This circuit for 12 V relays was found in the July 1992 Radio Electronics magazine. The circuit is set at R6.
This circuit converts a positive CMOS supply voltage to a negative one. We found it in a 90s...
The circuit is of the Motorola Linear Databook of 1990. The power source must be symmetrical and the...
Found in American documentation from the 1980s, this circuit operates in the frequency range 0.5...