Open Source DC controller

Post by **Thalass** » Thu, 07 May 2009, 22:53

I haven't been following this closely, as I'm going for AC, but Paul and Sabrina on the Ecomodder forums have been working on an open source 144 volt dc motor controller for a while now, and it seems like they're pretty much done.

Just in case it hasn't been noticed over here, here's the links:

The original thread, with all the gory details. (116 pages, so beware)

And their new site for the controller.

No idea on total cost, though it'd be different over here to whevever they are, of course.

Post by **Taffy** » Fri, 08 May 2009, 13:50

They are planning to do a bulk buy of the parts and ship out packs for people to assemble.

Its a mamoth read, with some fairly funny moments.

Post by **jstan** » Wed, 08 Jul 2009, 05:17

anyone interested in a bulk buy here in Australia

Post by **Taffy** » Wed, 08 Jul 2009, 13:58

I am interested, though i was waiting until they do this round of testing before jumping in.
Need to find a way to cost effectively do the boards, if its better off joining in a US bulk buy of them or do my own this side of the large ditch.

There are a few aussies on eco forum so should be able to get a few people in on 1.

First off would be to source the parts and find $. I think i saw (on the forum) someone was already doing that in Aussie $.

Post by **jstan** » Wed, 08 Jul 2009, 16:11

That was me doing the aussie dollars on the forum, I have now converted the whole list to AU$ and not counting the boards it came to $250, I may have missed or guessed a couple that they did not have part Nos for.
Looking around here in aus the parts seemed to be more expensive or they would not sell one item so I sort of decided that it would be best to get them from Mouser or Digi-Key in the US.
I also have been waiting for the results of the tests but would like to move as soon as pos as I have a blown Curtis that I am trying to repair and at present am using a Logisystems which is not suitable for my EV which is clutchless, the Logisystems has a pronounced jerk at the start that I have not been able to adjust out.

Post by **jstan** » Wed, 08 Jul 2009, 16:35

I could not load a word doc so I have made my parts list into a poor quality JPEG, the Mouser parts are in AU$ the Digi-Key in US$.
If you want a better copy let me have your Email.

Post by **Taffy** » Wed, 08 Jul 2009, 17:08

You can contact me at taffy(dot)flynn(at)baesystems(dot)com

$250 err well that was cheaper then i thought (even with a few parts missing). I was looking at $450-500.

Re: US parts source, well that makes sense. Try to get a few more on board and should be good for postage savings too.

Post by **Richo** » Wed, 08 Jul 2009, 18:41

Mouser do free delivery to Australia for orders over $200 via fed-ex.
Digikey have a similar deal as well I think.
So prob better to buy from one place and save on freight.

Post by **jstan** » Wed, 08 Jul 2009, 23:33

Sorry Guys
I picked out the wrong list, the one I used had mouser prices in US$ so my $250 was wrong will put the right price on here tonight.
John

Post by **jstan** » Thu, 09 Jul 2009, 00:31

Here is the uptodate price. I am not a tech so if anyone can add to this please do.
Mouser Total                                                  AU$60.53
Digi-Key Total                              US$170.89          AU$217.78
               Based on conversion at 6.00pm 8/7/2009                    AU$278.31
Total does not include   C25 ( don’t know what power is required)
alsoU5A, U5B, U5C, U5D, which I am told is one part with four outputs I am told it should be 25c, also does not include the boards.
Taffy I will Email the list to you now.
John

Post by **Richo** » Thu, 09 Jul 2009, 17:32

So if you could buy it at the same place then postage will be free.
Otherwise you'll be up for another ~USD$35.

Also what was the spec's of thier controller ie max kW, V, I ?

Post by **Johny** » Thu, 09 Jul 2009, 18:07

It looks like broad specs. are:

Any voltage input in the range of 0 to 144v. 15.6 kHz switching frequency. Adjustable hardware overcurrent shutdown in the range 495 amps to 776 amps. Hardware over-current shutdown until the next cycle. RS-232 interface. Reprogrammable. High pedal lockout. The controller will not close the main contactor if the mosfets have failed shorted.

A link straight to the nitty gritty is http://ecomodder.com/wiki/index.php/ReVolt

Post by **Johny** » Thu, 09 Jul 2009, 18:19

jstan wrote:Total does not include C25 ( don’t know what power is required)

Same as C22 which is a 25V Ceramic. Looks like they added it to avoid false tripping of the under voltage lockout.

