On 11/28/2014 11:11 PM, Scott Dorsey wrote:
Jerry Stuckle wrote:
No, these have electronic power supplies in them. Otherwise they would
dissipate huge amounts of heat. Think about it. LED's run at about 3V.
That means a 9W LED requires about 3 amps of power. 3 amps at 240V is
720W - or about 711W of power wasted. They would be way less efficient
than any other type of bulbs. Plus LED's run on DC and would not work
as efficiently on 50Hz AC.

9W is an enormous amount of power for an LED. The LEDs used to replace
pilot lamps are normally running 10mA, not 3 amps. This is what allows
a dropping resistor to be used.
--scott



You are confusing LEDs with LED bulbs. A 9W LED bulb is equivalent to
about a 60W incandescent bulb.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

On 11/28/2014 11:16 PM, rickman wrote:
On 11/28/2014 11:01 PM, Jerry Stuckle wrote:
On 11/28/2014 10:39 PM, rickman wrote:
On 11/28/2014 8:52 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,


Sorry, but lighting control has been my job for much of the last 11
years. I am considered an expert in it by many of my peers and teach
courses on it. We also install many different lighting systems,
including LED.

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.


Which they aren't for many reasons that I won't get into here.

Really? So the standard dimmers in my home can't work with the dimmable
LED bulbs they are connected to and seem to control just fine?


Try reading a little...

http://www.ledsmagazine.com/articles...-magazine.html





This article is sorely lacking in facts. Notice the title: "LED
lighting must work with legacy dimming technologies".

There are a number of problems with dimmable LED bulbs and the standard
triac dimmer. See above. And I suggest you read more reliable
information. LED bulb manufacturer's information is a better start.

How do you explain the several LED bulbs I have working on standard
dimmers in my home?


Rick,

How do you explain the manufacturer of dimmers says standard dimmers
cannot be used reliably?

I don't see where they said that. They are only talking about their own
products.


"No, unlike incandescent bulbs that work with almost any dimmer, LED and
CFL bulbs perform differently depending on the dimmer you install. You
will need to select a dimmer designed specifically for dimmable LED/CFL
bulbs."

That seems to indicate they won't work reliably.


But since you want the details, here is a start. There are a number of
problems with standard incandescent dimmers. Since they cut off the
initial phase of the positive and negative phases, when they start
conducting there is a large surge of power. This surge causes
additional heat buildup in a switching power supply and can cause
premature failure of the bulb and/or dimmer.

Dealing with this heat would be part of the design requirements for a
"dimmable" LED bulb, no?


Not when used with a non-LED bulb dimmer.

Simple LED dimmers use MOSFETs to trim the trailing part of the
waveform, eliminating the surge.

You can argue design all you want. But the fact is this surge current
creates heat - which wastes energy, making the bulb less efficient. And
adding what is necessary to handle the extra current would add cost,
raising the price. Both make the product less competitive.


If you look at travel adapters for running U.S. devices on European
voltages, you'll find two different types - electronic switching and
standard transformer. You will notice the electronic switching supplies
are higher powered have cautions not to use them with electronic loads
such as radios and TV's. This is for the same reason as dimmers on LEDs
- the dimmer does not put out a clean waveform.

Transformer-based travel adapters have no such limitation because they
put out a clean signal, but have lower power ratings.

There are other problems, also. Conventional dimmers having a minimum
load (minimum current flowing through triacs). If the minimum load to
maintain conduction is 10W, a 15W LED will only dim to 2/3 power before
turning off.

Dimmable LED bulbs are also very sensitive to voltage fluctuations, and
can flicker with variations in the line voltage. This is especially
true when operating near that cutoff voltage noted above.

Again, this is a design issue and one that is present even when not
being dimmed.


No, they do not flicker at full power. They may dim a bit, but they
will not flicker. LED dimmers provide a stable voltage to the bulb,
eliminating flicker.


