[frodus]

Originally Posted by jimbo12d

I bought this vicor and am very unhappy. I ended up needing two so that the vacuum, lights, contactor, and potentially blower or windshield wipers could all be powered.

Since it only gives out 12 volts it does a fail job of charging the accessory battery. I need the accessory battery to turn on the contactor. I often use an extra charger to charge the accessory battery just because I don't trust the vicors will give me the required power.

I recommend against buying this, buy something that outputs 13.8 volts.

Jim

its only ~250W, of course you'd need two for a car.... at 12V, thats 20A, I'd use at least that on my motorcycle. I think a MINIMUM for a car/truck is 3-400W.

Did you trim it up with resistors to get 13.2V?

[TomA]

Originally Posted by jehan12413

I just found some dc-dc converters on ebay, I'm looking at a Vicor V1-251-09 200v to 12v model and am wondering if anyone is familiar with this one. I sent a request to the seller for the datasheet but while I'm waiting I figured I would post it here .

I have these exact Vicor DC-DC units, and I got them on ebay from Troy Gaud at Azure Dynamics. He does not have a data sheet for them; he will send you the generic VI 200-Series Vicor data sheet, which does not in fact have this part number listed anywhere on it.

The -09 suffix signifies that these converters were a from a custom run by Vicor for Solectria/Azure made around 2007. They vary a little in spec from a standard VI-251-xx converter, as they are listed at 200V nominal input voltage, and the part# call-out would normally be 150V. Vicor will not discuss the specs of these units with anyone not from Azure, (ask me how I know...) but Troy told me that according to the Azure engineers, they are good down to about 130V, and up to a little over 250V input. They are also in fact "IU" suffix-class, which means -40 to 85 degrees C operating range, and 200W max output. I also have the -09 series matching Booster units, which allow you to run several booster bricks off of one 200 Series control unit. I haven't installed them yet, but I'll be using 4 or 5 boosters and a control unit, for either 75 or 90 amps of max current at 13.2V. Just what a late-model car needs.

These DC-DC converters can be trimmed up to 13.2V output by installing a trim resistor. If you only have 200-Series units, and no boosters, you can match them in trim and still use them together, as Jack Rickard has documented. His implementation, complete with a schematic and some thoughtful instruction, is here:

http://jackrickard.blogspot.com/2009...ni-cooper.html

Don't use Jack's resistor values on the VI-251-09! The correct one is 422K, from Section 5 of the Vicor Manual. You could also put in a pot and trim the output manually. In any case, it is instructive to just RTFM:

http://cdn.vicorpower.com/documents/...ual_200J00.pdf

I actually think this unit and the matching booster are superb quality equipment, particularly for the price, and the ones I got from Troy were brand new. They are in fact the very units you will find if you open up the Azure Dynamics DC-DC converter, and at $50 versus the hundreds they cost new, you really can't go very wrong. My understanding is Azure has "hundreds" of them to sell...

TomA

Not a shill for Vicor or Azure Dynamics, though both have been nice to me on the telephone...

[Dave Koller]

Originally Posted by dtbaker

chennics arrived today.... box was pretty beat up, and fuse holder/fuse was broken on both units. looks like the box was really tossed around, but the units and heat sinks look ok. I won't be able to install the first one for another couple weeks as my new batteries have not arrived...

So Dan, do you think they test them with a baseball bat before shipping . That is three for three shipped lol ...
Let me know before I get mine "field tested" with a bat.......

[JRP3]

Let them know the packing is inadequate. I told Sharon the same thing, maybe they'll get the message if they get enough complaints.

[JimDanielson]

Originally Posted by TomA

These DC-DC converters can be trimmed up to 13.2V output by installing a trim resistor. If you only have 200-Series units, and no boosters, you can match them in trim and still use them together, as Jack Rickard has documented. His implementation, complete with a schematic and some thoughtful instruction, is here:

http://jackrickard.blogspot.com/2009...ni-cooper.html

Don't use Jack's resistor values on the VI-251-09! The correct one is 422K, from Section 5 of the Vicor Manual. You could also put in a pot and trim the output manually. In any case, it is instructive to just RTFM:

http://cdn.vicorpower.com/documents/...ual_200J00.pdf

Wow, thanks! I never knew that. I will be trying this first thing when I get home from school for the summer.

[jehan12413]

So if I'm only using one vicor what do I do with the two gate connections?

[frodus]

read the application manual....

http://cdn.vicorpower.com/documents/...ual_200J00.pdf

Gate IN is for disabling/enabling the DC-DC. Gate out is for driving Booster modules.

[Woodsmith]

Can I pose some questions here also?

I am going to get converters for both my compact tractor and my MR2.

For the MR2 I will wait until I know what voltage I am going to run at and then get an isolated 500W+ 13.8V converter. I figure that is the sort of thing I will need to run a car.

But for the tractor. I only have 48V. Can I use a golf buggy type non isolated 120W 12V converter?
I dont know if the 12V vs 13.8V and isolated vs non isolated will be an issue.
I am planning on running some lights and the reversing contactors.

Guidance will be much appreciated.
Thank you.

[JRP3]

How about just running a small 12 volt battery, charged separately when you charge your pack?

[dtbaker]

there are lots of choices for 48->12v... most of the ev wholesalers also cover the golf cart world...