Damper motor control circuit for an automotive air conditioning system
US4930567A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 1988 |
| Grant date | Jun 5, 1990 |
| Priority date | — |
| Expiry date | Jul 20, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05D23/1393
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An automotive air conditioning control system comprises a first control circuit for automatically controlling an angle of an air mix damper in accordance with a plurality of variable conditions, for example, an outside air temperature and an inside air temperature. A switching mechanism predetermines either a maximum heating or cooling when closed. A second control circuit moves the air mix damper to a position for either maximum heating or cooling independently of the variable conditions responsive to operation of the switching mechanism. The second control circuit includes a signaling circuit which outputs a drive signal to control the movement of the air mix damper to the position for maximum heating or cooling for only a predetermined period of time. Therefore, even though the air mix damper or a gear for reducing motor speed becomes locked at the time of maximum heating or cooling and a lock detecting function of a microcomputer of the first control circuit fails to operate, a motor of a motor actuator for moving the air mix damper is saved from destruction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.