Electromagnetic device with current regulated closure characteristic
US5546268A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 28, 1994 |
| Grant date | Aug 13, 1996 |
| Priority date | — |
| Expiry date | Jul 28, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H47/002
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electromagnetic switch includes separable contacts, an electromagnet having a coil which is energized to close and hold closed the separable contacts, a power supply for applying current to the coil, and a closed-loop control circuit for sensing and regulating, throughout a contact closure cycle, the current applied to the coil to a selected current reference. The current reference may include a closing current reference for closing the contacts and a holding current reference for holding the contacts closed. The control circuit may include a microcomputer for generating the current reference and, further, may include a first switching circuit and an associated control circuit for actuating the first switching circuit between enabled and inhibited states, a second switching circuit and an associated control circuit for actuating the second switching circuit between conductive and non-conductive states, a feedback circuit for sensing the coil current and generating a related feedback signal, and a comparator circuit for comparing the current reference and the feedback signal, and for inhibiting the second switching circuit whenever the feedback signal is greater than the current …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.