On 11/29/2014 9:47 AM, Jerry Stuckle wrote:
On 11/29/2014 12:12 AM, rickman wrote:
On 11/28/2014 11:50 PM, Jerry Stuckle wrote:
On 11/28/2014 10:51 PM, rickman wrote:
On 11/28/2014 9:34 PM, Jerry Stuckle wrote:
On 11/28/2014 7:05 PM, rickman wrote:
On 11/28/2014 6:16 PM, Jerry Stuckle wrote:
On 11/28/2014 5:24 PM, wrote:
In rec.radio.amateur.boatanchors Jerry Stuckle
wrote:
On 11/28/2014 4:11 PM, wrote:
In rec.radio.amateur.boatanchors Michael Black
wrote:
On Fri, 28 Nov 2014, wrote:
In rec.radio.amateur.boatanchors gareth
wrote:
These LED replacements for 240V mains lamps; if one were to
open them, would one find a high voltage regulator suitable for
some of our valve experiments and repairs?
As the regulators are potted in and would be difficult to
remove,
and
since LED's run on voltages on the order of 2-3 volts, no.
How many 3 volt valves can you name?
I think that point was that if a regulator was used to drop the
line
voltage to those 3volts, it could handle high voltage input. The
probably
false assumption is that the regulator would be variable from
some
very
high output voltage to some very low output voltage, so one could
use it
for tubes by making that adjustment.
Given that manufacturers want the least cost in a product, and the
regulator in a light bulb would have no need for a variable
regulator,
and that these things are made in the millions, it would be
extremely
silly to assume that the regulator is anything other than a fixed
regulator for LED's and is designed to handle the load of some
fixed
number of LED's.
Once again, incorrect. Have you ever heard of "dimmable LED
bulbs"?
How do you dim without an adjustable regulator?
You do realize that a dimmable light bulb is dimmed by changeing the
supply voltage and not by anything else connected to the bulb?
For incandescent, yes. But not for LED bulbs. If that were the
case,
why would some LED bulbs be dimmable and others not?
To specifically answer your question, you design a regulator who's
output
is some precentage of the raw input as opposed to a regulator who's
output is always equal to some reference voltage.
Again, it all depends.
And to be yet more specific, since LED brightness is proportional to
current and resistors would waste power, the regulator would be a
current regulator with an average current output proportional to the
raw input voltage.
Then why can't you use standard incandescent dimmers with LED bulbs?
A lot of IC regulators can't handle high voltage. If nothing
else, nobody
saw the need, it was the solid state age. So dissipation issues
aside,
most regulators expect at most a relatively low DC voltage input.
True for IC regulators. Hoever high voltage transistors exist
these
days which makes designing a high voltage regulator pretty
trivial.
Sure. But how do you handle the current requirements without some
kind
of transformer?
Well, assuming you want some voltage greater than the wall plug
maximum,
the need for a transformer is pretty much a given unless some
sort of
voltage multiplying rectifier is sufficient for the need, which is
where the current requirement becomes relevant.
However, the subject was high voltage regulators, not where does the
raw high voltage come from.
And where do you get the current necessary to supply the LEDs in the
bulbs? A typical LED required around 3V (usually 2.7V to 3.3V,
depending on the LED)? A 9 watt LED would require 3 amps of current.
Or, if the LEDs were in series, something less. But without a
transformer, the current would still exceed that of an incandescent
bulb.
You obviously are unfamiliar with the structure of LED bulbs.
You two are both speculating and have limited information to base
either
of your opinions on. Jim says,
You do realize that a dimmable light bulb is dimmed by changeing the
supply voltage and not by anything else connected to the bulb?
which is not correct in that most dimmers work by reducing the phase
angle of the applied AC or to reduce noise some simply don't turn
on for
entire half cycles.
Jerry says,
Then why can't you use standard incandescent dimmers with LED bulbs?
Which is wrong because you can use "standard" dimmers, but the LED
bulb
has to be designed for it.
Try reading a little...
http://www.ledsmagazine.com/articles...-magazine.html
Rickman, here's a better page from the manufacturer of dimmers (and one
of the lines we carry):
http://www.lutron.com/en-US/Educatio...LsandLEDs.aspx
Note the paragraph under "Do all LED and CFL light bulbs work with all
dimmers?"
That has even less information than the page I referred you to.
But it is accurate information from a manufacturer.
Your link says nothing about LED lights in general, only the Lutron
devices. As the article I referenced indicated, LEDs can be made to
work with generic phase control dimmers and the several LED bulbs I have
that work prove the point. I especially like Lutron's compatibility
list. They have a wide definition of "compatible"....
Of course. But check any manufacturer of LED dimmers. They all say the
same thing in one way or another.
"Products on this list are considered compatible with the respective
Lutron C·L dimmers. Depending on the quality of the bulb you select,
compatible bulbs may still:
- have less dimming range than an incandescent or halogen bulb
- dim less smoothly than an incandescent or halogen bulb
- flicker or shimmer at certain light levels
- buzz"
LOL. If the combination does any of these things I don't consider that
to be "compatible".
