| 摘要 |
PURPOSE: To obtain a current supply device having a sufficient dynamic control range with less circuit elements by operating a control transistor with emitter arrangement during active voltage adjustment and operating it with base arrangement during active current restriction. CONSTITUTION: The output terminal of a second control amplifier OP2 is connected to the emitter of the control transistor T2 through a resistor R5. The transistor T2 is operated with emitter arrangement during active voltage adjustment and operated in base arrangement during active current restriction. Thus, a first control amplifier OP1 becomes active for voltage control during a regular operation. When the measured voltage UM of a current measuring resistor R10 becomes more than a restricted value decided by second reference voltage and the output voltage increases, the transistor T2 operates with base arrangement and load current reduces by quantity that measured voltage increases. Thus, voltage control or current restriction easily becomes active by combining the two amplifiers OP1 and OP2 with the transistor T2, and the sufficient control range is provided with the less elements.
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