If you were Registered and logged in, you could reply and use other advanced thread options
|
Posted by Paul Soderman on November 6, 2007, 6:33 pm
Today I realized that our light dimmer switch, when set at the highest
point, does not seem to get the lights as bright as they had
previously been. I should point out that the power was also out a bit
today in my area.
I am suspecting that perhaps a power surge or else maybe just the age
of the switch may have caused this problem to "come to light", but I
had though that if the switch failed, the lights would simply be at
their brightest and that the dimming mechanism would not work.
I am going to replace the switch anyway, but wanted to check out if my
suspicions were correct; can the dimmer fail so as to result in a mid-
level brightness of the lights?
Thanks for any help!
Paul
|
|
Posted by franz frippl on November 6, 2007, 10:20 pm
On Tue, 06 Nov 2007 23:33:22 +0000, Paul Soderman wrote:
> Today I realized that our light dimmer switch, when set at the highest
> point, does not seem to get the lights as bright as they had previously
> been. I should point out that the power was also out a bit today in my
> area.
> I am suspecting that perhaps a power surge or else maybe just the age of
> the switch may have caused this problem to "come to light", but I had
> though that if the switch failed, the lights would simply be at their
> brightest and that the dimming mechanism would not work.
>
> I am going to replace the switch anyway, but wanted to check out if my
> suspicions were correct; can the dimmer fail so as to result in a mid-
> level brightness of the lights?
>
> Thanks for any help!
> Paul
Dimmer switches are no more than rheostats. If carbon were to build up
on part of the switch, it may be sufficient to affect voltage. Might
cause a voltage drop.
You could test this with a volt/ohm meter.
|
|
Posted by lee h on November 6, 2007, 10:35 pm
franz frippl wrote:
>
> Dimmer switches are no more than rheostats. If carbon were to build
> up on part of the switch, it may be sufficient to affect voltage.
> Might cause a voltage drop.
>
> You could test this with a volt/ohm meter.
In ye olde days, you were right. However for many years,
the triac-based dimmer switch has been the more common.
There is a rheostat used in the dimmer, but it it is used
to control the triac. For a more detailed explanation:
http://home.howstuffworks.com/dimmer-switch6.htm
|
|
Posted by Chris Lewis on November 7, 2007, 9:27 am
> franz frippl wrote:
> > Dimmer switches are no more than rheostats. If carbon were to build
> > up on part of the switch, it may be sufficient to affect voltage.
> > Might cause a voltage drop.
> > You could test this with a volt/ohm meter.
> In ye olde days, you were right. However for many years,
> the triac-based dimmer switch has been the more common.
"More common"? Even in ye olde days, rheostat dimmers were extremely
rare, and they're now essentially non-existant.
Hint: rheostats have to dissipate a _lot_ of power, and a switch
box is not a good place to try doing that.
A rheostat capable of, say, dimming a 100W light bulb probably
wouldn't fit into a switch box, and if it did, you could use the
wall around it as a cooking surface.
Dimmers tend to fail in one of two ways:
1) Complete failure, no light at any position.
2) triac control fails, get erratic behaviour.
I suspect that the OP is simply seeing a brownout.
--
Chris Lewis,
Age and Treachery will Triumph over Youth and Skill
It's not just anyone who gets a Starship Cruiser class named after them.
|
|
Posted by lee h on November 7, 2007, 2:34 pm
Chris Lewis wrote:
>> franz frippl wrote:
>
>>> Dimmer switches are no more than rheostats. If carbon were to build
>>> up on part of the switch, it may be sufficient to affect voltage.
>>> Might cause a voltage drop.
>
>>> You could test this with a volt/ohm meter.
>
>> In ye olde days, you were right. However for many years,
>> the triac-based dimmer switch has been the more common.
>
> "More common"? Even in ye olde days, rheostat dimmers were extremely
> rare, and they're now essentially non-existant.
Chris, I suspect that your definition of 'ye olde' and 'many years'
is more short term than mine. The SCR which enabled solid-state
control of dimmers was not invented until the late fifties. Rheostat
dimmers and auto transformers (Variacs) were the *only* means of
dimming lights until then. So they were hardly rare. Solid state
dimmers were not commonly used in homes until the late
sixties. But, you are right about the rheostat dimmer's heat
output. Most were mounted in a box on the outside surface of
a wall, not in a switchbox.
|
Page 1 of 5 1 2 3 > last >>
| Similar Threads | Posted | | Which uses more electricity, a 75 watt light bulb or a 150 with a dimmer so that it is as bright as the 75? | May 19, 2006, 10:41 pm |
| Toggle Lighted Dimmer light switch | December 11, 2005, 2:51 pm |
| Singing light bulb on dimmer switch | May 20, 2006, 3:22 am |
| Does a Clock/Dimmer light switch exist? | July 4, 2008, 11:57 pm |
| How do I combine lights on single pole switch with lights on 3-way switch? | April 24, 2008, 12:54 pm |
| Neighbor with bright light | June 1, 2006, 4:39 am |
| Dimmer For LV Recessed Lights | August 3, 2005, 6:00 pm |
| Porch lights on dimmer? | June 15, 2007, 10:27 pm |
| Pilot safety switch chronic failure | March 12, 2006, 4:19 am |
| 3 way dimmer switch | March 17, 2006, 6:33 am |
|
|
Yahoo! 
Google 
Windows Live 
del.icio.us 
digg 
Netscape 
XML Sitemap