| 摘要 |
PURPOSE:To increase operating speed of an inductive load by clamping through a Zener diode and power supply the voltage generated at the both ends of the inductive load when the load is turned off. CONSTITUTION:A load 1 is actuated when transistors Tr1 and Tr2 are turned on by a switching control circuit SC. At this time, the series circuit including diode D1 and Zener diode ZD remains off. When the load 1 is actuated by pulse voltage, the voltage across the both ends of inductance L is flywheeled by a diode D2 to the duration between the pulses. If the transistors Tr1 and Tr2 are turned off, the voltage generated at the both ends of the inductance L becomes equal to the voltage V=VC+VZ across the ends of the load through ZD-D1-power supply VC-P2. Therefore, attenuation time Ta can be shortened because the attenuation speed of current iL on the L may be proportional to the V. In such a constitution, the heat generated in the Zener diode ZD can be suppressed by supplying from the power supply a considerable amount of the power consumed by the ZD. Furthermore, a cost can be lowered by utilizing the Zener diode having a low rated voltage and the inductive load can also be operated at a high speed. |
