Cutting led light string.

[75redman]

I have a 50ct led mini light string that I would like to cut down to 35 bulbs. Can I just cut it? I know with incans there would be a lot more voltage going to the 35 bulbs.

Since leds draw much less do you need to do anything to the string?

Thanks for your time.

[Mr. P]

There have been many threads about this, you can check one out here:

 

http://forums.lightorama.com/index.php?/topic/25931-cuttingshortening-led-strings/

[jimswinder]

Check This out:

 

http://forums.lightorama.com/uploads/imported/308642=16881-LED%20Modifications%20%281%29.pdf

[75redman]

Thanks Jimswinder.

[Max-Paul]

There is a law, Its something like Kirchoff's law. It says that the voltage applied has to equal the sum of all voltages dropped in the circuit. So lets say 120 volts dropped across 50 lamps equals 2.4 volts per lamp. So now you want to drop 120 volts across only 30 LED. The voltage across each LED is going to be more like 4 volts per LED. Now your red, orange and yellow usually only good for 2.2 or 2.4 volts each. Where as your other colors usually operate at about 3.6 volts. LEDs are very touchy about any voltage over their rated voltage. Sure they might work for a time a few .1 volts over. But pushing them will greatly reduce their life.

[shfr26]

I have a 50ct led mini light string that I would like to cut down to 35 bulbs. Can I just cut it? I know with incans there would be a lot more voltage going to the 35 bulbs.

Since leds draw much less do you need to do anything to the string?

Thanks for your time.

 

  Not only do they "draw much less"  , they weigh less too,   not all those heavy filaments in there.

[Orville]

It  really depends on how the strand is made.   I have successfully cut 50 LED strands down to 25 LED strands, you usually can cut them in half, to find out if you can cut a LED strand down, say a 100 count to 50 count, 70 count to 35 count, 50 count to 25 count. 

 

It's an easy thing to test, if you have a 50 count strand, remove one LED from the beginning or end of the strand, if half the strand{25 LED's} still light, you can cut the strand in half.  Just make sure to UNPLUG the strand before making the cut.  

 

I use a silver sharpie and mark the wire just after the lit LED and before the unlit LED.   Then all you have to do is cut the strand at that 1/2 way mark, add a male vampire plug to the second half to make it usable.  

 

If you need or want to add other strands to the strand, you'll need to add a female receptacle at the end of the first half you cut.   If not, you can just put some silicone or super glue over the exposed ends, fold each wire back onto itself, and put a piece of heat shrink over each piece, shrink, then another a little larger over both wires and shrink to help keep it waterproof.  

 

And now you'll have 2 - 50 count, 2 - 35 count, or 2 - 25 count LED strands depending on the number of LEDs that were on the entire original strand before you cut it down.

 

 

However, if you remove one LED and the entire string goes dark, then you can't cut it.  

 

Also if you happen to use sealed strands, then this method won't work since you can't pull a bulb out of the socket, and it would be a hit or miss, and I wouldn't even try it with a strand I couldn't remove a LED from, and then test the strand in this manner.    And this is why I prefer LED strands with replaceable LED bulbs as opposed to sealed strands, where replacement is quite different in replacing a burned out LED bulb.

 

Good Luck with your project.