This power source was found in a 1968 Electronics World. The transistors are from that time. The current of each output is limited by the transformer.
This shield circuit is suggested by Motorola, using a 4N26 type coupler and an MC1733 type...
This circuit for measuring very low currents was found in an American documentation from the...
This circuit was found in the ON Semiconductor thyristor manual of the 1980s. As the drive is done by...