Hi,

we have one of those floor standing lamps from Ikea which have an uplighter
(150W screw in bulb) and a reading lamp.

All worked via a foot switch with a slider (rheostat?) for the uplighter and
an on/off switch for the reading lamp.

The uplighter isn't working - hasn't been for some time as I thought it was
the bulb and they don't sell them apart from in Ikea.

I now have a new Ikea bulb, but have also checked the old one in another
Ikea uplighter and it works.

I have cleaned up the contacts with (dry) wet&dry so they are shiny.

I have checked with my little analogue multi-meter and I am getting about
240 volts to the contacts in the bulb holder.

As far as I can tell, the bulb is touching both contacts (bent them out, the
bulb pushed them back).

So all I can think of is that the rheostat is knackered - putting out 240V
but at such low power that it won't light the bulb.

As the switch is a sealed unit I can't get at the innards.

Any suggestions about what to do next (apart from just use the reading
light)?

TIA

Dave R

--

"David W.E. Roberts" wrote in message
...
Hi,

we have one of those floor standing lamps from Ikea which have an
uplighter
(150W screw in bulb) and a reading lamp.

All worked via a foot switch with a slider (rheostat?) for the uplighter
and
an on/off switch for the reading lamp.

The uplighter isn't working - hasn't been for some time as I thought it
was
the bulb and they don't sell them apart from in Ikea.

I now have a new Ikea bulb, but have also checked the old one in another
Ikea uplighter and it works.

I have cleaned up the contacts with (dry) wet&dry so they are shiny.

I have checked with my little analogue multi-meter and I am getting about
240 volts to the contacts in the bulb holder.

As far as I can tell, the bulb is touching both contacts (bent them out,
the
bulb pushed them back).

So all I can think of is that the rheostat is knackered - putting out 240V
but at such low power that it won't light the bulb.

As the switch is a sealed unit I can't get at the innards.

Any suggestions about what to do next (apart from just use the reading
light)?


.... or the mains is wired backwards and the dimmer (electronic) is on the
neutral.
We mended one at work and had to replace a fast blow fuse.

I've never put a meter on the output of a dimmer, but I guess it might read
240 volts on the average multimeter if for some reason the slider had become
disengaged from the slider potentiometer - might just not be enough mark to
space to light the lamp visibly.

... I never found an electrical appliance that couldn't be opened BTW - if
you discount the coffee percolator which saw me in casualty when the 3mm
drill snapped and went through my finger :-(

Jeremy

"brugnospamsia" wrote in message
k...

"David W.E. Roberts" wrote in message
...
Hi,

snip

... or the mains is wired backwards and the dimmer (electronic) is on the
neutral.

sorry - this would only expain a lit neon screwdriver which you didn't
use... (previous poster)


=================

We mended one at work and had to replace a fast blow fuse.

I've never put a meter on the output of a dimmer, but I guess it might
read 240 volts on the average multimeter if for some reason the slider had
become disengaged from the slider potentiometer - might just not be enough
mark to space to light the lamp visibly.

... I never found an electrical appliance that couldn't be opened BTW - if
you discount the coffee percolator which saw me in casualty when the 3mm
drill snapped and went through my finger :-(

Jeremy

David W.E. Roberts wrote:

we have one of those floor standing lamps from Ikea which have an
uplighter
(150W screw in bulb) and a reading lamp.

All worked via a foot switch with a slider (rheostat?) for the
uplighter and
an on/off switch for the reading lamp.

The uplighter isn't working - hasn't been for some time as I thought
it was
the bulb and they don't sell them apart from in Ikea.

Any suggestions about what to do next (apart from just use the
reading
light)?


150w bulbs are standard kit in both GLS and halogen, just not very
popular domestically.

If you get 240v oc but 0v when bulb is in, you'd be right to say youve
got a high impedance source. I'd wire over the dimmer, so its on a
switch but doesnt dim, thats your most likely culprit at least.


NT

In article ,
David W.E. Roberts wrote:
All worked via a foot switch with a slider (rheostat?) for the uplighter
and an on/off switch for the reading lamp.

Unlikely to be a rheostat - a 150 watt one would get extremely hot. It
will likely be a 'conventional' triac dimmer with a slider pot rather than
the more usual rotary one.

And trying to measure the output of one of these with a meter is pretty
meaningless.

--
*Windows will never cease *

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote:

In article ,
David W.E. Roberts wrote:
All worked via a foot switch with a slider (rheostat?) for the uplighter
and an on/off switch for the reading lamp.

Unlikely to be a rheostat - a 150 watt one would get extremely hot. It
will likely be a 'conventional' triac dimmer with a slider pot rather than
the more usual rotary one.

And trying to measure the output of one of these with a meter is pretty
meaningless.

No reason why. Even if the meter is not true RMS you can usually get
a reasonable indication of a phase switched dimmer output with any
meter.


--

No Spam wrote:
"Dave Plowman (News)" wrote:

In article ,
David W.E. Roberts wrote:
All worked via a foot switch with a slider (rheostat?) for the
uplighter and an on/off switch for the reading lamp.

Unlikely to be a rheostat - a 150 watt one would get extremely hot.
It will likely be a 'conventional' triac dimmer with a slider pot
rather than the more usual rotary one.

And trying to measure the output of one of these with a meter is
pretty meaningless.

No reason why. Even if the meter is not true RMS you can usually get
a reasonable indication of a phase switched dimmer output with any
meter.

Only if there is a load though surely. The current drawn by a DMM will be
many orders of magnitude smaller than that required.

Chris Key

"Christopher Key" wrote:

Only if there is a load though surely. The current drawn by a DMM will be
many orders of magnitude smaller than that required.

Agreed, but that detail was obvious to me ;-)


--

No Spam wrote:
"Christopher Key" wrote:

Only if there is a load though surely. The current drawn by a DMM
will be many orders of magnitude smaller than that required.

Agreed, but that detail was obvious to me ;-)

I didn't doubt it ;-) ! I did get the impression that it wasn't to the OP
though, hence the post.

Chris Key