Also, since LED's respond immediately to current changes (unlike
incandescent, which have a high thermal inertia), there is a tendency
for them to flicker when the wrong dimmer is used. Sure, it's 120 hz
flicker - but some people are sensitive to it and can suffer headaches.
Worst case, but fortunately very rare, the flash can cause epileptic
seizures those sensitive to it.

I have seen no information that 120 Hz flicker is in any way noticeable
or that anyone is sensitive to it. Monitors have flickered at much
lower rates for a very long time. Plus... again, this is an issue
without dimmers.


You haven't been reading the medical engineering data. It is not so
much an issue without dimmers because there is a slight inertial effect
in the switching supply (capacitors) such that the bulb doesn't dim to
0, even at zero crossing. However, when you start cutting the AC cycle
going to the bulb, the capacitors totally discharge and you get a
relatively long period when the LEDs are completely black.

Monitors are not a problem because they work completely differently.
First of all, the original CRTs had a phosphor, which had a certain
amount of persistence. Newer LCD monitors (even "LED" monitors are LCD
monitors, just with an LED backlight) do not turn pixels on and off at a
scan rate.


These are some of the most serious problems with using conventional
dimmers with LED bulbs. It's also why manufacturers spend a lot of
money developing special dimmers for LED bulbs.

I would also recommend you check other manufacturer's of LED bulb
dimmers. You will find they all have the same cautions. But since
these pages are intended for consumers, they obviously leave out the
technical details. Those are available to dealers, though, either
through dealer-only pages or dealer support.

And yet, I have dimmers that work...


See above - and check other manufactures of LED dimmers, also. They all
say the same thing. Argue with them, not me.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

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.

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.

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.

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.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

On 11/28/2014 11:02 PM, wrote:
In rec.radio.amateur.boatanchors Jerry Stuckle wrote:

snip

Note the paragraph under "Do all LED and CFL light bulbs work with all
dimmers?"

No, thet don't, it depends on the manufacturer of the bulb.

Here's a couple of references from someone that does not sell light bulbs
or dimmers:

http://www.cnet.com/how-to/five-thin...ing-led-bulbs/

http://www.cnet.com/news/which-led-l...t-for-dimming/




I find cnet to be more reliable than PC Magazine - but that isn't saying
much. They are a consumer-oriented site, and dumb down their reports
significantly to meet the average reader's intelligence (which means
about the third-grade level - seriously). And please note the first
reference is a person who is a "CNET How-to expert" and the second a
"text-based adventure connoisseur".. Neither is an engineer. What are
their credentials - except that they got paid?

I'll go by the manufacturers which product the goods - and they all say
the same thing. When in doubt, find out from the experts.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

On 11/28/2014 11:09 PM, wrote:
In rec.radio.amateur.boatanchors Jerry Stuckle wrote:
On 11/28/2014 9:10 PM, wrote:
In rec.radio.amateur.boatanchors Jerry Stuckle wrote:

snip

No, I am arguing from facts - unlike you. I've been in the business of
installing lighting control (and other things) for 11 years now. We
install numerous LED control systems every year.

I forgot that you are an expert on EVERYTHING and to call into question
anything you say is the ultimate insult.


You've just proven once again that you're an expert in NOTHING.

And you've just proven once again that all that you know is what you have
supposedly done, not what exists in the world.

Here is a couple of articles on the subject from people who do NOT make
a living selling either light bulbs or controls.

http://www.cnet.com/how-to/five-thin...ing-led-bulbs/
http://www.cnet.com/news/which-led-l...t-for-dimming/

It seems that yes, dimmable LED bulbs are available for legacy dimmers,
and they work just fine.

snip


Right. By a "CNET How-to expert" and a "text-based adventure game
connoisseur". Real experts!

I'll go by what the engineers who design the devices say. You keep
reading the funnies.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

On 11/28/2014 11:46 PM, Jerry Stuckle wrote:
On 11/28/2014 11:16 PM, rickman wrote:
On 11/28/2014 11:01 PM, Jerry Stuckle wrote:
On 11/28/2014 10:39 PM, rickman wrote:
On 11/28/2014 8:52 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,


Sorry, but lighting control has been my job for much of the last 11
years. I am considered an expert in it by many of my peers and teach
courses on it. We also install many different lighting systems,
including LED.

