WEEK 13

TITLE:

Preparation for FYP Presentation

OBJECTIVE:

To do a preparation for FYP presentation

DISCUSSION/ANALYSIS:
At this week, I had prepared my poster for my presentation. I also study more about my circuit driver. I went to see my supervisor, Mr Suhairi to show my poster. He give some comment about my poster. Below is the poster that I will present during my FYP presentation.

Conclusion:

As the conclusion, I had successfully preparing the poster for my presentation next week.

WEEK 11 and 12

TITLE:
Testing the circuit driver with the BLDC motor 

OBJECTIVE:
To test the circuit driver with 3-phase BLDC motor

DISCUSSION/ANALYSIS:
During this week, I had prepared the circuit driver to be tested with the 3-phase BLDC motor. At week 12, I went to UPM with Mr. Suhairi to do the testing. We had to go there because there is no proper equipment at BMI for the testing. Although at first, my circuit driver not functioning well but after do a troubleshooting, my circuit driver functioning. Below, I attach the video of the testing.

 

CONCLUSION:
From this task, we can see that my circuit driver was functioning well during testing with the 3-phase brushless dc motor.

WEEK 10

TITLE: Testing and troubleshoot the circuit

OBJECTIVE: 
To test the circuit and identify the problem occurred during troubleshooting

DISCUSSION/ANALYSIS:
At this week, I test the circuit with my advisor, Mr. Suhairi using the oscilloscope. By using the hall sensor, I attach the probe of oscilloscope to one of the hall sensor signal leg. As the hall sensor get supply from the battery, it should working properly. By using a magnet, I test the circuit driver to get an output signal. Below is the result of my testing. The result that I get is only for one phase. I can only get result for 3 phase if I test the circuit with the BLDC motor.

Connection of circuit and oscilloscope

 Result of the testing

CONCLUSION:
I had successfully design and fabricate the circuit driver for 3 phase BLDC motor as I get the output result from the testing.

WEEK 9

TITLE:

Description of the circuit driver

OBJECTIVE:
To give reader an understanding about the function of the components in circuit driver

DISCUSSION/ANALYSIS:

The circuit showing in the Week 8 is the complete driving circuit system with values of each component. This one set of circuit is used for three phase output. The power MOSFET IRF 640 is chosen because it has high Vdss (200 V), high Id (15 A), low Rds (on) and high switching capability. When dealing with the power MOSFET, several things have to pay attention like it is extremely static sensitive and if the Gate is left open, the power MOSFET can be self destruct. The Gate is a very high impedance device and noise can trigger the power MOSFET. Therefore resistor R3, R4, R7, R8, R11 and R12 (10kΩ) are added to stop the power MOSFET from self destructing. The MOSFET become more stable after these resistors are installed. The resistors pull down the Gate and turn off the MOSFETs and add some static protection to them.

The resistor R1, R2, R5, R6, R9 and R10 (22Ω) are connected in series with the Gate. This resistor can help to reduce the ringing of the MOSFET.For instant, a higher value of resistance will reduce the ringing of the MOSFET but the efficiency of the switching will also reduced. The efficiency is affected because the resistance courses the MOSFETs gate voltage to rise slower as opposed to a MOSFET with no Gate resistance.

The IRF 640 consists of built-in diodes, so they are no need to add another one outside it. The motor can make a lot of electrical spikes when starting and stopping especially when changing direction. The capacitor C4 (250 V, 470 uF) was used to suppress the noise spikes and remove the AC components which not needed. The power MOSFET is mounted on the heat sink for dissipating the heats. This will protect the power MOSFET from overheating and destruct. The protections method or components used in this circuit are:

1. MOSFET driver (IR 2110) – This driver consists of a built- in level shifting protection which can isolate the high power side from the low power side. This chip is control a set of high and low side power MOSFET; it will ensure that this six MOSFET will not on together to prevent the short circuit happen. It also has under voltage and overvoltage lockout protection.
2. Resistor – Limit the current flowing through the path
3. Capacitor – Reduce the AC components in the signal which may defect the DC components.

