"My Dimmers fail and fail, why?"

W

Wdyorchid

Guest
I'd been destroying dimmers on a handful. I'd been making homemade dimmer
control (from ordinary residential dimmers) for my reading lamp. (Don't know if
this violates safety codes.) I would plug the dimmer to the wall receptacle
outlet and then plug the lamp into the dimmer. It's a handy device I carry
around the house to any reading corner.
But the problem is that sometime while plugging the dimmer into the
wall (with the lamp turned on) the dimmer tends for fail (or turn on at full).
The dimmer is then discarded. The dimmer's death come at the same time as I
noticed an arch inside the wall outlet while attempting to plug it in. It's
probably not design for this since an aftermarket lamp dimmer I also have won't
fail in any abusive condition. My homemade dimmers have a problem I have no
solutions for and like to solve it. Any suggestions?

Why am I making homade lamp dimmers? A friend gave me a shoe-box half full of
used dimmers.
-w orchid
 
[This followup was posted to sci.electronics.repair and a copy was sent to
the cited author.]

In article <20030823042315.21471.00000647@mb-m01.aol.com>,
wdyorchid@aol.com says...
I'd been destroying dimmers on a handful. I'd been making homemade dimmer
control (from ordinary residential dimmers) for my reading lamp. (Don't know if
this violates safety codes.) I would plug the dimmer to the wall receptacle
outlet and then plug the lamp into the dimmer. It's a handy device I carry
around the house to any reading corner.
But the problem is that sometime while plugging the dimmer into the
wall (with the lamp turned on) the dimmer tends for fail (or turn on at full).
The dimmer is then discarded. The dimmer's death come at the same time as I
noticed an arch inside the wall outlet while attempting to plug it in. It's
probably not design for this since an aftermarket lamp dimmer I also have won't
fail in any abusive condition. My homemade dimmers have a problem I have no
solutions for and like to solve it. Any suggestions?

Why am I making homade lamp dimmers? A friend gave me a shoe-box half full of
used dimmers.
Click to expand...
How many watts is the reading lamp? Is it a plain incandescent bulb,
halogen, or something else?

Why leave the light on when plugging in the dimmer? Turn it OFF first,
plug things in, then turn on the light.

--
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All junk mail senders will be prosecuted to the fullest extent of the
law!!
http://home.att.net/~andyross
 
It's a plain100W incandescent bulb. Sometimes somebody would leave the lamp on
accidently.
-W

How many watts is the reading lamp? Is it a plain incandescent bulb,
halogen, or something else?

Why leave the light on when plugging in the dimmer? Turn it OFF first,
plug things in, then turn on the light.

--

I'd been destroying dimmers on a handful. I'd been making homemade dimmer
control (from ordinary residential dimmers) for my reading lamp. (Don't
know if
this violates safety codes.) I would plug the dimmer to the wall receptacle
outlet and then plug the lamp into the dimmer. It's a handy device I carry
around the house to any reading corner.
But the problem is that sometime while plugging the dimmer into
the
wall (with the lamp turned on) the dimmer tends for fail (or turn on at
full).
The dimmer is then discarded. The dimmer's death come at the same time as I
noticed an arch inside the wall outlet while attempting to plug it in. It's
probably not design for this since an aftermarket lamp dimmer I also have
won't
fail in any abusive condition. My homemade dimmers have a problem I have no
solutions for and like to solve it. Any suggestions?

Why am I making homade lamp dimmers? A friend gave me a shoe-box half full
of
used dimmers.
Click to expand...
 
Dimmer circuits, as simple as they look, the design and part values can
be a bit critical. But, if your dimmer circuit is actually okay, then
you have to investigate the load.

Some of these reading lamps use a small transformer inside. This is to
step the mains voltage down for a small type of reading bulb.

You cannot run a transformer or reactive device on a simple thyristor
dimmer. If so, the transformer may either burn out the dimmer, or be
damaged. This has to do with a number of complex reasons which is
really beyond what I can get in to over an email.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
==============================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
Instruments http://www.zoom-one.com/glgtech.htm
==============================================
"Wdyorchid" <wdyorchid@aol.com> wrote in message
news:20030823042315.21471.00000647@mb-m01.aol.com...
I'd been destroying dimmers on a handful. I'd been making homemade
dimmer
control (from ordinary residential dimmers) for my reading lamp. (Don't
know if
this violates safety codes.) I would plug the dimmer to the wall
receptacle
outlet and then plug the lamp into the dimmer. It's a handy device I
carry
around the house to any reading corner.
But the problem is that sometime while plugging the dimmer
into the
wall (with the lamp turned on) the dimmer tends for fail (or turn on at
full).
The dimmer is then discarded. The dimmer's death come at the same time
as I
noticed an arch inside the wall outlet while attempting to plug it in.
It's
probably not design for this since an aftermarket lamp dimmer I also
have won't
fail in any abusive condition. My homemade dimmers have a problem I have
no
solutions for and like to solve it. Any suggestions?

