| 摘要 |
<p>PROBLEM TO BE SOLVED: To remove a ringing voltage which greatly exceeds a driving voltage by providing a load to be driven and a limit circuit which is constituted in parallel to the load. SOLUTION: An NPN transistor(TR) 10 of the driving circuit has its collector and base shorted and is applied at its emitter with a limiting source voltage 9 (source voltage value Vmax). Namely, when a load voltage includes a ringing and its value exceeds Vmax+Vbe, the diode composed of the NPN TR 10 turns on to suppress the ringing. Namely, the voltage applied to the load 4 can be controlled by the NPN TR 10 and limiting source voltage 9. Here, Vbe is the base-emitter voltage when the NPN TR 10 is ON. Consequently, an excessive voltage generated by the ringing can be suppressed without making the load response speed slow and the elements can be prevented from deteriorating.</p> |
