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.
This is the circuit of a “follow the line” type robot with inductive sensors published in Radio...
With a unijunction transistor and a tunnel diode it is possible to obtain rise times of 1 ns with...
This receiver for listening to headphones and 2-battery power was found in Japanese documentation from the...