CFL on photo on/off?

What is the problem with operating a CFL on a dusk to dawn device that
uses a photo sensor? Does it suffer the same fate as running the CFL
on a dimmer that is full on? That's my guess. My motion sensor
security light has an option to turn the lamps on manually and shut
them off in the morning automatically when it's light enough out. But
it has a relay that makes an aduible click. I would assume a simple
light sensing fixture is switched with a triac and this causes a
pulsedvoltage that harms the CFL ballast.

 

[Samuel M. Goldwasser]

Meat Plow writes:

What is the problem with operating a CFL on a dusk to dawn device that
uses a photo sensor? Does it suffer the same fate as running the CFL
on a dimmer that is full on? That's my guess. My motion sensor
security light has an option to turn the lamps on manually and shut
them off in the morning automatically when it's light enough out. But
it has a relay that makes an aduible click. I would assume a simple
light sensing fixture is switched with a triac and this causes a
pulsedvoltage that harms the CFL ballast.

The problem is that these photosensitive devices draw their power through
the lamp, so there's a trickle of current flowing even when it's supposed
to be off. With an incandecent lamp, this doesn't matter. But with a CFL,
if you're lucky, the result is the lamp flashing on momentarily like a strobe
periodically but no damage to it.

--
sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

 

On 11 Mar 2010 19:00:12 -0500, sam@repairfaq.org (Samuel M.
Goldwasser)wrote:

Meat Plow writes:

What is the problem with operating a CFL on a dusk to dawn device that
uses a photo sensor? Does it suffer the same fate as running the CFL
on a dimmer that is full on? That's my guess. My motion sensor
security light has an option to turn the lamps on manually and shut
them off in the morning automatically when it's light enough out. But
it has a relay that makes an aduible click. I would assume a simple
light sensing fixture is switched with a triac and this causes a
pulsedvoltage that harms the CFL ballast.

The problem is that these photosensitive devices draw their power through
the lamp, so there's a trickle of current flowing even when it's supposed
to be off. With an incandecent lamp, this doesn't matter. But with a CFL,
if you're lucky, the result is the lamp flashing on momentarily like a strobe
periodically but no damage to it.

Makes sense, thanks Sam.

 

[Allodoxaphobia]

On 11 Mar 2010 19:00:12 -0500, Samuel M. Goldwasser wrote:

Meat Plow writes:

What is the problem with operating a CFL on a dusk to dawn device that
uses a photo sensor? Does it suffer the same fate as running the CFL
on a dimmer that is full on? That's my guess. My motion sensor
security light has an option to turn the lamps on manually and shut
them off in the morning automatically when it's light enough out. But
it has a relay that makes an aduible click. I would assume a simple
light sensing fixture is switched with a triac and this causes a
pulsedvoltage that harms the CFL ballast.

The problem is that these photosensitive devices draw their power through
the lamp, so there's a trickle of current flowing even when it's supposed
to be off. With an incandecent lamp, this doesn't matter. But with a CFL,
if you're lucky, the result is the lamp flashing on momentarily like a strobe
periodically but no damage to it.

I hedge my bets: In a 2 lamp device I use 1 incandecent and 1 CFL.

Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
38.24N 104.55W | @ config.com | Jonesy | OS/2
* Killfiling google & XXXXbanter.com: jonz.net/ng.htm

 

[Samuel M. Goldwasser]

Allodoxaphobia <bit-bucket@config.com> writes:

On 11 Mar 2010 19:00:12 -0500, Samuel M. Goldwasser wrote:
Meat Plow writes:

What is the problem with operating a CFL on a dusk to dawn device that
uses a photo sensor? Does it suffer the same fate as running the CFL
on a dimmer that is full on? That's my guess. My motion sensor
security light has an option to turn the lamps on manually and shut
them off in the morning automatically when it's light enough out. But
it has a relay that makes an aduible click. I would assume a simple
light sensing fixture is switched with a triac and this causes a
pulsedvoltage that harms the CFL ballast.

