| 摘要 |
PROBLEM TO BE SOLVED: To provide a circuit arrangement for controlling an almost constant electric current even if supply voltage fluctuates. SOLUTION: A first bipolar transistor 6 is arranged in a load passage including a load 5. A base-emitter path and a second resistor 10 of a serially connected second bipolar transistor 8 are connected in parallel to a base-emitter path of the first bipolar transistor 6. Collector voltage of the second bipolar transistor 8 controls a third bipolar transistor 9 as a bypass to the base-emitter path of the first bipolar transistor 6, and becomes inverse to a fluctuation in base-emitter voltage of the first bipolar transistor 6. For example, when the base-emitter voltage of the first bipolar transistor 6 increases as a result of the high supply voltage, since a collector current of the third bipolar transistor 9 increases, an increase in a base current of the first bipolar transistor is reduced, thereby causing negative feedback. COPYRIGHT: (C)2004,JPO
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