best method to get AC to power 12 V DC

[BC Dave]

ok so I've wired lots of 12V DC lights that Id like to use when I have AC power; whats the simpliest way to achive this without being connected to / use up a 12 V battery? ie I could hook up a 12 V charger; but what amper would be best? I have a small 1A charger that I could leave hooked up to the battery but thats waring on the battery or maybe direct connect a 2-10-60 amp charger or I could get an RV 110 AC to 12V DC inverter any good recomendations?

Cheers BC D

[bobhenry]

I installed 12 volt lights in the barn and wanted to ac power them just like the bigger 22-26 pull behind campers do. So I found a small 120 ac to 12 volt power supply.

http://www.12volt-travel.com/12-amp-12-volt-power-supply-p-4801.html?zenid=51a1a6659e3f27cc25352a0d3bc4ecb7

No not that one ! Mine is smaller but I took what they had at the yard sale for $5.00

I tried using a battery charger and found it ok for lighting and some 12 volt appliances but 12 volt higher end electronics like radios and tv's don't like the (dirty) 12 volt they create and they can wind up with hum's and static. The power supplies are better filtered.

I had feelers out with my junking buddies and located a power converter out of one of the larger trailers it is ac powered and will supply 12 volt direct and at the same time float charge an on-board battery. They found me a nice one and I intend to use it in the caboose build so lighting can be 12 volt DC LED's .

I would start looking and asking about damaged campers at the local scrap yard you should be able to pick up a nice one for 1/3 of retail maybe less.

[jss06]

I run a Progresive Dynamics AC to Dc power converter w/ built in multi stage battery charger. It produces enough DC current to run all my DC in the trailer plus charge the battery. It will automatically change to maintenace mode once the battery is fully charged to keep from damaging it.

This is the one I have:
http://www.progressivedyn.com/prod_details/rv_conv/rv_converter_pd9245c_2.html

[GuitarPhotog]

I use a WFCO 8725 Converter, which like the Progressive Dynamics unit mentioned in the previous post, provides 12VDC power adequate to power everything in the trailer, but will properly charge and maintain a deep-cycle battery as well.

The WFCO 8725 is ~$100. I believe the Progressive Dynamics unit is in the same price range.

Search this forum for PD or WFCO to see the discussions comparing the units.

<Chas>

[aggie79]

If you're not needing to charge a battery, I'd use an old computer power supply.

[StPatron]

If you're not needing to charge a battery, I'd use an old computer power supply.

+1!

[BC Dave]

ah good ideas!

Im looking for a low power but safe option; the $100 options are in the high end of the ball park I suppose; but if they could double as charges too all the better;

now the computer power idea is really intresting

or maybe just a plain plug in converter that I used to have for that skilectric car set! Humm;

Id like to power 2 of 4 10 W halogen bulbs that draw probably 1.5 amps tops ... maybe the cooler in warm weather would be the energy hog at 5? amps;

OR mybe I could reverse feed a cigerett lighter converter ... or just connect those 120 v converters I removed form the halogen lights; I think the big consideration might be the abount of amps that is needed ... right? Just thinking this one out loud here ... thanks!

[Breezy13]

If your going down to 12v, I'd use LED lights, you can get a lot of different ones for really cheap prices on ebay. If you don't have shore power, your battery will last a lot longer. Just my two cents.

Breezy

[bobhenry]

Another reason for 12 volt led lighting is someday when your ship comes in you can add a solar panel !

[Keith]

Here's a Youtube video on how to convert a computer power supply to use for charging remote control car batteries. It would also work to power your twelve volt lights ect. I converted one for charging my rc batteries. It only took about half an hour and it works great and it cost nothing. I had several old computers sitting around.

http://www.youtube.com/watch?v=ityrHaBLepg&context=C340eacbADOEgsToPDskKZYvRIxXnHktsg0AQfT7w8

Keith

[jss06]

Just the lights and the cooler you are talking about is almost 10 Amps DC.

LEDs will drop that down to less than 7 amps depending on which ones you get.

[BC Dave]

Here's a Youtube video on how to convert a computer power supply to use for charging remote control car batteries. It would also work to power your twelve volt lights ect. I converted one for charging my rc batteries. It only took about half an hour and it works great and it cost nothing. I had several old computers sitting around.

http://www.youtube.com/watch?v=ityrHaBLepg&context=C340eacbADOEgsToPDskKZYvRIxXnHktsg0AQfT7w8

Keith

Just the lights and the cooler you are talking about is almost 10 Amps DC.

LEDs will drop that down to less than 7 amps depending on which ones you get.

ok both are good suggestions; heres another question (no question is stupid right?:) its late ...

...so.... assuming i connect a 110V computer converter and get 12V AC output of 10 amps (im assuming AC; which it doesnt really matter if its AC or DC right?); the 10W halogens lights were Ikea's that had an inverter that says 10 v AC 0.8 amps (i'll have to recheck), im asssuming I wouldnt pop the haolgens (or some other amperage that would melt some wire insulation) as Iv already been connected to a 12V 120AH DC battery that they work well on ... should I have any concerns? so theoreticly I could have all 4 haolgens on at 0.8 amps and the cooler at 5 amps total 8.2 some odd amps 1.8 buffer amps left over to trickle charge the 12V dc battery ... and hey! to be fancy .... through my little solar panel charge controller and never worry aout overcharging the 12V DC deep cycle ... thanks for the creative suggestions!

[jss06]

...so.... assuming i connect a 110V computer converter and get 12V AC output of 10 amps (im assuming AC; which it doesnt really matter if its AC or DC right?);

It does matter if it is AC or DC. But a computer power supply should provide DC power which is what you want. You never want to hook 12V AC to a car battery.

AC power occilates between + and - voltage in a sine wave. Try putting negative 12 volts into a computer chip and see what happens to it. I did on accident in college. It lets the genie out and the chip does not work anymore. that little mistake cost me $25 for a new chip.

DC power is a constant voltage.

[bdosborn]

should I have any concerns?!

Just one, you can't charge a battery with a computer power supply so keep that in mind if you ever plan to install a battery in your trailer.

Bruce

[StPatron]

When utilizing electrical hook-up sites, I'm running all my 12 volt from a computer power supply. Works great. When off-grid, I use a rechargeable jump-starter power pack. Works great also. My power needs are minimal.... vent fan, occasional interior lighting, Ipod recharge, etc. Outside at night, I prefer the light of a Coleman lantern or campfire.

I don't forecast my power needs changing. However, should I later decide to add a permanent deep cycle battery it would take but a few minutes to switch over from one system to another.

One should assess their own 12 volt power needs and plan accordingly. What works for someone else will not be the best plan for another. It can be done in stages depending on budget, changing needs, etc.