| 摘要 |
PURPOSE:To obtain the drive conditions of an electromagnetic coil in the magnet for driving hammers by controlling the current of the electromagnetic coil by digital signals and also by controlling the drive circuit of the electromagnetic coil by a switching method. CONSTITUTION:A transistor 2 is operated in a continuous ON-OFF manner by pulse train signals D. When timing pulse A in a signal A rises, coil current I in an electromagnetic coil 1 rapidly rises. When the pulse C is weakened after the lapse of time T, the transistor 2 is turned ON-OFF by pulse signal B. When the transistor 2 is turned off, a diode 3 goes on by the counter electromotive force of the coil 1. The coil current I becomes continuous current by current returning actions with high efficiency, and the level of the current can be controlled according to the duty cycle of the pulse train signal D. In the ending period of the drive, the coil current I is quickly damped by the resistor 4. |
