| 摘要 |
PROBLEM TO BE SOLVED: To provide a bidirectional step-up/down circuit that implements bidirectional control by means of a single simple logic circuit by tolerating disturbance and stably and reliably switching a current direction.SOLUTION: The bidirectional step-up/down circuit has switches SA-SD arranged in respective branches of an H bridge with a bridging coil L, and repeats a first combination of turning on/off the switches SA-SD to create a current flow through the coil L and a second combination of tuning on/off the switches SA-SD to generate an induced current in the coil L to whereby step up or down a voltage applied across two of the switches connected in series. The bidirectional step-up/down circuit comprises: a detector 4 for detecting a current value through the coil L; means (8) for determining whether or not the current value detected by the detector 4 has reached a predetermined value at a startup; and means (8) for prohibiting synchronous rectification switches to be turned on out of the second combination of turning on/off the switches SA-SD from being turned on until the determination means (8) determines that the predetermined value has been reached. |
