Why are revlimiters uneven?

On Tue, 04 May 2021 18:33:20 +0100, Rod Speed wrote:



"Fredxx" wrote in message
...
On 04/05/2021 13:23, Brian Gaff (Sofa) wrote:
OK what do they use then, All I remember from my brief experience trying
to
dim leds was that the most successful way of doing that was by duty
cycle,
ie on to off times with them driven by some kind of oscillator with
variable
mark space ratios. However it is obvious that even the briefest of ons
and
the longest offs tends to still be visible in most cases, and not
terribly
accurate if many leds are used as the load, there being a spread of
linearity in any given number.

PWM is the cheapest way as it needs no other component.

For a small improvement in efficiency then a constant current source would
be best but obviously costs more.

Doesn’t necessarily cost anything more at all with leds. Same price as
voltage regulators.

But if I buy a "dimmable LED" lightbulb, I can dim it with a dimmer that's on the wall, at 240V AC. Is there electronics inside the bulb sensing the PWM from the dimmer and using that to control its internal current limiter?

--
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On Wed, 05 May 2021 09:14:18 +0100, The Natural Philosopher wrote:

On 04/05/2021 22:00, Max Demian wrote:
On 04/05/2021 17:38, Fredxx wrote:
On 04/05/2021 13:23, Brian Gaff (Sofa) wrote:

OK what do they use then, All I remember from my brief experience
trying to
dim leds was that the most successful way of doing that was by duty
cycle,
ie on to off times with them driven by some kind of oscillator with
variable
mark space ratios. However it is obvious that even the briefest of
ons and
the longest offs tends to still be visible in most cases, and not
terribly
accurate if many leds are used as the load, there being a spread of
linearity in any given number.

PWM is the cheapest way as it needs no other component.

Yes, I made a PWM dimmer circuit (for fun) based on circuits I found on
the Internet and it works well, and dims to nothingness. (12VDC working
a white LED strip.)

do it at high enough frequency and there is no visible flicker, and you
can feed the LEDS via a small ferrite inductor with a parallel capacitor
and reduce HF flicker too.

Please tell the car manufacturers how to do this so I don't have to watch flickering tail lights while driving behind someone, or flashing headlights on TV.

--
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"Commander Kinsey" wrote in message
news
On Tue, 04 May 2021 18:33:20 +0100, Rod Speed
wrote:



"Fredxx" wrote in message
...
On 04/05/2021 13:23, Brian Gaff (Sofa) wrote:
OK what do they use then, All I remember from my brief experience
trying
to
dim leds was that the most successful way of doing that was by duty
cycle,
ie on to off times with them driven by some kind of oscillator with
variable
mark space ratios. However it is obvious that even the briefest of ons
and
the longest offs tends to still be visible in most cases, and not
terribly
accurate if many leds are used as the load, there being a spread of
linearity in any given number.

PWM is the cheapest way as it needs no other component.

For a small improvement in efficiency then a constant current source
would
be best but obviously costs more.

Doesn’t necessarily cost anything more at all with leds. Same price as
voltage regulators.

But if I buy a "dimmable LED" lightbulb, I can dim it with a dimmer that's
on the wall, at 240V AC. Is there electronics inside the bulb sensing the
PWM from the dimmer and using that to control its internal current
limiter?

I was talking about led bulbs that dim without a dimmer that’s on the
wall. The dimmer is internal and just has a current regulator instead
of a voltage regulator that costs the same. No PWM involved.

On Mon, 10 May 2021 05:24:27 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

FLUSH the two subnormal sociopathic cretins' endless absolutely idiotic
blather

--
Another typical retarded conversation between our two village idiots,
Birdbrain and Rodent Speed:

Birdbrain: "You beat me to it. Plain sex is boring."

Senile Rodent: "Then **** the cats. That wont be boring."

Birdbrain: "Sell me a de-clawing tool first."

Senile Rodent: "Wont help with the teeth."

Birdbrain: "They've never gone for me with their mouths."

Rodent Speed: "They will if you are stupid enough to try ****ing them."

Birdbrain: "No, they always use claws."

Rodent Speed: "They wont if you try ****ing them. Try it and see."

Message-ID:

On Thu, 06 May 2021 21:05:33 +0100, The Natural Philosopher wrote:

On 06/05/2021 18:35, Commander Kinsey wrote:
On Wed, 05 May 2021 21:34:31 +0100, Rod Speed
wrote:



"Commander Kinsey" wrote in message
news On Tue, 04 May 2021 03:01:29 +0100, rbowman wrote:

On 05/03/2021 10:13 AM, Commander Kinsey wrote:
Is it to warn you? Even my toilet cistern can slow down smoothly.

On cars? Yes. Cutting the engine abruptly when you hit the red line
wouldn't be good so they simulate ignition breakup to give you a hint.

