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.
We found this sensitive moisture detector in an old documentation. The circuit uses a common JFET,...
This circuit, with the assembly in a contact matrix, was found in a publication from the 90s. The...
This modulator circuit for transmitters was found in American documentation from 1964. It can be...