GB1446459A - Vend control circuits - Google Patents

Abstract

1446459 Vending machine control circuit H R ELECTRONICS CO 5 Nov 1973 [12 Feb 1973] 51271/73 Heading G4V In a control circuit for a coin or credit card freed vending machine, a selection monitor circuit 58 enables a vend operation after actuation of a product selection switch 12-18 when credit in an accumulator 56 is at least equal to a product price but inhibits the accumulator via a gate 63 from initiating a vend operation before actuation of a selection switch 12-18 so that escrow means 67 may be operated by a switch 68 at all stages until such selection is made. The selection monitor 58 is a two-part circuit, one part being connected to the switches 12-18 and the other being under control of the first part to operate a vend relay 45 via gate 63. The two-part circuit 58 may comprise an electromagnetic switch, an LED- phototransistor circuit, an SCR circuit or a simple pulse transformer Figs. 2-5, not shown) all operating between lines 38, 62 to switch current in line 64. When gate 63 receives signals from the circuit 58 and the accumulator 56 when the vend conditions are met, relay 45 transfers its contacts 44 and further contacts 46 establish a holding circuit maintaining another relay 42 energized. Contacts 40 establish a circuit through the particular product selection switch 12-18 which has been actuated to operate a vend device 20-26 each of which has an 'empty' switch 28-34 and indicator. Two circuits 58 and two sets of switches 12-18 may be provided for two series of products at different prices (Fig. 6, not shown). Before a switch 12-18 is actuated when the accumulator registers the correct credit, a customer may operate the switch 68 to obtain a full refund, An indicator light is operated by a switch 70 when a coin tube in a change-giver is empty so indicating that exact change is necessary to operate the machine. CREMS 72, 74 prevent coin acceptance when this occurs or when the power fails.