| 摘要 |
PURPOSE: An improved circuit for compensating temperature is provided not to require selecting a diode or a transistor having the same temperature characteristic with an electric power transistor to be used while selecting the diode of compensating temperature by adjusting the value of resistance by connecting serially the resistance of a certain value to the diode of compensating temperature. CONSTITUTION: Q2(130) is biased by a resistance R1(140) adjusted properly for flowing the same sized current with the diode current of D1(150) and D2(170) to the base of the emitter flower Q2. Therefore, the emitter current of Q2 amplified from the current in the base biases an electric power transistor Q1(100). The same voltage fall with the voltage between the base-emitter in the Q2 is existed in the D1. Herein, the addition of the voltages of resistance R2(160) and the temperature compensating diode D2 is the same with the voltage between the base-emitter in the electric power transistor Q1 while having opposite polarities. Therefore, the turn-on voltage of the diode is changed by the change of temperature caused by the ordinary temperature characteristic of diode. Herein, the polarities of the Q1 and the D2 are connected in opposite state for compensating the change in the turn-on voltage according to the change in the temperature. Moreover, the resistance R2 serially connected to the D2 realizes the temperature characteristic of R2 to be the same with the temperature characteristic of the Q1.
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