These optical relays, which can act as a shield, were found in an American documentation from the 1980s. The circuit has a LDR sensor. It can be adapted for other types of sensors.
Found in a 73 magazine for radio amateurs of the 1980s, this circuit uses a dual-gate MOSFET. This...
This is a bridge for the measurement of low value resistances and high values too. The circuit...
This complementary or bilateral emitter follower was found in American documentation from the 90s....