We found this circuit in 1964 General Electric documentation. The circuit works with mechanical drive and can be adapted to operate as a didactic shield sensor.
We have in the figure a traditional amplifier configuration with operational amplifier. The source...
This circuit was found in a 1977 Radio Shack documentation. The circuit is TTL, which must be...
This circuit is suitable for modulating small FM transmitters for eavesdropping or espionage. The...