But at that point you've already gone over the peak of the power curve.
I'd just make it drop the curve more quickly so it can never go too
fast.

Not possible to do that and still get the best performance.

You're getting **** all performance if you've gone over the power curve
anyway.

That depends entirely on how the engine is set up. A turbocharged angine
for racing can easily be delivering nearly flat torque all the way to
disitegration and will develop full power on the limiters edge

I've never seen a power curve like that. Admittedly I've usually looked at curves for residential [1] cars, but I've seen a handful for racing.

That really isn't the word I want to use there.

--
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On Fri, 07 May 2021 11:54:14 +0100, TMS320 wrote:

On 06/05/2021 18:35, Commander Kinsey wrote:
On Wed, 05 May 2021 21:34:31 +0100, Rod Speed
"Commander Kinsey" wrote in message

But at that point you've already gone over the peak of the power curve.
I'd just make it drop the curve more quickly so it can never go too
fast.

Not possible to do that and still get the best performance.

You're getting **** all performance if you've gone over the power curve
anyway.

It's a primitive technique for an engine under-endowed with torque. When
you change up, there is an inevitable drop in power so the idea of
revving beyond peak power is to get further up the curve in the next gear.

Perhaps there should be more gears then.

--
Sent from my iPhone, this spam courtesy of Apple incorporated.

On 10/05/2021 19:09, Commander Kinsey wrote:
On Thu, 06 May 2021 21:05:33 +0100, The Natural Philosopher
wrote:

On 06/05/2021 18:35, Commander Kinsey wrote:
On Wed, 05 May 2021 21:34:31 +0100, Rod Speed
wrote:



"Commander Kinsey" wrote in message
news On Tue, 04 May 2021 03:01:29 +0100, rbowman
wrote:

On 05/03/2021 10:13 AM, Commander Kinsey wrote:
Is it to warn you?Â* Even my toilet cistern can slow down smoothly.

On cars? Yes. Cutting the engine abruptly when you hit the red line
wouldn't be good so they simulate ignition breakup to give you a
hint.

But at that point you've already gone over the peak of the power
curve.
I'd just make it drop the curve more quickly so it can never go too
fast.

Not possible to do that and still get the best performance.

You're getting **** all performance if you've gone over the power curve
anyway.

That depends entirely on how the engine is set up. A turbocharged angine
for racing can easily be delivering nearly flat torque all the way to
disitegration and will develop full power on the limiters edge

I've never seen a power curve like that.

Its not my fault you are a thick ignorant ****, is it?



--
“The ultimate result of shielding men from the effects of folly is to
fill the world with fools.�

Herbert Spencer

On 10/05/21 7:42 am, Peeler wrote:
On Mon, 10 May 2021 05:24:27 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

FLUSH the two subnormal sociopathic cretins' endless absolutely idiotic
blather

Peeler's musculature differs from jawed vertebrates in that he does not
have a horizontal septum nor vertical septum, junctions of connective
tissue that separate the hypaxial musculature and epaxial musculature.

On 10/05/21 6:38 am, Peeler wrote:
On Fri, 7 May 2021 10:57:08 +1200, Peter Keller, the dumb gay masochistic
little cyclist, blabbered again:


I wonder whether your car, too, thinks that you are an endlessly driveling
senile gossip, lowbrowwoman. BG


Peeler's slime has been proven to impair the function of a predator
fish's gills. In this case, Peeler's mucus would clog the predator's
gills, disabling their ability to respire.

VBG Poor idiotic gay cyclist!


The unidirectional water flow passing Peeler's gills is produced by
rolling and unrolling velar folds located inside a chamber developed
from the nasohypophyseal tract, and is operated by a complex set of
muscles inserting into cartilages of the neurocranium, assisted by
peristaltic contractions of the gill pouches and their ducts.

As I said: You poor idiotic gay cyclist! BG

Peeler does, however, have true myomeres and myosepta like all vertebrates.

On 10/05/21 6:37 am, Peeler wrote:
On Sun, 9 May 2021 23:17:59 +1200, Peter Keller, the dumb gay masochistic
little cyclist, blabbered again:


Peeler is the only known vertebrate with osmoregulation isosmotic to his
external environment. Renal function of Peeler remains poorly described.
Hypothetically, he excretes ions in bile salts.

Buahahahahahahaaa!!! Poor demented gay cyclist!

The complexity of Peeler's brain has been an issue of debate since the
late 19th century, with some morphologists suggesting that he does not
possess a cerebellum, while others suggest that it is continuous with
the midbrain.[

Like I just said: "Buahahahahahahaaa!!! You poor demented gay cyclist!"

The mechanics of peeler's craniofacial muscles in feeding have been
investigated, revealing advantages and disadvantages of the dental plate.