| 摘要 |
A computer system employs a thermal sensor in the main CPU housing to detect operating temperature. If a preselected trip point is reached indicating that ov erheating may be about to occur, the system goes into an orderly shutdown mode. A standby mode uses a low-power service processor which continues to operate even when the main unit is shut down. The service processor has limited functions, including detecting t emperature within the main housing, and communicating by a network with a system administra tor unit and reporting on the temperature in the main housing, and on the operating statu s of the main unit. A mechanism is provided to prevent the main processor unit from being unnecessarily shut down when the operating temperature is near but not beyond th e trip point, as may occur due to variations in the power supply voltage and the voltage-dependence of the thermal sensor. This mechanism employs voltage stabili zation of the supply for the thermal sensor when the computer is in its standard operating mod e and the power supply for the main processor unit is running. Here the sensor is supplied from a precision voltage reference of a high degree of accuracy. However, when entering the standby mode, the main power supply is shut down, and so the thermal sensor is t hen operating from an auxiliary voltage source that is not stabilized. A simple isol ating circuit allows one sensor to be used in both operating conditions, using one or the othe r of the power supplies. Since the trip point is much less important in the standby mode, there is no problem caused by the lack of precision in the voltage source.
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