| 摘要 |
PCT No. PCT/US81/00881 Sec. 371 Date Aug. 27, 1982 Sec. 102(e) Date Aug. 27, 1982 PCT Filed Jun. 26, 1981 PCT Pub. No. WO83/00211 PCT Pub. Date Jan. 20, 1983.In one exemplar embodiment, an improved evaporating coil defrost control (28) for use in a refrigeration system is disclosed, and which includes a pair of thermostatically controlled switch contacts (42, 44) positioned adjacent the evaporator coil (14) and responsive to the temperature of the coil, the contacts being heated by a resistor or thermister heater (46) to maintain the temperature of the contacts above a predetermined "low" temperature level. The refrigerator compressor (18) is operated through one of the normally closed switch contacts (42) when the switch (40) is maintained above the "low" temperature level. A defrost initiation means (48) de-energizes the heater (46) when defrost is necessary, permitting the thermostatically controlled switch contacts (42, 44) to cool below the "low" temperature level and closing the normally open switch contact (44) to actuate a defrost means (26) to defrost the evaporator coil (14). The defrost means (26) heats the evaporator coil (14) until the melting point of the frost or ice is reached to remove frost and ice, and in turn heats the switch contacts (42, 44) until a predetermined "high" temperature level is reached for changing the state of the switch (40) and re-energizing the compressor (18), cooling the evaporator coil (14), and de-energizing the defrost means (26). The resistor or thermistor heat (46) is re-energized to maintain the temperature of the thermostatically controlled switch contacts (42, 44) above the "low" temperature. |
