This circuit retriggers when a new pulse arrives. It does this by discharging the capacitor. The circuit is from a documentation from the 80s. The transistor can be any general purpose one.
This circuit uses a resonant reed relay to recognize the frequency of an input signal. Adaptations...
The operational used is uncommon today, but equivalents can be used. Unlike the previous one, this...
This simple circuit uses a zener diode and two LEDs to indicate whether the voltage of a power grid...