The problem is that these photosensitive devices draw their power through
the lamp, so there's a trickle of current flowing even when it's supposed
to be off. With an incandecent lamp, this doesn't matter. But with a CFL,
if you're lucky, the result is the lamp flashing on momentarily like a strobe
periodically but no damage to it.

I hedge my bets: In a 2 lamp device I use 1 incandecent and 1 CFL.

Good solution! The only concern would be if the photosensor device doesn't
switch (mostly) on or off cleanly.

--
sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

 

[William R. Walsh]

Hi!

The problem is that these photosensitive devices draw their power
through the lamp, so there's a trickle of current flowing even when
it's supposed to be off.  With an incandecent lamp, this doesn't
matter.

I'm glad someone brought this up, because there is something I'd like
to know.

I've got an outdoor porch light on a post that has a 100 watt
equivalent CFL bulb in it. The fixture itself is made of cheap
plastic, and the light is on fairly often, so I feel better using the
CFL as opposed to a 100 watt incandescent. (However, I haven't noticed
a maximum wattage rating on the fixture itself.)

I'd like to switch this light via photocell.

To prevent any possible "abuse" to the CFL, I'd like to have the
photocell device turn a relay on and off. Is it possible to do that,
or would it result in unacceptable behavor (buzzing, etc) from the
relay?

If it won't work, I could always use a timer of some sort.

William

 

[David Nebenzahl]

On 3/12/2010 7:02 AM William R. Walsh spake thus:

The problem is that these photosensitive devices draw their power
through the lamp, so there's a trickle of current flowing even when
it's supposed to be off. With an incandecent lamp, this doesn't
matter.

I'm glad someone brought this up, because there is something I'd like
to know.

I've got an outdoor porch light on a post that has a 100 watt
equivalent CFL bulb in it. The fixture itself is made of cheap
plastic, and the light is on fairly often, so I feel better using the
CFL as opposed to a 100 watt incandescent. (However, I haven't noticed
a maximum wattage rating on the fixture itself.)

I'd like to switch this light via photocell.

Keep in mind that CFLs are often not good candidates for this kind of
application, because the length of time they take to warm up is often
the same as the length of time they're on, so they don't do a very good
job of lighting up the area you want illuminated. For an intermittent
application like this, it's probably just as cost-effective overall just
to use a good old-fashioned incandescent lamp.


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"

 

On Fri, 12 Mar 2010 10:42:15 -0800, David Nebenzahl
<nobody@but.us.chickens>wrote:

On 3/12/2010 7:02 AM William R. Walsh spake thus:

The problem is that these photosensitive devices draw their power
through the lamp, so there's a trickle of current flowing even when
it's supposed to be off. With an incandecent lamp, this doesn't
matter.

I'm glad someone brought this up, because there is something I'd like
to know.

I've got an outdoor porch light on a post that has a 100 watt
equivalent CFL bulb in it. The fixture itself is made of cheap
plastic, and the light is on fairly often, so I feel better using the
CFL as opposed to a 100 watt incandescent. (However, I haven't noticed
a maximum wattage rating on the fixture itself.)

I'd like to switch this light via photocell.

Keep in mind that CFLs are often not good candidates for this kind of
application, because the length of time they take to warm up is often
the same as the length of time they're on, so they don't do a very good
job of lighting up the area you want illuminated. For an intermittent
application like this, it's probably just as cost-effective overall just
to use a good old-fashioned incandescent lamp.

But it would be ok for a dusk to dawn security light?

 

[David Nebenzahl]

On 3/12/2010 10:52 AM Meat Plow spake thus:

On Fri, 12 Mar 2010 10:42:15 -0800, David Nebenzahl
nobody@but.us.chickens>wrote:

On 3/12/2010 7:02 AM William R. Walsh spake thus:

The problem is that these photosensitive devices draw their power
through the lamp, so there's a trickle of current flowing even when
it's supposed to be off. With an incandecent lamp, this doesn't
matter.

