We found this circuit in the 1983 Radio Electronics Special projects magazine. The components are common, and the circuit drives a relay. The power supply must be isolated.
This filter was obtained from a Linear Technology manual from the 1990s. The power supply must be...
Found in a 90s Popular Electronics, this circuit is intended for amplifying analog video signals....
Based on a 555, this 80's American documentation circuit detects the voltage of a battery and can then...