Found in Radio Electronics from the 90s, this circuit is intended for analog TV applications of the time. The transistor used as well as the module are uncommon components today.
This dual adjustable power supply was found in the June 1990 issue of Radio Electronics magazine....
We found this simple alarm circuit in a 1986 documentation. The circuit uses sensors of the NA...
This circuit, from a 1973 documentation, can be made with BC549 transistors. The frequency depends on...