| 摘要 |
PURPOSE:To linearly accelerate or decelerate the rotating speed change of a fan motor by dividing the points of obtaining the maximum rotating speed and of obtaining the mimimum rotating speed into any predetermined steps, and starting the phase control of a thyristor at the point. CONSTITUTION:The outputs 5, 6, 7 of a zero crossing point detector 2 for detecting the zero phase timing of a power supply, an operation setting controller 3, and a signal conversion controller 4 are applied to a central processing unit CPU1 of a microcomputer having a clock oscillator 10. The output of the CUP1 is applied to a phase controller 11 to control the phase of the thyristor for controlling the rotating speed of a fan motor. The points of obtaining the maximum and minimum rotating speeds of the fan motor are divided so that the rotating speed of the fan motor at the respective steps thus divided becomes at predetermined ratio to the rotating speed at the fore and aft steps of the motor to start the phase control of the thyristor at this point to thereby linearly accelerate or decelerate the rotating speed change of the fan motor. |
