Electronic coin tester with inductive sensor - has mechanically actuated timer switch magnetically coupling power to sensor primary

摘要

In the electronic coin tester the tested coins pass between a primary alternating current coil and a secondary, so affecting the inductive coupling, is able to distinguish valid coins from a practically unlimited number of false coin types without unduly reducing the correct type acceptability range. The alternating voltage source supplying the primary coil contains a circuit enabling variation of the frequency and/or amplitude of the primary coil voltage during coin testing. Frequency variation may be continuous or by switching between two values. The coin testing is limited to the short period whilst the coin is between the primary and secondary coils using a three lever coil primary power switch actuated by the coin and magnetically coupled to a reed contact switch.