Thershold. 2. Sensitivity. 3. Full Range. 4. Linearity. 5. Accuracy. 6. Precision. 7. Stability. 8. Hysteresis. 9. Noise. Question 2 Given the circuit below (using a SYH-2R humidity sensor) determine the output voltage for a relative humidity of 70 % at 30 °C if RT = 50 kΩ and VDD= 2.5 V. Solution: Check specification for Humidity Sensor of SYH-2R.pdf at: http://www.rhopointcomponents.com/images/SYH-2R.pdf 2 Week 04 Homework - Solutions Check Thermistor - Wikipedia.pdf at http://en.wikipedia.org/wiki/Thermistor Calculate the Humidity Sensor resistance at 30°C T = 273.15°C +30°C = 303.15°C T0 = 273.15°C +25°C = 298.15°C R60% 30°C =25.5858 kΩ - Matlab code: 33*exp(4600*(1/303.15-1/298.15)) = 25.5858 Calculate the Humidity Sensor resistance at relative humidity 70% See the above graphic for the standard resistance: Exercises - Solutions 3
R1 100 b) When VOUT = 0,5 V {under strain}, R1 R3 VOUT VIN 1 R R 2 R3 R4 100 100 0,5V 5V 100 50 100 R4 R4 RS 76,46 Question 4 Figure below shows the thermistor circuit (R25 = 2kΩ). The data sheet and the specifications are provided: Midterm Exam - Solutions 3 D.C. Dissipation Constant: 2 mW/°C Required accuracy: 1.5 °C Sensor circuit VREF = 4 V Application temperature: 0°C to 40 °C a. Calculate the resistance of the thermistor, RTH , at 0°C and 40°C respectively? From the given information, the thermistor resistance at 25°C or R25= 2 kΩ, and RTH
R2 ∙ R3 RS= =100 Ω R1 b) When VOUT = 0,5 V {under strain}. 100 200 0,1= − 150 200+ RS 200 200 0,56= =¿> RS= −200=¿> RS=157 Ω 200+ RS 0,56 RS ≈157 Ω Week 04 Homework 3 Question 4 You want to measure temperature ranging from -10 °C to 50 °C using a negative temperature coefficient (NTC) thermistor. You are using the circuit given below. (1 RF VRRF RF ) V V OUT Sensor RL RH RH a) Draw the resistance-temperature characteristic for the thermistor over the specified operating range. b) Assume VR = 5V
Read Chapter_6_Analog_Outputs.pdf and Chapter_8_EMI_ElectroMagnetic_Interference.pdf Question 1 Given the below open sensor detection: a. Derive equations for both outputs VO and Vsense as a function of VR, R1, Rth, RH, RL and RF. b. What value will appear on each output if the thermistor fails (becomes an open circuit)? c. How can the above schem be modified to implement temperature reading with open sensor detection using only one ADC and one digital input pin of the microcontroller? Solution: a. Derive equations for both outputs as a function of VR, R1, Rth, RH, RL and RF. Rth Writing the equation for V1 : V1 VSense VR th
setpoint if PID control settled at offset from setpoint. 2. Three delays that occur when a heater is used to increase the temperature of a metal block: · The time it takes for the heater to respond to a control change. The temperature of the heater does not change instantly just because thecontrol signal to it did. · The time it takes the heat to be transferred to the load. · The time it takes the thermistor to respond to changes in the load temperature. 3. Using Matlab: a. Proportional gain must be decreased b. Integral gain must be increased c. Derivative gain must be decreased 4. I presenting for II presenting for III presenting for
figured as an input. Figure 2.17B shows how a single analog input can be used to read two switches. When both switches are open, the analog input will read 5v. When switch S1 is closed, the analog input will read 3.9v. When switch S2 is closed, the input will read 3.4v, and when both switches are closed, the input will read 2.9v. Instead of switches, you could also use this technique to read the state of open-collector or open-drain digital signals. Figure 2.17C shows how a thermistor or other variable-resistance sensor can be combined with an output. The microcontroller pin is programmed as an analog input to read the temperature. When the pin is programmed as an output and driven high, the comparator output will go low. To make this work, the operating temperature range must be such that the voltage divider created by the thermistor and the pullup resistor never brings the analog input above 3v. Like the example shown in 2.17A, this circuit works best if the output is
79 kiirusega, mis on võrdne staatori magnetvälja kiirusega. Takistus Juhi omadus avaldada liikuvatele elektrilaengutele takistavat mõju. Resistance Takistus on pinge, mis tekkib elektrivoolu ühikulisel muutusel. Termistor Takisti, mille takistuse väärtus muutub sõltuvalt temperatuurist. Thermistor Tööstusrobot Automaatselt juhitav, ümberprogrammeeritavat, multifunktionaalne, Industrial robot mitme vabadusastmega manipulaator, mis on kas paikselt või mobiilselt installeeritud automatiseeritud tootmissüsteemidesse. Tööstusrobot Automaatselt juhitav, ümberprogrammeeritav, multifunktionaalne, Industrial robot mitme vabadusastmega manipulaatorit sisaldavad masin, mis on kas
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