Post by **jstan** » Thu, 09 Jul 2009, 19:56

Thanks Johny
now can anyone tell me a suitable part No for U5B, etc.
If anyone wants my parts list sorry I don't seem to be able to post it here but you can get it on page 195 of Paul and Sabrina's 144 volt controller

Post by **Johny** » Thu, 09 Jul 2009, 20:24

U5 is a single SN74HC00 (Quad nand gate).
Not sure if it's DIP or SMD - that depends on the PCB.

Just a thought. If you are sourcing the components yourself, make sure that the ones you are getting are physically compatible with the PCB artwork.
Same value and voltage component does not guarantee that they will fit in the same holes.

Post by **mcudogs** » Fri, 10 Jul 2009, 03:31

All of the components are through hole not surface mount. I have been following the thread for a while now and the design looks to be fairly mature. There are a few qualified designers working in the background backing up Paul's hard work.

I have put my hand up to do a PCB layout for the power section as the existing design uses a milled PCB.

There are still some details that need to be specified regarding construction, but IMHO it looks like a goer.

Post by **jstan** » Fri, 10 Jul 2009, 03:57

New parts list for new power section (16 820uf power caps etc)posted on Paul's forum. present cost AU$303.01

Post by **Johny** » Fri, 10 Jul 2009, 16:17

My two cents worth. I have seen a couple of DIY controller designs here and there and they look pretty suss. This one looks very carefully thought out. I agree that it looks to be a good investment. Their web site is also very helpful for the mechanical "bits".

Post by **Richo** » Fri, 10 Jul 2009, 19:37

Excuse my lack of interest in reading the 100+ pages but what are they using to measure current?

Post by **Johny** » Fri, 10 Jul 2009, 19:43

Richo wrote: Excuse my lack of interest in reading the 100+ pages but what are they using to measure current?

A hall effect device. LEM HASS 300S
One of those ones where you route the cable through it.
Maximum current 900A.

Post by **Tritium_James** » Fri, 10 Jul 2009, 20:17

What gets me is that from what I can tell they're paying the $$ and extra complexity to measure current, but then only using it for an overcurrent trip! If you've got the hardware, why would you not run a control loop on that current? Then your throttle pedal can control motor torque, not PWM (~motor voltage) and you'll get a normal feel to the pedal, smooth starts, and no worries about overcurrent.

Post by **Johny** » Fri, 10 Jul 2009, 20:52

TJ - I thought that at first then I noticed they also feed the output of the hall sensor (around the bottom of the schematic via R6) to the micro. It's kind of a belt and braces approach. If the micro looses control the hardware limits the current anyway. Good idea during development...

Post by **jstan** » Fri, 10 Jul 2009, 21:38

mcudogs
I am a complete novice so do not know how you make the power board, I understand that Paul is using a mill machine, it would be a bit unreasonable to ask him to mill the boards for everone who wants one. If you are able to produce them here in aus that would solve one problem that I can think of, the control boards don't seem to be a problem as they are arranging for a bulk lot that should be low cost.
John

Post by **mcudogs** » Sat, 11 Jul 2009, 01:13

jstan wrote: mcudogs
I am a complete novice so do not know how you make the power board, I understand that Paul is using a mill machine, it would be a bit unreasonable to ask him to mill the boards for everone who wants one. If you are able to produce them here in aus that would solve one problem that I can think of, the control boards don't seem to be a problem as they are arranging for a bulk lot that should be low cost.
John

John, I will design the PCB layout for the power board once I get a copy of the CNC files. We can then order the boards from a PCB manufacturer. In quantities of 50 I have been quoted as low as $US10 per board.

James, the latest software implements a current control loop as per your suggestion.

Post by **Tritium_James** » Sat, 11 Jul 2009, 03:11

mcudogs wrote:John, I will design the PCB layout for the power board once I get a copy of the CNC files. We can then order the boards from a PCB manufacturer. In quantities of 50 I have been quoted as low as $US10 per board.

The catch might be the copper thickness, but I guess if you're designing the board then you probably know that!

mcudogs wrote:James, the latest software implements a current control loop as per your suggestion.

Ah, OK. That makes sense, it's such a basic and incredibly useful thing to have, and yet so many DC controllers don't do it.