Electronic temperature control
US4325225A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 28, 1980 |
| Grant date | Apr 20, 1982 |
| Priority date | — |
| Expiry date | Jul 28, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05D23/24
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An electronic temperature control having a temperature sensor (10) and a user-adjustable temperature range control (12). A difference amplifier (14) amplifies the difference between the signals from the temperature sensor and range control. A hysteresis comparator (16) then accepts the signal from the difference amplifier and uses it to control a transistor relay driver (18), which in turn controls the clutch coil (20) of the air conditioning system controlled by the temperature control. The transistor relay driver is disabled by an evaporator fan sensor (22) to avoid freeze-up of the evaporator when the fan is turned off. Since auto air conditioning systems rob the car's engine of power, an acceleration cut-out (24) is provided to disable the transistor relay driver when other power demands on the car's engine are great, such as on hard acceleration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.