| 摘要 |
PURPOSE:To detect the temperature with a high precision to attain an effective heat shielding capability by giving the current, which is obtained with the first and second PNP and NPN transistors TRs and the first resistance, to the second resistance as it is. CONSTITUTION:The first resistance R1 is connected between emitters of the first and second NPN TRs Q3 and Q4, and the second resistance R2 is connected between the emitter of the second NPN TR Q4 and the ground. The base of the third NPN TR Q5 is connected to the emitter of the second NPN TR Q4, and the emitter of this NPN TR Q5 is connected to the ground, and the collector of the third NPN TR Q5 is led out as an output terminal TOUT. The voltage applied to the second resistance R2 is a positive temperature coefficient, and the second resistance R2 is selected properly to turn on the TR Q5 in the outside side at a prescribed temperature or higher. Thus, the temperature is detected with a high precision to obtain the effective heat shielding capability, and the circuit constitution is made relatively simple and inexpensive.
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