摘要 |
A circuit for controllably positioning an air baffle to control flow of air from a freezer compartment to a fresh food compartment of a refrigeration apparatus. The circuit energizes a first solenoid coil to close the baffle when the temperature sensed in the fresh food compartment is lower than a desired temperature and energizes a second solenoid to open the baffle when the temperature sensed is greater than the set point temperature. A capacitor, acting as a timer, carries a charge providing a voltage which eventually exceeds a voltage generated according to either the set point or the sensed temperature. If the capacitor voltage exceeds the sensed temperature voltage the open solenoid coil is energized. If the capacitor voltage exceeds the set point voltage the close solenoid coil is energized. Each solenoid is selectively energized when a charge on the capacitor is transferred through the solenoid, thereby discharging the capacitor and resetting the timer. The operation is repetitively performed to control the temperature in the fresh food compartment of the apparatus.
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