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.
The previous oscillators that use gatesshown in this section, and the 4093 in the basic version,...
This voltage controlled oscillator uses a varicap to change the frequency. Usin a 100 turns coil...
The circuit shown in the figure is indicated for alternative sources of energy, such as those...