Circuit arrangement in a coin acceptor unit
US4492296A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 2, 1981 |
| Grant date | Jan 8, 1985 |
| Priority date | — |
| Expiry date | Dec 2, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07D5/08
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
The coins (37) come within the coil field of an oscillator (2,6,7). Within a reverse feedback path of the oscillator amplifier (2), several resistances (11 to 18) are arranged, switchable parallel to each other individually or in any desired combination, by switching transistors (21 to 28), each controlled by a program (29). This makes the amplification controllable step by step. The program (29) has a constant-value-storage (49) with a stored standard value for the amplification in which oscillations cease whenever the field coil area is free and a calibrating resistance (35) is connected parallel to the condenser (7) of the oscillator (2,6,7). For each coin type, two pre-determined standard limit values of amplification are stored in the constant-value-storage (49), with the oscillations ceasing between them in the presence of an acceptable coin (37). Prior to each testing operation, the program (29), with calibrating resistance (35) being connected parallel to the condenser (7) increases the amplification step by step until oscillations cease. The quotient of the thus obtained amplification value and the standard value is multiplied by the two standard limit values of each type …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.