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 12V battery charging circuit automatically shuts off at the end of the charge. The disconnect...
We do not know exactly what sound a flying saucer makes, or if it makes a sound! But this is not...
This simple 1 transistor circuit was found in an American documentation from the 60's. The...