On Sun, 16 Apr 2017 09:03:35 -0400, Leon Fisk
wrote:
On Sat, 15 Apr 2017 19:37:25 -0700
Larry Jaques wrote:
On Sat, 15 Apr 2017 13:08:22 -0400, Leon Fisk
wrote:
snip
https://www.youtube.com/watch?v=jqRlBHJ3Fnw
I kinda wondered how they were making these. If you have a
little bit of electronics knowledge you should be able to
grasp it.
Gonna have to watch that and see why some of my p/ses have blown.
There are several ways to make these. This just happens to be one of
them and I suspect one of the cheapest...
Interestingly I just ordered some similar 5050 LED strips
to play with. Suspect they will be laid out different though being for
12vdc power.
They are, usually in sets of 3 with a resistor limiting current for
the 3.
The 5050 has three LED's in it.
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.
I like the minimal electronics in the "power supply" but not the
"christmas lights" in series aspect.
Series-parallel.
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...
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.
Also wonder how they will hold up to lightning strikes in the area...
They respond instantly to strikes, opening the circuit in an attempt
to stop further damage, and never work again. g
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.
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?
cringe
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 
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. g So, I have only half of my show and tell set.
--
I started out with nothing and
I still have most of it left!
--anon