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Maker Pro

LED car lights flicker - no need!

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Dave Plowman

Jan 1, 1970
0
The LED bulbs I have used have been anything but "crap". They use 1/10th
the electricity of equivalent halogen bulbs and can be bought as flood or
spotlight versions.

They may well use less electricity. But if that's the only criterion for
domestic lighting a fluorescent tube will do the job rather better and for
less cost.
 
S

Steve Firth

Jan 1, 1970
0
Dave Plowman said:
They may well use less electricity. But if that's the only criterion for
domestic lighting a fluorescent tube will do the job rather better and for
less cost.

Where did I say it was the only criterion? The major objection from SWMBO
is that they are "too bright".

Way better than CFL and, as I mentioned, equivalent to halogen, in fact a
3W LED with SMD elements providers better illumination than a 35W halogen.
 
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Dave Plowman

Jan 1, 1970
0
Where did I say it was the only criterion?

It's the first thing you mentioned about them?
The major objection from
SWMBO is that they are "too bright".

Typically yes - when you look at them. Sadly the actual usable light from
them is anything but.
Way better than CFL and, as I mentioned, equivalent to halogen, in fact
a 3W LED with SMD elements providers better illumination than a 35W
halogen.

Define better. That usually means the latest thing to impress the gullible.

There are no LEDs on the domestic market that come even close to matching
the quality of light from halogen. Of course that doesn't much matter to
many.
 
S

Steve Firth

Jan 1, 1970
0
Dave Plowman said:
It's the first thing you mentioned about them?


Typically yes - when you look at them. Sadly the actual usable light from
them is anything but.


Define better. That usually means the latest thing to impress the gullible.

There are no LEDs on the domestic market that come even close to matching
the quality of light from halogen. Of course that doesn't much matter to
many.

I love the way your opinion masquerades as fact.
 
D

Dave Plowman

Jan 1, 1970
0
I love the way your opinion masquerades as fact.

Then publish some plots of their spectrum that proves me wrong. I'll not
hold my breath.
 
M

Major Scott

Jan 1, 1970
0
No, the series resistor merely determines the maximum current that could
flow through the LED.

Take for example a 6 volt DC supply connected to an LED in series with a 200 ohm resistor.
2V 20mA at the LED, 4V 20mA in the resistor.

Now change the supply to 4V.
2V 10mA at the LED, 2V 10mA in the resistor.

Lowering voltage will dim the LED.
 
M

Major Scott

Jan 1, 1970
0
Because a large number of morons in and around the motor industry have
become attached to the idea that if some lighting is good, brighter lights
must be better.

Thy don't seem to recognise that the the current standard of lighting is
making the roads more dangerous.

Some xenon headlights, yes. But LED brakelights are not too bright. They're just too flickery. They appear the same brightness as a standard 21W brakelight bulb to me.

So why can't this pretend brightness be applied to domestic lighting? An LED lamp which currently equates to a 50W incandescent could give out what looks like 100W. If it's not done because people are more likely to notice the flicker at home, then why not have a higher pulse frequency?
 
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Major Scott

Jan 1, 1970
0
No idea. They are crap and I wouldn't have one in the house.

Have you ever seen a CREE LED? I've got a load of GU10 CREE LED spots and they're better than the 50W halogens they replaced. 6W in, 50W out, and to my eyesight they look more like 75W out, and a whiter light too. And they don't keep tripping the circuit breaker when they go, or making the fitting to hot to touch which is worrying next to a wood panelled ceiling.
 
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bm

Jan 1, 1970
0
Major Scott said:
Take for example a 6 volt DC supply connected to an LED in series with a
200 ohm resistor.
2V 20mA at the LED, 4V 20mA in the resistor.

Now change the supply to 4V.
2V 10mA at the LED, 2V 10mA in the resistor.

**** a duck, they DID teach you something.
 
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Dave Plowman

Jan 1, 1970
0
Take for example a 6 volt DC supply connected to an LED in series with a
200 ohm resistor. 2V 20mA at the LED, 4V 20mA in the resistor.
Now change the supply to 4V.
2V 10mA at the LED, 2V 10mA in the resistor.

Not so, since the forward voltage drop of an LED is a constant.
Lowering voltage will dim the LED.

That bit is at least correct.
 
B

bm

Jan 1, 1970
0
Dave Plowman said:
That makes two of you who failed GCE electronics.

Sorry, Dave, but I think you'll find that his 'sums' are pretty much
correct, amazingly.
 
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bm

Jan 1, 1970
0
bm said:
Sorry, Dave, but I think you'll find that his 'sums' are pretty much
correct, amazingly.

Treat the LED as a 2V Zener and you won't go far wrong.
 
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Dave Plowman

Jan 1, 1970
0
Sorry, Dave, but I think you'll find that his 'sums' are pretty much
correct, amazingly.

I must be from a different generation. 'Sums' are either correct or not.
Anything else is a guess.
 
B

bm

Jan 1, 1970
0
Dave Plowman said:
I must be from a different generation. 'Sums' are either correct or not.
Anything else is a guess.

How correct do you wanna be? 10mA/11mA 20mA/21mA?
You have to admit he's in the right ballpark or thereabouts.
I'm still recovering.
PHucker with a clue? Blimey.
 
M

Mike Tomlinson

Jan 1, 1970
0
Adrian said:
Which, on the law of averages, means you won't find a job for nearly two
years.

Kinda explains why he spends so much time posting shite to usenet, when
he could be looking for gainful employment.
 
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DavidR

Jan 1, 1970
0
Major Scott said:
Some xenon headlights, yes. But LED brakelights are not too bright.

When you get stuck behind a new Audi (can't remember whether it was A1 or
A3) in a slow moving queue you might change your mind. Though it would help
if people hadn't developed the habit of using the pedal as a foot rest. I
find that popping on the handbrake allows the foot to find a far more
relaxed position.
 
I

Ian Jackson

Jan 1, 1970
0
When you get stuck behind a new Audi (can't remember whether it was A1 or
A3) in a slow moving queue you might change your mind. Though it would help
if people hadn't developed the habit of using the pedal as a foot rest. I
find that popping on the handbrake allows the foot to find a far more
relaxed position.
Not many people know that if you are obviously going to be stationary
for more than a few seconds, you should apply the handbrake.
Unfortunately, that won't stop them using the pedal as a foot rest.
 
M

Mr Pounder

Jan 1, 1970
0
Major Scott said:
I'm applying for about 2 a week at the moment. They seem to come like
London Buses.


You've never met me. I can be extremely polite and diplomatic when
required.

{Falls off chair}
 
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