Thread: Running 12v DC equipment on 120v AC (indoors)

Originally Posted by Outdoor Ed

A good (not dead) battery in parallel will help filter the power, but a proper DC power supply is always best if at all possible.

Absolutely! A suitable battery in parallel does a reasonable job of cleaning up the power.

Just remember to not smoke near it.

Originally Posted by Jtsou

What I did was make a plywood box, housing an old PC powersupply, with about 52amps on ONE(1) single 12V rail. I mounted the powersupply in the box and ran the AC cord out of the box. I took a SPST switch and connected one end to ground on the powersupply and the other end to the GREEN wire on the 20 pin motherboard connector(someone earlier mentioned jumping the purple wire to ground, that is a 5v wire and jumping that is not good...) This way, I can cut the powersupply on and off at my leisure. I took 3 cigar lighter sockets and mounted them in the box, wiring them to a 12v lead from the power supply. I also ran a 12v "hot" post and a ground post on top of the box with alligator clips so if i needed something besides a cigar socket, i had it. You can also use the 3.3v and 5v leads if you choose to.

I thought this was a rockin' idea -- and at least in my part of the country, these things are dirt cheap by the pallet-load. (And thanks for the GREEN wire tip -- saved me lookup the pin-out to fire it up!)

Here's the question: any experience / issues with the wires on many/most PC power supplies being on the small side relative to the potential load of a fully lit up bar? So far I've only connected it up to four LED bulbs in a hokey retrofit within an MX7000 bar, just trying not to burn down our leased space.

The goal we're aiming for is an array that can power up a stack of bars in a venue open to others... lovin' the PC supply idea versus the AC-to-DC inverter (keeps costs down)... just not looking to see sparks when visitors press the "light 'er up" buttons. Thanks!

Hi wfd67!
This link here might have been posted before but here it is again:
How to Convert a Computer ATX Power Supply to a Lab Power Supply: 13 steps (with pictures) - wikiHow

How to convert a Computer power supply.
If I understood your question correctly, you are referring to the wires delivering 12Volts from the power supply being too small too handle the juice of a big bar. In this link, the guy groups the yellow 12Volts wires together at the connection post. I tried it with 2 PC power supplies and it worked great. The wires are not hot to touch. The only thing is it seems that PC power supplies sometime don't handle the "cold crank" amperage pull of some bigger bars.

I had a JetSonic (4x 50 watts rotators) that, when lit up with bulbs being cold, stopped the PC power supply straight. When the bulbs were hot, though, I could keep going.
Some newer PC power supplies have tripping/overload protection so you don't fry it if you ask too much out of it.

Here's a mini Code 3 XL, with 4x 30 watts bulbs, running from a CORSAIR CX 430 modified power supply, using the method linked above. The 12 Volts rail can supply up to 28 amps.

Hope this helps!

That'll do the trick, I bet -- thanks!

Love the red/green bar BTW.

You're welcome!
Thanks for the compliment. My mini-XL has now changed color until next Chritmas
I hope your project turns out well!

i seen a vid on youtube or her with a man that had lights all over what look to be his basement,
and had them on a switch box,
that is what i need,
can anyone help me with this,

Is this what your talking about Infernoemeq.



and the other video is on my next post

and



I wonder how he got the power from the switches to the lightbars. That must call for a lot of wiring! Here's what he says he runs it on:

I power the system with 2 27 series deep cycle batteries, that have a 2 bank Minnkota battery charger that stays hooked up all the time, keeping the batteries topped off. I also use a battery switch to unload the system.

yes this is it, thanks,
now for the hard part, to see how i can do this,

Would a duracomm dps-55 be ok for running lower amperage lightbars like a liberty?

DuraComm DPS-55 Product Reviews

Originally Posted by ryan81986

Would a duracomm dps-55 be ok for running lower amperage lightbars like a liberty?

DuraComm DPS-55 Product Reviews

Amperage wise yes...

Originally Posted by JohnMarcson

Amperage wise yes...

Alright, I wasn't sure if there was a way to over-power it the same way you can with voltage.



Here is a better page for it:

DuraComm Corporation

Would it be easier and inexpensive to attach a portable battery jump starter to a switch box, such as FS SW400...which is then connected to a lightbar? I assume those jump starters provide a lot of amps, correct?

Originally Posted by Wheels

Would it be easier and inexpensive to attach a portable battery jump starter to a switch box, such as FS SW400...which is then connected to a lightbar? I assume those jump starters provide a lot of amps, correct?

That works fine, I use this system for testing bars. .... you get about 3 minutes of power on a full bar though. These are meant for cranking amps, not a long term power source.

I just bought a New 10 amp regulated P/S Goldsuorce $49.99 shipped. On/off lighted switch, banana plugs. fan cooled.
It worhs great for beacons.

I need to set up a Unity RV-26 at a local business to run off 110 down to 12 Volt. Anyone know of any inverters that are better than any others ?? Want it to be reasonably priced also.
digger

The one in the above post for $50 shipped seems to do a fine job, but it's new to me, so I have no long term experience.

This is what I use to bench-test and run display equipment in my collection (for short periods of time).



I've been doing this for several years with the same power pack and have had no problems. I originally bought this after a nasty tornado went thru my area and we were without power for several hours (it has a 110v inverter behind the flip-down). Eventually I bought a genset, but this still serves as backup power, jump starting, and of course lightbar testing/operation. This thing holds a charge well, I probably charge it up every three months.

Originally Posted by diggerdug.517

Anyone know of any inverters that are better than any others ??

An inverter takes DC as its input, and makes AC as its output.

A power supply takes AC as its input, and makes DC as its output.

For your application, you need a power supply, not an inverter.

Another advise is to get a power supply that has good amperage margin. The cold start of a beacon/lightbar could trip your power supply if the margin is too small. I.e: a 7-8 amps beacon might be too much to start on a 10 amps power supply.

I just bought one of these POWERMAX PM3-100 12 VOLT 100 AMP CONVERTER CHARGER WITH 3 STAGE AUTOMATIC SMART CHARGING, I am very pleased with it.

Originally Posted by 50theman

I just bought one of these POWERMAX PM3-100 12 VOLT 100 AMP CONVERTER CHARGER WITH 3 STAGE AUTOMATIC SMART CHARGING, I am very pleased with it.

Nice find -- I may have to look that direction; I have a Pyramid 52 amp ps, but even before the display is finished its becoming obvious its under-powered (and that's after we split the twinsonic off); hafta get a few pics up one of these days...