Powering a 12.1" Elo Touchsystems LCD...

Tripwire · 10-17-2006, 07:10 PM

First of all, I have to say i'm VERY glad I found this site by accident. All praise to google.

I've been reading up on these forums, and I've decided to power my touchscreen via the Monolithic 20-pin connector coming off of my power supply, OR the 4-pin for the P4 mobo's.

I didn't see these covered in other topics, and while the search function is great for generalizations, In a forum with such plentiful posts as this one it would be near impossible to weed out a very specific result that may or may not hold the answer... I tried, and after 2 hours of searching I'm just making a new thread...

First of all, I found the documentation for the 12" Touchscreen I am considering (HERE: http://cgi.ebay.com/Elo-Touchsystems...QQcmdZViewItem) and the manual I found claims it uses 10 watts of power. Is that it? Is LCD that efficient? I thought the 12" width as opposed to the standard 7" or 8" would call for more power. I figured it would call for a larger PSU for that matter...
Also, about drawing power from the PSU within the mainframe, I assume you guys are talking about splicing the wires from the molex to the external wires leading from the adapter into the back of the monitor, correct? I know it's stupid, but clarification is always nice. It makes sense, being a 12V DC current on both paths, but I want to be completely positive before I mod anything.

EDIT: Wait... I just realized by simply saying MOLEX it was probably implied to use the Hard drive power cable... I thought about it and that is a 12v down that wire... But that leads me to another question. How would wiring the power to the 4-pin P4 connector make a monitor turn on automatically, as opposed to the hard drive connector?? I'm and A+ Computer Hardware Certified Tech and this stuff is still confusing me!

Motorcity · 10-18-2006, 01:43 AM

you need to look at the pictures in that auction again.
That monitor pulls 2.5 amps @ 12v dc.
If you want it to turn on/off with the pc, then using a molex hdd connector will work. As you know, the yellow wire is 12v, the red is 5v and the blacks are grounds.
Simply buy a molex power splitter that will have the male side you need, and solder in 2 wires the length you need. Solder a barrel connector to the other end. Center positive on the barrel conn.
There are more than enough amps available on the 12 volt rail to power that monitor without taking away from the pc, even a power hog.

I made this one for Planar's 12.1" touch monitor. Works great.
You still have the ability to power the monitor on/off with the power button, and power is cut when the pc is off.

Tripwire · 10-18-2006, 06:00 AM

Thank you for the detailed reponse. From what you say it sounds like you can't put too many amps through the monitor off the Molex? Does the monitor have to "pull" the amps as opposed to volts being "forced" through?

Motorcity · 10-18-2006, 02:55 PM

Quote: Originally Posted by Tripwire

Thank you for the detailed reponse. From what you say it sounds like you can't put too many amps through the monitor off the Molex? Does the monitor have to "pull" the amps as opposed to volts being "forced" through?

When I say pull, I mean that is the draw that the monitor is rated at.
Using the same guage wire as the existing wire from your psu, like I showed in my pic will be plenty to handle the load.

When it comes to power, how many amps available vs. how many are used is irrelevant to your application. Your basic atx psu usually has 16 amps available on the 12v rail. having this there does not mean a device receives that much. The device uses what it needs.

Volts= the size of the fist, amps = the "punch" behind it.

All in all, you will be fine making a cable as I suggested to run your monitor and you will have good results.

Tripwire · 10-19-2006, 01:51 PM

Just double checking. I've been in several networking courses and yet not an electronics, so everything I picked up on the way is fuzzy. Thanks for the help, it truly is appreciated. Now, onto my DC-DC PSU...

Wiredwrx · 10-19-2006, 01:57 PM

Quote: Originally Posted by Motorcity

When it comes to power, how many amps available vs. how many are used is irrelevant to your application. Your basic atx psu usually has 16 amps available on the 12v rail.

That is not true of DC-DC PS, and you should be concerned with the power requriements of your system by Voltage rail.

The M2, for instance, only has 8 amps on the 12 volt rail (http://resources.mini-box.com/online...anual-engl.pdf) He can EASILY overload the 12 volt rail if he doesn't keep the amperage of the Supply and the amperage needs of his system in mind.

Please READ THE FAQ ABOUT POWERING YOUR SYSTEM before you go any further, perhaps both of you should, but definitely the OP should.

Michael

Motorcity · 10-19-2006, 02:20 PM

Quote: Originally Posted by Wiredwrx

That is not true of DC-DC PS, and you should be concerned with the power requriements of your system by Voltage rail.

