Motorized actuator with a variable stall level
US6495981B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 2001 |
| Grant date | Dec 17, 2002 |
| Priority date | — |
| Expiry date | Feb 22, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H7/0851
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An actuator for an HVAC system includes a motor coupled by a gear train to an output connector. A spring coupled to the gear train stores energy when the motor is driven in one direction and releases stored energy when the motor is driven in the opposite direction. The spring returns the output connector to a normal position in the event that electrical power is lost. A motor stall current threshold for the motor is determined dynamically in response to operation of the actuator. The position of the spring, direction of motion and the temperature are sensed. The motor stall current threshold value is selected from a table in response to the values of the sensed operating parameters. A determination is made that the motor has stalled when the electric current applied to the motor exceeds the selected motor stall current threshold value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.