Found in a 1980s American documentation, this circuit is based on the common CMOS series activating a relay. The circuit is double-timed.
This power supply also has a fine adjustment feature. The transformer is 16 + 16 V with 3 A and...
This circuit was obtained in a 1985s English magazine. The circuit can still be assembled with...
The circuit shown in the figure is suggested by Texas Instruments in its Linear Circuits...