No dimmer manufacturer can control how bulbs are built. Lutron does its
best to specify what will and will not work.
So why are you citing dimmer makers when we are discussing the bulbs?
Because of the claim that any dimmer can be used with LED bulbs. And
depending on the bulbs, they may or may not work with dimmers - even
ones specifically made for LED bulbs.
For instance, there are a some cheap Chinese LED bulbs which claim to be
dimmable - but don't work reliably with ANY dimmer. And when you use
them with a dimmer, they don't last long.
Actually I find Lutron to have some real crap product as well as very
poor customer support. In order to assure I could get compatible dimmer
and lamp, I bought an LED fixture that listed part numbers for
compatible dimmers (tested in conjunction with the dimmer companies) and
bought a compatible Lutron dimmer. The result was they didn't work
properly. Clearly this particular fixture was *not* compatible with
generic dimmers and wasn't even compatible with the specified dimmer.
They have excellent dealer support. And most of their sales is through
dealers like us.
You mean dealers like Home Depot who have zero support other than
letting you return the crap that doesn't work? Like I said, the box was
labeled as being compatible with the "tested" dimmers. It wasn't unless
you define "compatible" (by the Lutron web page) as
- have less dimming range than an incandescent or halogen bulb
- dim less smoothly than an incandescent or halogen bulb
- flicker or shimmer at certain light levels
- buzz"
Obviously Lutron has a very broad definition of "compatible". I would
stop using them as an authority if I were you.
Maybe the local store has no support, but that's not the end of their
support. To become an authorized dealer, our tech people had to go
through a lot of training (common for the better brands). Home Depot
had to do the same thing, but obviously they don't have every employee
in the country trained (nor could they maintain the training).
Good luck trying to find *anyone* in the store with "training" in
dimmers. I did and found no one who could help me pick out compatible
devices.
And yes, "compatible" means they will work - but not necessarily how
*well* they will work. And some bulbs work fine, while some don't -
even when they are the same model from the same manufacturer.
There you go. A bulb or dimmer can be total crap, producing totally
unacceptable operation and that is ok with the maker. But as long as it
was certified as "compatible" by an engineer, that's ok with you too.
They have been a very reliable manufacturer for us in both the
residential and commercial sectors for a number of years. When properly
installed, we have had almost zero problems with their products. And we
install a lot every year.
But you don't like Lutron's comments? Here's another manufacturer:
http://www.leviton.com/OA_HTML/Secti...minisite=10251
This page doesn't say anything like what you are saying.
Or this one (a non-engineering sales pitch, but saying the same thing)
http://www.legrand.us/resources-and-...l-dimmers.aspx
(download the article)
This one isn't even about the bulbs, it is only about dimmers. You seem
to be looking at this from the wrong perspective. Let me recap...
You...
Then why can't you use standard incandescent dimmers with LED
bulbs?
Me...
Which is wrong because you can use "standard" dimmers, but the LED
bulb
has to be designed for it.
No, you can't use just any dimmer with just any bulb. But as the
article from the possibly "non-engineer" there are bulbs that will work
with any dimmer which is what I said.
I contacted both Lutron and the company who made the fixture. I don't
recall the response of the LED fixture company but Lutron simply
recommended another dimmer with no mention of why they were on the
compatibility list and yet were not compatible.
Probably because they are not high on consumer sales. Dealers like us
get excellent support from them (and most manufacturers). I can even
call and talk directly with an engineer.
Do me a favor and ask them why they consider flickering, less dimming
range, unsmooth dimming and buzzing as being acceptable in compatible
products.
Compatible does not mean it will work perfectly. True in ANY business.
Lol! That is the road to returns and is a line of BS.
Their main consumer support is through the dealer you purchased it from.
If you got it from the internet or similar, you got what you paid for.
If you got it from an authorized Lutron dealer, they should support
you.
Sure, I expect I can *still* return it to Home Depot. But the point is
Lutron and the lamp company has a crappy definition of "compatible"
which means I won't be buying any more Lutron dimming products. By
their own definition they work like crap.
Meanwhile I have LED bulbs that do work properly with conventional
dimmers. Also, you have not mentioned anything about how LED bulbs are
design to work with *any* dimmers. The page I referenced provided a
design that will provide a properly functioning LED bulb truly
compatible with legacy dimmers.
No, their definition is the same as that in any market. Compatible does
not mean things will work perfectly.
As to the article - you mean the one titled "LED lighting must work with
legacy dimming technologies"? The one with an obvious agenda?
Really? What is the agenda?
Did you even read the article? How about Table 1 where it states that
phase dimmers have problems with LED lighting? In fact, some of the
same problems I have already mentioned?
No one ever said all LEDs will work with all dimmers. You keep
recycling the same arguments.
And BTW - what are the author's credentials? Is he an engineer who
knows what he's talking about, or just some blogger who's read a few
articles? The lack of a short bio is noticeable.
How many engineers does it take to screw in a lightbulb?
Ok, I guess I'm done with this conversation. Enjoy.
--
Rick