Help powering 12" lcd

mattdisaster · 08-07-2005, 03:59 PM

Hi everyone-
So I've found myself in another odd spot. I recently bought a touchscreen lcd rfom a member on the board.(http://www.mp3car.com/vbulletin/showthread.php?t=54269). I received the item and it looks like it will be the best purchase for the carpc ive made all year long. But heres the problem- I will be powering my system using an 800w inverter which will then output to the cpu and the lcd, thereby using its two plugs. The snag is upon looking at the lcd, i noticed it took 2 power inputs, 1 for a heater that allows it to work in cold conditions (which we get during the winter) and the actual lcd power. The other side of the snag is both of the power connectors were cut off. I emailed the orig owner and he was planning on powering it straight off the battery. I have no clue on what I should do. Looking at the specs I know they both take 12v power supplies and can use anywhere from 9-26 volts of elctricity. Any recommendations will be greatly appreciated. Thanks in advance!

-matt

numbers · 08-07-2005, 04:16 PM

I could be reading that wrong, because your situation sounds ideal to me. If both the power inputs to the lcd are designed to take 9-26 volts, and the connectors are already hacked off, then you need only connect them both to the power that you are feeding to your inverter. Of course you'd want to put a fuse on each one, but we're not that far just yet. Did I misunderstand you?

mattdisaster · 08-07-2005, 04:56 PM

No that sounds about right, so basicly all I need to do is put a fuse between the two and connect them right to the battery? Sounds pretty simple to me, what about the fact that its 2 seperate cables? Should I put splice them together? Or attact one with a fuse before it, then the other slightly after it? Will connecting these two componants before the inverter interfer with its operation? Thanks alot numbers, you've helped me out a buncha times already!

-matt

numbers · 08-07-2005, 05:27 PM

What you'll want to do is take the ground wire from each input on the lcd. (that is to say - you have four power wires total coming out of the lcd, and you're grabbing the two ground wires) and find a good chassis ground close to the lcd. This could be a seatbelt bolt going into the frame of the car, a bare metal screw, just anything that makes a good ground. The idea here is the same that applies to car audio, so anything you can read about that can be applied here. Ground them both together wherever you decide to do so.

Now then, take the two positive wires and route them to wherever you're going to power them from. You can pretty much do this however you want as long as you fuse them properly and whatnot. If the battery is closer, go there. If the inverter is closer, go there. You'll want to fuse each wire separately. Now the wire going from the battery to the inverter should already be fused, but you still need to fuse these wires even if you run them from the inverter's wire. Inline fuses may be a good option here. Pick a fuse that is rated higher than the power rating of the lcd, but only barely. Again, car audio wiring stuff applies here. The difference is that where they're dealing with 100-150 amp fuses, you'll likely be dealing with 5-10 amp fuses. Just keep in mind that we put fuses on wires to protect them from shorting. It has nothing to do with protecting the device at the end of that wire. Anyone who tells you otherwise is just wrong.

mattdisaster · 08-07-2005, 06:14 PM

Thanks again for the information, I'll be printing this out for installation day(s). heh. I see you said "inline fuses may be a good option here". I was planning on using inline fuses throughout the entire project (including in between the battery->inverter) should i use a different style fuse for that one? Thanks alot again!

-matt

numbers · 08-07-2005, 06:30 PM

Many folks use fused distrobution blocks. I happen to like them simply because they tend to make a 'cleaner' looking install. However, in the case of few wires or small wires, inline fuses seem to make more sense sometimes. Really it's just up to you. There are no secrets here. The differences are plain as day when looking at them and it just depends on which one you'd rather work with. I tend to use inline for single or few small gauge wires, and distrobution blocks for single large or many small/large gauge wires.

I am glad to hear that I've done some good around here. I'm sorry to admit that when I don't see an avatar to tie to a person, I don't tend to notice who I'm talking to. Taking a look through your previous posts I see that we have indeed met before, and you are certainly most welcome for the help.

mattdisaster · 09-28-2005, 03:32 PM

Back from the dead! I'm still getting ready to do my install, I'de love to hook the lcd up for setup before it hits the hardwire to the battery, I found a mod'd liliput egg I had, instead of using a cig hookup it uses a morex connecter so it can be hooked up to a psu. Can I hook it up to an extra psu I have, and cut the wires going to the liliput power plug and connect them to the lcd to power it up? The egg says it rated for 9v-12v, will that work? Thanks for the help.

-matt