| 摘要 |
PURPOSE:To provide a cooling device for preventing an unneeded power consumption by controlling the rotary speed of a fan based on the temperature of an object to be cooled and then a printing device using the cooling device. CONSTITUTION:The output of a differential amplifier 3 is obtained based on the difference in the output voltage between a thermocouple 1 and a reference voltage generator 2. The output is input to a comparator 8 and the output of the comparator 8 is input to a transistor 11 for driving a fan 9 via a resistor 14. An FG 10 for generating a voltage proportional to the rotary speed of a fan 9 is connected to the fan 9 and the output voltage is divided by resistors 12 and 13 for dropping to a proper voltage value and then is input to the comparator 8. A diode 15 prevents an inverse bias voltage from being applied to the transistor 11. With the above configuration, when the output voltage value of the thermocouple 1 is lower than the reference voltage value, the fan 9 is stopped. On the other hand, when the output voltage value of the thermocouple 1 becomes higher than the reference voltage value, the rotary speed of the fan 9 increases in proportion to temperature. |
