Theremin Circuit

This is the only musical instrument known to the writer that is played without being touched! The Theremin is named after Professor Theremin who, in 1928, amazed New York audiences when he demonstrated his ability “to obtain music from the ether”. The instrument has two rods protruding from its housing, each one forming one ‘plate’ […]

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Simple Metal Detector Circuit

In this post we will how to make a simple metal detector circuit at home This metal detector is a low sensitive type  can be powered by a battery 3 to 15V, and may be constructed employing four exclusive OR gates from a CMOS integrated circuit 4030. The gates have been connected as two oscillators […]

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Magnetic Proximity Switch Circuit

This is the circuit diagram of a magnetic proximity switch that finds a number of operations in many large areas. The Magnetic Proximity Switch Circuit is based on a magnetic reed switch(S1) as being the proximity sensor. A monostable multivibrator calculated on NE555 (IC1) and a toggle flip flop in line with CD4013 (IC2) performs […]

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Light Activated Switch Circuit

This light activated switch circuit relay is activated only in the presence of light. It has many applications, it could be used as a photocell and to off the light in a room or turn on the radio when it is dawning, etc. Working of light activated switch The photoresist / LDR whose ohmic value […]

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