In message 5058061f.6040...@clanbaker.org, Michael Baker writes:
I was wondering, after seeing some 100 watt LED series
wired assemblies that were listed at 30-34 VDC @ 2.9A if a
number of LEDs could be wired in series and powered directly
from a rectified 110 VAC power source.
You wouldn't want
Hm Maybe if an 1:1 isolation transformer is used
except that it would be too heavy and large
Mike Baker
Mike,
As long as one is spending on a transformer.. might as well use a
step down transformer and use lower voltage lights!
Raj
time and frequency measurement
Subject: Re: [time-nuts] Hi Power LED Light power supply...
LEDs change brightness very fast and will flicker at 120Hz if you do
that. Many people can see 120Hz flicker.
Also you would not be getting all the brightness you could. Better to
low pass filter
On Mon, Sep
Shouldn't be a problem with the standard UV - phosphor style white
LED's that are on the market today. The phosphor has a hang time that
runs into the minutes, if all of the glowing LED bits in my lamps are
an indication. They glow softly for several minutes after turn off.
-Chuck Harris
In message ac9e4c92327746d4a521facd35d9d...@vectron.com, Bob Camp writes:
I suspect those same 120Hz sensitive people would not be able to watch TV or
a movie :)
I suggest you either carry out a couple of experiments yourself, or
go a little easy on the irony.
CRTs, and LCDs go out of their
: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Poul-Henning Kamp
Sent: Tuesday, September 18, 2012 9:05 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Hi Power LED Light power supply...
In message ac9e4c92327746d4a521facd35d9d
On Tue, Sep 18, 2012 at 5:21 AM, Bob Camp li...@rtty.us wrote:
Hi
I suspect those same 120Hz sensitive people would not be able to watch TV or
a movie :)
In the old CRT type TV sets, the phosphor has some persistence.
Movies are modulated with a square waves, the frame blinks off and
goes
measurement
Subject: Re: [time-nuts] Hi Power LED Light power supply...
On Tue, Sep 18, 2012 at 5:21 AM, Bob Camp li...@rtty.us wrote:
Hi
I suspect those same 120Hz sensitive people would not be able to watch TV
or
a movie :)
In the old CRT type TV sets, the phosphor has some persistence
li...@rtty.us said:
There are a *lot* of TV's out there that refresh at 60 Hz or less.
Many years ago, we had a busted fluorescent light at work. I could see the
flicker out of the corner of my eye. I found it annoying, so I'm a firm
believer that some people can see flicker in some
If you all check, they are using LEDs in traffic signals now by the
thousands. These are variations of multiple LEDs used in these signals and
they
are all powered by 115vac thru the traffic controllers.
Joe k3wry
In a message dated 9/18/2012 1:28:18 A.M. Eastern Daylight Time,
@febo.com
Subject: Re: [time-nuts] Hi Power LED Light power supply...
If you all check, they are using LEDs in traffic signals now by the
thousands. These are variations of multiple LEDs used in these signals and
they
are all powered by 115vac thru the traffic controllers.
Joe k3wry
measurement
Subject: Re: [time-nuts] Hi Power LED Light power supply...
In message ac9e4c92327746d4a521facd35d9d...@vectron.com, Bob Camp
writes:
I suspect those same 120Hz sensitive people would not be able to watch TV
or
a movie :)
I suggest you either carry out a couple of experiments
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Hi Power LED Light power supply...
In message ac9e4c92327746d4a521facd35d9d...@vectron.com, Bob Camp
writes:
I suspect those same 120Hz sensitive people would not be able to watch TV
or
a movie
The local sandwich shop that I frequent recently switched to LED lighting. When
I walk up to the counter I can see the flicker when people's hands are moving.
The same applies for LED taillights when a vehicle is moving as well as newer
LED tower lighting.
Bob
On Sep 18, 2012, at 13:15, Hal
If you take your garden variety boost converter and place a resistor as the
load, the current in the inductor is regulated. (Current is vreference over
this resistor value.) All these dedicated LED drive chips do is reduce the
voltage across the resistor to improve efficiency. In addition, they
On 18 Sep, 2012, at 12:42 , Chris Albertson wrote:
On Tue, Sep 18, 2012 at 5:21 AM, Bob Camp li...@rtty.us wrote:
Hi
I suspect those same 120Hz sensitive people would not be able to watch TV or
a movie :)
In the old CRT type TV sets, the phosphor has some persistence.
