| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a voltage converter that converts DC voltage to an output voltage while reducing the influence of a dead time of a transistor. <P>SOLUTION: A control device 30 receives the DC voltage Vb and the output voltage Vm from voltage sensors 10, 13, respectively, and operates a ripple current Ir by using the received DC voltage Vb and the output voltage Vm. When a reactor current IL from a current sensor 11 is larger than the ripple current Ir, or when the reactor current IL is smaller than a ripple current-Ir, the control device 30 sets the carrier frequency fc of a signal PWU for turning on/off the NPN transistor Q1, Q2 to an optimal carrier frequency. When the reactor current IL satisfies a formula of-Ir≤IL≤Ir(except for IL=0), a boosting converter 12 is controlled by lowering the carrier frequency fc of the signal PWU than the optimal carrier frequency. <P>COPYRIGHT: (C)2004,JPO |
