Found in documentation from the 1980s, this circuit can have several adaptations to use modern transistors and LEDs instead of the lamp. The power supply voltage can also be changed.
When this circuit is activated the LED flashes for a moment indicating that the function has been...
This 1970 Electronic Design circuit uses a varactor or varicap. The circuit divides the frequency...
Found in a 1993 Electronics Hobbyst Handbook, this passive circuit can be used with common...