Circuit for estimating the speed of an electromagnetic actuator
US6788490B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 2002 |
| Grant date | Sep 7, 2004 |
| Priority date | — |
| Expiry date | Mar 6, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B21/083
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A circuit estimates speed of an electromagnetic actuator associated with a reading head of a disk storage unit and a digital controller. The circuit includes first and second supply terminals and an output terminal, with the first supply terminal being connected to the electromagnetic actuator. A measuring resistor is connected to the second supply terminal, and is connected in series with the electromagnetic actuator for measuring a current which passes therethrough when a supply voltage is applied between the first and second supply terminals. An adder has an output connected to the output terminal for providing an output voltage, a first input is connected to the first supply terminal, and a second input is connected to the second supply terminal. An adjustable-gain amplifier is connected between the measuring resistor and the second input of the adder for transferring the supply voltage and a voltage across the measuring resistor to the adder. A determination circuit is connected to the adjustable-gain amplifier for determining a gain thereof. The determination circuit includes a coarse setting circuit and a fine calibration circuit controlled by the digital controller.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.