The M2, for instance, only has 8 amps on the 12 volt rail (http://resources.mini-box.com/online...anual-engl.pdf) He can EASILY overload the 12 volt rail if he doesn't keep the amperage of the Supply and the amperage needs of his system in mind.

Please READ THE FAQ ABOUT POWERING YOUR SYSTEM before you go any further, perhaps both of you should, but definitely the OP should.

Michael

I was refering to a/c powered psu's. But, 8amps on the 12v rail will still run a typical car pc with a hard drive, cd and the monitor in question.
If I can run a 60watt backlight inverter, 15" lcd, usb touch, a Pentium M cpu, and a 2.5" harddrive (all on an Aaeon 945t mainboard) with a 120w Pico dc-dc psu, I am sure the 30 or so watts that the ELO monitor needs won't overload the 12 v rail on a dc-dc psu.

Wiredwrx · 10-19-2006, 03:13 PM

Quote: Originally Posted by Motorcity

I was refering to a/c powered psu's. But, 8amps on the 12v rail will still run a typical car pc with a hard drive, cd and the monitor in question.
If I can run a 60watt backlight inverter, 15" lcd, usb touch, a Pentium M cpu, and a 2.5" harddrive (all on an Aaeon 945t mainboard) with a 120w Pico dc-dc psu, I am sure the 30 or so watts that the ELO monitor needs won't overload the 12 v rail on a dc-dc psu.

I told the guy to run a power calcualtor. You don't do anyone any good by making blanket statements like, You can power everything you want with a PS, which is essentially what you have done. And, what the hell is a "TYPICAL" system? Again, you are just throwing lanket statements out there, which are not 100 percent correct.

This place is for carputers. MOST of the applications involve DC-DC PS's, and not AC-DC, so again, ASSUMING that it is an AC-DC doesn't help the OP.

Next, just because YOUR PARTICULAR system runs fine, someone with a different system may not run fine. Your system specs are obviously under the specs of the Pico PSU you are using. Why do you assume that the OP, or anyone else for that matter, will be so lucky. There are MANY instances of people overloading their DC-DC PS's.

Additionally, the PICO doesn;t regulate the 12 volt output. So, you must be powering this with some sort of 12 volt regulator. That ight be able to supply more then enough current on the 12 volt rail for your items. THat 120 watt rating is therefore a COMPLETE FALLACY, and in essence, might be much higher if your 12 volt supply is providing more then 8 or so amps.

You are NOT using that in a car, are you. That is a VERY POOR choice, with out any additional voltage regulation on the 12 volt side.

Michael

Motorcity · 10-19-2006, 05:42 PM

Quote: Originally Posted by Wiredwrx

I told the guy to run a power calcualtor. You don't do anyone any good by making blanket statements like, You can power everything you want with a PS, which is essentially what you have done.

I never said you can power anything you want with a psu...

Quote: Originally Posted by Wiredwrx

And, what the hell is a "TYPICAL" system? Again, you are just throwing lanket statements out there, which are not 100 percent correct.

typical meaning just that. A mainboad, harddrvie, memory, optical drive, monitor and usb device(s). Not that hard.

Quote: Originally Posted by Wiredwrx

This place is for carputers.

I am well aware of that fact, professor.

Quote: Originally Posted by Wiredwrx

MOST of the applications involve DC-DC PS's, and not AC-DC, so again, ASSUMING that it is an AC-DC doesn't help the OP.

and the OP never said he was using an AC or a DC psu, now did he?

Quote: Originally Posted by Wiredwrx

Next, just because YOUR PARTICULAR system runs fine, someone with a different system may not run fine.

The OP did not provide enough information, so that poiint is mute.

Quote: Originally Posted by Wiredwrx

Your system specs are obviously under the specs of the Pico PSU you are using. Why do you assume that the OP, or anyone else for that matter, will be so lucky. There are MANY instances of people overloading their DC-DC PS's.

I wasn't assuming anything. Simply trying to show the OP an option for powering a 30w 12v dc monitor, that he asked about. And, just because others have problems overloading a psu, does not mena I was providing ill advice.

Quote: Originally Posted by Wiredwrx

Additionally, the PICO doesn;t regulate the 12 volt output. So, you must be powering this with some sort of 12 volt regulator.

yes, on a 9 amp brick.

