This simple circuit is intended to test the zener test. RV1 can be calibrated in terms of voltage. The maximum voltage of the tested zener is that used in the circuit supply.
The circuit we showed was obtained from our publication on relays and makes use of any...
This preamp with a transistor for turntables with crystal capsules was found in a Japanese...
The basic idea of this circuit is to convert the indication of a magnetic sensor to an audio tone...