So why aren't the bulbs hooked up in parallel?
Draws too much current. Older strands used to be parallel and were a frequent cause of fires.
LEDs use less power but don't work well in parallel.
Are Christmas Lights in Series or Parallel?
21–30 of 55 posts
Re: Are Christmas Lights in Series or Parallel?
#22I thought those christmas lights had bee replaced by led strips.
Re: Are Christmas Lights in Series or Parallel?
#23So why aren't the bulbs hooked up in parallel?
Apart from other reasons mentioned. LEDs don’t work well in parallel. Even if you have just 2 of them, one will be bit brighter (drawing more current) than the other.
Re: Are Christmas Lights in Series or Parallel?
#24The answer to this, at least for longer strings, is usually 'both'. You'll usually find several sets of series wired runs connected in parallel and sometimes mid run branches.
Re: Are Christmas Lights in Series or Parallel?
#25I thought those christmas lights had bee replaced by led strips.
Even LEDs need electricity, and electricity can be delivered to them serially or in parallel too.
Re: Are Christmas Lights in Series or Parallel?
#26Earlier quoted context omitted.
Huh? Why not just use two wires and connect one wire to the other with each bulb. Like this: http://www.planetchristmas.com/Images/MinisA.gif I think the real answer is that if you did it this way (in traditional pre-transformer light sets), each bulb would have to be rated for 120v, or whatever your local line voltage is, which would make them both more expensive, and more dangerous.
Interesting: That would suggest that if you let enough bulbs on a strand go out, you reach a cascading-failure threshold at some point, where the voltage across the remaining filaments is higher than their rating. And then I guess the breaker trips.
Higher voltage on the remaining filaments really just shortens their life. So yes it's a type of cascading failure, but it's not catastrophic (each set has a fuse in the plug anyway, otherwise that 28AWG wire would function as the filament of last resort, if you get my drift).
This means you want to replace burnt out bulbs when you notice them, rather than waiting for the whole segment to go dark.
Re: Are Christmas Lights in Series or Parallel?
#27I 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.
Re: Are Christmas Lights in Series or Parallel?
#28tl;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.
Re: Are Christmas Lights in Series or Parallel?
#29A truly appropriate article for a site whose name is "wired".
LED sets are usually wired in series too, since they're current-driven devices.
Re: Are Christmas Lights in Series or Parallel?
#30Earlier quoted context omitted.
Probably to save wire, if you hooked em up in parallel you'd need to send a wire to every bulb from the outlet. With 10 bulbs at 1 inch spacing, you're wiring 1 + 2 + 3 + ... + 9 + 10 = 55 inches of wire instead of 10 Follows a roughly N^2 law
Why would you need a separate wire for each bulb? Seems to me like you could have a ladder topology: two bus wires running from the outlet, and then the bulbs going between them.
You're right, I don't know why I thought the way I did back there