| 摘要 |
<p>A switching circuit including three series circuits each having a pair of switching elements series-connected on the upstream side and downstream side with respect to current flow, each of the connection nodes between the paired switching elements of the series circuits being connected to a corresponding one of the phase windings. A DC voltage output from a DC voltage circuit is applied to the series circuits of the switching circuit. One of the upstream side switching element in one of the series circuits of the switching circuit and the downstream side switching element in a different one of the series circuits is continuously set in the ON state, the other switching element is intermittently turned ON, and the switching elements to be turned ON are sequentially changed so as to sequentially energize the phase windings of a brushless DC motor. In this case, the switching element, which is one of the switching elements to be turned ON and which has been set in the ON state, is forcedly continuously set in the ON state for a initial preset period of time and one of the switching elements which is newly turned ON is forcedly intermittently turned ON for the initial preset period of time.</p> |
