This circuit was found in an English magazine from 1977. Signal inputs and outputs must be shielded, and the circuit can be powered by battery, since its consumption is low.
This circuit receives the local stations of medium waves listened to in a piezoelectric capsule or...
This circuit was published in an 80's American documentation, but it is still current. The power...
This simple neon lamp power indicator circuit was found in the January 1971 Radio Electronics...