Why am I making homade lamp dimmers? A friend gave me a shoe-box half
full of
used dimmers.
-w orchid
 
Indescant bulbs use to die at power on due to the current peak that occurs
as the cold filament has much lower a resistance then a hot one. The triac
of a dimmer may be killed by the same current peak, especially when its
maximum peak current is too low and/or the control circuit has not been
developped to handle the triac with (full) load at power on. The arch you
noticed points in that direction. I would (like) to reverse engineer both
the failing and the aftermarket dimmer. I'm sure the difference will explain
the cause of the failure.

pieter



"Wdyorchid" <wdyorchid@aol.com> schreef in bericht
news:20030823220109.02463.00000329@mb-m23.aol.com...
It's a plain100W incandescent bulb. Sometimes somebody would leave the
lamp on
accidently.
-W

How many watts is the reading lamp? Is it a plain incandescent bulb,
halogen, or something else?

Why leave the light on when plugging in the dimmer? Turn it OFF first,
plug things in, then turn on the light.

--

I'd been destroying dimmers on a handful. I'd been making homemade
dimmer
control (from ordinary residential dimmers) for my reading lamp. (Don't
know if
this violates safety codes.) I would plug the dimmer to the wall
receptacle
outlet and then plug the lamp into the dimmer. It's a handy device I
carry
around the house to any reading corner.
But the problem is that sometime while plugging the dimmer
into
the
wall (with the lamp turned on) the dimmer tends for fail (or turn on at
full).
The dimmer is then discarded. The dimmer's death come at the same time
as I
noticed an arch inside the wall outlet while attempting to plug it in.
It's
probably not design for this since an aftermarket lamp dimmer I also
have
won't
fail in any abusive condition. My homemade dimmers have a problem I
have no
solutions for and like to solve it. Any suggestions?

Why am I making homade lamp dimmers? A friend gave me a shoe-box half
full
of
used dimmers.
Click to expand...

---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.511 / Virus Database: 308 - Release Date: 18-8-2003
 
Incandescent lamps can have an inrush current that is 10 times normal
due to the cold filament. Always start dimmers in the low position
which allows the filament to gradually reach operating temp.

Grumpy
 
"Jerry G." <jerryg@total.net> wrote in message news:<bi9cma$i2h$1@news.eusc.inter.net>...
Dimmer circuits, as simple as they look, the design and part values can
be a bit critical. But, if your dimmer circuit is actually okay, then
you have to investigate the load.

Some of these reading lamps use a small transformer inside. This is to
step the mains voltage down for a small type of reading bulb.

You cannot run a transformer or reactive device on a simple thyristor
dimmer. If so, the transformer may either burn out the dimmer, or be
damaged. This has to do with a number of complex reasons which is
really beyond what I can get in to over an email.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
==============================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
Instruments http://www.zoom-one.com/glgtech.htm
==============================================
"Wdyorchid" <wdyorchid@aol.com> wrote in message
news:20030823042315.21471.00000647@mb-m01.aol.com...
I'd been destroying dimmers on a handful. I'd been making homemade
dimmer
control (from ordinary residential dimmers) for my reading lamp. (Don't
know if
this violates safety codes.) I would plug the dimmer to the wall
receptacle
outlet and then plug the lamp into the dimmer. It's a handy device I
carry
around the house to any reading corner.
But the problem is that sometime while plugging the dimmer
into the
wall (with the lamp turned on) the dimmer tends for fail (or turn on at
full).
The dimmer is then discarded. The dimmer's death come at the same time
as I
noticed an arch inside the wall outlet while attempting to plug it in.
It's
probably not design for this since an aftermarket lamp dimmer I also
have won't
fail in any abusive condition. My homemade dimmers have a problem I have
no
solutions for and like to solve it. Any suggestions?

