# AC to DC Power Converter



## kimck99 (Oct 20, 2009)

Hello,

My apology in advance as this is not flashlight electronics per se but I am need of assistance and I figured some of the fine folks here with much more knowlege than I could help.

I am looking for a AC to DC power converter to run a tire inflator at home without having to plug it into my car. The portable compressor has a max amp draw of 11 amps (as confirmed by manufacturer) and I figured I could find a AC to DC converter. Well, after seaching the Net for a while, the ones I did find were for smaller electronics and rated for 5 amps or less.

Are there solution to the problem I am trying to solve that is not expensive or requires DIY effort? I can done some electrical work but I required specific instructions so would prefer not to build anything.

Your help is greatly appreciated.
Thanks!

P.S. - Moderator, my apology if this post belongs somewhere else. Please move as you see it.


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## Wok (Oct 20, 2009)

I use this to charge batteries & my 12V air compressor [for tyres].

http://www.manson.com.hk/productdetail.php?ProductID=17

eng hoe


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## kimck99 (Oct 20, 2009)

Hi Wok,

This product will certainly do it. However, I was looking for something considerably less. The portable compressor is only $55 USD so I was looking for a more cost effective solution. (I should have mentioned that in my initial post.)

If the available option is more than $50 USD, I may need to just buy a standard AC compressor.

Thanks for your suggestion.


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## Mr Happy (Oct 20, 2009)

If you're on a budget you might be able to cannibalize a discarded computer power supply. See this article for details:

http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply


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## kimck99 (Oct 20, 2009)

Mr Happy said:


> If you're on a budget you might be able to cannibalize a discarded computer power supply. See this article for details:
> 
> http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply


 
Hi Mr. Happy,

That was a very good tutorial. If all else fails, I may have to give this a go just to do it! So, it appears that one additional item I will need is a cigrarette charger adapter.

Thanks


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## qwertyydude (Oct 20, 2009)

At 11 amps you'll have one pretty big startup kick. I'd take a look at the fuse rating of the compressor and the current rating of the 12v rail on the power supply. Make sure it can supply enough to handle the fuse rating on the compressor.


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## BVH (Oct 20, 2009)

The Pyramid 12 Amp continuous/14 peak power supplies are about $55 to $65 IIRC. I would guess that the 11 Amp you quote might be starting amps?


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## Lynx_Arc (Oct 20, 2009)

11 amps is probablly the total current needed or close to it as cigarette lighter sockets usually have a 15 or 20 amp fuse and manufacturers would not sell too many if they were blowing fuses they would be returned the same day. If you are not using it all the time during the day and have a battery charger it may be just as easy to get a car battery and use it and recharge it after use.


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## KiwiMark (Oct 20, 2009)

Mr Happy said:


> If you're on a budget you might be able to cannibalize a discarded computer power supply. See this article for details:
> 
> http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply



I read that as my starting point and then decided to go with a solution that didn't involve any modding or even opening of the power supply.

I used this info:
http://www.wikihow.com/Use-an-Old-ATX-Power-Supply-As-a-Lab-Power-Supply-Without-Modification
and this:
http://www.magicratproductions.com/magicforum/viewtopic.php?f=5&t=131

It really wasn't hard to create a box with a m/board connector to plug the PSU into and extract 12V DC from. I currently have a power supply rated at 30A for the 12V output - more than enough to run a couple of hobby chargers. It is not hard to find an old ATX PSU rated at 20A for 12V.

You could buy a cheap plastic box of some sort and use a M/Board socket, switch & cigarette lighter socket - plug in an ATX PSU and viola!


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## Vinniec5 (Oct 20, 2009)

A few ideas come to mind but first i was wondering why you don't want to use the Lighter/power outlet plug in your car? If you don't want to damage the outlet or it draws too much I would get a lighter socket adapter with battery post clips and just connect it to the battery directly
Second you could use a (manual) Auto battery charger as a power supply as long as it has atleast a 10amp output
Third get a 110 volt inflator/compressor at Sears/Kmart $40-$50 and have both (the AC powered inflator is a heckuva lot faster


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## TranceAddict (Oct 20, 2009)

strongly recommend www.xantrex.com

well build quality and very long lasting, it is still working after 10 years in my truck.


beware some charger (SMPS) might be damaged due to modified sine wave. but whatever has a transformer should be fine.


do not use on:
certain type of cheap SMPS power supply
anything has triac to control duty cycle (power tools with variable speed controller)


you will fry them instantly and see the smoke come out.


