Monthly Archives: July 2010

Ticking Bomb Sound Simulator

Posted on July 26, 2010 by Rust
TICKING BOMB

Sound similar to a loud clicking clock that is  usually attached to a timed bomb is produced by this circuit.  Use this circuit for fun, don’t use it for terror. The 200k pot adjust the frequency of the tick. By … Continue reading →

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Dynamic Microphone Pre-Amplifier

Posted on July 21, 2010 by Rust
DYNAMIC MICROPHONE AMPLIFIER

Dynamic microphone uses a moving coil around magnetic field to convert mechanical movement into electrical signal. The ordinary mini speaker is turned into a very sensitive microphone.  Although it looks like misusing the speaker as a microphone, but actually a … Continue reading →

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Ambulance (Hee-Haw) Siren

Posted on July 18, 2010 by Rust
Ambulance Siren

The circuit below consists of two multivibrators. The first multivibrator provides the speed of the change from “hee” to “haw” and operates at a low frequency. By allowing full voltage to appear at the bottom of the 220R and then … Continue reading →

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