We found this circuit in Radio Electronics Special Projects from 1992. The circuit turns on the power when the microphone plug is inserted into the input jack.
This circuit is from a publication from the 50's. Inductive components are critical, and...
This simple two-transistor circuit used transistors from the 60s, having been found in a...
This circuit uses an oscillator that generates a signal of approximately 1450 kHz to test...