We found this circuit in an old Mullard (Philips) documentation. The sensor consists of a reed-switch that is coupled to a magnet on one of the wheels of the vehicle.
This circuit produces a signal that has the waveform of the sound produced by or near the banjo....
This is a circuit with a period component that consisted of a voltage reference. The circuit is...
This circuit doubles the frequency of a rectangular signal applied to its input. The circuit has a...