This interesting digital counter with relays with complementary outputs was found in the Radio Electronics magazine of October 1961. The supply voltage is in accordance with the relays used.
This circuit can be used as an input shield by removing the signal directly from the second port,...
This sensitive circuit was found in an Electronics Hobbyists Handbook from the 1990s. The circuit can...
We found this circuit in an 80's documentation. The circuit has a gain of 30 dB and uses a varicap...