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.


Which they aren't for many reasons that I won't get into here.

Really? So the standard dimmers in my home can't work with the dimmable
LED bulbs they are connected to and seem to control just fine?


Try reading a little...

http://www.ledsmagazine.com/articles...-magazine.html





This article is sorely lacking in facts. Notice the title: "LED
lighting must work with legacy dimming technologies".

There are a number of problems with dimmable LED bulbs and the standard
triac dimmer. See above. And I suggest you read more reliable
information. LED bulb manufacturer's information is a better start.

How do you explain the several LED bulbs I have working on standard
dimmers in my home?


Rick,

How do you explain the manufacturer of dimmers says standard dimmers
cannot be used reliably?

I don't see where they said that. They are only talking about their own
products.


"No, unlike incandescent bulbs that work with almost any dimmer, LED and
CFL bulbs perform differently depending on the dimmer you install. You
will need to select a dimmer designed specifically for dimmable LED/CFL
bulbs."

That seems to indicate they won't work reliably.

And yet I have units in my home that work...reliably. Rather than cite
dimmer companies, why not cite the bulb companies? That is what we are
discussing.


But since you want the details, here is a start. There are a number of
problems with standard incandescent dimmers. Since they cut off the
initial phase of the positive and negative phases, when they start
conducting there is a large surge of power. This surge causes
additional heat buildup in a switching power supply and can cause
premature failure of the bulb and/or dimmer.

Dealing with this heat would be part of the design requirements for a
"dimmable" LED bulb, no?


Not when used with a non-LED bulb dimmer.

Simple LED dimmers use MOSFETs to trim the trailing part of the
waveform, eliminating the surge.

You can argue design all you want. But the fact is this surge current
creates heat - which wastes energy, making the bulb less efficient. And
adding what is necessary to handle the extra current would add cost,
raising the price. Both make the product less competitive.

I never said anything about "wasted" energy or competitiveness. I said
LED bulbs can are are designed that work with existing dimmers.


If you look at travel adapters for running U.S. devices on European
voltages, you'll find two different types - electronic switching and
standard transformer. You will notice the electronic switching supplies
are higher powered have cautions not to use them with electronic loads
such as radios and TV's. This is for the same reason as dimmers on LEDs
- the dimmer does not put out a clean waveform.

Transformer-based travel adapters have no such limitation because they
put out a clean signal, but have lower power ratings.

There are other problems, also. Conventional dimmers having a minimum
load (minimum current flowing through triacs). If the minimum load to
maintain conduction is 10W, a 15W LED will only dim to 2/3 power before
turning off.

Dimmable LED bulbs are also very sensitive to voltage fluctuations, and
can flicker with variations in the line voltage. This is especially
true when operating near that cutoff voltage noted above.

Again, this is a design issue and one that is present even when not
being dimmed.


No, they do not flicker at full power. They may dim a bit, but they
will not flicker. LED dimmers provide a stable voltage to the bulb,
eliminating flicker.

There is nothing inherent in a phase angle dimmer that causes flickering
in a properly designed bulb. A few uF capacitance takes care of that.


Also, since LED's respond immediately to current changes (unlike
incandescent, which have a high thermal inertia), there is a tendency
for them to flicker when the wrong dimmer is used. Sure, it's 120 hz
flicker - but some people are sensitive to it and can suffer headaches.
Worst case, but fortunately very rare, the flash can cause epileptic
seizures those sensitive to it.

I have seen no information that 120 Hz flicker is in any way noticeable
or that anyone is sensitive to it. Monitors have flickered at much
lower rates for a very long time. Plus... again, this is an issue
without dimmers.


You haven't been reading the medical engineering data. It is not so
much an issue without dimmers because there is a slight inertial effect
in the switching supply (capacitors) such that the bulb doesn't dim to
0, even at zero crossing. However, when you start cutting the AC cycle
going to the bulb, the capacitors totally discharge and you get a
relatively long period when the LEDs are completely black.

