| 摘要 |
<p>PURPOSE:To reduce a cost by setting a base voltage for turning OFF a transistor to a value slightly lower than a threshold value voltage at an ambient temperature of the transistor. CONSTITUTION:When a voltage of a level H is applied to a normal rotation input terminal 13 and a voltage of a level L is applied to a reverse rotation input terminal 14, a transistor Q1 is turned ON, a transistor Q3 is turned OFF, a transistor Q2 is turned OFF, and a transistor Q4 is turned ON. When a voltage drop of a resistor R2 is VR2, a voltage between the collector and the emitter of the transistor Q1 is VCE1, a threshold voltage between the base and the emitter of the transistor Q2 is Vth2, the transistor Q2 is turned OFF by setting to satisfy Vth2>VR2+VCE1.</p> |
