Actuator positioning apparatus
US5132602A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 1990 |
| Grant date | Jul 21, 1992 |
| Priority date | — |
| Expiry date | Oct 2, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B2219/50042
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A method and apparatus for accurately and reliably positioning an actuator arm (12) is disclosed. The actuator arm (12) is driven by a conventional DC motor (38). The conductors which supply current to the motor (38) serve as primary windings (60) of a current transformer (58). The signal induced on secondary windings (62) of the transformer (58) responds to fluctuations in average current flowing in the motor (38). These fluctuations are amplified (64) and filtered (66) so that an AC burst (68) is produced in response to each commutation of the motor (38). The AC burst (68) triggers a one-shot timing circuit (72), which generates a pulse that remains active until the AC burst (68) has decayed. The pulse disappears prior to a subsequent commutation of the motor (38). Thus, one pulse is generated for each commutation of motor (38). A counter (76) is clocked by these pulses. The counter (76) increments when the motor (38) moves in one direction and decrements when the motor (38) moves in the opposing direction. Thus, the counter (76) maintains a current count which describes the position of the motor (38). A controller (16) compares this current count with an input signal (14) and co…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.