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 appears elsewhere on this site using the most diverse transistors. This version is...
Frequency in this oscillator is controlled by a crystal. Any 1 MHz to 15 MHz can be used. The JFET can...
This was one of the National Semiconductor clock modules very popular in the 70s and 80s. In the...