Detector system for detecting the occurrence of welding using detector feedback
US5252817A · kind A · utility
39Cited by
26References
15Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 25, 1991 |
| Grant date | Oct 12, 1993 |
| Priority date | — |
| Expiry date | Mar 25, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J2001/0276
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A power supply circuit for a liquid crystal welding lens or shutter develops a relatively low voltage AC signal for driving or powering the liquid crystal shutter to the clear state and two relatively higher or larger magnitude AC electrical signals for initially driving the shutter to the dark state and then for maintaining the shutter in the dark state; a variable frequency circuit for varying the frequency of the driving signal to the shutter to minimize power usage in the dark state and to avoid flicker in the clear state; and power saving and battery level indicator features are included.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.