Electrostatic powder coating gun and method of generating a high voltage in such a gun
US5506746A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 24, 1993 |
| Grant date | Apr 9, 1996 |
| Priority date | — |
| Expiry date | Sep 24, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M3/33507
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention provides a method of generating a high voltage in an electrostatic powder coating gun with a high-voltage generator having a transformer and a high-voltage cascade arrangement. The primary coil of the transformer is fed with an a.c. supply voltage operating at a working frequency. During operation of the coating gun, the frequency of the supply voltage is continuously varied about the working frequency, the current intensity of the primary coil current of the transformer is also continuously detected and the direction of frequency variation is reversed every time an increase in the current intensity of the primary coil current is determined. An electrostatic powder coating gun operating with the present high-voltage generating method includes a current detection circuit for continuously detecting the current intensity of the primary coil current of the transformer, a sweep generator for continuously varying the frequency of the supply voltage about the working frequency, and a control for controlling the operation of the sweep generator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.