Electromagnetic contactor with control circuit for providing acceleration, coast and grab functions
US4720763A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 19, 1987 |
| Grant date | Jan 19, 1988 |
| Priority date | — |
| Expiry date | Feb 19, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H47/22
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electromagnetic contactor or controller is taught in which the voltage which is impressed across the electromagnetic armature accelerating coil is compared by a microprocess against a menu of memory stored voltages with related delay angles. The delay angles are utilized to alter the conduction interval of a triac or similar gated device which is connected in series circuit relationship with the coil in question. During an ACCELERATION interval a number of consecutive full-wave rectified half-cycles of voltage pulses are phase angle or delay angle controlled so that the amount of energy provided to the moving armature of the contactor is approximately sufficient to cause the armature to abut a fixed magnetic member. Furthermore, there is provided a separate memory menu for mid-flight adjustment of the armature to compensate for unknown variations to fine tune the closing operation. This latter correction is known as COAST. There is also provided a GRAB function which supplies limited, relatively low level current to the armature at or near the time of abutment for preventing "bounce". Mechanically, interconnected with the armature is a set of contacts which are caused to close u…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.