Electronic circuit for piezoelectric switch assembly
US5170087A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 1991 |
| Grant date | Dec 8, 1992 |
| Priority date | — |
| Expiry date | Aug 26, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/962
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An electronic circuit for a contactless, piezoelectric switch assembly. The piezoelectric switch assembly includes a piezoelectric module which generates voltages under manual pressure and electronic circuit operative to perform a predetermined switch function upon receipt of these electrical signals. The electronic circuit performs a variety of switching functions, such as: toggle on and off; dimmer setting; momentary on. The sensing means of the electronic circuit is coupled to the piezoelectric module via a reference voltage and a negative current source that pulls one terminal of the piezoelectric module toward the reference voltage. A slew rate limited buffer amplifier drives a comparator with hysteresis achieved by changing the comparison voltage. This hysteresis serves to reduce detection of jitter and noise in the initial application of pressure. In the momentary on mode the reference voltage supplied to the piezoelectric module is above the second threshold of the comparator when initial manual pressure is detected. This causes the comparator to remain tripped. Upon release of pressure on the piezoelectric module, a piezoelectric signal of the opposite polarity causes the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.