| 摘要 |
PURPOSE:To secure the favorable start up of a load current without bringing about size up and cost up, using a low-pressure power circuit. CONSTITUTION:This driver is provided with a step-up circuit, which consists of an induction element Lc, a diode Dc, a switching element Trc, an oscillator, etc., a capacitor Cc which is charged by the step-up circuit, a switch circuit Trpl which supplies load with charge charged in the capacitor Cc, a control circuit Tr which controls the timing of the opening and closing of the switch circuit Trpl, etc., and a current control circuit which detects the current flowing in the load L and controls the value. Furthermore, the power source voltage Vb is boosted, making use of the transient property of the induction element Lc, and using this, the capacitor Cc is charged up to high voltage, and this charged voltage is discharged at start of driving, and is utilized as drive start voltage, whereby the favorable rise of a load current is secured. |
