# Possible problem Iota DC-DC converter



## etischer (Jun 16, 2008)

Apparently I'm not the only one who has had a problem

http://www.evdl.org/pages/iotamods.html


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## dimitri (May 16, 2008)

Ouch, that sucks. Thanks for sharing. I will have to open mine up and see if its the same.

Every time I swear not to mess with the car again, something comes up


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## etischer (Jun 16, 2008)

I talked with IOTA, and they said they have a 2 year warrantee. I gave them my serial number, reciept and pictures of the damage, and they said they would ship me a replacement unit tomorrow =) Pretty good service!





dimitri said:


> Ouch, that sucks. Thanks for sharing. I will have to open mine up and see if its the same.
> 
> Every time I swear not to mess with the car again, something comes up


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## Woodsmith (Jun 5, 2008)

That is good.

Are they going to replace it every time it fails for the reasons listed in your link or are they going to harden it?


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## Tesseract (Sep 27, 2008)

etischer said:


> Apparently I'm not the only one who has had a problem
> 
> http://www.evdl.org/pages/iotamods.html


I pretty much agree with all of the advice given on that page EXCEPT for #7 - don't change the value of the snubber resistor unless you can verify with a scope that overshoot and ringing are still well controlled across the expected input voltage range and all output currents.

EDIT: I just noticed that the suggestions were made by Lee Hart, so, semi-disregard the above.


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## etischer (Jun 16, 2008)

Im happy to get a replacement. A two year warranty is almost unheard of these days, I'm not gonna bust their chops.

I will probably try to ruggedize the replacement supply I get. The large inductors inside are just waiting to break loose from the board, so I'll try to find a way to mechanically anchor them. I also like the idea of having a soft start, I hate always having to precharge the supply before closing my fuse holder, it has a huge inrush. 





Woodsmith said:


> That is good.
> 
> Are they going to replace it every time it fails for the reasons listed in your link or are they going to harden it?


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## Dave Koller (Nov 15, 2008)

etischer said:


> I will probably try to ruggedize the replacement supply I get. The large inductors inside are just waiting to break loose from the board, so I'll try to find a way to mechanically anchor them. I also like the idea of having a soft start, I hate always having to precharge the supply before closing my fuse holder, it has a huge inrush.


I have had to do the same thing - and have warned people about the others.. I'm sure you know that the DC side needs a relay also. If left hooked up, with input off - it slowly bleeds your battery ... 

I left the bridge in and put in the CL-30's (as in # 4) and can use mine on AC or DC.. as you say the first thing you notice is the inductors - waiting to do as the fuse! I am going to tear mine down again to look at what you have pointed out on the fuse . Thanks! 

They were never really intended for EV use - but even with common sense mods - the price is right!

I have an extra fan I think I will blow across it with..

Thanks again for finding that one ..

EDIT: has anyone tried the cl-30's as a pre-charge for Curtis?


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## Dave Koller (Nov 15, 2008)

39 42
I took my Iota apart to check the fuse and shot the way I put in CL-30's ..

My fuse looks fine BUT will put something in there to hold it.. Probably replace the Caps -- The 45 amp is set up different-- but there is a good heat sink on the bridge - work needed on inductors - heat sink IS riveted on the reg but seems OK (not so smart but OK) ..


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## etischer (Jun 16, 2008)

I got my warranty replacement, and looks like the fuse is still an issue, you can see the fuse is just a few mils away from the capacitor. I made sure to bend it out of the way. 










Some other goofyness, looks like these two resistors are not needed. 












Dave, how are the CL-30's working out? How much inrush do you see? I'd like to eventually work that mod in. Would be nice not having that huge pop when I plug in the 330vdc!


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## Dave Koller (Nov 15, 2008)

Seems to show slow inrush - not very good testing on my part - watching amps - seems to take the PUNCH out of cold start - you could do it external to the supply - as you see I just trimmed back the cord and reset the strain-relief to give me more wire inside.. tinned Black and White and series fed each CL-30 --- The terminal fits in there perfect...

I purposely loaded the output and switched it on and off on AC - not a whole lot of delay - thought most of it was in the the headlamps I used on one test.. I was looking at the current rush with and without CL-30's... had it set for a bit and hit it under output load.. (better with )

A lot of audiophiles seem to use them on amps for the same reason of slower capacitor inrush charge.. That was why I thought (but have not tried) they may be useful as a fast pre-charge on controllers.. I am in the middle of some other projects and have put things back rather fast.. 

The "resistor kludge" on yours is strange -- see you have a "pop rivet" heatsink - check it !

Yours seems to have higher voltage caps - and I was looking to replace mine BUT -- time again... I wont reach 200 volts so with inrush calmed and not being connected during charge - I will take a chance.. 
Let me know if you experiment as pre-charge - Might be good..

They (CL-30's), are cheap protection...


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## Dave Koller (Nov 15, 2008)

Quick note - I had forgotten just how much voltage you are running - I am lower .. So check that out - I think have been tested at 240 AC --but maybe not at your 330 dc


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