Speakers vs. Lamp

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I hope that someone has seen this problem before and can offer an
opinion, or better, a low-cost solution.

I have a halogen desk lamp at work that operates on the same power
circuit as my computer speakers. The lamp is plugged into the top
outlet, the UPS for the computer is plugged into the bottom outlet and
supplies the computer, monitor and speakers. When I turn the lamp on or
off, the speakers "pop". I am worried as to the effect this pop will
have on the life of my speakers, since it seems to be similar to an
over-power situation that I have heard will damage the speakers.

My alternative to the current setup is to move the lamp into another
outlet, but I am reasonably sure that all the outlets in the office are
on the same breaker circuit, so I doubt that it will make a difference.


Any ideas would be welcome.

Thanks!

[Pooh Bear]

wrote:

> I hope that someone has seen this problem before and can offer an
> opinion, or better, a low-cost solution.
>
> I have a halogen desk lamp at work that operates on the same power
> circuit as my computer speakers. The lamp is plugged into the top
> outlet, the UPS for the computer is plugged into the bottom outlet and
> supplies the computer, monitor and speakers. When I turn the lamp on or
> off, the speakers "pop". I am worried as to the effect this pop will
> have on the life of my speakers,

Zero.

> since it seems to be similar to an
> over-power situation that I have heard will damage the speakers.
>
> My alternative to the current setup is to move the lamp into another
> outlet, but I am reasonably sure that all the outlets in the office are
> on the same breaker circuit, so I doubt that it will make a difference.
>
> Any ideas would be welcome.

You're worrying about nothing. Sounds like you have a dodgy switch in the
lamp that's arcing though.

Graham

[Walt]

wrote:

> I have a halogen desk lamp at work that operates on the same power
> circuit as my computer speakers. The lamp is plugged into the top
> outlet, the UPS for the computer is plugged into the bottom outlet and
> supplies the computer, monitor and speakers. When I turn the lamp on or
> off, the speakers "pop". I am worried as to the effect this pop will
> have on the life of my speakers, since it seems to be similar to an
> over-power situation that I have heard will damage the speakers.
>
> My alternative to the current setup is to move the lamp into another
> outlet, but I am reasonably sure that all the outlets in the office are
> on the same breaker circuit, so I doubt that it will make a difference.

If the lamp was going to do any damage, it would have happened by now.

But the fact that crap on the AC line makes it from the lamp through the
UPS and into the computer/speakers suggests that you need a better surge
supressor for your computer. i.e. the lamp isn't a problem, but if
something else comes along you may be vunerable.

//Walt

[Pooh Bear]

Walt wrote:

> wrote:
>
> > I have a halogen desk lamp at work that operates on the same power
> > circuit as my computer speakers. The lamp is plugged into the top
> > outlet, the UPS for the computer is plugged into the bottom outlet and
> > supplies the computer, monitor and speakers. When I turn the lamp on or
> > off, the speakers "pop". I am worried as to the effect this pop will
> > have on the life of my speakers, since it seems to be similar to an
> > over-power situation that I have heard will damage the speakers.
> >
> > My alternative to the current setup is to move the lamp into another
> > outlet, but I am reasonably sure that all the outlets in the office are
> > on the same breaker circuit, so I doubt that it will make a difference.
>
> If the lamp was going to do any damage, it would have happened by now.
>
> But the fact that crap on the AC line makes it from the lamp through the
> UPS and into the computer/speakers suggests that you need a better surge
> supressor for your computer. i.e. the lamp isn't a problem, but if
> something else comes along you may be vunerable.

No. The PC supply needs a better *filter*.

Graham

[Trevor Wilson]

"Pooh Bear" > wrote in message
...
>
>
> Walt wrote:
>
>> wrote:
>>
>> > I have a halogen desk lamp at work that operates on the same power
>> > circuit as my computer speakers. The lamp is plugged into the top
>> > outlet, the UPS for the computer is plugged into the bottom outlet and
>> > supplies the computer, monitor and speakers. When I turn the lamp on or
>> > off, the speakers "pop". I am worried as to the effect this pop will
>> > have on the life of my speakers, since it seems to be similar to an
>> > over-power situation that I have heard will damage the speakers.
>> >
>> > My alternative to the current setup is to move the lamp into another
>> > outlet, but I am reasonably sure that all the outlets in the office are
>> > on the same breaker circuit, so I doubt that it will make a difference.
>>
>> If the lamp was going to do any damage, it would have happened by now.
>>
>> But the fact that crap on the AC line makes it from the lamp through the
>> UPS and into the computer/speakers suggests that you need a better surge
>> supressor for your computer. i.e. the lamp isn't a problem, but if
>> something else comes along you may be vunerable.
>
> No. The PC supply needs a better *filter*.

**Incorrect. The SWITCH on the lamp requires suppression. It is highly
unlikely that the interference is entering through the power supply.


