This circuit was found on an old EDN and can be used as a shield. Optical couplers are from the era and modern equivalents can be used.
This variable voltage reference uses a Norton operational amplifier. The voltage is adjusted at...
This 6 transistor TR26 commercial radio was sold in Japan in the 60s. It is a super heterodyne circuit...
n be assembled with BC558 transistors for low power transistors and a BD136 for the output. The...