Flyback current dampening apparatus
US5055961A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 6, 1989 |
| Grant date | Oct 8, 1991 |
| Priority date | — |
| Expiry date | Nov 6, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H9/047
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An apparatus for dampening current in a coil has a switchable member which controls the current level in the coil and a flyback circuit that allows current in the coil to slowly dissipate when the switchable member changes from an "ON" to an "OFF" state. The flyback circuit has a high resistance when the switchable member changes from the "ON" to the "OFF" state so that the coil current is dampened as quickly as possible without creating a destructive voltage and low resistance when the switchable member is in the "ON" state to conserve energy. A signaling device creates a voltage signal as a function of current passing through the flyback circuit and a receiving device varies the resistance of the flyback circuit in response to the voltage signal. The apparatus is particularly suited for use in a motor control circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.