I'm glad someone brought this up, because there is something I'd like
to know.

I've got an outdoor porch light on a post that has a 100 watt
equivalent CFL bulb in it. The fixture itself is made of cheap
plastic, and the light is on fairly often, so I feel better using the
CFL as opposed to a 100 watt incandescent. (However, I haven't noticed
a maximum wattage rating on the fixture itself.)

I'd like to switch this light via photocell.

Keep in mind that CFLs are often not good candidates for this kind
of application, because the length of time they take to warm up is
often the same as the length of time they're on, so they don't do a
very good job of lighting up the area you want illuminated. For an
intermittent application like this, it's probably just as
cost-effective overall just to use a good old-fashioned
incandescent lamp.

But it would be ok for a dusk to dawn security light?

Yup, that would be a good place for a CFL. (Assuming it plays nicely
with the controller, that is.)


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"

 

[Michael A. Terrell]

David Nebenzahl wrote:

On 3/12/2010 10:52 AM Meat Plow spake thus:

On Fri, 12 Mar 2010 10:42:15 -0800, David Nebenzahl
nobody@but.us.chickens>wrote:

On 3/12/2010 7:02 AM William R. Walsh spake thus:

The problem is that these photosensitive devices draw their power
through the lamp, so there's a trickle of current flowing even when
it's supposed to be off. With an incandecent lamp, this doesn't
matter.

I'm glad someone brought this up, because there is something I'd like
to know.

I've got an outdoor porch light on a post that has a 100 watt
equivalent CFL bulb in it. The fixture itself is made of cheap
plastic, and the light is on fairly often, so I feel better using the
CFL as opposed to a 100 watt incandescent. (However, I haven't noticed
a maximum wattage rating on the fixture itself.)

I'd like to switch this light via photocell.

Keep in mind that CFLs are often not good candidates for this kind
of application, because the length of time they take to warm up is
often the same as the length of time they're on, so they don't do a
very good job of lighting up the area you want illuminated. For an
intermittent application like this, it's probably just as
cost-effective overall just to use a good old-fashioned
incandescent lamp.

But it would be ok for a dusk to dawn security light?

Yup, that would be a good place for a CFL. (Assuming it plays nicely
with the controller, that is.)

They sell dusk to dawn security lights made for CFL. My dad
installed one with a 65 Watt CFL he bought at Lowe's or Home Depot for
his place. It was several years ago and he doesn't remember, for sure.
He also bought a smaller one, to light the sidewalk to his driveway.


--
Lead free solder is Belgium's version of 'Hold my beer and watch this!'

 

[[SMF]]

On 3/12/2010 9:02 AM, William R. Walsh wrote:

Hi!

The problem is that these photosensitive devices draw their power
through the lamp, so there's a trickle of current flowing even when
it's supposed to be off. With an incandecent lamp, this doesn't
matter.

I'm glad someone brought this up, because there is something I'd like
to know.

I've got an outdoor porch light on a post that has a 100 watt
equivalent CFL bulb in it. The fixture itself is made of cheap
plastic, and the light is on fairly often, so I feel better using the
CFL as opposed to a 100 watt incandescent. (However, I haven't noticed
a maximum wattage rating on the fixture itself.)

I'd like to switch this light via photocell.

To prevent any possible "abuse" to the CFL, I'd like to have the
photocell device turn a relay on and off. Is it possible to do that,
or would it result in unacceptable behavor (buzzing, etc) from the
relay?

If it won't work, I could always use a timer of some sort.

William

You shouldn't have any problems running a relay with a photo-cell.

