External force measuring system and component mounting apparatus equipped with same
US5523642A · kind A · utility
9Cited by
16References
3Claims
0Family size
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Inventors
Key dates
| Filing date | Apr 20, 1995 |
| Grant date | Jun 4, 1996 |
| Priority date | — |
| Expiry date | Apr 20, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K13/082
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In an external force measuring system comprising a piezoelectric element 61 or producing a charge when acted on by an external force, and a charge amplifier 7 chargeable with a variation in the charge produced by the piezoelectric element to output a voltage signal, the charge amplifier 7 comprises a feedback loop having an on-off controllable switch 8 connected in parallel therewith. The switch 8 is on-off controlled by a comparator 81 for comparing the output voltage with a reference value and is closed while no external force acts on the element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.