Control-safe capacitive switch
US5233231A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 29, 1991 |
| Grant date | Aug 3, 1993 |
| Priority date | — |
| Expiry date | Nov 29, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/962
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A palm-button control system provides for machinery control with minimized operator hand pressure by use of capacitive switches and reduced susceptibility to radio frequency interference. The system employs first and second capacitive palm-button switches, both of which must be contacted before machinery is activated. Each capacitive palm-button includes a radio frequency sensor which functions to disable machine activation in the presence of a sufficiently strong radio signal. Circuitry for periodically testing the radio frequency sensors provides periodic visual operator feedback indicative of operability of the system. All controls are synchronized or enabled in accordance with a series of digital pulses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.