Abstract: A coin validation arrangement, usable for example in pay telephones, uses one or more inductive sensors having a small effective magnetic field so that the inductive sensor responds only to the material of a strip across the coin. Preferably a plurality of inductive sensors are used, mounted at different heights above the floor of a coin guide, at different positions along the coin path. At each position along the coin path there may be either one or a plurality of inductive sensors. Preferably the inductive sensors are surface mount inductors on a printed circuit board which forms part of one wall of the coin guide. Such arrangements are particularly useful for recognizing coins having an outer ring made of a different material from the central disc, and for distinguishing such coins from uniform composition coins.

Abstract: A coin detecting mechanism for pay telephones detects the presence of a coin by causing the coin to complete a circuit between pins, or between one pin and the chute of the coin sorter. A plastic block supports the pins, the plastic block being such as to absorb the energy of falling coins without damage. One form of the invention uses two closely spaced pins that are connected by the presence of a coin, and another form of the invention uses a single pin angled across the chute so the pin and the chute are connected by a coin. The plastic block has a circuit printed thereon for connection of the pins, and a debounce circuit is connected to the printed circuit.