Bean Sprouting Machine Constant Temperature Controller

Published:2011/7/10 7:27:00 Author:Sue | Keyword: Bean Sprouting Machine, Constant Temperature, Controller | From:SeekIC

When the power is on, the temperature of the bean sprouting machine is lower than RP3's given control temperature. RT's resistance value is large and IC's pin 2's and pin 6's voltages are both lower than pin 5's voltage. Pin 3 outputs high level and VT is connected. Heating wire EH begins to be heated. As the temperature is becoming higher and higher, RT's resistance value is becoming smaller and smaller. When the temperature reaches the given temperature, IC's pin 2's voltage is higher thanhalf of pin 5's voltage. When its pin 6's voltage is higher than or equal to pin 5's voltage, IC's inner circuit will be reversed. Its pin 3 outputs low level and VT is disconnected and EL stops being heated. As the temperature is becoming lower and lower, RT's resistance value is becoming higherand higher which will make IC's pin 2 and pin 6 have lower voltages. When IC's pin 6's voltage is lower than pin 5's voltage, its pin 2's voltage is lower than or equal to half of pin 5's voltage, IC's pin 3 will have high level again which will make VT connected. EH begins to be heated again.



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