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 171 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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Touch controlled musical bell.

john April 7, 2010 4 Comments
Description. This circuit produces a musical tone whenever someone touches the touch point designated as TP in the circuit. The circuit works from two AA cells and produces enough sound. The circuit uses IC UM 3481 commonly used in...
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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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Water Sensor Circuit with Alarm

john October 12, 2012 17 Comments
If you are looking for a Water level indicator or a Water level controller, there are pretty good circuits we have developed. This one is just a fun project made for hobby purpose! You can call this a water...
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Night security light

john July 9, 2014 19 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 109 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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