 

[GregS]

In article <3j8eko.9cf.19.5@news.alt.net>, Meat Plow wrote:

What is the problem with operating a CFL on a dusk to dawn device that
uses a photo sensor? Does it suffer the same fate as running the CFL
on a dimmer that is full on? That's my guess. My motion sensor
security light has an option to turn the lamps on manually and shut
them off in the morning automatically when it's light enough out. But
it has a relay that makes an aduible click. I would assume a simple
light sensing fixture is switched with a triac and this causes a
pulsedvoltage that harms the CFL ballast.

Most photodensors use a relay. No different from a switch.

greg

 

[GregS]

In article <hnlbvt$g53$2@usenet01.srv.cis.pitt.edu>, zekfrivo@zekfrivolous.com (GregS) wrote:

In article <3j8eko.9cf.19.5@news.alt.net>, Meat Plow wrote:
What is the problem with operating a CFL on a dusk to dawn device that
uses a photo sensor? Does it suffer the same fate as running the CFL
on a dimmer that is full on? That's my guess. My motion sensor
security light has an option to turn the lamps on manually and shut
them off in the morning automatically when it's light enough out. But
it has a relay that makes an aduible click. I would assume a simple
light sensing fixture is switched with a triac and this causes a
pulsedvoltage that harms the CFL ballast.

Most photodensors use a relay. No different from a switch.

greg

That said, I don't remember if there was a warning, but I can hear a click on mine.
I used to keep it on, and would last a year or more. I'll see how long
it lasts not with a sensor, along with two led spotlights.

greg

 

On Mon, 15 Mar 2010 13:20:42 GMT, zekfrivo@zekfrivolous.com
(GregS)wrote:

In article <3j8eko.9cf.19.5@news.alt.net>, Meat Plow wrote:
What is the problem with operating a CFL on a dusk to dawn device that
uses a photo sensor? Does it suffer the same fate as running the CFL
on a dimmer that is full on? That's my guess. My motion sensor
security light has an option to turn the lamps on manually and shut
them off in the morning automatically when it's light enough out. But
it has a relay that makes an aduible click. I would assume a simple
light sensing fixture is switched with a triac and this causes a
pulsedvoltage that harms the CFL ballast.

Most photodensors use a relay. No different from a switch.

greg

Even the kind that screw into a light fixture?

 

On Mon, 15 Mar 2010 13:54:04 +0000 (UTC), "Geoffrey S. Mendelson"
<gsm@cable.mendelson.com>wrote:

Meat Plow wrote:
What is the problem with operating a CFL on a dusk to dawn device that
uses a photo sensor?

I'm not sure I'd bother. For example, we have a bathroom with no windows
in the middle of a dark hallway. I just out in a CFL and leave it on.

Lights up the room, lights up the hallway.

At what I pay for electricity it costs under $9 a year, which is less than the
cost of a light operated switch or timer, and probably less current than
a timer anyway.

Geoff.

Outside Lamp post for my mom. She says traditional bulbs don't last
long enough and there is no way to enable it in an always on mode.
Besides she is too frugal to want to let it operate 24/7. She's the
kind of person who washes out tin foil and reuses it

 

[Geoffrey S. Mendelson]

Meat Plow wrote:

What is the problem with operating a CFL on a dusk to dawn device that
uses a photo sensor?

I'm not sure I'd bother. For example, we have a bathroom with no windows
in the middle of a dark hallway. I just out in a CFL and leave it on.

Lights up the room, lights up the hallway.

At what I pay for electricity it costs under $9 a year, which is less than the
cost of a light operated switch or timer, and probably less current than
a timer anyway.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com N3OWJ/4X1GM
New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or
understanding, as in he has a sub-wikipedia understanding of the situation.
i.e possessing less facts or information than can be found in the Wikipedia.

 

[GregS]

In article <3ji43u.i4g.17.14@news.alt.net>, Meat Plow wrote:

On Mon, 15 Mar 2010 13:54:04 +0000 (UTC), "Geoffrey S. Mendelson"
gsm@cable.mendelson.com>wrote:

Meat Plow wrote:
What is the problem with operating a CFL on a dusk to dawn device that
uses a photo sensor?

