Hi,

I know some here don't like CFLs. Up to now, I haven't had a problem
with branded on/off types, such as Scram and Philips, though I have
had no-name ones that take a long time to light or light dimly.

I wanted to have a dimmerable CFL, which was new territory for me. I
did some research on the www, and megaman was the recommended brand. I
do find that it suffers from being dim when switched on before
building up to full brightness after a couple of minutes, which is a
pain.

But my biggest concern is that I have been spending a lot of time in
the room redecorating and when I have my back tot he light, I am
annoyed by a flickering. If I turn to face the light, the light
appears to be on continually.

I'm wondering whether to take out the dimmer switch and replace with a
light switch and on/off type bulb.

What is causing this strange effect?

TIA

On Tuesday, April 10, 2012 8:33:17 PM UTC+1, Fred wrote:

But my biggest concern is that I have been spending a lot of time in
the room redecorating and when I have my back tot he light, I am
annoyed by a flickering. If I turn to face the light, the light
appears to be on continually.
....

What is causing this strange effect?

I've seen that before even with non-dimmed, non-dimmable CFLs. Your eyes are _much_ more sensitive to peripheral movement than to movement in front of you, it's a survival instinct, so my theory is that all CFLs flicker but we only notice when we are looking at them sideways.

Alex

alamaison wrote
Fred wrote

But my biggest concern is that I have been spending a lot of time in
the room redecorating and when I have my back tot he light, I am
annoyed by a flickering. If I turn to face the light, the light
appears to be on continually.

What is causing this strange effect?

I've seen that before even with non-dimmed, non-dimmable CFLs.
Your eyes are _much_ more sensitive to peripheral movement than to
movement in front of you, it's a survival instinct, so my theory is that all
CFLs flicker but we only notice when we are looking at them sideways.

You could get the same effect with the original long tube fluoros too with
the flicker only being noticable when you arent looking directly at them.

The difference with the modern CFLs is that they dont operate
at the mains frequency, so likely that one is just operating at a
lower freq than the others he doesnt get that effect with.

alamaison wrote:
Your eyes are _much_ more sensitive to peripheral movement than to
movement in front of you, it's a survival instinct, so my theory is that
all CFLs flicker but we only notice when we are looking at them sideways.

A better way of putting it is that the eyes do not process peripheral
images so as to obtain persistence of vision.

Bill

Fred wrote:

Hi,

I know some here don't like CFLs. Up to now, I haven't had a problem
with branded on/off types, such as Scram and Philips, though I have
had no-name ones that take a long time to light or light dimly.

I wanted to have a dimmerable CFL, which was new territory for me. I
did some research on the www, and megaman was the recommended brand. I
do find that it suffers from being dim when switched on before
building up to full brightness after a couple of minutes, which is a
pain.

They all do that - probably more noticeable on the dim setting.

But my biggest concern is that I have been spending a lot of time in
the room redecorating and when I have my back tot he light, I am
annoyed by a flickering. If I turn to face the light, the light
appears to be on continually.

The CFL will have a high frequency "ballast" so on full power, there is not
much flickering. Howerver on lower settings you are probably getting a 100Hz
flicker as the ballast circuit cannot maintain enough stored power with long
gaps between the feed pulses (remmeber the dimmer switch is chopping the AC
at double the mains frequency by delaying the firing of the triac (usually).

I'm wondering whether to take out the dimmer switch and replace with a
light switch and on/off type bulb.

You might be better off with a CFL with an integral dimmer that responds to
a quick on-off-on from a regular switch (ie replace the dimmer with a
switch). That way the CFL is receiving full power nad can shape its internal
power to the tube any way it wants (hopefully in a more pleasing manner).

It really would be good to have a new 3 pin lamp socket (or sockets) as a
new standard where the switch could

a) Totally isolate power to the lamp when off;

b) Use the 3rd pin as a dimmer control signal with ONE universal standard*

* There's already a sort of a standard of sending a 0-10V DC (IIRC) signal
to indicate how bright the lamp should be.

1) No more silly flickering when off if using the "wrong" dimmer with the
"wrong" LED/CFL lamp.

2) You could use any lamp on any circuit - you would simply not be able to
dim a lamp if the lamp were not dimmable - or - there was no dimmer switch.
But you would have light if you'd run out of the right lamps.

3) Dimmer switches would not dissipate heat.

4) The lamp in dim mode would maintain a decent lack of flicker.


