Found in a 1970 documentation, this circuit makes use of 741 operational amplifiers that are common today. Note that the power supply must be symmetrical.
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...