Coin checking device for vending machine or pay telephone - uses variation in HF field across magnetic air gap to calculate coin dia.

摘要

The coin-checking device for a vending machine or pay telephone classifies the coins (8) according to their dia. using an electromagnet lying in the path of the coins fed along the coin chute. The coins pass through the air-gap defined between opposing pole faces (6) of a magnetic core (5) positioned at a distance above the chute (2) corresponding to the min. dia. of the coins (8), the length (A) of each pole face (6) corresponding to the difference between the max. and min. dia. of the coins (8). The HF field applied across the air-gap (7) is detected during the passage of each coin (8), to allow the coin dia. to be calculated in dependence on the field variation. ADVANTAGE - Simple classification of coins according to their measured dia.