dc-dc converter - Page 2 - DIY Electric Car Forums
Go Back  

DIY Electric Car Forums > EV Conversions and Builds > Technical Discussion

Register Blogs FAQ Members List Social Groups Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
  #11  
Old 04-27-2010, 04:39 PM
frodus's Avatar
frodus frodus is offline
Senior Member
 
Join Date: Apr 2008
Location: Portland, OR
Posts: 3,638
frodus will become famous soon enoughfrodus will become famous soon enough
Default Re: dc-dc converter

Quote:
Originally Posted by jimbo12d View Post
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?
__________________
Travis Gintz
Electro Motive Force, LLC.
Reply With Quote
Sponsored Links
Advertisement
 
  #12  
Old 04-27-2010, 10:06 PM
TomA TomA is offline
Senior Member
 
Join Date: Mar 2009
Posts: 270
TomA is on a distinguished road
Default Re: dc-dc converter

Quote:
Originally Posted by jehan12413 View Post
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...
Reply With Quote
  #13  
Old 04-27-2010, 10:19 PM
Dave Koller's Avatar
Dave Koller Dave Koller is offline
Senior Member
 
Join Date: Nov 2008
Location: Northwoods of Wisconsin
Posts: 733
Dave Koller is on a distinguished road
Default Re: dc-dc converter

Quote:
Originally Posted by dtbaker View Post
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.......

__________________
Dave

Use URL below to see some of my build..
http://www.diyelectriccar.com/forums...urn-30356.html
Reply With Quote
  #14  
Old 04-28-2010, 06:21 AM
JRP3's Avatar
JRP3 JRP3 is offline
Senior Member
 
Join Date: Mar 2008
Location: Central New York
Posts: 7,897
JRP3 will become famous soon enoughJRP3 will become famous soon enough
Default Re: dc-dc converter

Let them know the packing is inadequate. I told Sharon the same thing, maybe they'll get the message if they get enough complaints.
Reply With Quote
  #15  
Old 04-28-2010, 06:24 AM
JimDanielson JimDanielson is offline
Senior Member
 
Join Date: Oct 2008
Location: California
Posts: 139
JimDanielson is on a distinguished road
Default Re: dc-dc converter

Quote:
Originally Posted by TomA View Post
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.
Reply With Quote
  #16  
Old 04-28-2010, 10:43 AM
jehan12413 jehan12413 is offline
Senior Member
 
Join Date: Feb 2010
Posts: 130
jehan12413 is on a distinguished road
Default Re: dc-dc converter

So if I'm only using one vicor what do I do with the two gate connections?
Reply With Quote
  #17  
Old 04-28-2010, 10:50 AM
frodus's Avatar
frodus frodus is offline
Senior Member
 
Join Date: Apr 2008
Location: Portland, OR
Posts: 3,638
frodus will become famous soon enoughfrodus will become famous soon enough
Default Re: dc-dc converter

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.
__________________
Travis Gintz
Electro Motive Force, LLC.
Reply With Quote
  #18  
Old 05-03-2010, 06:25 PM
Woodsmith's Avatar
Woodsmith Woodsmith is offline
Admin: 'one of many'
 
Join Date: Jun 2008
Location: Manchester UK
Posts: 4,677
Woodsmith will become famous soon enough
Default Re: dc-dc converter

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.
Reply With Quote
  #19  
Old 05-03-2010, 08:01 PM
JRP3's Avatar
JRP3 JRP3 is offline
Senior Member
 
Join Date: Mar 2008
Location: Central New York
Posts: 7,897
JRP3 will become famous soon enoughJRP3 will become famous soon enough
Default Re: dc-dc converter

How about just running a small 12 volt battery, charged separately when you charge your pack?
Reply With Quote
  #20  
Old 05-03-2010, 08:34 PM
dtbaker's Avatar
dtbaker dtbaker is offline
Senior Member
 
Join Date: Jan 2008
Location: santa fe, nm
Posts: 4,002
dtbaker is on a distinguished road
Default Re: dc-dc converter

there are lots of choices for 48->12v... most of the ev wholesalers also cover the golf cart world...
__________________
Dan
http://www.envirokarma.org/ev - '97 Suzuki Swift
http://www.envirokarma.org/ev2_mx5e - '94 Mazda MX5 Miata
Reply With Quote
Reply

Share or Bookmark this

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

 
Support DIY Electric Car
Sponsors

All times are GMT -6. The time now is 07:02 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.

Ad Management by RedTyger