| 摘要 |
<p>PURPOSE:To make it possible to detect the effective current of a motor accurately without using a correction circuit as well as the current direction by connecting the current detecting resistance serially to the motor in the current detecting circuit of the motor for driving the circuit of switching elements by the PWM-controlled voltage. CONSTITUTION:When a motor M is driven, the whole current during the motor M being driven flows in the same direction to the current detecting resistance RS. That is to say, a fry wheel current, after passing through a fry wheel diode D3 or D1 connected parallel with a transistor T3 or T1 by electromagnetic energy stored in the motor M at the time of the transistor T1 or T3 being turned off, also flows into the current detecting resistance RS in the same direction as the current flowing at the time of the transistor T1 or T3 being turned on. As a result, polarity corresponding to the direction of the current flowing in the motor M is generated between both ends of the current detecting resistance RS so as to generate voltage corresponding to the current value.</p> |
