Temperature Controller System Explanation - Lab Report Example

Running head: XE121 – Lab 1 Temperature Controller System Temperature Controller System Student’s Name Group Instructor’s Name Course Name: Table of Contents Introduction 3 Block diagram explanation 3 Link between temperature and Vout 5 Amplifier circuit design 6 Another sensor 6 Digital control 6 Discussion 7 Conclusion 7 References 8 APPENDIX 10 Introduction The modern fans are as result of several transformations occasioned by failures. The fan control system as particularly developed thinks to many attempted at automation, improvement in efficiency and proper communication channels. It will be used to warn fan users when it just to breakdown because fans are very critical in some buildings. This paper intends to explain the operations of the digital system of a fan. The temperature controller is developed using LED light which will switch automatically when the changes in temperature and the fan are functioning proper. When there is a temperature change a sensor detects and sends a signal for rectification. Block diagram explanation Fig 1 Block diagram of the temperature Control System. From the block diagram above 555 Timer senses changes in temperature and is it inverts the voltage that is provided from a fixed current source. When Vf is 0 the fan is off while when Voltage Vf increases to 1 then fan goes on. Temperature sensor detects changes in temperature it sends signals to the amplifier which compares the set voltage and the voltage produced by the signal if the voltage set is less than the set parameter then the voltage turns on the fan. When the temperature is very high, it will have a voltage of 5 which means it is too hot. This will in turn activate the heater controller which is managed by the heat circuit and at the same time the fan will be on, if Vh=1 and Vf=0 it means it is cold. This controller is critical in the operations of temperature controller of the fan (Crowe and Hayes-Gill, 1998). When there is changes in temperature a signal is transmitted to a computer through a number of wires. This is to ensure that the signal is received by the computer. A triplex channel, for instance, includes three such channels. After the computer receives the signal, it performs a number of calculations chief of which involves adding signal voltages, before dividing them by the number of channels received. This gives he average signal voltage. Another channel is then added to the three signals, and the four signals then sent to the digital control on the control surface. This moves the surface. A series of potentiometers within the actuator then returns a signal to the computer to report the current position of the digital controller. This signal is usually a negative signal. When the desired position of the actuator is attained, the outgoing and incoming signals cancel out each other thereby stationing the digital control at its present position. One end of these cables is connected to the computer and the other to a connector. The whole process majorly involves chain reactions. That is, one computer generates and transmits a signal of its desired action. This signal is transmitted through the cables, to the connector, back to the cables, then through the connector again, then to the cables again and eventually to their intended receiving computer. Connectors are grouped into various forms. The feedback signal to the computer ensures that there is information regarding the digital control that is being relayed. This signal is usually appositive signal and it is relayed when the desired results as been attained. These sensors are capable of sensing any changes in temperature. With these, any movements of the fan causing signals to be sent to the computer. These signals cause automatic movements in control digital controls thereby stabilizing the fan. The flexibility of the fan control system is improved tremendously because the computers are capacitated to receive signals from a myriad of sensors. The digital system also increases electronic stability since the control system depends less on the input values of critical electrical components as it happens in the digital systems. Link between temperature and Vout When the temperature is on normal conditions is off there are no output at Vout but when it is high there is an output. At this point it is noted that V0 increases as result of sensor resistance from the increase in V1. Some of the resistance are connected to provide load resistance and help form voltage (Shah and MacGregor, 2005). The 339 provides a stable current through the divider and produces a voltage drop across the 555. As a result, the output voltage Vout is a function of current concentration. When the temperature reduces 30oC there is oxidation which forms some substances that will send signals to digital computer. When in use, the temperature fan controls system converts fan control movements into electronic signals that are transmitted through wires. The movement of digital controls at control