| 摘要 |
PURPOSE:To adjust the speed of fan without any stage and reduce the electrical loss accompanied by the adjustment by changing an average power of pulse and controlling the electric current for fan, especially applied for cooling and heating equipment installed on a vehicle. CONSTITUTION:A pulse of constant cycle is generated from a pulse generator 10. The pulse is transmitted to a current control member 9. Under this condition, the pulse generator 10 is controlled by a pulse control member 11 responding to the cooling and heating conditions, thereby changing the frequency or the width of the output pulse. The average electric power of the pulse varied with the change of the frequency or width of the output pulse. The electric power is supplied to the electric current control member 9. With this construction, switching elements such as the transistors of the electric current member 9 merely repeat the ON, OFF operation, thereby reducing the heat volume. As a result, the accident accompanied by heat volume can be prevented. At the same time unnecessary power consumption will not be required. |