I can see why in the old days of BC and ES they did not want a new base, but
these days, theres a new base every year, so why not?



What is causing this strange effect?

TIA
--
Tim Watts

On Tue, 10 Apr 2012 22:16:49 +0100, Tim Watts
wrote:

The CFL will have a high frequency "ballast" so on full power, there is not
much flickering. Howerver on lower settings you are probably getting a 100Hz
flicker as the ballast circuit cannot maintain enough stored power with long
gaps between the feed pulses (remmeber the dimmer switch is chopping the AC
at double the mains frequency by delaying the firing of the triac (usually).

Thanks for all the replies. I should explain that the flicker and dim
on start occur when the bulb is set to full brightness. It will become
my son's bedroom when finished, so I put the dimmer in there to allow
us to dim the light to make a nightlight. I'm decorating in there at
the moment so the dimmer is always on full.

Fred wrote:
Hi,

I know some here don't like CFLs. Up to now, I haven't had a problem
with branded on/off types, such as Scram and Philips, though I have
had no-name ones that take a long time to light or light dimly.

I wanted to have a dimmerable CFL, which was new territory for me. I
did some research on the www, and megaman was the recommended brand. I
do find that it suffers from being dim when switched on before
building up to full brightness after a couple of minutes, which is a
pain.

But my biggest concern is that I have been spending a lot of time in
the room redecorating and when I have my back tot he light, I am
annoyed by a flickering. If I turn to face the light, the light
appears to be on continually.

I'm wondering whether to take out the dimmer switch and replace with a
light switch and on/off type bulb.

What is causing this strange effect?

Presumably the frequency its working at.

Try waving your finger in a vertical plane between your eyes and the light
when looking at the light directly. You should see some fixed images of
your finger with a gap between them with the gap varying with how fast
you wave your finger. Try that with both the CFL that flickers when you
face away from it and the ones that dont flicker. You should find that the
difference is obvioius if its just the frequency that differs.

On Apr 10, 8:33*pm, Fred wrote:
Hi,

I know some here don't like CFLs. Up to now, I haven't had a problem
with branded on/off types, such as Scram and Philips, though I have
had no-name ones that take a long time to light or light dimly.

I wanted to have a dimmerable CFL, which was new territory for me. I
did some research on the www, and megaman was the recommended brand. I
do find that it suffers from being dim when switched on before
building up to full brightness after a couple of minutes, which is a
pain.

But my biggest concern is that I have been spending a lot of time in
the room redecorating and when I have my back tot he light, I am
annoyed by a flickering. If I turn to face the light, the light
appears to be on continually.

I'm wondering whether to take out the dimmer switch and replace with a
light switch and on/off type bulb.

What is causing this strange effect?

TIA

an inadequte reservoir cap in the cfl. Replace this cap with one of
more capacity, or parallel a 2nd one onto it. Use high temp
electrolytic caps in cfls.


NT

On 10/04/2012 20:33, Fred wrote:
Hi,

I know some here don't like CFLs. Up to now, I haven't had a problem
with branded on/off types, such as Scram and Philips, though I have
had no-name ones that take a long time to light or light dimly.

I wanted to have a dimmerable CFL, which was new territory for me. I
did some research on the www, and megaman was the recommended brand. I
do find that it suffers from being dim when switched on before
building up to full brightness after a couple of minutes, which is a
pain.

But my biggest concern is that I have been spending a lot of time in
the room redecorating and when I have my back tot he light, I am
annoyed by a flickering. If I turn to face the light, the light
appears to be on continually.

I'm wondering whether to take out the dimmer switch and replace with a
light switch and on/off type bulb.

What is causing this strange effect?

Increased 100Hz ripple when the dimmer is active.

Probably worse because your peripheral vision is a lot more sensitive to
flicker/movement than your forwards high resolution field of view. This
had survival value back when we were prey for large carnivores.

It used to be very annoying in a room with a wall full of old TVs
flickering at 50Hz. Not surprised that dimmed CFLs are borderline.

--
Regards,
Martin Brown

"Fred" wrote in message
...
Hi,

I know some here don't like CFLs. Up to now, I haven't had a problem
with branded on/off types, such as Scram and Philips, though I have
had no-name ones that take a long time to light or light dimly.

I wanted to have a dimmerable CFL, which was new territory for me. I
did some research on the www, and megaman was the recommended brand. I
do find that it suffers from being dim when switched on before
building up to full brightness after a couple of minutes, which is a
pain.

