Re: Ping Don Klipstein - Series String Bulb Shunts

hr(bob) hofmann@xxxxxxx wrote:
On Dec 9, 6:20 pm, Jeff Wisnia <jwis...@xxxxxxxxxxxxxx> wrote:

hr(bob) hofm...@xxxxxxx wrote:

On Dec 8, 7:47 pm, d...@xxxxxxxxxxxxxx (Don Klipstein) wrote:

In <INmdnWDTzqsAAaDUnZ2dnUVZ_jidn...@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>, Jeff

Wisnia wrote:

Just what is in the "shunt" built into series string decorative lamp
bulbs which takes over when the filament opens?

Is it something like a PTC thermistor which heats up and melts some
powdered metal into a permanent short?

My curious mind wants to know.

As it turns out, I don't really know what those things are made of.

I would guess the whole string needs some sort of fuse - eventually all
of the shorting devices will do so.

- Don Klipstein (d...@xxxxxxxxx)

The fuse in the plug is both for the light string itself, and to
protect against too many strings being plugged one after another into
previous strings and overloading the wires in the string closest to
the power source.

I believe you must be writing about parallel strings with 120 volt bulbs
in them. I was asking about series strings, and I don't think you can
plug another string into those, can you?

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.- Hide quoted text -

- Show quoted text -


I have in my possession several 100 light sets, 2 50-light sets in
series, with a male plug for providing power and a female plug at the
other end of the 100 lights to plug in another string, and so forth.
Eventually there is too much current draw and one or both of the fuses
in the first circuit will blow. Frequently there will be a label on
such types of sets saying how many strings can be connected in
series. Take a look at some of the lights in the stores right now.


Thanks for teaching me that. I suspected that might be the case after thinking about it a bit more after posting my last reply.

Being Jewish, the electric holiday lights I've had hands on experience with have been limited in size, like "electric menorahs" I was at a son's home last weekend as he was putting one of those in a window. It was a flat plastic cutout with a series string of about 20 bulbs threaded around and attached to it.

I noticed the fuses in the plug and also the spare fuses and bulbs which came with it, along with a warning on the instructions to replace "burned out" bulbs promptly.

That's when I started wondering what the "shorting shunt" was made from. So I made my original post starting this thread.

Happy Holidays,

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.
.

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