sci.electronics.repair@googlegroups.com

Today's topics:

* Kill-o-watt meter used on computer UPS - bad readings? - 3 messages, 3
authors
http://groups.google.com/group/sci.electronics.repair/t/01a9482b8c5ce589?hl=en
* CFLs - retrofitting low ESR capacitors - 4 messages, 4 authors
http://groups.google.com/group/sci.electronics.repair/t/4b33f31f667954a0?hl=en
* splice fail - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/cae74cda683b83fa?hl=en

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TOPIC: Kill-o-watt meter used on computer UPS - bad readings?
http://groups.google.com/group/sci.electronics.repair/t/01a9482b8c5ce589?hl=en
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== 1 of 3 ==
Date: Mon, Sep 19 2011 6:11 pm
From: Sylvia Else

On 20/09/2011 10:41 AM, Bob F wrote:
> I just unplugged the Belkin 1200 VA UPS powering my computer, and plugged it
> into my Kill-o-watt meter. After the UPS quit beeping after power was restored,
> the meter shows 7-11 watts being consumed by the UPS feeding the computer, which
> is way less than the computer (quad core core-duo processor) uses.
>
> Does the killowatt have a problem reading accurately with UPS units?

The reading seems strange (typically one would expect it to show a
higher than true figure), but cheap power meters often have difficulty
with anything other than appliances that behave like resistive loads.
Neither the UPS itself nor the PC is likely to do so.

Sylvia.

== 2 of 3 ==
Date: Mon, Sep 19 2011 7:00 pm
From: "Bob F"

Dave Platt wrote:
> In article <j58nff$bjn$1@dont-email.me>, Bob F <bobnospam@gmail.com>
> wrote:
>
>> I just unplugged the Belkin 1200 VA UPS powering my computer, and
>> plugged it into my Kill-o-watt meter. After the UPS quit beeping
>> after power was restored, the meter shows 7-11 watts being consumed
>> by the UPS feeding the computer, which is way less than the computer
>> (quad core core-duo processor) uses.
>>
>> Does the killowatt have a problem reading accurately with UPS units?
>
> What does the meter read, if you connect the computer to it directly,
> and entirely bypass the UPS?
>
> Most of these consumer-grade "UPS" systems are *not*. That is, they
> aren't "uninterruptable" - they are "standby power supply" devices.
> During normal operation, when the AC mains are up normally, they
> actually connect the load (PC) directly to the mains... their own
> output circuitry is switched off. All they have running, internally,
> is monitoring circuitry, and a trickle-charger for the battery. The
> "UPS" only disconnects the load from the mains, turns on its inverter,
> and begins generating AC power to feed to the load.
>
> So, if the Belkin isn't beeping, it's probably just routing the AC
> mains power through to the PC, and you'd find the meter reading almost
> the same as if you plugged the PC directly into the meter...
>

I'll try bypassing the UPS when my computer is not busy and report the results
later.

== 3 of 3 ==
Date: Mon, Sep 19 2011 11:37 pm
From: Jeff Liebermann

On Mon, 19 Sep 2011 17:41:18 -0700, "Bob F" <bobnospam@gmail.com>
wrote:

>I just unplugged the Belkin 1200 VA UPS powering my computer, and plugged it
>into my Kill-o-watt meter.

What model Belkin UPS?
<http://www.belkin.com/IWCatSectionView.process?Section_Id=206698>
What model kill-o-watt meter?
<http://www.p3international.com/products/>

>After the UPS quit beeping after power was restored,

Some UPS power supplies will stop beeping BEFORE they switch from
internally generated power back to wall plug power. It's not clear
from your description if the attached computah is running on UPS
power, or wall plug power.

>the meter shows 7-11 watts being consumed by the UPS feeding the computer, which
>is way less than the computer (quad core core-duo processor) uses.

Make and model of the computer? Anything else plugged into the UPS
such as a monitor, printer, modem, etc?

>Does the killowatt have a problem reading accurately with UPS units?

