WEEK 7

Title: Proceed with literature review

Objective: To give student more understanding about project

Discussion/Analysis:

Brushless DC motors are commonly used where precise speed control is necessary, as in computer disk drives or in video cassette recorders, the spindles within CD, CD-ROM (etc.) drives, and mechanisms within office products such as fans, laser printers and photocopiers.

Basically, the driving system is the low power side and high power side or control circuit. The low power side of circuit is operated in range 5V while the high power side is operating in higher voltage from 15V -50V. these side circuits have to separated for safety protection of the controller. Therefore , an isolation circuit is needed to isolate the low power side circuit from high power side circuit as shown in the figure below.

Figure 1 : Block diagram of the overall project implementation

The MOSFET driver is needed to switch on or off the power MOSFET in the H-bridge circuit. It is used because it has floating channel which can supply the bootstrap up to 500 Vdc and can supply gate voltage 10V- 20V to the power MOSFET. The switching circuit that used is H-Bridge circuit. This H-bridge circuit acts as inverter which can convert the dc voltage from the power rail to the ac voltage and then supply to BLDC motor.