基于SG3525的小型直流电磁铁升压与驱动电路设计

Design of Boost and Driving Circuit for Small DC Solenoid with Modulator SG3525

小型直流电磁铁受行程或驱动电压的限制,在有效行程范围内难以获得满意的速度或冲量。为此,提出了一种升压电路,利用高电压短时驱动小型直流电磁铁的方法来满足应用要求。该电路基于Boost升压原理,主要由电池组、PWM芯片SG3525、电感、快恢复二极管、储能电容和大功率MOS管等组成。PWM芯片控制大功率MOS管的导通和关断,来实现电感交替通电与断电。电感快速交替通断产生的高电压脉冲对储能电容间断地充电。另外,利用可调电阻的反馈电压可控制PWM芯片的波形输出,从而控制充电电压的大小。该储能电容可作为电源驱动小型直流电磁铁,在有限行程中可短时获得较高冲量。

Satisfactory speed or impulse is difficult to obtain for small DC solenoid in operational voltage due to the limitation of displacement. In this paper a new way is presented to meet the requirement of the application, using high voltage created by the principle of Boost circuit to drive solenoid within short time. The boosted voltage circuit mainly consists of a battery group, a pulse width modulator chip SG3525, an inductance, a quick-restored diode, a storage capacitor and a large power MOS tube. The PWM chip makes the MOS tube interval open and close in order to control the inductance interval open and close. A high peak voltage created by the inductance would be put into the storage capacitor continuously when the interval fast current supplied with battery power is passed to the inductance. Moreover, the feedback voltage produced by the adjustable resistance could stop the PWM wave output and the different output voltage would be obtained. The storage capacitor as the power can actuate the small DC solenoid and the high impulse is obtained in short time in the limited displacement.