| 摘要 |
PURPOSE:To detect the operation of a plunger for a short time by detecting the change of current flowing into the plunger. CONSTITUTION:When a control input is applied to a driving circuit 1, a transistor (TR) starts to operate and current is made flow into the plunger P. The current is converted at its voltage by a resistor R1. The current is delayed by its self-induction. When the internal iron core of the plunger P starts to move, inductance L is increased and the self-induction is also increased, so that current is reduced. When the attraction operation of the plunger P has been completed, the increment of the inductance is stopped and the current is increased again. Thus, the operation of the plunger P can be found by detecting a dip point from the increase/decrease of the current.
|