I'm not sure I'd bother. For example, we have a bathroom with no windows
in the middle of a dark hallway. I just out in a CFL and leave it on.

Lights up the room, lights up the hallway.

At what I pay for electricity it costs under $9 a year, which is less than the
cost of a light operated switch or timer, and probably less current than
a timer anyway.

Geoff.

Outside Lamp post for my mom. She says traditional bulbs don't last
long enough and there is no way to enable it in an always on mode.
Besides she is too frugal to want to let it operate 24/7. She's the
kind of person who washes out tin foil and reuses it

Many neighborhoods are too dark at night. My old neighborhood
in the 60's, My mother complained about no street lights.
Realitor said there is enough light from the neighbors outside
lights, and it was true. Every fourth house also had a gas lantern.
That neighborhood is now too dark. If those people started using CFL's
they could afford to keep them on.

greg

 

[GregS]

In article <hnlgnv$h66$2@usenet01.srv.cis.pitt.edu>, zekfrivo@zekfrivolous.com (GregS) wrote:

In article <3ji43u.i4g.17.14@news.alt.net>, Meat Plow wrote:
On Mon, 15 Mar 2010 13:54:04 +0000 (UTC), "Geoffrey S. Mendelson"
gsm@cable.mendelson.com>wrote:

Meat Plow wrote:
What is the problem with operating a CFL on a dusk to dawn device that
uses a photo sensor?

I'm not sure I'd bother. For example, we have a bathroom with no windows
in the middle of a dark hallway. I just out in a CFL and leave it on.

Lights up the room, lights up the hallway.

At what I pay for electricity it costs under $9 a year, which is less than
the
cost of a light operated switch or timer, and probably less current than
a timer anyway.

Geoff.

Outside Lamp post for my mom. She says traditional bulbs don't last
long enough and there is no way to enable it in an always on mode.
Besides she is too frugal to want to let it operate 24/7. She's the
kind of person who washes out tin foil and reuses it

Many neighborhoods are too dark at night. My old neighborhood
in the 60's, My mother complained about no street lights.
Realitor said there is enough light from the neighbors outside
lights, and it was true. Every fourth house also had a gas lantern.
That neighborhood is now too dark. If those people started using CFL's
they could afford to keep them on.

I also like to complain about light that shines in my eyes. Much of the light
from lights goes up into the air where its useless, and also into
my eyes.

greg

 

[Geoffrey S. Mendelson]

Meat Plow wrote:

Outside Lamp post for my mom. She says traditional bulbs don't last
long enough and there is no way to enable it in an always on mode.
Besides she is too frugal to want to let it operate 24/7. She's the
kind of person who washes out tin foil and reuses it

There are standard bulbs made for use in these places. They are made
with thicker filaments so they last much longer. Another trick is to
use a 240 volt bulb, they run at much lower intensity (and are that much
less efficent) but they supposedly last "forever".

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com N3OWJ/4X1GM
New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or
understanding, as in he has a sub-wikipedia understanding of the situation.
i.e possessing less facts or information than can be found in the Wikipedia.

 

[GregS]

In article <slrnhpshq8.1um.gsm@cable.mendelson.com>, gsm@mendelson.com wrote:

Meat Plow wrote:
Outside Lamp post for my mom. She says traditional bulbs don't last
long enough and there is no way to enable it in an always on mode.
Besides she is too frugal to want to let it operate 24/7. She's the
kind of person who washes out tin foil and reuses it

There are standard bulbs made for use in these places. They are made
with thicker filaments so they last much longer. Another trick is to
use a 240 volt bulb, they run at much lower intensity (and are that much
less efficent) but they supposedly last "forever".

While not being efficient I much prefer the warm whites, but they
can be more efficient seeing in foggy conditions.

I once built a lantern with a variable light control. A resistor.
Shining the light at full brightness into Lake Erie showed nothing. getting
it nice and dim, you could see right through the water.

greg