Vending machine control with improved vendor selector switch detection and decoding apparatus
US4817010A · kind A · utility
7Cited by
57References
17Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 2, 1987 |
| Grant date | Mar 28, 1989 |
| Priority date | — |
| Expiry date | Mar 2, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07F9/002
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A vending machine control with an improved vendor selector switch detection and decoding circuit is described which detects and decodes the closure of selector switches in a vending machine utilizing a low cost decoding arrangement. Each selector switch is associated with a corresponding impedance in a keyboard network so that a unique impedance is presented on a keyboard decode line from the keyboard network. Decode circuitry and a decode algorithm are also disclosed for a period based decoding scheme which compensates for various tolerances and environmental affects.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.