Why am I making homade lamp dimmers? A friend gave me a shoe-box half
full of
used dimmers.
-w orchid
Click to expand...

My guess is that with a 100 watt incandescent bulb, the initial inrush
current is causing the problem. The bulb has a very low cold
resistance, and there is a surge of curent for the first few cycles
until the filament heats up. This surge may be the problem. Think of
how most incandescent lights fail, they fail with a flash when they
are first turned on. Very few fail while they are in the steady-state
on mode. The inrush curent problem is why most dimmers say to turn
the dimmer to the off position while installing the dimmer.

H. R. (Bob) Hofmann
 
yokeman65bb@netscape.net (Grumpy OM) writes:

Incandescent lamps can have an inrush current that is 10 times normal
due to the cold filament. Always start dimmers in the low position
which allows the filament to gradually reach operating temp.
Click to expand...
Yes, but normal dimmers don't die when switched on at full brightness.

When light bulbs die, the instantaneous current can be much higher.

--- sam | Sci.Electronics.Repair FAQ Home Page: 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 Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the Feedback Form at repairfaq.org. Thanks.
 
hrhofmann@att.net (H. R. Bob Hofmann) writes:

"Jerry G." <jerryg@total.net> wrote in message news:<bi9cma$i2h$1@news.eusc.inter.net>...
Dimmer circuits, as simple as they look, the design and part values can
be a bit critical. But, if your dimmer circuit is actually okay, then
you have to investigate the load.

Some of these reading lamps use a small transformer inside. This is to
step the mains voltage down for a small type of reading bulb.

You cannot run a transformer or reactive device on a simple thyristor
dimmer. If so, the transformer may either burn out the dimmer, or be
damaged. This has to do with a number of complex reasons which is
really beyond what I can get in to over an email.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
==============================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
Instruments http://www.zoom-one.com/glgtech.htm
==============================================
"Wdyorchid" <wdyorchid@aol.com> wrote in message
news:20030823042315.21471.00000647@mb-m01.aol.com...
I'd been destroying dimmers on a handful. I'd been making homemade
dimmer
control (from ordinary residential dimmers) for my reading lamp. (Don't
know if
this violates safety codes.) I would plug the dimmer to the wall
receptacle
outlet and then plug the lamp into the dimmer. It's a handy device I
carry
around the house to any reading corner.
But the problem is that sometime while plugging the dimmer
into the
wall (with the lamp turned on) the dimmer tends for fail (or turn on at
full).
The dimmer is then discarded. The dimmer's death come at the same time
as I
noticed an arch inside the wall outlet while attempting to plug it in.
It's
probably not design for this since an aftermarket lamp dimmer I also
have won't
fail in any abusive condition. My homemade dimmers have a problem I have
no
solutions for and like to solve it. Any suggestions?

Why am I making homade lamp dimmers? A friend gave me a shoe-box half
full of
used dimmers.
-w orchid


My guess is that with a 100 watt incandescent bulb, the initial inrush
current is causing the problem. The bulb has a very low cold
resistance, and there is a surge of curent for the first few cycles
until the filament heats up. This surge may be the problem. Think of
how most incandescent lights fail, they fail with a flash when they
are first turned on. Very few fail while they are in the steady-state
on mode. The inrush curent problem is why most dimmers say to turn
the dimmer to the off position while installing the dimmer.
H. R. (Bob) Hofmann
Click to expand...
Push-on, push-off dimmers do not die if switched on at full brightness!

--- sam | Sci.Electronics.Repair FAQ Home Page: 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 Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the Feedback Form at repairfaq.org. Thanks.
 
When they fail; do they fail such that they are at full brightness or no
light at all?

Wdyorchid wrote:
I'd been destroying dimmers on a handful. I'd been making homemade dimmer
control (from ordinary residential dimmers) for my reading lamp. (Don't know if
this violates safety codes.) I would plug the dimmer to the wall receptacle
outlet and then plug the lamp into the dimmer. It's a handy device I carry
around the house to any reading corner.
But the problem is that sometime while plugging the dimmer into the
wall (with the lamp turned on) the dimmer tends for fail (or turn on at full).
The dimmer is then discarded. The dimmer's death come at the same time as I
noticed an arch inside the wall outlet while attempting to plug it in. It's
probably not design for this since an aftermarket lamp dimmer I also have won't
fail in any abusive condition. My homemade dimmers have a problem I have no
solutions for and like to solve it. Any suggestions?

