This circuit for 12 V relays was found in the July 1992 Radio Electronics magazine. The circuit is set at R6.
This one is from an 80's EDN. Transistors can be general purpose types. The frequency is...
This power supply is not protected from shorts in the output. Output voltage is given by the...
This static switch or electronic contactor was found in a 1968 Motorola publication. The triac...