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## kimck99 (Oct 20, 2009)

Vinniec5 said:


> A few ideas come to mind but first i was wondering why you don't want to use the Lighter/power outlet plug in your car? If you don't want to damage the outlet or it draws too much I would get a lighter socket adapter with battery post clips and just connect it to the battery directly
> Second you could use a (manual) Auto battery charger as a power supply as long as it has atleast a 10amp output
> Third get a 110 volt inflator/compressor at Sears/Kmart $40-$50 and have both (the AC powered inflator is a heckuva lot faster


 
I have three kids and it seems that I need to inflate their bikes and their friends all the time. I wanted something small that I could mount to the wall. Thought about getting a small pancake compressor but I like idea of having a portable compressor to take on trips as well. Here is what I was looking at - Slime Comp 06.



TranceAddict said:


> strongly recommend www.xantrex.com
> 
> well build quality and very long lasting, it is still working after 10 years in my truck.
> 
> ...


 
Well, I had a Xantrex PowerSource 400 previously but the compressor died. Also, if to inflat a tire, it takes a long time. The idea was to pick up a portable air compressor/inflator and mount it to wall with a coil hose.


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## kimck99 (Oct 20, 2009)

BVH said:


> The Pyramid 12 Amp continuous/14 peak power supplies are about $55 to $65 IIRC. I would guess that the 11 Amp you quote might be starting amps?


 
Hi,

You are probably right about the 11 amps being the starting amp. I called the manufacturer to understand the AMP requirement and they said that it was 11 amp max.

Thanks


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## Vinniec5 (Oct 20, 2009)

Thats a nice comp, If you don't mind it being 12volts get the 12v lighter adapter at the bottom too and your all set. But to use it at home with out using the car you're going to need a battery charger or 12v power supply to run it from the wall. Radio Shacks 15 amp power supply is $85, A 110v compressor is $50-$60 its up to you.


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## kimck99 (Oct 20, 2009)

Vinniec5 said:


> Thats a nice comp, If you don't mind it being 12volts get the 12v lighter adapter at the bottom too and your all set. But to use it at home with out using the car you're going to need a battery charger or 12v power supply to run it from the wall. Radio Shacks 15 amp power supply is $85, A 110v compressor is $50-$60 its up to you.


 
Given the cost of a 12V power supply with appropriate amp, short of building my own 12V PS per the instructions posted above (which I do have spare PC parts ) it would seem that I am better off with two compressors - a 110V comp for the home and 12V for the car...

Thanks


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## Bones (Oct 20, 2009)

kimck99 said:


> Given the cost of a 12V power supply with appropriate amp, short of building my own 12V PS per the instructions posted above (which I do have spare PC parts ) it would seem that I am better off with two compressors - a 110V comp for the home and 12V for the car...
> 
> Thanks



The cost of the compressor for your vehicle would offset a significant portion of a VPX emergency kit.

It could include a 110V inverter, a 5V USB mobile booster, a 3 LED emergency light and an inflater:

http://www.amazon.com/VPX3101-Li-Ion-Inverter/

http://www.amazon.com/VPX1401-VPX-Flashlight/

http://www.amazon.com/VPX1501-Li-Ion-Inflator/

http://www.amazon.com/VPX0511X-Battery-Charger/

The VPX battery pack contains two A123Systems 18650 cells.


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## Mr Happy (Oct 20, 2009)

When I was a kid we used one of these:





Provides exercise and teaches self-reliance when the kids are old enough to use it


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## kimck99 (Oct 20, 2009)

Bones said:


> The cost of the compressor for your vehicle would offset a significant portion of a VPX emergency kit.
> 
> It could include a 110V inverter, a 5V USB mobile booster, a 3 LED emergency light and an inflater:
> 
> ...


 
Interesting product line. But the reviews indicated that the VPX line has been discontinued. So, not sure I want to have equipment with no replacement options when parts run out - battery. Also, inflating car tires seems a bit week.

Thanks for the suggestion.


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## J_C (Oct 20, 2009)

Keep in mind that if it has a max draw of 11A, that would be at the max battery voltage which is 13.nV not 12V which with the typical DC motors those use, means you won't need more than a 10A/12V supply and it would probably run with even less if it folds back instead of shutting off at undervoltage conditions. http://www.mpja.com/prodinfo.asp?number=16020+PS http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=66783 (or there are many automotive SLA battery chargers out there for under $50 capable of 10A or more, buying locally would save shipping cost).


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## Bones (Oct 20, 2009)

kimck99 said:


> Interesting product line. But the reviews indicated that the VPX line has been discontinued. So, not sure I want to have equipment with no replacement options when parts run out - battery. Also, inflating car tires seems a bit week.
> 
> Thanks for the suggestion.



I hadn't realized the VPX line was discontinued, so thanks for the heads-up.

