Methods for controlling power delivered to an SMA actuator
US11326583B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 5, 2019 |
| Grant date | May 10, 2022 |
| Priority date | — |
| Expiry date | Jul 5, 2039 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF03G7/0665
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
Broadly speaking, embodiments of the present techniques provide techniques for delivering, when required, higher powers to SMA actuator wires by using a single controller/control circuit that implements pulse width modulation (PWM). Typically, when PWM is used to deliver power, the PWM frequency may be fixed, and power may be applied to each SMA actuator wire during each PWM cycle/period. The present techniques provide a method for delivering higher powers to SMA actuator wires (i.e. increasing the length of individual PWM pulses) without changing the duration of the PWM cycle/period. The present techniques also provide techniques for making accurate resistance measurements to determine position of a moveable component that is moved by the SMA actuator wires.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.