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View Full Version : OT: AC / DC question.



0100
02-17-2004, 11:40 PM
Ok I know you can buy an inverter to run ac items off of DC.

But is it possible to run dc item off of ac?

Do they sell something to accomplish this?

Thanks

SilverHorseRacing
02-18-2004, 12:34 AM
Transformers, with a rectifier bridge. The answer is yes, they sell them. Most of your electronics have one built into the transformer (the black box) that plugs into your wall. You can also use a battery charger to simulate a large DC source, although this is not a "recommended" practice. They also sell DC power sources for electronics work, with adjustable outputs.

HTH.

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-Marcello Canitano
www.SilverHorseRacing.com (http://www.SilverHorseRacing.com)

IPRESS
02-18-2004, 01:15 AM
Dang I thought this was about something else. http://Forums.ImprovedTouring.com/it/biggrin.gif Carry on.

Bill Miller
02-18-2004, 07:44 AM
Originally posted by IPRESS:
Dang I thought this was about something else. http://Forums.ImprovedTouring.com/it/biggrin.gif Carry on.

So, you thought this was a music thread, eh? http://Forums.ImprovedTouring.com/it/biggrin.gif

Years ago, we used a small trickle charger as a DC power supply for some lab instruments we were running.



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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608

jhooten
02-18-2004, 08:35 AM
If you have a Fry's near you they sell 12VDC regulated power supplies from 1 to about 30 amps. If not a Fry's try your radio shop.

planet6racing
02-18-2004, 09:51 AM
If you have a spare desktop computer lying around, you have a 12V and 5V DC power supply. Just search the web for the pin-outs, but I'm pretty certain you can pull this from the hard drive power cables.

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Bill
Planet 6 Racing
bill (at) planet6racing (dot) com

0100
02-18-2004, 04:11 PM
What I want to do is run a DC winch for both my garage and trailer.

The DC winchs are cheaper and seem to be rated for more hp. Am I looking at these specs right or is the AC more powerful. The warn DC is like 100 cheaper.

DC http://www.warn.com/works/dcwinches/DC3700.shtml

AC http://www.warn.com/works/acwinches/AC3200.shtml

The DC

PERFORMANCE SPECS
Line Pull
Lbs.(Kgs.) Line Speed
FT./min(M/min.) Motor
Current Pull by layer
layer/Lbs(Kgs.)
0(0) 20.4(6.2) 30 amps 1/3700(1680)
500(226.8) 15.8(4.8) 76 amps 2/3410(1550)
1000(453.6) 14.2(4.3) 111 amps 3/3170(1440)
2000(907.2) 10.9(3.3) 180 amps 4/2950(1340)
3000(1360.8) 7.7(2.4) 249 amps 5/2700(1260)
3700(1680) 5.4(1.7) 297 amps


What amp transformer would I need to get for this?

planet6racing Bill, can you explain this a little more I am slow at this kind of stuff.

http://members.aol.com/TKirk3rd/logo.gif

[This message has been edited by 0100 (edited February 18, 2004).]

planet6racing
02-18-2004, 04:24 PM
Well, it doesn't matter. It wouldn't have the amps to power a winch.

The cheapest route: Buy another battery and keep it where you might use the winch.

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Bill
Planet 6 Racing
bill (at) planet6racing (dot) com

Greg Gauper
02-18-2004, 05:30 PM
For that type of application, you would need something extremely heavy duty like for boosting dead batterys, or an arc welder.

I agree with Bill. Your best is buy the smallest, cheapest battery you can find and use #4 wire as a minimum. Use a trickle charger when not in use.

If you were to build one yourself, you would need a transformer with a minimum VA of 5KVA

(Actual VA = 14V * 300A = 4200, 5000 is the closest commercial size).

You can use either 120VAC or 240VAC primary. 120VAC primary would require approximately 35Amps while a 240VAC primary would require about 17Amps.

Your looking at a couple of hundred $$ to make up something like this. Batteries are much cheaper!

Bill Miller
02-18-2004, 08:18 PM
A friend of mine rigged up a 2500# winch so that we could use it on a variety of different trailers, etc. We just use a good, deep-cycle marine battery. It goes on a battery minder when not in use.

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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608

dickita15
02-19-2004, 08:50 AM
as long as we are all getting a charge out of this thread, let me ask for opinions. we often have batteries that are infrequent use.
do battery minders make a difference vs trickle chargers in battery life. is the technology on all minders the same.
dick

x-ring
02-19-2004, 10:26 AM
I run my trailer winch, 3000 lb, with a car battery jumper pack from Harbor Freight. It used to run off the trailer battery, but when I left the lights on overnight once and killed the battery I tried the jumper pack, not expecting much I might add. Well, it works great. Loading the car doesn't even move the charge state meter much.

The trailer battery has since died, but I haven't found any need to replace it.

Ty

JohnRW
02-19-2004, 11:41 AM
Originally posted by dickita15:

do battery minders make a difference vs trickle chargers in battery life. is the technology on all minders the same.
dick

Yes. They make a HUGE difference. Don't know the internal battery chemical details (batteries are a chemical device, after all...) or the differences between 'tender' devices, but things like "Battery-Tender" work great.