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.
The critical point in this 2005 project is the adjustment of the optical system, mainly to avoid...
This simple SCR trigger was found in a 1965 General Electric SCR manual. The circuit makes use of a...
We found this circuit in a 1976 technical documentation, but it can be assembled with modern...