Optical Theremin

Normally, Theremin works by detecting hand proximity using capacitive coupling method. A Theremin circuit shown in the schematic diagram below use different method to control the pitch. The oscillator of this tone generator, both the volume and frequency  are controlled using LDRs, a light sensitive electronic component, so we can call this circuit an optical Theremin.  Look at the following […]

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Cuckoo Sound Simulator (Synthesizer/Generator)

A two tone effect very much alike cuckoo sound is generated by this circuit. We can use this circuit for door-bells or other purposes thanks to a built-in audio amplifier and loudspeaker. Used as a sound effect generator, it can be connected to external amplifier, tape recorder, etc. The built-in audio amplifier and loudspeaker may be omitted and the output […]

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Electronic Metronome

Metronome is very important tool if you studying music playing. There are mechanical metronome device in the past, but today, electronic metronome is much more popular since it can be very simple, compact/small, reliable, and also has the most interesting feature: cheap. Here is one example of the electronic metronome schematic: Parts: C1 1 uF 63V Polyester Capacitor C2 10nF […]

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Wailing Alarm Siren

This alarm siren circuit produce warbling sound, you can use it in your toys or  in security alarm.  The circuit use two 555 IC oscillator. In this alarm siren circuit, the first oscillator is employed to produce audio frequency. The second oscillator is employed to produce a modulating signal. This modulating signal make this alarm siren generates warbling sound. Here […]

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