Gravure press with crowbar circuit
US5243487A · kind A · utility
5Cited by
11References
13Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 20, 1990 |
| Grant date | Sep 7, 1993 |
| Priority date | — |
| Expiry date | Dec 20, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H9/041
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A gravure printing press with an electrostatic assist unit having a fault detection circuit and crowbar circuit in which the crowbar circuit has a transformer with a primary winding and a plurality of secondary windings. Each of the secondary windings has a field-effect transistor which is turned on in response to the detection of a fault condition whereby the voltage applied to the press is substantially reduced to zero and any electrostatic charge is substantially removed. A capacitor is coupled in parallel with the gate and source terminals of each field-effect transistor to lengthen the on-time of the transistors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.