Why am I making homade lamp dimmers? A friend gave me a shoe-box half full of
used dimmers.
-w orchid
Click to expand...
 
In article <20030823220109.02463.00000329@mb-m23.aol.com>, Wdyorchid wrote:
It's a plain100W incandescent bulb. Sometimes somebody would leave the lamp on
accidently.
-W
Click to expand...
the problem is in your dimmer/s. i have been using a wall type dimmer
on my night stand to control a table lamp for over 10yrs. the only
problem i have had is when i spilled water on it while on and it blew
the dimming function. it still turns on/off. this is one with both
a knob for dimming and a sw for on/off.

prior to this one, i had a cheapie that lasted about 6mos. there
used to be (are still?) a ton of crappy dimmers produced by good
ol amerikans. --Loren

How many watts is the reading lamp? Is it a plain incandescent bulb,
halogen, or something else?

Why leave the light on when plugging in the dimmer? Turn it OFF first,
plug things in, then turn on the light.

--

I'd been destroying dimmers on a handful. I'd been making homemade dimmer
control (from ordinary residential dimmers) for my reading lamp. (Don't
know if
this violates safety codes.) I would plug the dimmer to the wall receptacle
outlet and then plug the lamp into the dimmer. It's a handy device I carry
around the house to any reading corner.
But the problem is that sometime while plugging the dimmer into
the
wall (with the lamp turned on) the dimmer tends for fail (or turn on at
full).
The dimmer is then discarded. The dimmer's death come at the same time as I
noticed an arch inside the wall outlet while attempting to plug it in. It's
probably not design for this since an aftermarket lamp dimmer I also have
won't
fail in any abusive condition. My homemade dimmers have a problem I have no
solutions for and like to solve it. Any suggestions?

Why am I making homade lamp dimmers? A friend gave me a shoe-box half full
of
used dimmers.
Click to expand...
 
The dimmer dies only when on low brightness. They die as full brightness. The
dimmers are cheap no-name brands. I have a few 120V triacs I'd collected from
old dimmers but won't work when swap on the dead dimmers?? Does adding
capacitors reduce arching?
I didn't point out that many die at the same single wall receptacle outlet.
And this is a really bad outlet known to produce archs. This outlet killed my
expensive Toshiba DVD player with a display of smoke from the power supply.
I can hear a buzz inside the dimmers when it's set on low. Thinking it's
just working too hard when set to low brightness, should I turn it on at full
blast like Samuel G. pointed out?

-worchid (Thanks for suggestions from many people.)


When they fail; do they fail such that they are at full brightness or no
light at all?

Wdyorchid wrote:
I'd been destroying dimmers on a handful. I'd been making homemade dimmer
control (from ordinary residential dimmers) for my reading lamp. (Don't
know if
this violates safety codes.) I would plug the dimmer to the wall receptacle
outlet and then plug the lamp into the dimmer. It's a handy device I carry
around the house to any reading corner.
But the problem is that sometime while plugging the dimmer into
the
wall (with the lamp turned on) the dimmer tends for fail (or turn on at
full).
The dimmer is then discarded. The dimmer's death come at the same time as I
noticed an arch inside the wall outlet while attempting to plug it in. It's
probably not design for this since an aftermarket lamp dimmer I also have
won't
fail in any abusive condition. My homemade dimmers have a problem I have no
solutions for and like to solve it. Any suggestions?

Why am I making homade lamp dimmers? A friend gave me a shoe-box half full
of
used dimmers.
-w orchid
Click to expand...
 
wdyorchid@aol.com (Wdyorchid) writes:

The dimmer dies only when on low brightness. They die as full brightness. The
dimmers are cheap no-name brands. I have a few 120V triacs I'd collected from
old dimmers but won't work when swap on the dead dimmers?? Does adding
capacitors reduce arching?
I didn't point out that many die at the same single wall receptacle outlet.
And this is a really bad outlet known to produce archs. This outlet killed my
expensive Toshiba DVD player with a display of smoke from the power supply.
I can hear a buzz inside the dimmers when it's set on low. Thinking it's
just working too hard when set to low brightness, should I turn it on at full
blast like Samuel G. pointed out?

-worchid (Thanks for suggestions from many people.)
Click to expand...
Duh, and you haven't replaced the outlet? You may have more than a dimmer
problem if you don't

--- sam | Sci.Electronics.Repair FAQ Home Page: 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
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Important: The email address in this message header may no longer work. To
contact me, please use the Feedback Form at repairfaq.org. Thanks.
 
