1、附录 C The integrated temperature sensor is a kind of semiconductor integrated circuit in fact, it is who utilizes the transistor b-e Form saturation value lowered to press VBE With thermodynamics temperature T With passing the emitter electric current I Relation. It is good that the integrated temper
2、ature sensor is linear, such advantages as the precision ismoderate, the sensitivity is high,small, easy to use, used widely. The output form9 of the integrated temperature sensor is divided into two kinds voltage exporting and electric current outputs. The sensitivity of the voltage outputting type
3、 is generally 10mV/K, Temperature0 Degrees Centigrade are exported hour 0 ,Temperature25 Degrees Centigrade are exported hour 2.982V . The sensitivity of the outputting type of the electric current is generally 1 A/K . AD590 It is the single integrated temperature sensing electric current source of
4、both ends where U.S.A. simulation device Company produces. Its main characteristic is as follows: (1) flow through device electric current ( A )Mean the reading of thermodynamics temperature (turns on gently ) of living in environment of the device. (2) AD590 Examine warm range -55 Degrees Centigrad
5、e- +150 Degrees Centigrade. (3) AD590 Power voltage range 4V -30V . The voltage of the power can be here 4V6V The range changes, electric current Change 1 A,In other words temperature changes 1K . AD590 Can bear 44V To voltage sum 20V Reverse voltage, therefore the transposition of the device will n
6、ot be damaged either. (4) the resistance of output is 710M. (5)the precision is high. AD590 Own in common I J K L M Five shelves, among them M The shelf is the highest in precision, here -55 Degrees Centigrade- +150 In one degrees Centigrade of ranges, the non-linear error is 0.3 Degrees Centigrade.
7、 1、 the application circuit basically Pursue 1 ( a)AD590 Encapsulation form, pursue 1 ( b )AD590 Used for measuring using the circuit basically of thermodynamics temperature. Because flow through AD590 Electric current in direct proportion to thermodynamics temperature, look on as resistance R 1 Wit
8、h the electric potential device R 2 Resistance sum 1k Hour, output the voltage VO The change which is up to temperature is 1mV/K . But because AD590 Gain by deviation of having, resistance too it have error of, so should adjust to circuit. The method to adjust is: One AD590 Put in the frozen water m
9、ixture, the electric potential adjusting device R 2 ,Make VO =273.2mV . Or under the room temperature (25 Degrees Centigrade ) Pursue 1 ( a)AD590 Encapsulation form, pursue 1 ( b )AD590 Used for measuring using the circuit basically of thermodynamics temperature. Because flow through AD590 Electric
10、current in direct proportion to thermodynamics temperature, look on as resistance R 1 With the electric potential device R 2 Resistance sum 1k Hour, output the voltage VO The change which is up to temperature is 1mV/K . But because AD590 Gain by deviation of having, resistance too it have error of,
11、so should adjust to circuit. The method to adjust is: One AD590 Put in the frozen water mixture, the electric potential adjusting device R 2 ,Make VO =273.2mV . Or under the room temperature (25 Degrees Centigrade) too it have error of, so should adjust to circuit. The method to adjust is: One AD590
12、 Put in the frozen water mixture, electric potential adjusting device R 2 ,MakeVO =273.2mV . Or under the room temperature (25 Degrees Centigrade )Adjust the electric potential device under the condition ,Make VO =273.2+25 =298.2 ( mV ). But it is here to change and only guarantee like this 0 Degree
13、s Centigrade or 25 There is high accuracy degrees Centigrade of nearby. 2、 Centigrade temperature survey circuit Such as pursuing2 Show, the electric potential device R 2 Used for adjusting the zero point, R 4 Used for changing and transporting putting LF355 Gain. Adjust the method as follows: Here
14、0 Degrees Centigrade are adjusted hour R 2 ,Enable exporting VO =0 ,Then here 100 Degrees Centigrade are adjusted hour R 4 Make VO =100mV . Such repetition change numerous, until 0 A hour, VO =0mV ,100 A hour VO =100mV . Carry on check-up under the room temperature finally. For example, if the room
15、temperature is 25 Degrees Centigrade, so VO Answer 25mV . The frozen water mixture is 0 One degrees Centigrade of environments, the boiling water is 100 One degrees Centigrade of environments. Enable pursuing2 The output of China is 200mV/ Degrees Centigrade, can feedback through increasing (picture
16、 feedback resistance of for resistance from R 3 With the electric potential device R 4 Contact but become) realize. In addition, while measuring the Fahrenheit temperature , because Fahrenheit temperature is equal to thermodynamics temperature to deduct 255.4 Multiplied by again 9/5 ,So demand to ex
17、port 1mV/ , adjusts the resistance of feed backing about 180k ,Make temperature 0 A hour, VO =17.8mV ； Temperature is 100 A hour, VO =197.8mV .AD581 It is a high-accuracy integrated voltage stabilizer , most greatly input the voltage 40V ,Output 10V . 3、 the difference in temperature measures the ci
18、rcuit and application (1) Circuit and principle analysis Pursue 3 Utilize two AD590 Measure two circuit with bad temperature. Feed backing the resistance 100k Situation under, set up 1 # Sum 2 # AD590 The temperature of the place is respectively 1t (degrees Centigrade) sum 2t (whether degrees Centig
19、rade),it output voltage as 121 0 0 /t t m v C . Electric potential device in the picture R 2 Used for returning to zero.Electric potential device R 4 Used for changing and transporting putting LF355 Gain. (2) Use and give an example Take warm in some energy-efficient crude drugs warehouse , humidity
20、 control system as an example, if require the temperature of the storehouse is lower than T Degrees Centigrade, relative humidity is lower than A 1 B 1 %RH . Two kinds of control modes adopted are as follows: Control mode one: The relative humidity is higher than in the storehouse A 1 B 1 %RH And te
21、mperature is lower than outside the storehouse T A hour, ventilate inside and outside the storehouse. This way is to utilize bad exchange which carries on the air of the internal and external humidity of the storehouse, in order to reach the demand dehumidifying in the storehouse, its advantage is h
22、igh-efficient , energy-conservation , saving the fund. But this way receives strict control. First of all, the relative humidity outside the storehouse will lower than the storehouse, the difference between them should be greater than A 2 B 2 %RH ,Could guarantee to carry on the dehumidification in
23、the storehouse in time effectively in this way. Secondly, the temperature outside the storehouse should be smaller than badly in the storehouse.Degrees Centigrade, this because if temperature ventilate at higher than temperature in the store housing far outside storehouse, will lead to the fact the
