Temperature and current dependent regulated voltage source

摘要

A linear voltage regulator is operated by a temperature sensor and a current sensor. The temperature sensor is a thermistor in a voltage divider connected across the output of the regulator. The current sensor operates a voltage follower connected to adjust the voltage in the voltage divider. The regulator controls voltage supplied to a cooling fan in a power supply. The sensed temperature is the air temperature near the power supply enclosure. The sensed current is the output current of the power supply. When the ambient temperature increases and/or the power supply output current increases, the voltage regulator increases the fan speed by raising the voltage. The current sensor can also be used to sense other parameters, such as voltage.