Voice Scrambler (CB22462E)

We found this circuit in a Popular Electronics from 1992. It consists of a voice scrambler used in telephone transmissions.

Voltage Controlled Oscillator RC4558 (CB19784E)
This VCO makes use of an RC4558 which is an operational amplifier with characteristics close to...
Low battery indicator 555 (CB9551E)
This circuit can operate with different voltages, depending on the zener used. We found it in a...
Timer Using 7555 (CB860E)
This circuit can be used in the car to control the windscreen wipper or with other appliances at...