Entropy

Relax in southern comfort on the east bank of the Mississippi. You're just around the corner from Beale Street and Sun Records. Watch the ducks, throw back a few and tell us what's on your mind.
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mediatechnology
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Re: Entropy

Post by mediatechnology »

JR. wrote: Thu Dec 13, 2018 9:24 am I notice my low key Christmas window display, composed of two cheap strings of christmas lights has one burned out bulb... (I'm guessing its a bulb). Kind of surprised to find it must be wired in parallel to still light.

JR
I think they are likely series-connected with shunted filaments and possibly shunting sockets (for when a lamp is removed).
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JR.
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Re: Entropy

Post by JR. »

mediatechnology wrote: Thu Dec 13, 2018 1:58 pm
JR. wrote: Thu Dec 13, 2018 9:24 am I notice my low key Christmas window display, composed of two cheap strings of christmas lights has one burned out bulb... (I'm guessing its a bulb). Kind of surprised to find it must be wired in parallel to still light.

JR
I think they are likely series-connected with shunted filaments and possibly shunting sockets (for when a lamp is removed).
Now I may have to take it apart to see...

JR
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mediatechnology
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Re: Entropy

Post by mediatechnology »

The LED string I just finished troubleshooting is wired similar to most long incandescent strings.

Hot and Neutral extend from plug to receptacle end.
One end of the light string picks up Hot at the plug end.
A third conductor daisy-chains the lamps which pickup the Neutral at the far end.
The lamps are 2.4V RMS on a 50 light string.
The shunts, across the filament posts, are normally insulated.
When a lamp opens, the momentary open-circuit voltage (120V) causes insulation breakdown which then welds the shunts to the filament posts.
As more lamps fail the current and operating voltage for each lamp increases.

One morning a couple of years ago, pre-LED, I turned on the tree and watched several shunt at "almost" the same time.
It was sort of a rapid fire thing.
Then the whole string went dark as the remaining ones super-nova'd.

Home Depot rejected my "review."
They claimed that the product, outdoor lighting, was not being used correctly.
What I don't know is if they thought the "incorrect use" was using it outdoors or tearing it down after it burnt out to see how crappy it was made.
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JR.
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Re: Entropy

Post by JR. »

I'm shocked...

My best review request was to complain that they sent me the wrong item (shovel) and still had the wrong item picture on their website...The picture did not agree with the item.

I did get a review request about some seeds I bought and I answered too early to tell. :lol:

Got one review request this week, before the goods arrived. :lol:

====
OK back to the lights... yes they are wired in series... The over voltage breakdown fuse link seems clever... at least for the first handful of failures. It seems the end game could get pretty exciting. :lol: I'd watch that...

JR

[edit no new bird droppings today, but it did rain last night so evidence may be gone. [/edit]
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Re: Entropy

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I didn't plan to revisit this in my life time. After Hurricane Katrina I re-arranged my rain ditches and even buried a 100'+ pipe under my side yard to drain back ditches lower...

Needless to say I have learned a bunch in the 12 years or so since I did that. The drain pipe has gotten slower over time and I hoped to dig up just the top couple ten feet to remedy that... :roll:
DSCF0068.JPG
DSCF0067.JPG
Bzzt not gonna happen... some 30-40' in I can measure a 2" rise in the buried drain instead of a slow gradual fall off... This rise with probably an inch+ of sediment explains my poor drain behavior...

I have bit the bullet and ordered new pipe... I can't imagine flushing out the old pipe with anything less than a fire hose. This time I ordered 4x25' sections so it will be more manageable. The original is 50' or 100' length in one section. The drain is something like 120' total but I can deal with the odd end part, I already have the old shorty.

The new pipe won't arrive until after christmas so I have time to raise the old pipe and regrade the ditch... This time I will add a deeper silt trap at the top end to keep the fine silt out of my pipe...

I do not have enough drop to grade this properly. Advice calls for 1/4" per foot, and I only have about 1/10th" per foot to work with.

Its always something.

JR
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Re: Entropy

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I am thinking that since I have negative draft over the top 30+ feet maybe I should consider keeping the pipe roughly level and placing another drain/trap at 25' in. It is too far below grade for a standard drain/trap, but they sell 6" extensions so that may get it deep enough to keep the pipe level and give me a trap to monitor and clean out sediment.

I'll need to make some measurements 8-)

[edit- first measurements look like 1x 6" riser is not tall enough, and 2x6" makes it too deep... :( [/edit]

JR
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Re: Entropy

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JR. wrote: Wed Dec 12, 2018 12:08 pm Solar driveway lamps are now sorted with new batteries. Lights bright all night... :D

My neighborhood birds like to use one lamp for target practice, maybe payback for me sealing up the chimney vents with wire screens. The bird nests up there always made a racket, so blocked them off this summer while they were away.

JR
I am rethinking my decision to replace batteries costing almost as much as new lamps. :roll:

With fresh charged 600mAh batteries the lamps burn all night.... but after a couple days with mixed sun and clouds the lamps returned to bad behavior. They turn on within 10 minutes of each other, but one went dark after only 2 hours, the other maybe 4 hours.

So I fully charged and swapped in the other two brand new nicad batteries and cleaned the fresh bird dropping off the solar panels. One lamp had 4 direct hits the other only one. Last night with fresh batteries they once again burned all night but I am not optimistic about the future.

Inexplicably indoors one of the two lamps is pretty much unresponsive to one of my several LED lighting fixtures. It responds to all the others, but this much difference between same age production solar lamps seems odd..

If this craps out again, it's due to get trashed. I don't know why I even care but my inner nerd has been aroused.

JR
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Re: Entropy

Post by mediatechnology »

I've never had much luck with getting them to light all night after a cloudy or partly-cloudy day.
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Re: Entropy

Post by JR. »

mediatechnology wrote: Mon Dec 17, 2018 2:08 pm I've never had much luck with getting them to light all night after a cloudy or partly-cloudy day.
I'm OK with the stronger of the two, it stayed lit 2x or 3x the weak sister... I don't need driveway lights these days anyhow, since I stopped playing basketball in town.

I am really suspicious of the solar panel output in that weak one which could also explain the odd threshold behavior. A low output solar panel explains a lot. Too bad I threw away my old ones...(one of my very few missed pack-rat opportunities).

---

I am rethinking the bird bombing precision and expect instead that it is indiscriminate. I saw hundreds of birds in my neighbors yard across the street, so they could easily perform some carpet bombing in a random fly-over.

It was mostly sunny today so we'll see how the weak sister lamp does tonight but I have low expectations.

JR

PS: I uncovered about another 15-20' of buried drain pipe, they drier it gets the harder to dig up the hard packed sand. I am near the mid point and my level bubble still look like the pipe is not dropping off yet. Still dead flat.
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mediatechnology
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Re: Entropy

Post by mediatechnology »

Well at least its not like the sewer line we installed during the remodel.
You would be digging in solid limestone.
We started at just about a foot depth.
The tap was at 8' 3" so we had a gradual fall over the 125 foot run and then a rapid drop in the last 4-5 feet.
I paid about $50 per foot for that 3" line to be installed.

Enjoy your DIY savings.
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