| 摘要 |
<p>PURPOSE:To prevent the occurrence of frictional sound and coupling delay by constituting a control circuit such that exciting power is sequentially increased from low to the highest power according to the operation of a switch to improve damping connection. CONSTITUTION:A drive circuit is provided with a timer TIM, an oscillator OSC and a drive circuit DR. The timer TIM starts according to the operation of a switch SW while the oscillator OSC starts to send the pulselike oscillating output so that intermittent current is supplied to an exciting winding L in an electromagnetic coupling device by the drive circuit DR to restrain the exciting power to low voltage. When the time set by the timer TIM is up, the pulse oscillating power from the oscillator OSC is stopped and current is supplied continuously to the electromagnetic winding L by the drive circuit DR to maximize the exciting power. Thus, under the initial adsorbing condition of an armature, an adsorbing force is low and smooth slip is obtained so that the occurrence of frictional sound is blocked and complete adsorption is obtained according to the increase of the exciting power to permit satisfactory damping coupling.</p> |
