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Motor Controller Answered

Dear Sir,

Can you help me in developing a 24/36 mosfet controller for tricycle?




Should be able to please give more concise information like all the motor information.




load so on

Dear sir here is motor information:

volts 48v

watt 800w(rated) 1200w (max output)

amps 16-17A (rated and on load)

Hp ?? (not printed on motor)

load ?? if you are asking how much load I am going to put on this motor then it will be nearly around 500kg to 600kg with frame.

N.M (torque) 28(rated) 42(max output)

RPM 2700 to 3100 (+-100)

motor is a 3 phase DC motor. one more thing Sir, I have also designed MOSFET configuration. I will share it after completing it on schematic.



The horsepower is in the watts 746 watts is 1 Hp.

3 phase DC that is a bit different.

Does it have 3 or 4 wires going into it?

Where do the wires go in the motor? (Ie the stater Armiture)

Does the motor have 2 or three brushes?

ok Sir.

It is a 3 phase dc motor. It has 8 cables totally. 3 thick line of phase cable and 5 thin wires of holzer(hall element) and for starter Armiture I have to first disassemble the motor.

It sounds like you know what you are working with.

Are you planning to use the mosfets driven by a Pulse Width Modulator or a current regulator.

Not exactly Sir.

not sure. But according to planning mosfet will be driven by PWM.

Check the wires with a multi meter and see if the motor is wound like this.

3 Phase.jpg

I do not have multimeter yet. But I have already ordered and it will get arrived today or tomorrow.

And according to me thick wire diagram is correct but do not know thin wire diagram is correct or not.

OK that is a stepper motor sometimes called a 3phase stepper motor.

The first schematic for a half bridge driver.

To reverse the direction of the motor switch any two of 1, 2, 3, wires or any two of 6, 7, 8.

The second schematic is for an external input signal.

3 Phase.jpg

Sorry Sir,

Did not understand your schematic fully. I am planning to control motor by PWM signals. Second I am designing this for my tricycle and maybe for my high power green bike. The board which I am reversing is showing that all wires of hall sensor is directly connected to MCU pins. Configuring mosfet parallely is not major issue for me but I am facing problem in MCU section. I am confused here in selecting MCU because the board which I am reversing is based on a chinese MCU and those company is not going to share datasheet and sample code.

In the first circuit the hall sensors drive the half bridge push pull circuits to run the stepper motor at a fixed speed.

In the second circuit a PWM drives a 3 phase signal generator to run the stepper motor at variable speeds.

Do you have a pic of the MCU and its markings?

Uploaded all the shots. all 470uf 80v, 220uf 80v, IRFB3607(mosfet) has been removed from this PCB for RE


This is a simplified schematic of your circuit.

You can make a more accurate schematic by following my Instructable Reverse Engineering. I find getting datasheets and schematics hard also so I make my own.


You can get datasheets on the components here:



If you take your time and follow my Instructable, downloading the pdf files you can make schematics as complicated as this power inverter in this Instructable, it is not that different than your circuit.


You may find it easier to build your schematics in 123D Circuits here is a link to the on line circuit building program.



3 Phase 2.jpgOTG 8d.JPGInverter circuit.bmp

I cannot able to find details on net how to parallel connect 24 fet(I do not have Idea). The schematics I got from Atmel and Microchip is for 3 phase 6 fet controller. I am making a high current controller. I want to use 8 mosfet for each phase. So just want idea or schematics to know how to connect 8 fet parallel for each phase.


They are simple in the schematic I gave you are 12 fets in two banks for what you want is 24 fets in 3 banks 4 fets a side of a bank instead of three like in my schematic.

MCU Brand: GeneralPlus

MCU Part no.: GPM8F3116A