W09 314 HW02 solution

W09 314 HW02 solution - V 30 OUT vs. Angle 25 20 VOUT /...

Info iconThis preview shows pages 1–16. Sign up to view the full content.

View Full Document Right Arrow Icon
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
-150 -100 -50 0 50 100 150 0 5 10 15 20 25 30 Angle / degrees V OUT / volts V OUT vs. Angle
Background image of page 2
1/19/09 2:24 PM C:\Users\jeremydg\Desktop\probset2num1.m 1 of 1 %Use values calculated for a,b above and %the formula for Vout vs angle. %Graph will be linear a = 15; b = 0.1; angle = [-150:.01:150]; Vout = a + b.*angle; plot(angle,Vout, 'linewidth' ,2.5); xlabel( 'Angle / degrees' ); ylabel( 'V_O_U_T / volts' ); title( 'V_O_U_T vs. Angle' ) grid on ;
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 4
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 6
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 8
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 10
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 12
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
EECS 314 Winter 2009 Homework set 2 Student’s name ___________________________ Discussion section # _______ (Last, First, write legibly, use ink) (use ink) Instructor is not responsible for grading and entering scores for HW papers lacking clear information in the required fields above © 2009 Alexander Ganago Page 1 of 3 Solution by Idong Ebong Problem 4 Temperature controller circuit Resistive temperature sensor is a device whose resistance R T depends on the temperature; this dependence is described by the temperature coefficient dR T dT . Such sensors belong to two families: Thermistor is a semiconductor device with a negative temperature coefficient (NTC); Resistive Temperature Detector (RTD) is made of metal and has a positive temperature coefficient (PTC). Thermistors are the most popular temperature sensors. This diagram shows a temperature controller circuit with a resistive temperature sensor. You will build a similar circuit yourself in the Temperature Controller Lab. Circuit parameters: V S = +42 V V T = +3.5 V (the threshold gate voltage above which MOSFET conducts) R 1 = 120 k : R 3 = 120 k : R 4 = 91 k : . The resistance of the temperature sensor equals R T = 150 k : at 0 o F and R T = 75 k : at +100 o F; for simplicity, assume that R T is a linear function of temperature. Determine the following and write your answers below: Part 1 (5 points) The type of the temperature sensor. Your answer: ____NTC_____________ Part 1 2 3 4 5 Total Score
Background image of page 14
EECS 314 Winter 2009 Homework set 2 Student’s name ___________________________ Discussion section # _______ (Last, First, write legibly, use ink) (use ink) Instructor is not responsible for grading and entering scores for HW papers lacking clear information in the required fields above © 2009 Alexander Ganago Page 2 of 3 Solution by Idong Ebong Problem 4, continued The thermistor has a lower resistance at higher temperature, therefore NTC Part 2 (15 points) At what resistance R T is the Actuator turned on/off? Your answer: ___91 k ȍ ___________ The actuator is turned on when the MOSFET switch closes; this occurs when the V GS > V T . The comparator will make V OUT (connected to the MOSFET gate) equal to V S whenever V 2 >V 1 . Since V S = 42 V, this is sufficient to turn on the actuator. V 1 and V 2 are given by two voltage dividers: ܸ ൌܸ ܴ ܴ ൅ܴ ܸ ܴ ܴ Conveniently, R 1 = R 3 , so the on/off transition point occurs whenever R T = R 4 =91 k ȍ Since the thermistor’s resistance is a linear function of temperature, R T is given by: ܴ ൌ ͳͷͲ݇ߗ െ ܶ ͹ͷ݇ߗ ͳͲͲιܨ Solve for transition temperature by substituting R T = R 4 =91 k ȍ to get T=78.67 ° ܨ At what temperature is the Actuator turned on/off?
Background image of page 15

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 16
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 27

W09 314 HW02 solution - V 30 OUT vs. Angle 25 20 VOUT /...

This preview shows document pages 1 - 16. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online