| 摘要 |
<p>1491130 Coin detector COMPAGNIE GENERALE D'AUTOMATISME 4 June 1975 [19 June 1974] 24141/75 Heading G4V A device for recognizing coins made of ferromagnetic substance and having a given denomination utilizes a pair or pairs of closely adjacent magneto-resistances 9, 10 and 11, 12. These are positioned such that a coin to be recognized affects only one of the magneto-resistances. The resistances, as shown, are mounted on cylindrical magnets such that lines of magnetic force are perpendicular to the front faces thereof. The magneto-resistances form two branches of an electrical measurement bridge which is balanced when there are no coins present. In the presence of a coin an electronic circuit measures the imbalance of the bridge and provides an indication signal when the imbalance reaches a predetermined threshold. If a coin of larger diameter passes the magneto-resistances two thresholds are produced. A prescence channel in the circuitry prevents such a sequence producing an indication signal.</p> |