Yes, sorta. If it's an old UPS, that doesn't have PF (power factor)
correction, the kill-a-watt will show a difference between VA
(volt-amps) and the real part of the power (watts). You can measure
the PF with the kill-a-watt (depending on model) and see if this is a
problem. However, the error is usually not very large and does not
account for a ridiculously low reading of 7-11 watts. The computah
should draw about 100 watts. The LCD monitor about the same
(depending on size). Add whatever for unspecified accessories. Take
the UPS out of the circuit and measure just the active loads plugged
into the UPS.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

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TOPIC: CFLs - retrofitting low ESR capacitors
http://groups.google.com/group/sci.electronics.repair/t/4b33f31f667954a0?hl=en
==============================================================================

== 1 of 4 ==
Date: Mon, Sep 19 2011 6:36 pm
From: Jamie

Sylvia Else wrote:

> Has anyone here tried retrofitting low ESR capacitors to CFLs with a
> view to improving their turn-on performance - i.e. so that they reach
> full brightness quickly?
>
> Sylvia.
If you're referring to the inverter supply? I think those caps are
already of low ESR types. If not, they should be.

Jamie

== 2 of 4 ==
Date: Mon, Sep 19 2011 7:05 pm
From: Jeff Urban

The low brighness when cold is not due to low PS voltages or current,
it is due to the fact that it takes time for the gas to get it up
completely. It may be possible to overshoot the target current/power
when first started to accelerate the process but this is very likely
to decrease the overall life of the CFLs.

Newr units do seem to perform better in that respect, but short of
replacing things with newer versions I think you will just have to be
patient.

J

== 3 of 4 ==
Date: Mon, Sep 19 2011 7:51 pm
From: "larry moe 'n curly"

On Sep 19, 6:00 pm, Sylvia Else <syl...@not.here.invalid> wrote:
>
> Has anyone here tried retrofitting low ESR capacitors to CFLs with a
> view to improving their turn-on performance - i.e. so that they reach
> full brightness quickly?

I don't think capacitors are the reason for the brightness change
because even many brand-new CFLs take time to reach full brightness,
especially when in the cold (even 75F). More likely, the circuitry
just doesn't compensate for the temperature of the fluorescent tube.
For example, here's the circuit board from the base of a failed
Maxlife brand CFL. The fluorescent tube connects at F1, F2, F3, and
F4, and notice on the far right is a space for a thermistor (PTC) that
connects between F1 and F4 on the other side, through a capacitor, C8,
that's also missing. The circuit board was built so it shorts across
C8. The big capacitor in the middle is rated 22uF, 200V, and Aishi is
considered a junk brand.

Another problem is opening up the CFL to get to the circuit board and
reattaching the cover because regular glues don't work, and you want a
strong bond that won't fail at high temperature.

.

http://imageshack.us/f/62/cflinside.jpg/

== 4 of 4 ==
Date: Mon, Sep 19 2011 8:11 pm
From: "Trevor Wilson"

Sylvia Else wrote:
> Has anyone here tried retrofitting low ESR capacitors to CFLs with a
> view to improving their turn-on performance - i.e. so that they reach
> full brightness quickly?
>
> Sylvia.

**The full brightness thing is not associated with the electronics. It's an
issue with the gas in the tube and, to a lesser extent, the phosphor
coating. You can prove this for yourself, by measuring the light output of a
standard (iron ballast) fluoro. Light output gradually increases over a few
seconds (or minutes, depending on ambient temperature).

Don't sweat it anyway, LEDs will replace them in most applications very
soon. I've been mucking about with a couple of these recently:

http://www.dealextreme.com/p/12w-3500k-800lm-warm-white-led-emitter-metal-strip-12-14v-80310

It delivers almost double the light output of an 11 Watt T5 fluoro and is
far more compact, dimmable and has nicer colour temperature.

--
Trevor Wilson
www.rageaudio.com.au

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TOPIC: splice fail
http://groups.google.com/group/sci.electronics.repair/t/cae74cda683b83fa?hl=en
==============================================================================

== 1 of 1 ==
Date: Mon, Sep 19 2011 11:53 pm
From: Jeff Liebermann

On Mon, 19 Sep 2011 15:03:56 -0500, Jeffrey Angus <grendelair@aim.com>
wrote:

>On 9/19/2011 10:44 AM, malua mada! wrote:
>> I then use Epoxy filler to shape a unique plug body (comes as
>> a dough stick
>
>I found out the hard way that JB Weld, as good as it is, is
>conductive.
>Jeff

Huh? The JB Weld FAQ claims it's not conductive (even though it
contains iron filings).
<http://jbweld.net/faq.php#faq009>
Q: Will J-B Weld conduct electricity?
A: No. J-B Weld is not considered to be a conductor. It
is an insulator.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

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