You're absolutely right. Forgot to mention the landlord won't allow residents
to replace their own receptacles. The landlard workers came to take a look at
it (three times to be exact) and says it works just fine and left. They charge
fees for anyone tampering with anything. Since you've mentioned it, I'll
replace it right away even if violating their rules for your sake.

Duh, and you haven't replaced the outlet? You may have more than a dimmer
problem if you don't
Click to expand...

The dimmer dies only when on low brightness. They die as full brightness.
The
dimmers are cheap no-name brands. I have a few 120V triacs I'd collected
from
old dimmers but won't work when swap on the dead dimmers?? Does adding
capacitors reduce arching?
I didn't point out that many die at the same single wall receptacle
outlet.
And this is a really bad outlet known to produce archs. This outlet killed
my
expensive Toshiba DVD player with a display of smoke from the power supply.
I can hear a buzz inside the dimmers when it's set on low. Thinking
it's
just working too hard when set to low brightness, should I turn it on at
full
blast like Samuel G. pointed out?

-worchid (Thanks for suggestions from many people.)

Duh, and you haven't replaced the outlet? You may have more than a dimmer
problem if you don't

--- sam | Sci.Electronics.Repair FAQ Home Page: 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 Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the Feedback Form at repairfaq.org. Thanks.
Click to expand...
 
If the dimmers are dying when plugged in with a lamp that is already turned
on, it is possible that the inrush current is too much for them to stand.

How big of a lamp are you using and what type is it?

What are the dimmers rated for?

Have you ever tried a different brand and design?

William
 
100W incandescent bulbs, sometimes time 500W halogen.
All dimmers rated 500-600W.
I'd tried many brands but same simple designs.
w orchid


If the dimmers are dying when plugged in with a lamp that is already turned
on, it is possible that the inrush current is too much for them to stand.

How big of a lamp are you using and what type is it?

What are the dimmers rated for?

Have you ever tried a different brand and design?

William
Click to expand...
 
Are you dimming plain filament lamps? Or low-voltage lamps fed through
a transformer?

Dimmers don't like transformers. Some are /real/ transformers (heavy
because of iron core) and they present an inductive load which creates
high voltage spikes which kill the dimmer.

Other so-called transformers for 12 V lights are not really
transformers - they are preset dimmers! And because dimmers work by
"chopping" off the right fraction of one cycle of AC, you can't use
more than one such dimmer on the same load. If you try, one dimmer
tries to act later than the one which has already "chopped", so it's
seeing an infinite load impedance - which it can't handle.

BillJ (Edinburgh)

On Wed, 27 Aug 2003 22:25:55 GMT, "William R. Walsh"
<newsgroups1@idontwantjunqueemail.walshcomptech.com> wrote:

If the dimmers are dying when plugged in with a lamp that is already turned
on, it is possible that the inrush current is too much for them to stand.

How big of a lamp are you using and what type is it?

What are the dimmers rated for?

Have you ever tried a different brand and design?

William
Click to expand...
 
I didn't point out that many die at the same single wall receptacle outlet.
And this is a really bad outlet known to produce archs. This outlet killed my
expensive Toshiba DVD player with a display of smoke from the power supply.
Click to expand...
Why waste our time by withholding this?
 
BillJ <gm@8apx.freeserve.co.uk> writes:

Are you dimming plain filament lamps? Or low-voltage lamps fed through
a transformer?

Dimmers don't like transformers. Some are /real/ transformers (heavy
because of iron core) and they present an inductive load which creates
high voltage spikes which kill the dimmer.

I have made some 5 years ago a kit for ``sensor'' dimmer that uses a
Click to expand...
Siemens IC to drive the triac. Is connected to a 100VA 220/12V
transfomer that powers halogen lamps.
I don't know if that IC has a sort of protection for inducrive load
but it still works happily.


Mike
 
I have no excuse. But 40% die at this outlet. 60% accounts elsewhere. The DVD
player died not because of the outlet but how it's plugged in. Clumsily holding
the wire, I plug it in, it slips out then plug in but not fully in. The surge
of power similar to turning TV on and off quickly.

Why waste our time by withholding this?

I didn't point out that many die at the same single wall receptacle
outlet.
And this is a really bad outlet known to produce archs. This outlet killed
my
expensive Toshiba DVD player with a display of smoke from the power supply.
Click to expand...
 
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