Unless you add a bit more capacitance... again a bulb design issue.


Monitors are not a problem because they work completely differently.
First of all, the original CRTs had a phosphor, which had a certain
amount of persistence. Newer LCD monitors (even "LED" monitors are LCD
monitors, just with an LED backlight) do not turn pixels on and off at a
scan rate.

Lol. Monitors do flicker and have always flickered. At 60 Hz most
monitors bother me a lot. At 80 Hz not at all. I don't know anyone or
have read anything that says 120 Hz is not sufficient to preclude the
perception of flicker.


These are some of the most serious problems with using conventional
dimmers with LED bulbs. It's also why manufacturers spend a lot of
money developing special dimmers for LED bulbs.

I would also recommend you check other manufacturer's of LED bulb
dimmers. You will find they all have the same cautions. But since
these pages are intended for consumers, they obviously leave out the
technical details. Those are available to dealers, though, either
through dealer-only pages or dealer support.

And yet, I have dimmers that work...


See above - and check other manufactures of LED dimmers, also. They all
say the same thing. Argue with them, not me.

Ok, I guess we are done then.

--

Rick

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?


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.


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.


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.

--

Rick

On 11/28/2014 11:57 PM, Jerry Stuckle wrote:
On 11/28/2014 11:02 PM, wrote:
In rec.radio.amateur.boatanchors Jerry Stuckle wrote:

snip

Note the paragraph under "Do all LED and CFL light bulbs work with all
dimmers?"

No, thet don't, it depends on the manufacturer of the bulb.

Here's a couple of references from someone that does not sell light bulbs
or dimmers:

http://www.cnet.com/how-to/five-thin...ing-led-bulbs/

http://www.cnet.com/news/which-led-l...t-for-dimming/




I find cnet to be more reliable than PC Magazine - but that isn't saying
much. They are a consumer-oriented site, and dumb down their reports
significantly to meet the average reader's intelligence (which means
about the third-grade level - seriously). And please note the first
reference is a person who is a "CNET How-to expert" and the second a
"text-based adventure connoisseur".. Neither is an engineer. What are
their credentials - except that they got paid?

I'll go by the manufacturers which product the goods - and they all say
the same thing. When in doubt, find out from the experts.

Great review link. I think this shows conclusively that there are LED
bulbs that work with legacy dimmers. Regardless of what the "experts"
may say.

--

Rick

On Fri, 28 Nov 2014, 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?

That may be semantics. LEDs are current driven, voltage won't have much
effect other than when fed through a resistor that does convert to
current.

More likely the LEDs would be driven with a square wave, and changing the
ratio of on to off would vary the light output of the LED.

Michael

On Sat, 29 Nov 2014, Barry OGrady wrote:

On Fri, 28 Nov 2014 15:00:46 -0500, 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.

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.

Of course, one can run tubes on low voltage. The Collins 75S receiver
line apparently kept plat voltage relatively low (somewhere around 120v if
I remember right) which had certain advantages. One can run regular tubes
at 12VDC on the plate, there were some articles in Popular Electronics
about this, calling them "starved circuits". Or there were those tubes
designed to run off 12VDC for those hybrid car radios, a last gasp before
transistors took over completely.

I had a hybrid car radio with four valves and two transistors.
The RF amp, mixer, IF amp, and first audio used valves.
Those valves had 12 volts on the plate.

I assumed all the audio would be transitorized. But it was right at that
point where transistors might not have yet been so good at higher
frequencies, so tubes handled the radio part of the radio.

Motorola had a hybrid "lunchbox" type transceiver. A diode mixer in the
receiver, if I'm remembering right, the local oscillator chain was
subminiature tubes, as well as the first IF, then a 455KHz transistorized
IF strip and solid state audio. They had to keep the tubes because the
transistors weren't good enough for VHF.



I also had a valve test oscillator that ran off a 9 volt grid bias
battery.

Yes, that sort of thing would have been quite handy.

Michael