Another Source For Cheap, Small LEDs

[gmpullman]

Hi, Folks

I'm taking the liberty to post this in General Discussion instead of Electronics, since it may benefit more modelers who might be interested in LEDs for structure and rolling stock lighting.

I stumbled across these in a listing at Amazon:

http://www.amazon.com/gp/product/B00GUDMO78/ref=s9_al_bw_g201_i2

Once I looked at what I recieved I began to get ideas for uses on the layout.

Similar to the peel-n-stick strip lights I mentioned in an earlier thread, http://cs.trains.com/mrr/f/11/t/225078.aspx these can be cut into multiples or used individually although there is no markings or no built in resistor.

Each SMD has a blob of epoxy that serves to diffuse the light and insulate the connection. There's no indication of polarity but that's a simple test with a battery or DC source. You could mark one of the wires with a Sharpie^® if you need polarity marking.

If you want to use them in a structure you can cut the length to suit and experiment with an approprate resistor to give you the brightness you want.

If you are going to use them in a metal shade or housing I would dab some clear glue or nail polish on the cut ends of the wire where it comes out of the LED "blob" to insulate the ends. You have to scrape away the clear insulation on the wire to make an electrical connection.

As an added bonus, the 1 amp wall-wart outputs 4.5 volts so it is perfect for a battery substitute to power your Miller animated signs if you aren't going to use it for the LEDs.

At 18¢ each, these work out to be a pretty reasonable source for handy, small LEDs!

[edit] I should mention that there are 100 LEDs on the string. As they are wired, there is a third wire which runs to the second group of 50 LEDs that I just cut away. It is a nice, soft copper and makes nice wire to represent hose or cable if you paint it a dark color.

Happy Modeling, Ed

[tstage]

Ed,

I picked up a roll of those at a Christmas store in Durham, NC a year or two ago with the exact same purpose in mind.  I think it cost me <$20 for the entire spool of LEDs.

I'm assuming you have a resistor soldered to that battery board connector?  Or, is that a special French or German 9V battery you have connected to the single LED?

Tom

[gmpullman]

tstage

I'm assuming you have a resistor soldered to that battery board connector? 

Hi, Tom

I bought that handy tester years ago from Lloyd's Toys, one of the early DCC suppliers. You guessed right, there's a resistor and a voltage regulator on the board. 

We do owe the French a tip 'o the hat for their contribution toward storage batteries:

The dry cell is a an improved voltaic cell with a cylindrical zinc shell (the zinc acts as both the cathode and the container) that is lined with an ammonium chloride (the electrolyte) saturated material (and not a liquid). The dry cell battery was developed in the 1870s-1870s by Georges Leclanche of France, who used an electrolyte in the form of a paste.

Regards, Ed

[mlehman]

Neat find, Ed. I've been working with these in the smaller strings previously available powered by batteries. Having a power supply that's a direct plug in to house current is useful -- and as was noted it alone could be used for other purposes.

Makes me wonder what color temperatures are available in these?

[gmpullman]

mlehman

Makes me wonder what color temperatures are available in these?

Hi, Mike,

I don't know what else is available in other brands but the specs on these say 2700 to 2900K which is a nice "warm white"

Just playing around with different supply currents I noticed that there is quite a bit of useable range in the brightness of the LEDs so you can dim them down to an almost yellow or have them near full brightness as in one of the photos above.

Thanks for looking, Ed

 

[-E-C-Mills]

Thank you Ed for the info and the size comparison photos.

[hon30critter]

Hi Ed:

Nice find. Nice colour too.

That certainly takes the hassle out of soldering leads to SMD LEDs, although I have to say I have gotten pretty good with the 0603s. However, I have to admit that I did break down and buy a bunch of pre-wired 0402s. That made life so much easier. I will still have to solder some 0402s with magnet wire to fit into the goose neck HO lamps from Ngineering so I'm not out of the woods just yet.

Dave