the old xmas LED light string ?

[BIG JERR]

yep , the " I want to cut appart a sting of LED lights" post.

 so got a string of 60 LED light ,it looks to be two strings of 30 dasey chained together as it uses 3.2 volt leds and has two resistor packs per 60 string ....help me if wrong here

I would like to split the 60 to (2) 30 led stings . the last led  in the first 30 has two wires to the next 30 ,if i recall both string share the the comon/load or daisey chained .

So, if I cut and install a female/male plugs @ the end of the first thirty where it goes back to (2) wires ,i would have (2) 30 led strings .yes ?    help me if Im wrong...

I use to do this with bad mini light sets years back ,and it worked fine ,so IM thikin same format, yes Im sure not a UL or better houskeeping approved  ...JW

[rrinker]

 I'm not really one for jury rigging something that gets plugged in BUT - if they are wired that way, there whousl be 3 wires in the bundle. Check though, rather than 30 and 30, they may alternate, so the fdirst LED is on Circuit A, the second on B, etc. That will be harder to seperate. The claculations whould be right, 30 LEDs at 3.2 volts in series plus a resistor to drop the remaining voltage and limit the current.

            --Randy

 

[cacole]

There are two reasons why it's cheaper in the long run to use different LEDs than the ones in Christmas light strings --

The leads on them have been cut very short and bent 180 degrees into their socket, which makes them difficult to remove and to connect wires.

They are usually "inverted cone" type LEDs that radiate light 360 degrees from the sides instead of being a pin-point LED, so most of the light will be lost if you intend to use them for locomotive headlights.  They're good for building lighting.

I have found some sellers on e-Bay offering 100 warm white LEDs with resistors for under $10, including postage (usually from China).  These LEDs have full-length leads.

[BroadwayLion]

LION is master of Christmas LEDs.

1) who cares about the wiring : Remove each led. The leads on the LEDs are long enough.

2) Wire LEDs directly into your circuit, do not try to emulate the circuit that they used.

3) Wire LEDs with a 1K ohm resistor in series. Some wire them is series with Tortoise switch machines, the LION does not do this, but him did wire them in series with some 12v DC relays. Had to bump the voltage up to 16 volts to get all of them to work reilably. Works just fine.

4) I signals, you wire them independently and put the resistor on the common. In structures (subway platforms) the row of LEDs are in parallel, each with a resistor in series.

 

[Mark R.]

I just picked up a couple 70 LED strings in warm white (nice color !) for $8.00 a string. They are standard 3mm LEDs with the typical rounded tip.

Snap off the fancy clear covers, unbend the leads and pull them out - there's still plenty of lead left to solder to. Probably a good half an inch.

The nice thing about these sets is that the color is consistent. A lot of times, those bulk packs off ebay, while dirt cheap, often aren't consistent in their color. "Warm white" can be anything from warm to pure to even having an ever so slight green or pink hue to them. Out of a bulk pack of 100, usually about half are what I expect. 

Mark.

[hon30critter]

I think the economies offered by salvaging Christmas LED light strings are a thing of the past. I just picked up 500 warm white LEDs with very nice colour for $21.00 plus shipping on eBay.

However, I don't think that is what the OP wants. If I understood his question, he wants to make two shorter light strings out of one longer one. For that purpose I would suggest using the LED strips available on eBay which can be cut every 3 LEDs to whatever length you need, like this one:

http://www.ebay.com/itm/5M-3528-SMD-Warm-White-Waterproof-LED-lamp-Strip-light-/360822397876?pt=US_String_Lights_Fairy_Lights&hash=item5402b0dbb4

This is only one example of what is out there, and this particular string doesn't look to be as warm a white as others are. The nicely coloured warm white strings will be a bit more expensive.

Dave

[mobilman44]

Hi,

I just finished stringing 5 new 30 led bulb sets so as to illuminate my lower level staging and incline to the main level.  They do a wonderful job and cost about $4 a string, and being LEDs, have a minimal electric draw.

That being said (establishing I'm familiar with the item in question), I would strongly hesitate to cut up strings for individual layout use (unless I REALLY knew what I was doing).