# homebuilt single igbt controller



## JimDanielson (Oct 19, 2008)

I am trying to make a really simple single igbt controller. Last night I tested it out on a mars motor with a 60v battery pack and it worked fairly well, it just need some heatsinking and I need to current limit the mosfet driver I am using.

It is a 600a, 1200v igbt. I had a 12amp diode across the motor terminals. I was running it at no load. I am not sure how big the diode will need to be at full load.

Does the diode need to match the current capability of the igbt?

Do I need capacitors? 

I did not have any during this test. When running a smaller motor, I tried it with and without capacitors at full load. I did not notice any difference in the wave form (should the capacitors effect the wave form) on my oscilloscope. I asked one EE and he said that since I will be using such a large battery bank, the batteries should act as a capacitor. During this test I had no oscilloscope hooked up. I plan to test it again this weekend with an amp clamp and oscilloscope.

Also, would you expect this to be enough isolation between the micro controller and the igbt: http://pdf1.alldatasheet.com/datasheet-pdf/view/85226/TI/UCC27321P.html


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## TheSGC (Nov 15, 2007)

jimbo12d said:


> I am trying to make a really simple single igbt controller. Last night I tested it out on a mars motor with a 60v battery pack and it worked fairly well, it just need some heatsinking and I need to current limit the mosfet driver I am using.
> 
> It is a 600a, 1200v igbt. I had a 12amp diode across the motor terminals. I was running it at no load. I am not sure how big the diode will need to be at full load.
> 
> ...


Ok, I have actually done this before. You need the freewheel diode to be the same amperage of the IGBT, so 600 AMPs. You also need about 9600 uF of low ESR capacitance just to keep up with moderate switching times and a lot more engineering. IGBT controllers are not that simple and if you are not an EE be prepared to destroy a lot of components. 

I have been working on a 3 phase AC controller and I have been building everything from scratch for the past few months, and I am an EE/CE student.


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## jackbauer (Jan 12, 2008)

Have a look at some of my videos. I built my own igbt controller based on the open revolt design. Working great.
start here:
http://www.youtube.com/watch?v=Y_VMPA-oO3w


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## Guest (Apr 28, 2010)

Jack,

Nice video. Watched a couple others too. I like that controller the best. I will keep watch as you progress to bigger and better controller building. That was nice smooth acceleration for that little starter motor. 

Pete


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## JimDanielson (Oct 19, 2008)

thanks for the replies, I hope to have some pictures and a video up soon.

what do the capacitors actually do? level out spikes from back emf?


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## jhuebner (Apr 30, 2010)

> thanks for the replies, I hope to have some pictures and a video up soon.
> 
> what do the capacitors actually do? level out spikes from back emf?


They keep the high PWM-frequency from distributing all over your vehicle through the bus cable. At the moment of switching high currents occur. The nearby capacitors provide these currents and the bus cables only need to deliver the continous current.


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## Qmavam (Aug 17, 2008)

jimbo12d said:


> I am trying to make a really simple single igbt controller. Last night I tested it out on a mars motor with a 60v battery pack and it worked fairly well, it just need some heatsinking and I need to current limit the mosfet driver I am using.
> 
> Hi Jimbo,
> I have a few of those large IGBTs that I would like to use for a
> ...


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