Found in a 90s Silicon Chip documentation this circuit is intended to protect a speaker system in case of amplifier failures.
Two operational amplifiers like the 741 or equivalent are used in this voltage-controlled...
This very interesting project was obtained in a 1980 publication. It consists of a device that is...
This circuit is from a manual of FETs of 1977. The FET can be the BF245 or MPF102 and the relay is of...