| 摘要 |
PURPOSE:To prevent generation of an abnormal current by prohibiting simultaneous conduction of transistors for driving a first phase coil and a third phase coil. CONSTITUTION:Collectors of a driving transistor(Tr) Q1 of a first phase coil and a driving TrQ2 of a second phase coil are connected through a diode D1, and the base of the TrQ2 is connected to the collector of the TrQ1 through a diode D2. When the TrQ2 is an ON state and the TrQ1 is an OFF state, a signal A is switched to change the TrQ1 to the ON state. The TrQ2 is not immediately turned OFF due to its switching delay time. The base current of the TrQ1 is escaped to the collector of the TrQ2 by the diode D1 so that the TrQ1 is not turned ON only for the switching delay time. Thus, it can prevent the transistors from damaging. |
