| 摘要 |
PURPOSE:To prevent a power source short circuiting and destruction of switching elements to be caused thereby by a method wherein an electric current suppressing circuit is provided in each of the two switching circuits composing power source short circuiting circuits in a forward-reverse rotation circuit consisting of four switching circuits. CONSTITUTION:In a forward-backward-drive controlling circuit wherein a DC motor 3 is connected to a bridge consisting of four switching circuits 1-5, 1-3, 2-5, 2-3, current suppressing circuits 35-1, 35-2 are provided in the two respective switching circuits forming power short circuiting channels. The current suppressing circuit 35-1, 35-2 suppress current in the ground side switching circuit 2-3 or 1-3 when the power source side switching circuit 1-5 or 2-5 is energized. |
