PCT No. PCT / GB96 / 00804 Sec. 371 Date Apr. 6, 1998 Sec. 102(e) Date Apr. 6, 1998 PCT Filed Apr. 2, 1996 PCT Pub. No. WO97 / 04424 PCT Pub. Date Feb. 6, 1997A
coin validator is provided with at least two reference positions (U, D) for determining a
diameter related characteristic of a
coin being validated. In order to reduce the running to the testing
station, the timing of a trailing point of the
coin passing a first reference position (U) is used to determine the
diameter related characteristic. Embodiments using optical inductive and piezo-electric sensors associated with the reference positions are disclosed. An
inductive sensor for a coin
validator comprises an elongate coil, which, when in use, is arranged such that the
magnetic field is substantially constant across the width of the passageway. The use of coils of this type have the
advantage of
wrap around coils but enable the coin passageway to be shallower and be opened. A coin
validator is described wherein the backwall of a coin passageway is movable to and fro so that the depth of the coin passageway can be adjusted. In an embodiment, a
cam bears against the backwall of the coin passageway to set the depth thereof.