onl...
 

Running Lights

The 555 Astable generates a clock for this circuit, an oscillator giving a square wave output at pin...
 

Simple Digital Counter

The basic digital circuits are Flip Flop and Counter, both are here. This circuit can be cascaded to...
 

Battery Level Indicator

The circuit is an untested design but it should work. I did it as many searches were made in my web...
 

Single Power Supply

This circuit uses a PNP Power Transistor TIP2955, you can use any other according to your current an...
 

Sound to light converter

this was made by me when i was a kid, it was even published in a magazine, i think it will work, it ...
 

Dimmer or power control

you can use it with a bulb to vary brightness of bulb, this is a live circuit it can give a shock, e...
 

Telephone status indicator

this will monitor telephone status without loading the telephone line, this way if you have two phon...
 

Water operated relay

this was done in my early days, i have upgraded it, it ought to work, reduce the number of transisto...
 

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