Hey folks,

I'm curious about power consumption of things like the power supply for my
dell laptop
its and AC/DC adaptor, and when the unit is charging my laptop it gets quite
warm.
from that I infer that its using a fair amount of power.

now, if I leave it plugged into the wall, but remove the laptop, it does
not heat up, but.
there is a little light on it that indicates it is receiving power.
aside from that little light, is it using any significant amount of power?
The label on the unit says the input is 1.5a

same question goes for my cell phone chargers 0.2a

I understand that some of these things do use power constantly, but... how
much?

I found this link but it doesn't get into the Nitti gritty I was looking
for

http://gizmodo.com/gadgets/gadgets/c...act-181497.php

Dave

Zephyr wrote:
Hey folks,

I'm curious about power consumption of things like the power supply
for my dell laptop
its and AC/DC adaptor, and when the unit is charging my laptop it
gets quite warm.
from that I infer that its using a fair amount of power.

now, if I leave it plugged into the wall, but remove the laptop, it
does not heat up, but.
there is a little light on it that indicates it is receiving power.
aside from that little light, is it using any significant amount of
power? The label on the unit says the input is 1.5a

same question goes for my cell phone chargers 0.2a

I understand that some of these things do use power constantly,
but... how much?

I found this link but it doesn't get into the Nitti gritty I was
looking for

http://gizmodo.com/gadgets/gadgets/c...act-181497.php

Buy a "Kill-A-Watt" (see eBay) and test it for yourself.

On Jun 13, 11:51 am, "Zephyr" an address @ some place .com wrote:
Hey folks,

I'm curious about power consumption of things like the power supply for my
dell laptop
its and AC/DC adaptor, and when the unit is charging my laptop it gets quite
warm.
from that I infer that its using a fair amount of power.

now, if I leave it plugged into the wall, but remove the laptop, it does
not heat up, but.
there is a little light on it that indicates it is receiving power.
aside from that little light, is it using any significant amount of power?
The label on the unit says the input is 1.5a

same question goes for my cell phone chargers 0.2a

I understand that some of these things do use power constantly, but... how
much?

I found this link but it doesn't get into the Nitti gritty I was looking
for

http://gizmodo.com/gadgets/gadgets/c...mpire-slayer-a...

Dave

If you add up everything you might save 15$ if you have an old tv,
dvd, microwave etc, Get kill a watt meter and do your own audit

Heres a link to "kill-a-watt". It was very useful to slay my vampires
http://www.meritline.com/kilwateldet.html



"HeyBub" wrote in message
...
Zephyr wrote:
Hey folks,

I'm curious about power consumption of things like the power supply
for my dell laptop
its and AC/DC adaptor, and when the unit is charging my laptop it
gets quite warm.
from that I infer that its using a fair amount of power.

now, if I leave it plugged into the wall, but remove the laptop, it
does not heat up, but.
there is a little light on it that indicates it is receiving power.
aside from that little light, is it using any significant amount of
power? The label on the unit says the input is 1.5a

same question goes for my cell phone chargers 0.2a

I understand that some of these things do use power constantly,
but... how much?

I found this link but it doesn't get into the Nitti gritty I was
looking for

http://gizmodo.com/gadgets/gadgets/c...act-181497.php

Buy a "Kill-A-Watt" (see eBay) and test it for yourself.

On Jun 13, 2:51 pm, "Zephyr" an address @ some place .com wrote:
Hey folks,

I'm curious about power consumption of things like the power supply for my
dell laptop
its and AC/DC adaptor, and when the unit is charging my laptop it gets quite
warm.
from that I infer that its using a fair amount of power.

now, if I leave it plugged into the wall, but remove the laptop, it does
not heat up, but.
there is a little light on it that indicates it is receiving power.
aside from that little light, is it using any significant amount of power?
The label on the unit says the input is 1.5a

same question goes for my cell phone chargers 0.2a

I understand that some of these things do use power constantly, but... how
much?

I found this link but it doesn't get into the Nitti gritty I was looking
for

http://gizmodo.com/gadgets/gadgets/c...mpire-slayer-a...

Dave

It gets hot when it is hooked up to the laptop because the laptop puts
a load on the charger. No load...there is not a lot of heat.

