christmas light problem

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carambola

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south jersey
i may not be the brightest bulb on the tree and that's my problem.
good customer wants those twinkle lights custom fit to his railing and by cutting out the unnecessary lamps i've broken the series. now one half burns at the correct brightness and the half that i've tampered with burns too bright.
i've taken out 25 lamps and need a way to add a resistor to compensate.
any suggestions
 
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The string is probably 2.5 V lamps. Change out the remaining 25 bulbs to 5.0 V lamps.

Or wire the other 25 lamps back in and wrap them in black tape to hide them in the dark. Little black boots are also available to cover the bulbs. (The boots melt on and eventually cause premature lamp burnout.

Or change out to LED style string which will use less power and isn't series wired.
 
If the lamps are too bright then they are getting too much voltage and they will burn out soon. You could add resistors but you need to know the load (current) of that section of the string before the lamps were removed, it might be easier to change the bulb type to one with a higher voltage. The total number of remaining lamps times the voltage on each lamp equals 120 or greater.
 
Most strings of lights use 3-volt bulbs. 40 3-volt bulbs wired in series on a 120-volt circuit will provide 3-volts per bub. You will need to rewire the lights so that you have 40 bulbs in series. You will notice that most strings of lights are in some multiple of 40 (40 lights, 80 lights, 120 lights, etc.). In these cases you could remove one entire series string to reduce the number of total lights. Sounds like an awful lot of work for a little bit of convenience. Just put the bulbs closer together on his railing leaving a loop of wire between the bulbs.
 
You will probably have trouble finding a resistor with a high enough power rating.

Say the string starts with 120V, and 1 amp. Then thats 120 watts. If you take out 1/4 of the lamps, you will need a resistor equal to that wattage. So, as an example, 120/4 = a 30 watt resistor.

Steve
 
Not the answer you'll want to hear, but...

Not the answer you'll want to hear, but...

You're taking a pretty big risk modifying those lights. Sadly, since the standards of quality have gone way down over the years, most of the sets aren't durable enough to adapt well. Many years back, the GE "Merry Midget" strings were made with good, bi-pin sockets and heavy (18awg) cords. I was able to safely custom- cut them to length to fit the eave line of our house, with no string less than 35 or more than 110 lamps. Worked great.

With that said, some ideas that may be helpful:

The best bet is to find strings that are about double the length of the rail and simply make two runs, "out and back".

Or, are there any shrubs or bushes near the railings that you can place the extra lights in?

The other best option as mentioned is to change the bulbs in the cut section to higher voltage bulbs.

A resistor is a bad idea..as mentioned, the wattage required wil be somewhat high..and how will you safely enclose it, to protect it fron the weather, allow it to dissipate heat, and keep from shocking someone?
 
steve66 said:
Say the string starts with 120V, and 1 amp. Then thats 120 watts. If you take out 1/4 of the lamps, you will need a resistor equal to that wattage. So, as an example, 120/4 = a 30 watt resistor.
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The string label or box should specify the power or amperage. I'm sure it's well below an amp.
 
haskindm said:
Most strings of lights use 3-volt bulbs. 40 3-volt bulbs wired in series on a 120-volt circuit will provide 3-volts per bub. You will need to rewire the lights so that you have 40 bulbs in series. You will notice that most strings of lights are in some multiple of 40 (40 lights, 80 lights, 120 lights, etc.). In these cases you could remove one entire series string to reduce the number of total lights. Sounds like an awful lot of work for a little bit of convenience. Just put the bulbs closer together on his railing leaving a loop of wire between the bulbs.
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Strings of 50 or 100 use 2.4 - 2.5 volt bulbs. Strings of 35 or 70 use 3.5 volt bulbs. Some older 100 light strings used to be 5 strings of 20, or 6 volt bulbs. And some older 35 lamp strings were wired in 2-circuits, 17 on one series, 18 on the other. Still used 6 volt bulbs. There are 10 light strings and treetoppers which use 12 volt bulbs.
 
2.5v per light 100 lights total 2 series of 50

so as it stands now my best option is to rewire each series to 37 lights apiece?






















anyone have green butt splices for 22g?
 
where's the quality?

where's the quality?

There was a similar recent post about Christmas lights. The concern was about the quality of the lights, but the poster did point out that they only paid $2 a strand! He said there was more lead in that one strand of lights, than a chinese Barbi doll! If they paid a lot more the quality probably would not have been much better. In past years it seemed that a strand of lights would last several years. Now you are better off to throw your lights away ever season!
 
rcwilson said:
Or change out to LED style string which will use less power and isn't series wired.
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All of the strings I've seen run them in series, usually in multiples of 35 for white or blue (other colors may be different voltages, so perhaps a different multiple) I've also had strings where entire sections went dark, save for a few bulbs that would flutter (I'm assuming that the circuit wasn't completely broken, just some failed diodes)

carambola said:
2.5v per light 100 lights total 2 series of 50

so as it stands now my best option is to rewire each series to 37 lights apiece?

anyone have green butt splices for 22g?
Click to expand...
I've used green self-sealing heat-shrink and solder before...

Who says you have to stretch everything straight. If you space the bulbs closer together you can fit the excess length into the whole span. I've crammed 300' of LED lights into a 4' circle.

Here's an example of my mild OCD at work:
(12 sets of 70 LEDs, each bulb individually zip-tied to a 1"x1" mesh backer. The whole thing runs on 60 watts. (That's our company logo BTW; you can see where some of the individual LEDs have died after a year, what you don't see is the 3 entire strings I replaced)

LED_fun.jpg
 
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christmas light problem

I didn't know that there were any trim/adapt/ cut to your preference light strings out there on the market.
Did they come in on the latest slow boat from china ?
Or perhaps someone figures since we're getting garbage from china we may as well just re engineer the product thats suposedly been UL approved because we can do it better--nice job--when the product that you changed [the lite strings]from it's original tested form, thru an xmas miracle ,results in a christmas eve fire..,
Don't tell me it can't happen-just tell me what you would say if there was even the most remote possibility that your "lighting customization " was called in to question?
As someone who has been privy to insurance reviews of such incidents I can tell you that your customizing of the lights ,wether involved or not would basically be a lump of coal for you and a present to the insurance company--and they get enough presents already.
 
just remember, if your customer's house burns down and the light strings that you tampered with are the cause, is the amount he's paying you going to put a dent in your legal woes ?
 
nakulak said:
just remember, if your customer's house burns down and the light strings that you tampered with are the cause, is the amount he's paying you going to put a dent in your legal woes ?
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Only if your price includes a $10K retainer.
 
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