7 inch monitor has DC to car - how do I convert it to use at home with AC?

[David Delaney]

I've got a 7 inch external monitor I want to set up with my camera and rig, it is made for a car 12V (comes with the car-lighter adapter).  Now, what do I do to make it so I can run it from my home - AC?  I don't want to take a chance trying it with an AC adapter before I figure this out.  The monitor says 12V 3A in the back, so I need to get it working with that, right?  I also have a couple of those DC -> AC converters for car (so you can plug a laptop etc into a car lighter) - do I need to somehow utilize one of these?   Any ideaS?

Thanks

[Tom Wills]

Many options here. You could easily just plug in a 12v wall adaptor. As long as it's 12v, the worst that can happen is that it either won't fit or won't have enough amperage. Also, if you're really paranoid, you could head off to RadioShack and spend $30 on an adaptor to give you a cigarette lighter socket from an AC plug, but it's unnecessary here.

Good luck!

[David Delaney]

Well, as far as AMPs, most houses run on more amps than a car battery (car battery I am assuming is about 3A because the back of the monitor says 12V 3Amp. - so therefore, am I not going to run the risk of having too much amperage for it?  I don't want to fry the thing...

[Tom Wills]

That will not be a problem. The house's amperage has nothing to do with it. The power adaptor will have a specific amperage it provides, not just let all the amperage in the house in.

[David Delaney]

Ok,

I have a car battery boaster - 12v .  Are you saying I could use the adapter that I use to charge this car battery boaster to run the monitor?

[Tom Wills]

That I wouldn't try. Go to Radioshack and bring your monitor. Say that you need a 12v AC adaptor for this monitor, and a salesperson there will walk you through what to get. It should run you under $10.

[David Delaney]

Ok Tom.  Here is what I did.  I went to Radio Shack (The source- Circuit City in Canada).  I brought in my monitor and specs and she gave me a $69.00 12V converter (on sale for $49.00).  They didn't say anything about something that cheap!  Do you have a name or product number I can work with?

[Tom Wills]

I just re-checked Radioshack's site, apparently nothing there will do 3Amps. Lemmie take a look on a real electronics supplier's site and pull up a part number for you. Are you alright about shopping online?

[Tom Wills]

I'm finding nothing on even the one electronics manufacturer that I know of that will do 3 Amps. That's a heck of a lot for an LCD.

I really am out of ideas here. I hope somebody else can help you out.

[David Delaney]

Thanks Tom, I appreciate it.  I am hoping someone can help out as well - this thread has been busy because of you, so maybe someone will chime in.  Thanks Tom, if you find anything else, let me know!

[Denis Collis]

Is your monitor LCD or CRT?  I ask because a CRT needs more power than an LCD, especially on power-up.  I have an 8.4" LCD TFT, and it needs only 1 Amp of current.  In addition to the 12V cigarette lighter adapter, it came with an AC "Wall Wart" adapter:

Input: 100-250V AC  50/60Hz  80mA
Output: 13.8V DC   1000mA

Although cars have a NOMINAL 12V system, if you measure it, its usually around 13.8V.

A really cheap 12 or 13.8V power supply is easy  to get.  Just search eBay with "13.8V power supply" or "12V power supply".  I've just done that and I found a 13.8V 3A supply for a home CB-HAM (radio) for $8.73.  Oh, and here's a used one for only $4.99.  I've just checked Radio Shack, and they appear to stock the most expensive 12V/13.8V power supplies on the planet!

An old PC power supply should also do the trick.  I scratched around my old stuff and found a power supply for an old HP external CD-Writer.  I plugged it in and it works fine.  Using a multimeter I found the common and +12V (and also +5V and -5V).

You could build one yourself for about $10.  Here's an example: http://sound.westhost.com/project77.htm

Hey! I keep a box of old wall-wart power supplies and I've now found at least 3 which will work.  If you lived nearby you could have one.

What about the battery charger that you use to charge your battery?  Connect the charger to the battery, and the battery to the monitor in the normal way.  Don't connect the charger directly to the monitor, unless you're sure that it produces a nice smooth current.  (With the battery also connected, you'll get a smooth current.)

Ask around.  Look around.  A 12V DC power supply is probably one the most ubiquitous pieces of electronic equipment.   It should cost you, well...   next to nothing!

Good luck

Denis