| 摘要 |
PURPOSE:To drive a fan positively by varying the width of pulses by a temperature information from a temperature sensor and controlling the rotational speed of the fan. CONSTITUTION:On the throwing-in of a power supply, the voltage V of the making power supply is applied to a differentiating circuit C formed to a control section 1, an output signal SA from the circuit C is compared with reference potential V0 by a comparator CMP1, and a fan 2 is supplied with a power supply (POW) shaped to a pulse shape through an OR gate G. During working, a signal S by the temperature detection of a temperature sensor 3 is compared with reference potential V0 by a comparator CMP2, and the fan 2 is supplied with the power supply POW through the OR gate G. Accordingly, the power supply is formed by pulse signals at rated voltage, thus ensuring the starting and driving of the fan. |