But my biggest concern is that I have been spending a lot of time in
the room redecorating and when I have my back tot he light, I am
annoyed by a flickering. If I turn to face the light, the light
appears to be on continually.

I'm wondering whether to take out the dimmer switch and replace with a
light switch and on/off type bulb.

What is causing this strange effect?


Alternatively, go for an alternative low energy bulb.
I ended up with what looks like a halogen headlight bulb inside a
traditional filament bulb outer.
Sold as low energy, claimed higher light output than equivalent
incandescent, and dimmable by a normal dimmer.
It could just be a way of circumventing the regulations but I have two in my
lounge light fitting and they seem to be performing well.

--
No plan survives contact with the enemy.
[Not even bunny]

Helmuth von Moltke the Elder

(\__/)
(='.'=)
(")_(")

On Apr 11, 8:35*pm, "David WE Roberts" wrote:
"Fred" wrote in message

...



Hi,

I know some here don't like CFLs. Up to now, I haven't had a problem
with branded on/off types, such as Scram and Philips, though I have
had no-name ones that take a long time to light or light dimly.

I wanted to have a dimmerable CFL, which was new territory for me. I
did some research on the www, and megaman was the recommended brand. I
do find that it suffers from being dim when switched on before
building up to full brightness after a couple of minutes, which is a
pain.

But my biggest concern is that I have been spending a lot of time in
the room redecorating and when I have my back tot he light, I am
annoyed by a flickering. If I turn to face the light, the light
appears to be on continually.

I'm wondering whether to take out the dimmer switch and replace with a
light switch and on/off type bulb.

What is causing this strange effect?

Alternatively, go for an alternative low energy bulb.
I ended up with what looks like a halogen headlight bulb inside a
traditional filament bulb outer.
Sold as low energy, claimed higher light output than equivalent
incandescent, and dimmable by a normal dimmer.
It could just be a way of circumventing the regulations but I have two in my
lounge light fitting and they seem to be performing well.

Theyre certainly not low energy.


NT

In article
,
NT wrote:
On Apr 11, 8:35 pm, "David WE Roberts" wrote:
"Fred" wrote in message

...



Hi,

I know some here don't like CFLs. Up to now, I haven't had a problem
with branded on/off types, such as Scram and Philips, though I have
had no-name ones that take a long time to light or light dimly.

I wanted to have a dimmerable CFL, which was new territory for me. I
did some research on the www, and megaman was the recommended brand. I
do find that it suffers from being dim when switched on before
building up to full brightness after a couple of minutes, which is a
pain.

But my biggest concern is that I have been spending a lot of time in
the room redecorating and when I have my back tot he light, I am
annoyed by a flickering. If I turn to face the light, the light
appears to be on continually.

I'm wondering whether to take out the dimmer switch and replace with a
light switch and on/off type bulb.

What is causing this strange effect?

Alternatively, go for an alternative low energy bulb.
I ended up with what looks like a halogen headlight bulb inside a
traditional filament bulb outer.
Sold as low energy, claimed higher light output than equivalent
incandescent, and dimmable by a normal dimmer.

It could just be a way of circumventing the regulations but I have two
in my lounge light fitting and they seem to be performing well.

Theyre certainly not low energy.

They are lower than convention incandescent for the same output, so lower
energy - by about 25%


NT

--
From KT24

Using a RISC OS computer running v5.18

On Apr 11, 10:43*pm, charles wrote:
In article
,
* *NT wrote:



On Apr 11, 8:35 pm, "David WE Roberts" wrote:
"Fred" wrote in message

.. .

Hi,

I know some here don't like CFLs. Up to now, I haven't had a problem
with branded on/off types, such as Scram and Philips, though I have
had no-name ones that take a long time to light or light dimly.

I wanted to have a dimmerable CFL, which was new territory for me. I
did some research on the www, and megaman was the recommended brand.. I
do find that it suffers from being dim when switched on before
building up to full brightness after a couple of minutes, which is a
pain.

But my biggest concern is that I have been spending a lot of time in
the room redecorating and when I have my back tot he light, I am
annoyed by a flickering. If I turn to face the light, the light
appears to be on continually.

I'm wondering whether to take out the dimmer switch and replace with a
light switch and on/off type bulb.

What is causing this strange effect?