Fortunately, the battery casing is literally a snap to disassemble and reassemble, so when the cells eventually fail, I'll simply have them rebuilt with the latest offering from A123Systems:







Bearing this in mind, I'm also going to assemble another kit for ease of access while the clearance sale pricing is in effect.

Meanwhile, I'm working at modifying the disassembled pack so I can strip the individual cells out for use in other devices and still utilize the pack to re-charge them in the VPX charger.


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## smopoim86 (Oct 21, 2009)

Bones said:


> Meanwhile, I'm working at modifying the disassembled pack so I can strip the individual cells out for use in other devices and still utilize the pack to re-charge them in the VPX charger.



I've done this for 3 different vpx packs. If you want one of the adapted packs, I'll send it to you for the cost of shipping. I charge by hobby charger now.

On topic: I would say, get a hand pump for bike tires, or just get a cheap 110 compressor. If you're dead set on getting a 12 power supply, i got this for powering my hobby chargers. It's 13.5v but that's closer to a car output that the 11.75v you'll get from the computer psu under load. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=160362053347


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## kimck99 (Oct 21, 2009)

Thanks everyone for your input. The battery charger/starter seems like a possible solution with little modification attached a "cigarette" adapter and I may go that route. But a simplier solutions to be to have a separate compressor for the car and for the house.

You inputs have been appreciated! Good night all.


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## qwertyydude (Oct 21, 2009)

Well you could get a small 5 or 10 gallon air tank 35 bucks at Lowes. These often can be filled using the tire inflator and then you can have the benefits of an air tank and take the compressor with you in your car and still have a supply of air at home.


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## J_C (Oct 21, 2009)

I suppose it depends on what you need to inflate and your storage space. A shop type air compressor with tank is certainly the most versatile for home use, though bulkier and costlier for something of fair quality. If you have tubeless tires on wheelbarrow/mower/tractor/etc, or are likely to replace tires yourself on a trailer, motorcycle or automobile, it can be hard to re-seat the bead on a rim with a low volume compressor like the one you have that plugs into the lighter outlet, either a much higher capacity racing/etc automotive pump "might" work (with smaller tires, probably not very good for anything over ~17" or so, tire dia. not rim size, or a shop compressor with tank is best. The one thing I probably wouldn't bother buying is an AC pump of low capacity (typically what you'd get for $50 or less), since it would add no new versatility beyond running off an outlet, but on the other hand it is smallest and cheapest, and quite suitable for lesser tasks like inflating toys and tubed bicycle or motorcycle tires... but on the other hand, most versatile is owning every tool possible... the one with the most toys WINS!


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## Bones (Oct 21, 2009)

smopoim86 said:


> I've done this for 3 different vpx packs. If you want one of the adapted packs, I'll send it to you for the cost of shipping. I charge by hobby charger now.
> ...



Thanks for the most generous offer smopoim86. But as long as I don't inadvertently break anything, I should be okay with the pack casing I have on hand.

I did bookmark you post though, just in case...


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## James2augestin (Nov 3, 2018)

J_C said:


> I suppose it depends on what you need to inflate and your storage space. A shop type air compressor with tank is certainly the most versatile for home use, though bulkier and costlier for something of fair quality. If you have tubeless tires on wheelbarrow/mower/tractor/etc, or are likely to replace tires yourself on a trailer, motorcycle or automobile, it can be hard to re-seat the bead on a rim with a low volume compressor like the one you have that plugs into the lighter outlet, either a much higher capacity racing/etc automotive air pump "might" work (with smaller tires, probably not very good for anything over ~17" or so, tire dia. not rim size, or a shop compressor with tank is best. The one thing I probably wouldn't bother buying is an AC pump of low capacity (typically what you'd get for $50 or less), since it would add no new versatility beyond running off an outlet, but on the other hand it is smallest and cheapest, and quite suitable for lesser tasks like inflating toys and tubed bicycle or motorcycle tires... but on the other hand, most versatile is owning every tool possible... the one with the most toys WINS!




_The Pyramid 12 Amp continuous/14 peak power supplies are about $55 to $65 IIRC. I would guess that the 11 Amp you quote might be starting amps?



_


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## Gauss163 (Nov 3, 2018)

James2augestin said:


> _The Pyramid 12 Amp continuous/14 peak power supplies are about $55 to $65 IIRC. I would guess that the 11 Amp you quote might be starting amps? _



As I mentioned here the Dell DA1 12V 150W PSU is usually availabel on eBay for < $10, and for a few dollars more you can get a 47A 575W HP DPS-600. Both are high quality power supplies . Such reuse of computer SMPS is heavily discussed on RC hobby forums (e.g. rcgroups.com)


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