LED Replacement tear down

Hi,

Happened to see this on youtube:

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I kinda wondered how they were making these. If you have a little bit of electronics knowledge you should be able to grasp it.

Interestingly I just ordered some similar 5050 LED strips to play with. Suspect they will be laid out different though being for

12vdc power.

I like the minimal electronics in the "power supply" but not the "christmas lights" in series aspect. Also wonder how they will hold up to lightning strikes in the area...

Reply to
Leon Fisk
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Gonna have to watch that and see why some of my p/ses have blown.

They are, usually in sets of 3 with a resistor limiting current for the 3.

Series-parallel.

They respond instantly to strikes, opening the circuit in an attempt to stop further damage, and never work again.

Reply to
Larry Jaques

There are several ways to make these. This just happens to be one of them and I suspect one of the cheapest...

The 5050 has three LED's in it.

I only watched this once but understood they were all in series for this application. Each 5050 has 3 LED's. Each strip has five 5050's. There are three strips plus one more 5050 on top. So Clive counted them as sixteen 5050's times 3 equals 48 total LED's in series. Any one of them opening up would kill it...

I worked for most of my career as a two-way radio tech in lightning territory. Stuff just plugged into the wiring in some way but not switched on could often be damaged. To be completely safe and protected from a lightning strike, all wires/connections had to be disconnected. Just switching stuff off isn't good enough.

I wish I would have kept my collection of lightning damaged parts I had accumulated when I retired. It was kind of interesting for show & tell :)

Reply to
Leon Fisk

Looking at my strips, the 3528 and 5630 each have one per three. The 5050 is like a COB, and has 3 diodes per SMD, as you said. I can't find my 5050 strip, so I'm looking online. Yeah, they must be wired in series outside the chip because there is 1 resistor per SMD on the strips. I had forgotten.

My undercabinet light is low density 3528 and was perfect for about 5 years until it developed an intermittent open. It's encapsulated so I'm not bothering to fix it.

Sorry, I haven't watched the vid yet. I was going by my 12v 5m strips. Some of the newer ones are being produced to run on 120v, but some of the corn cob lamps I've bought have had their own 120vac/12vdc supplies. Clive is cool. Watching now...yeah, straight series for those bulbs. Talk about a teensy power supply.

The 3528 strips can lose individual sets of 3 SMDs while the rest of the strip stays lit, so they're series-parallel. The 5050 strips should be able to lose a single SMD while the rest stay lit.

Strips are apples, bulbs oranges, I know.

A switch just acts as a resistor and the arc jumps it easily, I'm sure. I'm happy to say that I have no experience with lightning except to be thrilled by the displays as a kid in Little Rock, AR when the huge thunderstorms rolled by. And during a trip from Phoenix to Tucson once, we saw heat lightning galore. The news that night said it had started 119 forest fires in the hills on each side of I-10, the freeway we had just driven down. That's as close as I'd like to get, thanks. Did you ever have to work on said equipment during a storm?

I'll bet. I found an undamaged chunk of honeycomb catalytic convertor from a Pinto muffler, but can't find the other damaged chunk. The lady brought it in because it was sluggish. When I revved it up (sluggish) and not much volume came out the exhaust, I popped the cat and it revved right up. Upon removal, I saw the melted honeycomb right away. It turns out that her husband had been putting in the cheaper regular leaded gas into it for a year or so before it melted. I'll bet that thing lit up the parking lot and melted tar under the car every time she parked, it got so hot. I'm surprised it didn't catch the carpet on fire. So, I have only half of my show and tell set.

Reply to
Larry Jaques

Yeah, pretty sure it just jumps the switch, looking for the ground connection. I hated lightning storms. Usually made for long days, odd hours and a lot of chasing your tail around troubleshooting.

I wouldn't say have to but I did work at tower sites during storms. I didn't normally climb towers either. Happened to be ~100 ft up one checking an antenna one time when a storm rolled in. Always a guessing game but I felt the odds for getting done and down were in my favor :)

Had lightning hit the 120 ft tower at the shop once while we were working. The radio equipment was in the corner of the garage area. I happened to be in the garage when it hit. Nice "KERRZZITT" from the corner where the equipment was and some flashes like arc welding. Then the deafening "BOOM". We didn't have to go far for that "service" call...

Reply to
Leon Fisk

On 4/17/2017 1:50 PM, Leon Fisk wrote: [snip]

That happened to me one time. 600 ft up. I replaced the bad pigtail from the heliax to the antenna base and got down as fast as I could. It was moving in fast.

Reply to
gray_wolf

When the voltage is enough to jump miles, I'm sure it'll find its way through most circuits in strange ways.

Since you're here, I'm guessing that you were right. =:-0

A bit too close for my taste. I can't imagine how horrible it is to be hit by lightning, frying every cell on its way to ground. Or should I say "on its way up from ground."?

Reply to
Larry Jaques

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The old house I grew up in in South Texas had lightning rods which had been installed a long time ago. I was in the house when it was hit. The lighting rods gave a 'thrumm" sound from the hit. Vibrating like a plucked string from the current coupling to the Earth's magnetic field, I suspect.

Enjoy, DoN.

Reply to
DoN. Nichols

Reply to
Larry Jaques

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