led power supply

Maybe take a look at these.

Ray

Gerald ,

You could use any type  12-V, Power Supply as long as you use a resister in series with the positive side of your led's.

Good luck, John 

Ray,  What you mention is very interesting, i will keep this in mind.

John,  How would i determine what size resister to use ?,i would think it would depend on how many led's are to be powered .

Gerald,

Good information here.

 John, i allready have that web site in my files ,i forgot i had it thanks for reminding me.

Gerald Marafioti posted:

What is the difference between a power supply that is ac 100-240v to dc 5v 2a, 2000ma power converter,[  it does not say whether it is regulated or unregulated ],priced at $ 2.43 & one 2 amp regulated converter priced at $ 12.00,  would it really make any difference when it comes to powering led lights?    I would like to know for future reference ,if i decide to run a long string of led lights.   Thanks,   Jerry  M.

Since the input voltage range is AC 100-240V it is undoubtedly regulated at the output.  One way to think of it is some kind of automatic regulation/control must be going on inside if you can vary the input voltage by over 2-to-1.  $2-3 (free shipping) seems like the going rate on eBay for regulated 5V DC, 2 Amp wall-wart style adapters.

If you do order from eBay, many sellers also sell connector/adapters if you don't want to splice the wiring.  Here's a recycled photo from another thread that shows a typical adapter with the coaxial/barrel style plug and a companion adapter.

Of course if you're going with 5V DC wall adapter many are for USB gadgetry in which case there is a USB-style connector with no cable - in which case you probably already have a spare USB-cable from a cellphone or whatever from which to access the power.

If the application is for a string of LED lights, I'd seriously look at those LED strips/rolls that cost a few pennies per LED.  These are the ones the guys use in passenger cars or even layout lighting.  They run on 12V DC and have the built-in resistors to match the LEDs to 12V DC operation.  A 12V DC, 2 Amp wall-wart adapter also runs $2-3 (free shipping) on eBay.  In the big scheme of things, it's all about $/Watt.  5V, 2A is 10 Watts.  12V, 2A is 24 Watts.  If about the same price, the math is pretty straightforward!

Stan, You have given me a lot of great information that will be of great help to me in the near future,what i would like to do is put a string of led lights under the second level of my layout i don't know at this point how many lights it will involve,i have 1 or 2 other things i want to do before i get to this project right now i want to get as much information as possible now,i am in no rush,i like to do this stuff, but my problem is i don't have a lot of knowledge about these things,so i have to turn to the forum for help,& all you guys have been a big help to me,right now i am waiting for the rest of the parts for the lumber jack project,i already put the new motor in & it works ok,i tested it with a 9 volt battery, as soon as i get the rest of the parts i will finish hooking everything up.

I  am building a control panel using 12 volt L.E.D.s, no resistor needed using a 12volt system.

Dick

Dick, Because of my limited knowledge,could you explain to me why no resister is needed ?,it doesn't seem right to me ,unless the resister is built into the bulbs.  Thanks , Jerry  M.

Any "12 volt LED" would have a resistor as well.