| 摘要 |
PURPOSE:To decrease the current capacity of a power supply section and to simplify the power supply section by connecting an inductance element in series with a switch control element so as to match the change in the leading waveform of an ON-current to an inductive load current. CONSTITUTION:When a switching pulse given to a base of a transistor (TR) Q12 is at a high level, the Q12 is turned on, the base of a final stage TR13 is biased reversely to a -V power supply voltage, the Q13 is turned off and the base of the Q11 is biased reversely via a control line and turned off. When the pulse is at a low level, the Q12 is turned off, a +V power supply voltage is given to the base of the Q11, which is turned on and a base current is given to the Q13. The inductance L is connected between the collector of the Q11 and the +V power supply, and a current IB increased with time from turning-on of the Q11 flows from the Q11 to the base of the Q13. In making a collector current IC of the Q13 equal to the base current IB for the slope of leading, the power loss of the drive circuit is decreased by a required minimum current. |
