Found in old documentation, this circuit can use modern equivalent components. The signal has good strength thanks to the use of a power transistor. The Q1 transistor is a unijunction of the time.
This circuit visually indicates that a high voltage is present in an outlet or other point. The...
This circuit found in a 1988 documentation consists of a timer or sequential timer controller. The...
Using a 4017 as a base, this circuit from a 1990s Popular Electronics generates low-frequency...