Found in documentation from the 1990s, this circuit converts 12 V to 9 V from a car's power output. The 100mA current eliminates the need for a heatsink on the transistor.
This optically coupled circuit was found in the February 1968 Radio Electronics magazine. The...
We found this circuit in the April 1978 issue of Radio Electronics magazine. The power supply must...
This circuit supports several sets of coils and can oscillate from 1 to 44 MHz. The transistor is an old...