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 found this circuit in a documentation for 1977 American radio amateurs. The LM336 integrated circuit...
The frequency of this oscillator depends on the coil and the 10 nF capacitor. The circuit is from...
This circuit can work with the previous one generating signals, that can be decoded by it. The...