Direct current resistance welding machine and method of controlling the same
US5360959A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 14, 1993 |
| Grant date | Nov 1, 1994 |
| Priority date | — |
| Expiry date | Jun 14, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09F27/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A direct current resistance welding machine and a method of controlling the direct current resistance welding machine wherein primary current of a welding transformer is detected when a plurality of switching devices of an inverter are controlled based on corresponding pulses having a predetermined frequency and each having a time width corresponding to the value of a required secondary current. Rise and fall times of the detected primary current are detected. An upper limit frequency Of the primary current is computed based on the time width of each pulse and on the rise and fall times. Thus, the primary current of the welding transformer is controlled by controlling the switching devices based on pulses having a frequency falling within the computed upper limit frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.