'AAA" battery powered lamp conversion

[whitby guy]

Hi all:
Might be a silly question, but here goes.
I am looking for a reading / general purpose lamp for the shelf above the bed in the tear. Found a 8 light LED with a flexable neck from the base. Almost what I am looking for. Problem is they work on 3 'AAA' batteries. Can these be switched to work on the 12VDC system I have installed? (A simple solution would be nice, 'cus I'm a pretty simple guy). I have the 12V car outlet style plug ins available, or could wire them to a switch running from the fuse panel.
Thanks
Sandy

[madjack]

Sandy, you would havvta have 3 of them wired in series)when one comes on, they all comeon) OR have a resistor wired in series with the lamp to drop the extra voltage...3 AAA batteries are probably supplying 4.5volts and the other 7.5 volts would havvta be dropped somewhere(over the resistor)...
madjack

[Miriam C.]

Sandy you can also try the truck stops for a 12vdc solution. They have all sorts of gadgets.

[whitby guy]

Thanks for the advice and tips. My sister is a long haul trucker and she is finding all sorts of neat stuff for a 12V world.
Sandy

[Moe]

you might try this web site: www.12volt-travel.com/12-volt-products-c-17.html
Geared for the OTR trucker but it has anything you might want to work on 12 volts including LCD televisions and all types of cooking gear. Check under 12v spotlights, there are reading/map lights there.

[jmk1977]

Holly smokes! I have been to Circuit city, best buy, wal mart and sears looking for a better deal on a 12 volt tv for my truck. Cant find one. Heck, I couldn't even find a decent selection. Only one tv and it was almost $700! Screw that! I picked up another tv from 12volt-travel.com. I got a 19" audiovox and a wall mount. Great deal there - Great service!

I still wish I would have known about them months ago!

Thanks again,

[bobhenry]

http://www.radioshack.com/product/index.jsp?productId=2103680&cp=&sr=1&origkw=12+volt+voltage+adapter&kw=12+volt+voltage+adapter&parentPage=search

Saw one similar at a yard sale for 50 cents this weekend that's why I knew they made them. The one that I saw gave 3 , 4.5 or 6 volts by selecting with a slide switch. Guess I should have bought it ! Picked it up and layed it down twice. I should learn to trust my 1st instincts.

[ferociousllama]

Don't waste money on a radioshack junk adapter.

Get a LM317T. Here is the link:
http://www.radioshack.com/product/index ... 062601&cp=

Then you will need 2 resistors to set the voltage.

Go to:
http://www.cpemma.co.uk/317calc.html

In the top row of the calculator enter 4.5 for the volts, then enter a resistance that you can find at radioshack. I used 100 for resistor 1 and the calculator says 260 ohms for resistor 2. This gives an output of 4.5 volts.

Then connect resistor 1 between the "out" and "com" pins on the LM317T.
Next connect resistor 2 between the negative side of the battery and the "com" pin on the LM317T.

Done. For a few dollars you have 4.5 volts.

A resistor will only drop the voltage relative to the battery voltage. So when your battery drops to 11 volts for example the lowered voltage will probably be about 4 volts instead of the required 4.5 volts.

The best part of this regulator is that it will always put out 4.5 volts even if the battery voltage drops.

It can handle a load of up to 2.2 amps I think...but I wouldn't trust it at over about half that load.

If you can't solder I can build it if you send me a few bucks for parts.

[rlphoto]

Here is a converter. Never tried it though.

http://www.powerstream.com/dc6.htm

[wlooper89]

I would look for a 12V light(s) that one can wire in place. It will save money in the long run over replacing AAA batteries. I have seen some really nice flouresent ones from Taylorbrite and some very economical reading lights as well. Though I am not a fan of the bluish color of light from LEDs for reading, that is also an option.

Bill

[48Rob]

Don't waste money on a radioshack junk adapter.

Why?

Do you know a secret?


You can tell us!...

Rob

[hurricaner]

Here is an 11 dollar sollution. You could probably run 3 or 4 with one if you wanted to.
http://cgi.ebay.com/RadioShack-273-1857-power-adapter-12-24-vdc-to-4-5-volt_W0QQitemZ310081649258QQcmdZViewItem

Sam

[whitby guy]

I found a light that plugs in a 12V outlet...believe they are "map lights" for the car when driving. Flexable neck about 10" long. Incandescent light bulb like that in a flashlight. The wife doesn't care for the 'blue' light from the LEDs. This brings up to about 6 different styles and types of lights for inside the cabin...hope one of them fits the bill.
Thanks also for all the LED info. I think I'll try to make up an adapter over the winter.
SAndy