| 摘要 |
<p>"TEMPERATURE SENSING CIRCUIT WITH HIGH NOISE IMMUNITY" A refrigerator includes a compressor, a condenser, an evaporator, an evaporator fan and a temperature sensing circuit which includes a thermistor located to sense the average temperature of the cabinet air and a potentiometer manually adjustable to a desired temperature set point. The temperature sensing circuit also includes a first comparator stage which indicates whether the average temperature of the cabinet air is above or below a first value, the first comparator having little or no hysteresis in its response so that small changes in temperature can be detected. A second comparator stage indicates whether a signal at its input is greater or less than a second value, the second comparator stage having substantial hysteresis in its response to provide high noise immunity. An integrator is interposed between the first comparator stage and the second comparator stage to further enhance noise suppression.</p> |
