Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Are Christmas Lights in Series or Parallel?

wired.com

Post reply on HN
Print view View original

41–50 of 55 posts

Re: Are Christmas Lights in Series or Parallel?

#41

Post by mindslight »

raldi wrote: post #39
mindslight wrote: post #37

Earlier quoted context omitted.

Your intuition is correct, but a minor nit: bulbs aren't linear devices and don't have a fixed resistance. At low power, a bulb will look pretty close to a short circuit (it's just a piece of tungsten wire, after all). As power increases, the filament temperature rises and so does its resistance. This is why bulbs generally burn out when turning on - 170V across a mostly short circuit, with most of the resistance bei…

170?

The nominal voltage on an AC power line refers to the "RMS" average of the waveform. The peak voltage of a sine wave is sqrt(2)*RMS. Presumably bulbs tend to blow when they're turned on while the voltage is near a peak.

Re: Are Christmas Lights in Series or Parallel?

#42

Post by shreyas056 »

vortico wrote: post #28

tl;dr Christmas light bulbs each have a bypass wire which is initially insulated to avoid shorting the filament. If the filament burns out, the new high electric potential burns off the insulation, thus re-completing the circuit for the rest of the bulbs.

Actually this is what I hate about such articles, they extrapolate two sentence explanation into huge corpus.

Re: Are Christmas Lights in Series or Parallel?

#44

Post by fbe »

cpwright wrote: post #4

Unfortunately, the bypass wire doesn't actually always burn out to make the rest of the lights work. There is a device called a LightKeeper pro that sends a larger "zap" through the string to encourage the needed bypass wire to burn out. Its saved me a bunch of time figuring out which bulb was bad in a string of lights.

Or you can also DIY with a lighter : https://www.youtube.com/watch?v=7foDiXX-CcE

Re: Are Christmas Lights in Series or Parallel?

#45

Post by Rapzid »

I understand the article is about series vs parallel but I'm sort of... Taken aback by the premise setup in the beginning that:

A.) Its hard to find the burnt out bulb(hint its almost always the one with the broken filiment)

B.) You should just throw the strand away

Maybe I'm just too old at 30(?) or I grew up underprivileged because I recall untangling lights and replacing burnt out bulbs well, as far back as I can recall. 7 or so? And throwing the strand away is just wasteful.

I understand there is an article to write but on one hand we have some guy writing about creating a sou-vide oven and on the other someone suggesting burnt out light bulbs are too hard to find. :|

Re: Are Christmas Lights in Series or Parallel?

#47

Post by icebraining »

Rapzid wrote: post #45

I understand the article is about series vs parallel but I'm sort of... Taken aback by the premise setup in the beginning that: A.) Its hard to find the burnt out bulb(hint its almost always the one with the broken filiment) B.) You should just throw the strand away Maybe I'm just too old at 30(?) or I grew up underprivileged because I recall untangling lights and replacing burnt out bulbs well, as far back as I can…

I agree with you, and I also replaced burnt bulbs as a kid, but nowadays I'm seeing more and more Christmas lights using molded plastic instead of sockets (also, usually with LEDs instead of bulbs), so replacing them is much harder than it used to be.

Re: Are Christmas Lights in Series or Parallel?

#48

Post by prof_hobart »

Rapzid wrote: post #45

I understand the article is about series vs parallel but I'm sort of... Taken aback by the premise setup in the beginning that: A.) Its hard to find the burnt out bulb(hint its almost always the one with the broken filiment) B.) You should just throw the strand away Maybe I'm just too old at 30(?) or I grew up underprivileged because I recall untangling lights and replacing burnt out bulbs well, as far back as I can…

It's not always easy to see the broken filament, or at least didn't used to be (I've not really examined many in detail recently).

As a kid in the 80s, I used to work in my dad's hardware shop and people regularly used to bring in lights that didn't work. We had a little test area set up where we would put each bulb in turn to find out which one(s) wouldn't light.

Re: Are Christmas Lights in Series or Parallel?

#49

Post by robin_reala »

mindslight wrote: post #27
swah wrote: post #22

I thought those christmas lights had bee replaced by led strips.

Piercing blue, icy white, and unfocusing violet aren't so inviting on a cold winter's night. Black body 4 life.

If you’re going to do it properly you’d actually attach candles to your tree, although this is slightly riskier (I’ve been woken and run out of the house by my mum in the past while my dad attempted to put out a flaming branch).

Re: Are Christmas Lights in Series or Parallel?

#50

Post by _mulder_ »

Rapzid wrote: post #45

I understand the article is about series vs parallel but I'm sort of... Taken aback by the premise setup in the beginning that: A.) Its hard to find the burnt out bulb(hint its almost always the one with the broken filiment) B.) You should just throw the strand away Maybe I'm just too old at 30(?) or I grew up underprivileged because I recall untangling lights and replacing burnt out bulbs well, as far back as I can…

I completely agree.

"in the event of a string of lights going out on your tree, replacing the strand is usually the best option. It’s pretty difficult to find that one bulb that’s causing the problem"

That one sentence sums up most of what is wrong with Christmas, and society, today. I find the "just throw it away if it's broken" attitude really difficult to accept. I would hope everyone reading HN has the self-awareness to consider where their possessions come from and what happens to them when they're thrown away.

Post reply on HN