Quote: Originally Posted by Wiredwrx

That ight be able to supply more then enough current on the 12 volt rail for your items. That 120 watt rating is therefore a COMPLETE FALLACY, and in essence, might be much higher if your 12 volt supply is providing more then 8 or so amps.

probably right, when has any power supply manufacturer ever stated correct numbers?

Quote: Originally Posted by Wiredwrx

You are NOT using that in a car, are you. That is a VERY POOR choice, with out any additional voltage regulation on the 12 volt side.

no, I built these for a customer who is using as indoor kiosks that are ac/dc powered. Not in a car.

My reason for the pico reference was to show that the dc-dc psu had enough power to run that monitor to begin with. I chose the Pico to reference since it is on the lower side of power output compared to others.

Seems as though you need to relax a bit. No need to go into full blown tactical mode just because you don't agree with my staterments. I was simply commenting on what I know, based one what I have done. I know what can and can't work when it comes to powering equipment, with AC or DC psus.

Now, since the OP never gave any information on what psu he planned to use, or what all was being driven by said psu, I provided a power option based on previous hands on experience. If you don't agree, fine. But just as I, you don't know all the facts pretaining to the OP's build.

Wiredwrx · 10-19-2006, 06:20 PM

Quote: Originally Posted by Motorcity

I never said you can power anything you want with a psu...

typical meaning just that. A mainboad, harddrvie, memory, optical drive, monitor and usb device(s). Not that hard.

I am well aware of that fact, professor.

and the OP never said he was using an AC or a DC psu, now did he?

The OP did not provide enough information, so that poiint is mute.

I wasn't assuming anything. Simply trying to show the OP an option for powering a 30w 12v dc monitor, that he asked about. And, just because others have problems overloading a psu, does not mena I was providing ill advice.

yes, on a 9 amp brick.

probably right, when has any power supply manufacturer ever stated correct numbers?

no, I built these for a customer who is using as indoor kiosks that are ac/dc powered. Not in a car.

My reason for the pico reference was to show that the dc-dc psu had enough power to run that monitor to begin with. I chose the Pico to reference since it is on the lower side of power output compared to others.

Seems as though you need to relax a bit. No need to go into full blown tactical mode just because you don't agree with my staterments. I was simply commenting on what I know, based one what I have done. I know what can and can't work when it comes to powering equipment, with AC or DC psus.

Now, since the OP never gave any information on what psu he planned to use, or what all was being driven by said psu, I provided a power option based on previous hands on experience. If you don't agree, fine. But just as I, you don't know all the facts pretaining to the OP's build.

HENCE the reason I sent him to a power calculator.

All you did was provide information based on your thought and assumptions.

So, you don't know what he is using, what he is powering,and yet found it advantageous to him to tell him, Sure, no problem.

"There are more than enough amps available on the 12 volt rail to power that monitor without taking away from the pc, even a power hog."

"Your basic atx psu usually has 16 amps available on the 12v rail. having this there does not mean a device receives that much. The device uses what it needs."

"All in all, you will be fine making a cable as I suggested to run your monitor and you will have good results. "

All those statement don't take into account the OPs setup, and PS. Yet, you stated them with authority. HOW can you make those statements with out asking for more information. That is what I questioned in your posts. Your statements that have no bassis for this particular. O.P. You harp on the fact that I can not compare yours and the OPs systems, saying that it might draw too much, and is different then yours, because the OP didn't post any specs, yet, you told him, as quoted above, that it should be no problem, just connect it with a Y cable, yadda yadda yadda.

That is plain BAD INFORMATION.

You might think you are really smart and put together systems for customers and all that crap, but I have seen time and time again someone who thinks they know about computers come here, and find out that carputers, the subject of this forum, are totally different.

If you are not familiar with the subject, don't say anything.

Again, there are specs to speak of, so either ask for them, but don't answer the queestion based on some "Hypothetical" system YOU have built before. It is not relevant to the OP.

On a side note, I am calm. Just because I question you doesn't make me excited.

And, if you think a Typical system specs means a MB, CPU and some peripherals, you are nuts. There are a Multitude of CPUs with differing power requirements, and MB all are different, and 2.5 and 3.5 uses different voltages and amperage. There is NO such thing as a typical system.

Michael

Tripwire · 10-20-2006, 10:13 PM

And I'm sure no one took into account the fact that I'm using a 3.5" 9600rpm HDD....

turbocad6 · 10-20-2006, 11:13 PM

9,600 huh..., sata? how big of a drive?.... I'd suggest also looking into point source ps' to help lighten the load a bit.... one on the screen & one on the drive can help alot..