Actuator retraction circuit
US5495156A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1994 |
| Grant date | Feb 27, 1996 |
| Priority date | — |
| Expiry date | Jun 24, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B21/12
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Method and apparatus for retracting an actuator comprising determining back emf voltage generated by the actuator motor; applying the determined voltage to a capacitor-resistor network; applying a holding voltage to the capacitor-resistor network. The application of the determined voltage and the holding voltage together charges a capacitor in the capacitor-resistor network to develop a charged capacitor voltage. The method and apparatus further comprises terminating application of the determined voltage to the capacitor-resistor network upon charging of the capacitor, and discharging the capacitor through the capacitor-resistor network to provide a forcing voltage to the actuator for retract operation. The forcing voltage initially forces a high deceleration current in the actuator. Further, the forcing voltage decays with time to a predetermined holding voltage to complete the retract operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.