WEEK 8

TITLE:
Continue soldering components 

OBJECTIVE:
To attach the components with the PCB Board

DISCUSSION/ANALYSIS:
Last week, I get an opportunity to go to Jalan Pasar again to buy some of the components that I had misplaced before. After that, I able to solder that components to the PCB Board without any problem. At this moment, my three phase brushless dc motor driver circuit had completely finished. I only need to troubleshoot the circuit to see whether the circuit is functioning or not. Below is the circuit that I already completed.

Three Phase Brushless DC Motor Driver Circuit

CONCLUSION:
I successfully attached the components to the PCB Board although before this, there were some problem occurred.

WEEK 7

TITLE:
Correction on Chapter 1, Chapter 2 and Chapter 3 

OBJECTIVE:
To do a correction on the report draft

DISCUSSION/ANALYSIS:
This week, I focus on doing the correction the chapter stated above after my supervisor, Mr Suhairi give back the draft that I had submitted to him. Mr Suhairi told me about the mistake that I had done in my report. At first, I didn't know what to put in my chapter 2 which is literature review. After discussed about the problem with Mr. Suhairi, I finally understand what need to be put in the that chapter. He also tell me to follow to standard format of doing report. He said that I can refer to the format at Unikl-BMI Final Year Project website. The FYP committee had upload the format in the website. After that meeting, I redo the first three chapter and follow the format given in the website.

CONCLUSION:
I successfully redo chapter 1, 2 and 3 of the final year project and will submit to my supervisor in the following week.

WEEK 6

TITLE:
Soldering components 

OBJECTIVE:
To attach the components with the PCB Board.

DISCUSSION/ANALYSIS:
After finished fabricate my PCB Board last week. I start to attach the components with the PCB Board. It seems like easy to me at first but actually it a little bit hard. I need to identify the polarity of the components. If I make the wrong identification it will affect my circuit driver. The circuit driver will not work properly. This week, I already soldering about 90 percent of the components to the board. Another 10 percent I will done it next week because I had misplace some of the components. I need to go to Jalan Pasar first to buy it and then complete the circuit.

CONCLUSION:
I not successfully attached the components to the PCB Board due to misplace of some of the components.

WEEK 5

TITLE:

Fabricating the actual Printed Circuit Board

OBJECTIVE:

To fabricate the actual Printed Circuit Board

DISCUSSION/ANALYSIS:
After I had been to Jalan Pasar last week, I can make the actual PCB of my driver circuit. The step are shown below:

Step 1:

Take a mirror image print of the layout on the OHP sheet using a laser printer. Make sure that the design is correct with proper placement of the components.

Step 2:

Cut the copper board according to the size of layout. A copper board is the base of a PCB, it can be single layer, double layer or multilayer board

Step 3:

Rub the copper side of PCB using steel wool. This removes the top oxide layer of copper as well as the photo resists layer if any.

Step 4:  

Place the OHP sheet which has the printed layout on the PCB sheet. Make sure that the printed/mirror side should be placed on the copper side of PCB

Step 5:

Put a white paper on the OHP sheet and start ironing. The heat applied by the electric iron causes the ink of the traces on the OHP sheet to stick on the copper plate exactly in the same way it is printed on the OHP sheet. This means that the copper sheet will now have the layout of the PCB printed on it.

Step 6:

Now the layout is printed on PCB. The area covered by ink is known as the masked area and the unwanted copper, not covered by the ink is known as unmasked area. Now make a solution of ferric chloride. Take a plastic box and fill it up with some water. Dissolve 2-3 tea spoon of ferric chloride power in the water. Dip the PCB into the Etching solution for approximately 30 mins. The ferric chloride reacts with the unmasked copper and removes the unwanted copper from the PCB. This process is called as Etching. Use pliers to take out the PCB and check if the entire unmasked area has been etched or not. In case it is not etched leave it for some more time in the solution

Step 7:  

Take out the PCB wash it in cold water and remove the ink by rubbing it with steel wool. The remaining area which has not been etched is the conductive copper tracks which connect the components as per the circuit diagram.

Step 8:

Now carefully drill the PCB using a drilling machine on the pads

Below is the PCB layout that I had fabricate.

Front Actual PCB

 Back Actual PCB

CONCLUSION:
I had successfully fabricate the PCB of my circuit driver.