This simple low power triplicator was found in 90’s American documentation. The diodes can be general purpose types and the frequency is determined by the RC network of the 555.
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...