| 摘要 |
PURPOSE:To finely and smoothly adjust heating capacity by providing a hot water control valve driven by a stepping motor at the engine cooling water circulating circuit of the hot water heat exchange type air conditioner that is used in buses and controlling the motor through an electronic circuit. CONSTITUTION:When both temperature detected by an atmospheric temperature sensor 11a and a room temperature sensor 11b are below each preset temperature and an operation switch 26 is set to ON, the combined resistance of a temperature controller 30 and of each sensors 11a and 11b is maximized. Accordingly, a controller 15 generates the maximum number of pulses and revolves a stepping motor to the utmost. Thus, a contol valve is opened by the maximum degree and maximizes the hot water flow rate. Then, as the room temperature rises and the resistance of the room temperature sensor 11b is reduced, the combined resistance is also reduced, a stepping motor 20a is revolved inversely, and the degree of opening of the control valve is reduced. As a result, heating capacity can be finely and smoothly adjusted. |
