摘要 |
<p>The present invention provides a control system for a refrigerated display cabinet to keep the cabinet temperature constant or within a narrow range. To achieve this the system comprises two temperature sensors 50, 52 located at strategic positions in the flow path of the air which cools the storage space, and specifically the temperature sensors are located to either side of a refrigeration unit evaporator 30 over which the air flows. The temperature sensors are temperature sensitive resistances and the resistances thereof connected in series so as to be summed for the purposes of generating a control signal based upon the extent to which the aggregate resistance of the sensors deviate from a mean aggregate valve corresponding to the required cabinet temperature, as this provides for desirable response characteristics. <IMAGE></p> |