In fact, this 1967 Electronic Design circuit generates two symmetrical ramps whose frequency depends on the values of the components used. Modern equivalent transistors can be used.
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...