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?

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?

snip

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

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

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?

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.

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.

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.



--
Jim Pennino

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

Though, 3VDC does seem a tad low.

Michael

--
Judge John E. Jones wrote:
To be sure, Darwin’s theory of evolution is imperfect. However,
the fact that a scientific theory cannot yet render an explanation
on every point should not be used as a pretext to thrust an
untestable alternative hypothesis grounded in religion into
the science classroom or to misrepresent well-established
scientific propositions.

When faith comes in logic goes out

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

On Friday, November 28, 2014 8:20:14 AM UTC-5, 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?

There is not a whole lot in there.
AC/DC supply, Buck/Boost controller chip with triac dimmer sensing (if it's a dimmable LED lamp), small inductors caps, rectifiers.

TI and ONSemi have controllers and reference designs at their web sites.
I don't know if the govt regulators are requiring any sort of power factor correction.

There is a whole lot of power factor correction circuitry going into higher current consumer goods in the EU so there should be good parts(inductors rectifiers, switches, caps) in a few years when consumers begin yearning for newer models.

"gareth" wrote in message
...
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?

Apologies to all. I had thought that this might be an interesting area to
investigate. I did not mean for it to be a vehicle for the two infantile
Yank rednecks to vent their spleens (again)

In rec.radio.amateur.homebrew gareth wrote:

Apologies to all. I had thought that this might be an interesting area to
investigate. I did not mean for it to be a vehicle for the two infantile
Yank rednecks to vent their spleens (again)

Thus speaketh Colonel Blimp, the pikey, bloviating, gas bag.



--
Jim Pennino