摘要 |
The heat exchanger of the temperature control system for a vehicle passenger compartment exchanges heat with air entering the passenger compartment. The flow of heat-exchange medium through the heat exchanger is controllable for controlling passenger-compartment temperature. A servo comparator receives and compares a temperature command signal and a feedback signal and produces an error signal which operates an actuator which in turn actuates an adjuster for fluid flow through the heat exchanger. The command signal is derived from a command transducer whose setting is adjustable by a passenger. The feedback signal is derived from a passenger-compartment temperature sensor but additionally, in order to avoid system instability, is furthermore derived from a heat-exchanger temperature sensor. In particular, the feedback signal includes a component whose value is determined by the rate of change with respect to time of the temperature sensed by the heat-exchanger temperature sensor. In this way, when a steady-state condition is achieved and the rate of change of the temperature of the heat-exchanger becomes zero, the steady-state response of the system depends substantially exclusively upon the temperature sensed by the passenger-compartment temperature sensor.
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