INTRODUCTION
Background Study
The purpose of this project is to create a working prototype of a thin-film semiconductor experimental chamber with computer interface temperature control. According to the result obtained from a previous student, the new temperature control unit will exceed about 10 "C every time the heater turns on. According to the source code, the heater will turn on for 1 second after the temperature drops below the desired value.
The mechanism is simple, the microcontroller acts as a master switch while constantly refreshing the keyboard input and displaying the output temperature on the LCD. When the sensor detects a temperature lower than the desired value, it is triggered on the output for 1 second. Then the relay will turn on the heater at the same time.
Problem Statement
- Problem identification
- Significant of the Project
- Objective
From Fig.3, the on response of the temperature control unit is almost instantaneous, while the excessive heat generated by the heater for 1 second takes some time for the environment to cool down to the desired temperature. This is because the cooling effect is more significant due to the relative temperature with the environment. Power is applied in direct proportion to the current measured offset, in the correct sense to tend to reduce the offset (and thus avoid positive feedback).
Placing the heater directly into the base will also cause the base to absorb a large amount of heat from the heater and make the whole room very hot. By reducing the exhaust channel into one hole, the exhaust gas can be easily led to the filter. In addition, the built-in heater in the base can cause the whole body to become very hot during the operation session.
This makes the whole room very hot and dangerous for the user. The embedded heater will also increase the temperature momentum and cause the overshoot to get higher and the settling time to increase.
Feasibility of the Project
If the duct is not properly sealed, it will create an HSE problem as the gas can be dangerous. It will also reduce the efficiency of heating the thin film as the heating element also has to warm up the body.
LITERATURE REVIEW
PID controller
The output of the system can be subjected to PWM before connecting to the relay and heater. Carrier density of the majority carrier leaves (number of majority carriers per unit area). If you move the set point to the median error, the expected result will be similar to Fig.
However, the chamber bottom design is not feasible for the machine due to the limitation of the end mill. The base of the chamber will be designed based on the characteristics of ceramic fiber textiles. They should be on the border of the pattern (or as close to it as possible).
The simulation is to check the effect of the controller gain Kp to the steady state error. The proportional action will reduce most of the fluctuation normally generated by the on-off controller.
ME1HODOLOOY
Research Methodology and Project Activities
- ControllerDesign
- Chamber Design
- Sample Preparation
When the circuit is finished, the result of the previous student will be replicated and the research will be based on changing the algorithm inside the microcontroller to stabilize the output temperature. Since the temperature momentum of the previous experiment is positive, the set point can be moved to the median of the error so that the error deviation is reduced. The DAC output is input data from the PWM circuit and is required to determine the amount of heat generated by the heater.
The temperature transmitter will sense the temperature of the heater and send it to the controller in the signal form of 4-20mA, direct acting. Then the PWM will determine the duration of the heater ON time by sending signal to IGBT chopper. The concept of the new room base would be based mainly on HSE reason and efficiency of the heat preservation.
The ceramic fiber is available in a variety of shapes and forms to suit the use of the raised stand. With the brittle property of ceramic fiber, the small cylinder will break when making the screw railing in the ceramic fiber in Fig.20. In the new design, a block of ceramic fiber is simply placed under the heater and some ceramic fiber on the side of the heater, as shown.
Due to the lack of solid ceramic fiber material, the solid part of the ceramic fiber will be replaced with the ceramic fiber cloth insulator. The fabric insulator has properties similar to solid ceramic fiber, it has high temperature resistance up to 1 OSOA °C. Ceramic fiber textiles also have excellent properties of light weight, low thermal conductivity and chemical resistance that resist attack by most corrosive agents.
However, the change from ceramic fiber solid to ceramic fiber textile provides an excellent advantage to facilitate the design, since the thickness of the textile is only 1.3 mm. To set the ceramic fiber textile position in the chamber, a red silicon packing machine will be used. To use the van der Pauw method, the sample thickness must be much smaller than the width and length of the sample.
In practice, they should be as small as possible; any errors due to their non-zero magnitude will be of the order D I L, where D is the average diameter of the contact and L is the distance between the two contacts. To make a measurement, we cause a current to flow along one edge of the sample (for example In) and a voltage along the opposite edge (in this case V34).
Key milestone and Gantt Chart ...................................................... 3 8
- Softwares
RESULT AND DISCUSSION
P controller simulation
However, the error still exists until the end of the simulation because there is no integral action to compensate for the error.
Temperature Control Result
Fabricated Chamber Base and Gold Probe
This is because the proportional controller can vary the heat intensity needed to bring the temperature to steady state, while the on-off controller can only have two distinct states. Integral action will eliminate steady state error and derivative action will reduce settling time. The proposed room would be more efficient, more sensitive and save on raising the heater.
CONCLUSION
