Method for regulating the temperature of a medium by means of a temperature control loop, and a temperature-regulating device for implementing the method

摘要

Method and apparatus for controlling a prior art refrigeration system of the type having an evaporator, a variable capacity compressor arrangement, and switching apparatus between a control unit and the compressor arrangement. The compressor arrangement thereof has adding and subtracting inputs which translate input signals to respectively increase or decrease step by step the effective capacity of the compressor arrangement. The switching apparatus thereof has adding and subtracting inputs and outputs and a reset output which is made effective after each increase or decrease of the effective capacity of the compressor arrangement. The method and apparatus herein involves processing a data signal which is indicative of the temperature status of the evaporator. The data signal is compared with predetermined upper and lower temperature limits of an operating range for the evaporator and adding or subtracting temperature control signals are respectively putted when the data signal is higher or lower than those limits. The data signal has successive samples thereof examined to determined if it is rising or falling and differentiated signals are outputted depending on whether the value of a succeeding data signal is larger or smaller than the value of a preceding data signal. The adding and subtracting temperature control signals and the adding and subtracting differentiated signals are respectively ANDed and the resulting signal is applied to the adding or subtracting input of the switching apparatus. The availability of the differentiated signals for the ANDing operation are delayed for predetermined periods of time initiated by the switching apparatus.