surfaces is determined by computers thereby providing the expected response. Essentially, this command system may proceed even without the user’s knowledge and therefore transforms fan control into an electronics sphere. Amplifier circuit design Amplification is necessary in converting changes in temperature to signals to voltage. The diagram below is the circuit that is used in this case study to show the working of amplifier circuit. To begin with the system is supplied with voltage, where a resistor is used then another resistor is placed parallel to amplifier. Thus amplifier will have network of two resistors in a series of steps. At first, the only series or parallel combination is the two resistors in parallel between points B and C. No other pair of resistors has either the same current or the same voltage drop for parallel. Figure 2 Circuit the amplifier for the temperature sensor Another sensor Heater sensors senses heat within a fan and control it by sending signals. Digital control The two LEDS plugged into digital control corresponding to the temperature sensors then it is coded to give a digital output of 0 LED off when the corresponding input voltage is below a certain value and 1 LED on when the corresponding input voltage is above a certain value. The response is accepted to have two rights one that is red and the other one is yellow. When the red light is shown it means the temperature is declaring and it requires digital activation for the temperature to increase so that the fan will continue working. Discussion Temperature controller is programmability and flexibility as well they can be implemented with passive components which are portable. The controller estimates power stage parameters, such as output capacitance, load resistance, corner frequency and damping factor by examining the amplitude and frequency of intentionally introduced limit cycle oscillations. In steady state, the controller behaves as digital controller, and during transients it uses a continuous-time digital signal processor to achieve time-optimal response. The processor performs a capacitor charge balance based algorithm to achieve voltage recovery through a single on-off sequence of the power switches. Load transient response with minimal achievable voltage deviation and a recovery time approaching physical limitations of a given power stage is obtained experimentally. This is not the case of continuous controller responses however both are implemented voltage-mode or current-mode controllers. This is because digital controllers responses are from are of the voltage-mode type controller. Conclusion The digital fan control system is a complete makeover of the analog and mechanical operations of the conventional fan control systems. In this system, signal processing is undertaken through a digital computer. The flexibility of the fan control system is improved tremendously because the computer is capacitated to receive signals from a myriad of sensors. The digital system also increases electronic stability since the control system depends less on the input values of critical electrical components as it happens in the analog systems. Once the computer has sensed force inputs and positions from sensors, they manipulate a series of differential equations to determine which of the command signals is appropriate to best execute the rooms temperature. The movement of digital controls at control surfaces is determined by computers thereby providing the expected response. References Circuits today. 2012. Temperature controlled fan regulator. Retrieved March 21, 2015 from Crowe, J. & Hayes-Gill, B. 1998. Introduction to Digital Electronics. London: Butterworth-Heinemann. Dale, RP & Fardo SW, 2009. Industrial process control systems. Boca Raton: Fairmont press, Inc. Foreshoffer, WF, 2006. Rotating Equipment Handbooks: Principles of Rotating Equipment. Manchester: Elsevier. Franklin G.F., Powell J.D. & Emami-Naeini A., 2009. “Feedback Control of Dynamic Systems. New York: Prentice Hall. Giambattista, A., Richardson B. & Richardson R, 2007.College Physics. Boston: McGraw Hill Holdsworth, B., 2000. Digital Logic Design. London: Doctronics Educational Publishing for Design & Technology Lewin, DR, Seider WD & Seade, JD 2005. Integrated Process, Design Instruction: Computers and Chemical Engineering. Cache News. Shah, LS & MacGregor, FJ., 2005.Dynamics and Control of Process Systems. Oxford: Elsevier Smith, KC & Sedra AS. 2009. Microelectronic Circuits. Oxford: Oxford University Press. Zuo L., Fang L. & Muhammad H., 2003. Speed Nonlinear Control of DC Motor Drive With Field Weakening. IEEE. Ind. Applications. vol. 39. no 2, March/April 2003 APPENDIX Temperature controller system - components Figure A.1 Circuit for the heater Figure A.2 Circuit for the Motor . Figure A.3 the Comparator circuit (taken from the data sheet) Figure A.4 Basic Centigrade Temperature Sensor (+2ºC to +150ºC) [LM35DZ]. Figure A.5 the 555 timer circuit Figure 10 Actual Circuit board of the temperature controller circuit system. Read More