This powerful sound emitter used in defense to intimidate people was found in a 90s Popular Electronics. The circuit produces a strong modulated tone of 3 kHz. The modulation is 10 Hz.
This is the typical audio amplifier for a 1967 television. We found it in a magazine from the...
This alarm is designed for doors and windows, but nothing prevents it from being used in cars,...
With a unijunction transistor and a tunnel diode it is possible to obtain rise times of 1 ns with...