This circuit interrupts the power supply when grounding is missing. The circuit is from an old documentation (from the 80's) using current transformers and other components of the time.
We found this circuit in an English documentation from the 60s. The integrated circuits are the...
This circuit was found in a 90s Popular Electronics. It generates tones given by the oscillators and...
This amplifier circuit applies its signal to an ordinary audio amplifier to pick up signals from a...