| 摘要 |
<p>A refrigeration or freezer controller is formed as an ASIC or integrated circuit micro-controller to receive an actual temperature value from a temperature sensing thermistor (S1, S2). The circuit is supplied with or stores cut-in and cut-out temperature values for comparison (113) with the actual temperature value. In one embodiment a plurality of sets of cut-in and cut-out values is stored in non-volatile memory (100) and digital addressing means (101, 102) allow a user to select a set by means of an external actuator (104). Timing data may be stored in the controller to override temperature control when stored minimum and maximum refrigeration on and off times are attained, e.g. on failure of the temperature sensor or to prevent cycling of the controller. A temperature sensor simulator (Figure 6) may be used for calibration purposes. <IMAGE></p> |
