Lights

[dcphipps]

I was wondering if a person could cut a set of lights( not LED) to make shorter, I am working on faces, and need various lengths. These would be 120 volt lights.

[Jack Stevens]

That depends; how skilled are you with an ammeter?

 

OK, many rope light can be cut to 18" pieces; they're marked where you can cut them.

 

Other than that, you would have to measure the current running through the segment of lights you want to cut, then replace the missing lights with a resistor rated to carry the current and drop the required voltage.

 

You are dealing with lethal voltages, so don't make any mistakes.

[Dave Batzdorf]

the 100s incans can be cut in half at the third wire spot.  I have also used a few 35s in a shorter locale.

[james campbell]

the 100s incans can be cut in half at the third wire spot.  I have also used a few 35s in a shorter locale.

if you cut the lights in half wouldn't that overload the rest of the lights? in a 100 cound strand each light takes 1.2 volts so now you would have to spread 120 volts over 50 lights.thats why in the strands were if one goes out the rest stay on,but you get a cascade effect of others failing faster because of the extra juice

[George Simmons]

if you cut the lights in half wouldn't that overload the rest of the lights? in a 100 cound strand each light takes 1.2 volts so now you would have to spread 120 volts over 50 lights.thats why in the strands were if one goes out the rest stay on,but you get a cascade effect of others failing faster because of the extra juice

 

Hence Jack's explanation of how to do it.

 

With incans, 100's are basically two fifties, and 70's are basically two thirty-fives.  Those sets can be cut in the middle where there are only two wires bridging the two halves of the set without needing to insert any other electronics.

[Jack Stevens]

A quick test to see how many real light circuits are in a string of lights:

 

Pull a single bulb out.  What went out is a single light circuit.  Between the last light that is out and the first light that is lit, you will probably find just two wires.  You can cut at that point - AFTER you unplug the string!

 

Most of the time there isn't more than two light circuits per plug, except when it comes to icicle lights.  Many of those have 6 circuits - i.e. a 300 light icicle string will have 6 50 light circuits.

 

Many of the incandescent candy canes only have 20 lights in them, if that string is short enough.

 

If you need fewer lights than that, the easy thing to do is black out the lights you don't want; a 1/4" piece of heat shrink will do that.  Otherwise you will need to replace lights with resistors.

[james campbell]

Hence Jack's explanation of how to do it.

 

With incans, 100's are basically two fifties, and 70's are basically two thirty-fives.  Those sets can be cut in the middle where there are only two wires bridging the two halves of the set without needing to insert any other electronics.

wow never thought you could do it that way,but it's good for me ,I have several strings where only half light up and I need some 50 count strings.