--
Trevor Wilson
www.rageaudio.com.au

[Pooh Bear]

Trevor Wilson wrote:

> "Pooh Bear" > wrote in message
> ...
> >
> >
> > Walt wrote:
> >
> >> wrote:
> >>
> >> > I have a halogen desk lamp at work that operates on the same power
> >> > circuit as my computer speakers. The lamp is plugged into the top
> >> > outlet, the UPS for the computer is plugged into the bottom outlet and
> >> > supplies the computer, monitor and speakers. When I turn the lamp on or
> >> > off, the speakers "pop". I am worried as to the effect this pop will
> >> > have on the life of my speakers, since it seems to be similar to an
> >> > over-power situation that I have heard will damage the speakers.
> >> >
> >> > My alternative to the current setup is to move the lamp into another
> >> > outlet, but I am reasonably sure that all the outlets in the office are
> >> > on the same breaker circuit, so I doubt that it will make a difference.
> >>
> >> If the lamp was going to do any damage, it would have happened by now.
> >>
> >> But the fact that crap on the AC line makes it from the lamp through the
> >> UPS and into the computer/speakers suggests that you need a better surge
> >> supressor for your computer. i.e. the lamp isn't a problem, but if
> >> something else comes along you may be vunerable.
> >
> > No. The PC supply needs a better *filter*.
>
> **Incorrect. The SWITCH on the lamp requires suppression. It is highly
> unlikely that the interference is entering through the power supply.

You reckon ? I'd actually made a comnment regarding the switch in my earlier
post. It's always better to fix it at source. My comment above was mainly to the
effect that it's not about 'surge suppression'. Ppl get this idea about 'surges'
in their head that are totally mistaken.

Graham

[ComputerGuy]

Ok, so far, thanks for your opinions, I appreciate your time.

If anything I am now more confused.

I have never seen a switch that won't arc. Every physical switch will
arc as it closes or opens if there is power to one side.

What I am understanding, though, is that the lamp pulls enough power
that the switch opening produces a spike through the power circuit that
is causing an instantaneous full-power situation to the speakers.

One thing I have noticed is that neither the lamp nor the speakers have
ground posts on their power cords. Also, the lamp only causes the spike
when the lamp is turned off.

Now, as I don't have access to an o-scope or similar equipment, what
device would be a good method to suppress the spike from the lamp and
stop the pop sound?

Thanks!

[Arny Krueger]

"ComputerGuy" > wrote in message
oups.com...
> Ok, so far, thanks for your opinions, I appreciate your time.
>
> If anything I am now more confused.
>
> I have never seen a switch that won't arc. Every physical switch will
> arc as it closes or opens if there is power to one side.
>
> What I am understanding, though, is that the lamp pulls enough power
> that the switch opening produces a spike through the power circuit that
> is causing an instantaneous full-power situation to the speakers.
>
> One thing I have noticed is that neither the lamp nor the speakers have
> ground posts on their power cords. Also, the lamp only causes the spike
> when the lamp is turned off.
>
> Now, as I don't have access to an o-scope or similar equipment, what
> device would be a good method to suppress the spike from the lamp and
> stop the pop sound?

The usual fixes for a popping switch are:

(1) Replace the switch with one that simply arcs less. For example, a dimmer
doesn't arc at all, and the better ones are well-filtered for RF generation.

(2) Bypass the switch with a variety of electrical parts. A resistor and a
capacitor in series across the switch contact. Small inductors in series.

(3) Reduce the sensitivity of the device that is actually sending the pop to
the speakers. More capacitors and inductors, this time on inputs and if its
really bad, the outputs.

[Pooh Bear]

ComputerGuy wrote:

> Ok, so far, thanks for your opinions, I appreciate your time.
>
> If anything I am now more confused.
>
> I have never seen a switch that won't arc. Every physical switch will
> arc as it closes or opens if there is power to one side.

A good switch will have a 'snap action' though so the arc isn't there for
long. A poor or damaged switch may maintain an arc for longer.


> What I am understanding, though, is that the lamp pulls enough power
> that the switch opening produces a spike through the power circuit that
> is causing an instantaneous full-power situation to the speakers.

It's not very likely to be full power.

> One thing I have noticed is that neither the lamp nor the speakers have
> ground posts on their power cords.

That's normal. A ground wouldn't help here anyway.

> Also, the lamp only causes the spike
> when the lamp is turned off.

That's normal.

> Now, as I don't have access to an o-scope or similar equipment, what
> device would be a good method to suppress the spike from the lamp and
> stop the pop sound?

I'd replace the lamp switch first actually. Hmmmm... you say it's halogen.
I guess it uses a low voltage bulb ? That means it has a transformer and
that helps explain the arcing ( inductance ). You could look for a 'contact
suppressor'. It wasn't a cheap lamp from China by any chance ?

Graham