Paul & Sabrina's cheap DIY 144v motor controller

[MissileStick]

MPaulHolmes, could you put a link to the ORV wiki in your signature? I think it would get a lot more traffic (and so more editors ). Also, I think a FAQ would be fantastic for your sig, to preemptively answer a lot of the questions people raise. If I were to start one, could you link to that as well?

[slurryguy]

I have a completely different perspective.

Putting all the important links on the front page of this thread? ARE YOU CRAZY???

Schematics, Parts List, wiki, instructions, specifications, software...

If some WIMPY BUILDER isn't willing to read this entire freekin' thread to find all the important information, do they deserve the opportunity to build one of these controllers? REALLY? What is this country coming to? Everyone seems to need everything on a silver platter.

I think this thread should be a rite of passage. It should be required reading. I think every page should be printed out, engraved in granite, and and enshrined as one of the all time greatest documents in all of history. It should be right up there with the Magna Carta, the Declaration of Independence, and Martin Luther King's speech.

School children 50 years from now should think M Paul Holmes was a great American ReVolt-ionary. Greater than John Paul Jones!

This thread should be set to music and performed at the Metropolitan "Oprah"

There should be an Olympic Sport where newbies compete to read through this thread, and build a controller the fastest based upon the information contained in the thread.

If all the information is put where it's easy to find, people might think this thread was only a colossal waste of text full of bad puns!

[blowncurtice]

As someone who started when Paul made a controller to drive LED's I can only agree.

[MPaulHolmes]

You guys are funny!

[steiner]

Paul,

I saw your post on evtech pertaining to pcb software. I use FreePCB and it works well. If you want, you can send me the file you have that was created in Protel and I will see if it imports into FreePCB.

[MPaulHolmes]

Ok! Do I have your email? Man, I was just getting used to PCB artist. I wonder if the .pcb file that pcb artist generates can be converted to the gerber files by your software.

[steiner]

Paul,

I don't think so. My e-mail is rmwartman@yahoo.com. Send me both files and I will see what I can do with them.

Rick

[adamj12b]

Hi Guys,

I have been working over the past few weeks on getting ready to do high voltage testing on a small version of the controller. I have charged up 20 SLA 12V batteries and acquired a 130VDC 26A 2.65 HP treadmill motor and machined the small controller. I am going to start with 9 batteries and measure the voltage spikes and keep adding batteries till A: I reach 14 or 15 batteries, or B: I break the controller and call it as 1 less then what broke it.

Some pictures of the test controller:





Mosfets and Diodes are on the bottom side clamped to the heat-sink through the PCB:


Test Control Board:


While I was designing the 2 pair test controller, I came across a very very good layout for the controller. I decided to see where I could take this design. I ended up with a recreation of Paul's controller on a more friendly layout. He seemed to really like the layout. It contained 10 pairs just like his, but only had 15 caps. Since he decided to go with the 820uf caps now this is not a problem being 1 down. It also has places to mount 2 of the poly spike suppression caps. And its just beautiful!!



The controller uses a slimed down version of the fet driver board that I designed for my controller. This one is 5 fets per driver down from 7.




This controller is set up like the test stand where the PCB is the top clamp for holding the mosfets and diodes to the heat-sink. The heatsink I plan on using is from HeatsinkUSA.com. It is the small size they offer. It should be a perfect size for the controller. The PCB is 12" long and 5.3" wide and the heat-sink is 12" long and 5.375" wide. With a small aluminum box around the bottom of the heat-sink it would be perfect. The heat-sink will have a channel milled down the middle to allow room for the M- buss bar. The 3 buss bars will be 1/4" thick by 3/4" wide. Should be heavy enough for a continuous 600A. I will also drill and tap all 20 holes for the mosfets and diodes. The heat-sink could be made to only the length of the mosfet/diode section with just regular sheet metal over the rest, or it could just be the entire length of the controller. What do you guys think?





Now for the bad news....I dont have money to build this controller. It might be awhile before you will see one, but I plan on building one for my golf cart. I have the PCB, but it ends there for materials.

If anybody is interested in funding the building of one of these, I will build it for you and send it off for you to beat on. Just get ahold of me. Paul would love to see this power section in action, but wants somebody to test it first. Once it gets the all clear, we will make a bunch more.




I hope to start enlarging it, Im thinking 15 pairs and 24 caps. it will make the controller about 7-8" longer for a total of about 18" and 5.5" wide. Long and Skinny.


Please let me know what you guys think.

-Adam

[jyanof]

Originally Posted by adamj12b

d call it as 1 less then what broke it.

Some pictures of the test controller:




-Adam

Awesome! For both this project and others, I had been thinking of ways to get the switching devices right onto the heatsink, but I had been stuck in the mindset of no through-holes and using clamps. Not as elegant as this!

In the back of my mind, I was also wondering about temperature differences along the heatsink - will the mosfets and diodes in the middle be warmer than on the edges? I really don't know, but it might be something to keep an eye on once you have more mosfets and diodes to deal with.

is that thermal grease between the mosfets/diodes and heatsink? Are they electrically isolated?

[edown]

To adamj12b: Your set up looks like a good plan. It's hard to tell from the pics, but I think I'm seeing that you've installed the MOSFETs and diodes face-down onto the heat sink. If so, I'm afraid you won't get enough heat transfer since the components are designed to dissipate about 90% of their heat through the back (subplate). Can you flip things over? The diodes would be able to flip, but the MOSFETs would have to be re-configured on the board.
-edown