GB1327337A - Currency acceptor - Google Patents

Abstract

1327337 Banknote validators VENDO CO 30 June 1971 [9 Oct 1970] 30572/71 Heading G4X [Also in Division H2] A banknote validator comprises drive-roller pairs 36, 38, 40 and 42, a pair of belts 80, see also Fig. 2 (not reproduced), and idler-roller pairs 106, 108 and 110 which respectively form a belt/roller system 36, 80 and drive/idler roller pairs 38, 106; 40, 108; and 42, 110, a note inserted in entry slot 82 being conveyed from the slot through channel 102 past a testing device 112. Drive electric motor 52 is actuated when light from source 84 to phototransistor 116 is obturated, and is subsequently reversed if the note is found invalid or in response to an overload condition. Device 112 may be a combined optical and magnetic transducer and is mounted in an electronics module 92 together with phototransistor 116 and a further phototransistor 118. Motor 52 is governed by a centrifugal contact 124, Fig. 6, on shaft 54 and the arrangement is such that under normal drive conditions voltage to the motor assumes a chopped waveform 186, as contact 124 makes and breaks, with consequent charging and discharging of a capacitor 140. If, however, the drive becomes overloaded, e.g. by jamming of the note of failure of the operator to release it, the speed of rotation of shaft 54 decreases and the chopped waveform disappears. Voltage across capacitor 140 builds up until the firing potential of a programmable unijunction transistor 142 is reached which causes reversal of the motor drive via silicon controlled rectifier 156.