This circuit is designed to measure very weak currents, in the order of picoamperes. We found it in an American documentation from the 80s. The integrated circuit is from that time.
This conventional window detector circuit was found in a 1995 documentation. The trigger points, that...
Found in a Radio Electronics store from the 90s, this circuit is for cars of that era. The circuit...
This old circuit excites lamps but can be modified to excite high-power LEDs or other loads...