Movies are
-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf
Of Dennis Ferguson
Sent: Tuesday, September 18, 2012 1:52 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Hi Power LED Light power supply...
On 18 Sep, 2012, at 12:42 , Chris
: Tuesday, September 18, 2012 1:52 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Hi Power LED Light power supply...
On 18 Sep, 2012, at 12:42 , Chris Albertson wrote:
On Tue, Sep 18, 2012 at 5:21 AM, Bob Camp li...@rtty.us wrote:
Hi
I suspect those same
On 18 Sep, 2012, at 15:06 , John Lofgren wrote:
snip
I would hence believe that a 50 Hz flicker must be pretty close to the edge
of what can be perceived, so I'm having trouble believing that a flicker at
more than twice that rate would be perceptible at all by anyone.
snip
Oh, but it
On Tue, Sep 18, 2012 at 2:27 PM, gary li...@lazygranch.com wrote:
A similar problem occurs with matrixed LED displays mounted on machinery
that has vibration. Very common in industrial controls since they like LEDs
for readability.
This is very evident on the new L train cars in Chicago.
: Re: [time-nuts] Hi Power LED Light power supply...
On Tue, Sep 18, 2012 at 2:27 PM, gary li...@lazygranch.com wrote:
A similar problem occurs with matrixed LED displays mounted on machinery
that has vibration. Very common in industrial controls since they like
LEDs
for readability
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Dennis Ferguson
Sent: Tuesday, September 18, 2012 2:52 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Hi Power LED Light power supply...
On 18 Sep, 2012, at 12
On Tue, Sep 18, 2012 at 2:46 PM, Tom Miller tmil...@skylinenet.net wrote:
That's because the signs are scanned/multiplexed displays. It is not 60/120
Hz flicker.
Tom
Something new to research. Thanks!
--
Ryan Szekeres
KB9TQN
___
time-nuts mailing
with this one.
Dave
-Original Message-
From: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] On Behalf Of gary
Sent: Tuesday, September 18, 2012 12:28
To: time-nuts@febo.com
Subject: Re: [time-nuts] Hi Power LED Light power supply...
There are ways for the flicker
[mailto:time-nuts-boun...@febo.com] On Behalf Of Ryan Szekeres
Sent: Tuesday, September 18, 2012 12:55
To: Tom Miller; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Hi Power LED Light power supply...
On Tue, Sep 18, 2012 at 2:46 PM, Tom Miller
tmil
dennis.c.fergu...@gmail.com said:
[context is flicker from light bulbs running on 25 Hz power]
I would hence believe that a 50 Hz flicker must be pretty close to the edge
of what can be perceived, so I'm having trouble believing that a flicker at
more than twice that rate would be perceptible
, k9si
Date: Tue, 18 Sep 2012 13:23:41 -0400 (EDT)
From: k3...@aol.com
To: time-nuts@febo.com
Subject: Re: [time-nuts] Hi Power LED Light power supply...
If you all check, they are using LEDs in traffic signals now by the
thousands. These are variations of multiple LEDs used in these signals
On 9/18/12 10:57 AM, Tom Knox wrote:
I remember reading that Hollywood played with faster frame rates and found a
substantial number of people experience motion sickness.
Not so much the frame rate, but generating imagery that isn't realistic..
your eye expects motion blur (particularly
Time-Nutters--
I was wondering, after seeing some 100 watt LED series
wired assemblies that were listed at 30-34 VDC @ 2.9A if a
number of LEDs could be wired in series and powered directly
from a rectified 110 VAC power source. If enough LEDs are
wired in series such that the peak DC voltage
LEDs change brightness very fast and will flicker at 120Hz if you do
that. Many people can see 120Hz flicker.
Also you would not be getting all the brightness you could. Better to
low pass filter
On Mon, Sep 17, 2012 at 10:26 PM, Michael Baker mp...@clanbaker.org wrote:
Time-Nutters--
I was
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