摘要 |
An inductive coin detector to recognize the presence of coins (2) in a coin channel (1) uses a high-frequency alternating magnetic field. The detector is equipped with a flat coil (3) located outside the coin channel (1). A high-frequency alternating magnetic field produced by the rail (3) penetrates the coin channel (1) at a right angle to the coin movement direction (13). The coil (3) consists at least of a flat helicoidal conductor arrangement and is part of the LC oscillator. The oscillator circuit, together with a measuring circuit, constitutes a detector circuit (4) for the recognition of a change in oscillator frequency caused by the presence of the coin (2). The coil (3) and the detector circuit (4) are located on a common support in immediate proximity of each other and can be enclosed in a flat housing. The coin detector can be connected by means of a three-strand line comprising a feeder (7) and a signalling line (9).
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