How to make a Rheostat

john September 15, 2017 3 Comments
I have already explained in detail the working of a rheostat. To know more about the component click on the link below. TAKE A LOOK : POTENTIOMETER AND RHEOSTAT – WORKING AND COMPARISON Although the below explained process is...
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LED torch using MAX660

john April 7, 2010 20 Comments
Description. This is a simple LED torch circuit based on IC MAX660 from MAXIM semiconductors. The MAX 660 is a CMOS type monolithic type voltage converter IC. The IC can easily drive three extra bright white LEDs.The LEDs are...
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Electronic mosquito repeller

admin April 7, 2010 164 Comments
Description. Here is the circuit diagram of an ultrasonic mosquito repeller.The circuit is based on the theory that insects like mosquito can be repelled by using sound frequencies in the ultrasonic (above 20KHz) range.The circuit is nothing but a...
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Battery operated heater

john April 7, 2010 36 Comments
Description. Here is a simple heater circuit that can be operated from a 12V battery. The first part of the circuit is an astable multivibrator build around the two transistors Q1 and Q2 .The ON time of transistor Q2...
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Plant moisture level monitor

john January 3, 2018 12 Comments
Description. Here is a simple circuit that will give a visual indication when the soil water level inside your flower pot goes low below a certain limit. The U1C and associated components are wired as an oscillator producing a...
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Night security light

john July 9, 2014 14 Comments
Description.  Here is a simple circuit switches on a light around 2 hours after midnight, the time at which most of the robberies taking place. This simple circuit is build around a CMOS IC 4060 to obtain the required...
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Transistor intercom circuit.

admin April 7, 2010 107 Comments
Description. Here is a simple but effective intercom circuit that is based fully on transistors.The circuit is based on a three stage RC coupled amplifier. When the pushbutton S2 is pressed, the amplifier circuit wired around T1 & T2...
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Puff to OFF LED circuit.

admin November 11, 2011 28 Comments
Descrption. This is a simple circuit in which the glowing LED can be switched OFF just by a puff. A condenser mic (M1) is used to sense your puff. When the push button S1 is pressed, the transistors Q2...
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