Alternatively, go for an alternative low energy bulb.
I ended up with what looks like a halogen headlight bulb inside a
traditional filament bulb outer.
Sold as low energy, claimed higher light output than equivalent
incandescent, and dimmable by a normal dimmer.
It could just be a way of circumventing the regulations but I have two
in my lounge light fitting and they seem to be performing well.
Theyre certainly not low energy.

They are lower than convention incandescent for the same output, so lower
energy - by about 25%

Yes. Compared to real low energy lamps that eat around 25-33% of the
energy of an incandescent GLS.


NT

David WE Roberts wrote:
"Fred" wrote in message
...
Hi,

I know some here don't like CFLs. Up to now, I haven't had a problem
with branded on/off types, such as Scram and Philips, though I have
had no-name ones that take a long time to light or light dimly.

I wanted to have a dimmerable CFL, which was new territory for me. I
did some research on the www, and megaman was the recommended brand.
I do find that it suffers from being dim when switched on before
building up to full brightness after a couple of minutes, which is a
pain.

But my biggest concern is that I have been spending a lot of time in
the room redecorating and when I have my back tot he light, I am
annoyed by a flickering. If I turn to face the light, the light
appears to be on continually.

I'm wondering whether to take out the dimmer switch and replace with
a light switch and on/off type bulb.

What is causing this strange effect?


Alternatively, go for an alternative low energy bulb.
I ended up with what looks like a halogen headlight bulb inside a
traditional filament bulb outer.
Sold as low energy, claimed higher light output than equivalent
incandescent, and dimmable by a normal dimmer.

No they arent. They rely on running at a high temp as part of the
process and dimming them as much as he wants to doesnt work with them.

It could just be a way of circumventing the regulations but I have
two in my lounge light fitting and they seem to be performing well.

On Apr 10, 8:33*pm, Fred wrote:
But my biggest concern is that I have been spending a lot of time in
the room redecorating and when I have my back tot he light, I am
annoyed by a flickering. If I turn to face the light, the light
appears to be on continually.

Critical fusion frequency is higher for peripheral vision than fovea.
When you look at the light directly it is perceived as flicker free,
look at it out of the corner of your eye (or its cast on the wall) and
you may notice the flicker.

The same problem occurs with Osram Lunetta night lights in low light.
Looked at directly they are a solid yellow, viewed via peripheral
vision they are noticeably flickering. Like right now as it
happens :-)

Typically you want 67Hz or better, however some people can still
detect flicker some way above that. Some early ATC systems suffered
from it (along with poor consideration of reflections).

It could be an old bulb, some seem to lose brightness slowly, others
go a bit flickery (Philips seem worse than Osram) however I buy so few
that could be purely chance. Do not think quality is as good as it
once was (1990s).

In article ,
Fred writes:
Hi,

I know some here don't like CFLs. Up to now, I haven't had a problem
with branded on/off types, such as Scram and Philips, though I have
had no-name ones that take a long time to light or light dimly.

I wanted to have a dimmerable CFL, which was new territory for me. I
did some research on the www, and megaman was the recommended brand. I
do find that it suffers from being dim when switched on before
building up to full brightness after a couple of minutes, which is a
pain.

But my biggest concern is that I have been spending a lot of time in
the room redecorating and when I have my back tot he light, I am
annoyed by a flickering. If I turn to face the light, the light
appears to be on continually.

I'm wondering whether to take out the dimmer switch and replace with a
light switch and on/off type bulb.

Try it.

What is causing this strange effect?

The circuitry to dim a CFL on a conventional dimmer means leaving
out the smoothing capacitor, so you get the 100Hz flicker. It would
be possible to design this better, but no one seems to have done so.
Retrofit dimming CFL is a technology which the manufacturers don't
seem to have invested much effort in.

If you want reasonable dimming, with better than mains filament
efficiency, you have 3 choices:

1. Use 12V halogens (over twice the efficiency of mains, but that
also falls away when you dim down).
2. Use CFLs without integral ballasts, or linear fluorescents, and
in either case, use dimming ballasts.
3. Use LED with dimming controllers (but again, not retrofits).


I have converted a dimming mains lamp installation into method 1,
and I'm very happy with it. 60W clear candles have been replaced
with 35W 12V halogen capsules, which generate very noticably more
light. The other methods wouldn't work in my case (can't fit large
enough CFL or ballast in fitting, and nowhere near enough cooling
available to operate the required power of LEDs).

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]