Transistor based counting circuit diagram

The above picture can be used for detecting and counting equipment such as paper machines. When the magnet sweeps across L with the rotation of the drum, an electric potential (i.e., a signal) is induced in L, VTi is turned on, VT2 is turned off, and relay KA loses power and is released. When the working line speed of this switch is 0. 48-9.9m/s, the response distance is 15~55mm.

Among them, the inductor L is wound with 6500 turns of enameled wire with a diameter of 0.06mm on the permanent magnet. The permanent magnet is a paper end positioning magnet (ferrite) adsorbed on the side of the paper drum.