Air quantity controlling circuit for air conditioner for use in vehicle

Abstract

Abstract PURPOSE: To prevent occurrence of a hunting phenomenon of an air mixing door by automatically decreasing the degree of controlling the air quantity, in the case where the difference between the temperature of the car compartment and the set temperature and, the rotation control quantity of the air mixing door are so small that there is a margin in the control. CONSTITUTION: An air quantity control circuit 32 selects successively and automatically a resistor of a resistor group 19 in correspondence to the opening degree of an air mixing door by means of a slide switch 18 to control the quantity of power supplied from a power source 20, whereby the rotational number of a fan motor 1 is varied to automatically adjust the blow-out air quantity. In this case, there is provided a discriminating circuit 23 producing as output a signal when the deviation between signals S 1 and S 2 responsive to the compartment temperature and the set temperature is within the set range, and further the door opening degree is within the set range by signals S 3 and S 4 in correspondence to the opening degree of the air mixing door and its standard position. A suppressing circuit 31 which decreases by its output the degree of the control of the air quantity of the circuit 32 by at least one step, is also provided. COPYRIGHT: (C)1981,JPO&Japio

Inventors

• 👤 Kenzo Hirashima

Bibliographic Details