Convert computer monitor to 12 volt

Anything electric, AC or DC

Convert computer monitor to 12 volt

Postby daveesl77 » Tue Dec 26, 2017 9:19 am

I'm one that likes to play around with stuff, no matter how much it terrifies my wife. I have a bunch of pretty nice, but unused computer monitors laying around and I had seen the vids on converting them to run off straight 12 volt (no inverters). It didn't look difficult and could be pretty neat, so I did it.

I had an LG 23". First you take off all the plastic stuff. On this model of LG they made it easy as there were no screws at all. Everything was just snapped together. Once opened, the actual circuit boards were held in a metal enclosure that was (not kidding here) taped to the back of the panel. Cut the tape off, unplugged the connectors for the main drive, the 4 (you might only have 2) back-panel lights and the power/menu button connector(s). That took maybe 5 minutes. I then had a basic flat panel. Now I wanted a new "driver board", a 12v driver board.

On the back of the panel (all panels) there is a sticker that lists the panel model and some other info. This is important. Widely used panels, like the LG, have specific driver boards that are pre-set for them, but for most (not all) other panels there are boards you can buy that are "universal". They work the same as the dedicated, but you will have to load firmware into them. Loading the firmware into a universal is a bit hit-or-miss, but the wrong firmware doesn't hurt them. However, in that I had an LG, I didn't need to do that.

So, went to Amazon and entered the term "driver board LG XXXX" . You replace the LG XXXX with whatever make/model your panel is. Most of these driver board setups cost between$19 and $29. You can also get them directly from China for about $20, but you have to hope they send the right one. I don't use Prime, so I got the board, from Amazon from China in about 3 weeks.

It took maybe 5 minutes to attach the cables between the new board and the panel. Plugged in a 12v power source and bingo-bammo, it worked! 23" diagonal flat panel. Panel draws 38 watts when running. Has inputs for HDMI, DV-I, VGA. Outputs for audio. I did a slight modification on the original monitor plastic case and mounted the 3 driver components onto the inside of the case, and snapped the whole thing back together. Now it looks like it always did. Just runs on 12 volts. I'm using it now, a 23" wide screen monitor. Total build time, maybe 30 minutes. Total cost = $29.

The reason this all works is because in almost all cases, LCD panels actually run on 12 or 5 volts. However, for most systems, there is a 120/240v AC power, that is then reduced to 12volt DC. The DC is then split into two areas, one is boosted back up to either 19 or 39 volts for the back panel light. The other area either drives the monitor at 12 volt or is further reduced to 5 volt. So in a normal system you have all of this conversion going on. The 12v input just eliminates the first, and most power hungry step.

A word of caution...if you buy a "universal driver board" - one you can configure for almost any monitor - be absolutely certain you know the panel's needed input voltage. The driver boards can put out 3.3, 5 or 12 volt DC to the panel. If you have a 5 volt panel and have the switch set to 12 volt, then you will almost instantly cook your panel.

So, Conch Fritter now has a wide screen, high def monitor, running from 12 volt only, being driven by a Raspberry Pi 3. The entire setup consumes, at full operation, about 50 watts. Yes, I have my old laptop and have a 12 volt converter brick for it, but it is old and the new setup is really nice and a lot bigger!

dave

Oh, and total cost = $29. I had the monitor as it was a salvage I found several years ago. Only thing I needed was the driver board and a bit of hot-glue to attach to new components to the back monitor cover. Oh, and I had to trim out a bit of the back monitor cover so the inputs and control buttons can be access from the outside. Maybe a 3 minute job.
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Dave and Regina - Enjoying old age, a LOT!

Build Journal - http://www.tnttt.com/viewtopic.php?f=50&t=62386
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Re: Convert computer monitor to 12 volt

Postby John61CT » Tue Dec 26, 2017 11:14 am

Great job!

Just for others, lots of monitors have an AC-to-DC brick externally.

No need to open the monitor's case, you just need to match the brick output, volts physical plug and polarity.

If you're buying a new unit, look for ones where the brick puts out 12V, so no DC-DC conversion of voltage is even needed.

Nearly everything computer-related is DC internally, all these options are much more efficient than running through an inverter.
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Re: Convert computer monitor to 12 volt

Postby daveesl77 » Wed Dec 27, 2017 8:02 am

You are absolutely correct. If there is an external brick, then in most cases the actual feed is 12v DC anyway and no need to jump through hoops. I just had a bunch of monitors that use the 120v plug in. I did pick up a small 15" at a thrift store for $5 that is 12v, but I wanted bigger. And I wanted to see how well these boards work.

dave
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Build Journal - http://www.tnttt.com/viewtopic.php?f=50&t=62386
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