Any device with a transformer directly connected to the mains will
draw a very minute amount of power...it is called the magnetizing load
of the transformer.....if there is a rectifier and regulator after the
xfrmr...which there most likely is ...I dont see it drawing any power
unless there is a load passing thru it.

of course your indicator light will draw a small amount of power.....

On Wed, 13 Jun 2007 14:51:20 -0400, "Zephyr" an address @ some place
..com wrote:

Hey folks,

I'm curious about power consumption of things like the power supply for my
dell laptop
its and AC/DC adaptor, and when the unit is charging my laptop it gets quite
warm.
from that I infer that its using a fair amount of power.

now, if I leave it plugged into the wall, but remove the laptop, it does
not heat up, but.
there is a little light on it that indicates it is receiving power.
aside from that little light, is it using any significant amount of power?
The label on the unit says the input is 1.5a

same question goes for my cell phone chargers 0.2a

I understand that some of these things do use power constantly, but... how
much?

Good question. Not only the ones with wall warts, those black
"adaptor" boxes that plug into the wall with a cord coming out of
them, but many radios etc. with the transformers inside, have no
switch in the primary of the power transformer, and they are ON all
the time.

For electronic reasons I don't well understand, when there is no
current in the secondary of a transformer, there is higher impedance
in the primary of the transformer, so less current flows even through
the primary. The heat one can feel, that you feel, the waste heat
would be iiac the same percentage of energy used, as when the device
is running and there is current through the secondary.

From your touch, it sounds like the current is a lot lower, but otoh,
it's on all the time if the thing is plugged in, even for things that
are only used an hour a year.

Does anyone know what the percentage is, or how much these things use
when off?

xposted to sci.electronics.repair

I found this link but it doesn't get into the Nitti gritty I was looking
for

http://gizmodo.com/gadgets/gadgets/c...act-181497.php

Dave

On Jun 13, 10:53 pm, mm wrote:
On Wed, 13 Jun 2007 14:51:20 -0400, "Zephyr" an address @ some place





.com wrote:
Hey folks,

I'm curious about power consumption of things like the power supply for my
dell laptop
its and AC/DC adaptor, and when the unit is charging my laptop it gets quite
warm.
from that I infer that its using a fair amount of power.

now, if I leave it plugged into the wall, but remove the laptop, it does
not heat up, but.
there is a little light on it that indicates it is receiving power.
aside from that little light, is it using any significant amount of power?
The label on the unit says the input is 1.5a

same question goes for my cell phone chargers 0.2a

I understand that some of these things do use power constantly, but... how
much?

Good question. Not only the ones with wall warts, those black
"adaptor" boxes that plug into the wall with a cord coming out of
them, but many radios etc. with the transformers inside, have no
switch in the primary of the power transformer, and they are ON all
the time.

For electronic reasons I don't well understand, when there is no
current in the secondary of a transformer, there is higher impedance
in the primary of the transformer, so less current flows even through
the primary. The heat one can feel, that you feel, the waste heat
would be iiac the same percentage of energy used, as when the device
is running and there is current through the secondary.

From your touch, it sounds like the current is a lot lower, but otoh,
it's on all the time if the thing is plugged in, even for things that
are only used an hour a year.

Does anyone know what the percentage is, or how much these things use
when off?

xposted to sci.electronics.repair





I found this link but it doesn't get into the Nitti gritty I was looking
for

http://gizmodo.com/gadgets/gadgets/c...mpire-slayer-a...

Dave- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

Well, there's been a lot of discussion on this. Essentially, when
there's no load on the phone charger or other appliance, it's like
having an inductance across the power line of your house. There will
be some very small current flow, but only because it's not a perfect
inductance. All of the energy used in these wall transformers when
they're just idling is dissipated in the form of heat in their black
plastic case, so you can get an idea of how much power they're using
by just feeling them. It's not really very much. Note that you'll
have a tough time measuring the power drain with a multimeter, because
both current and voltage will show rather high readings. But since
they're almost 1/4 cycle out of phase, there's almost no power being
dissipated, and only a good power meter will take this into account.
(This problem is the basis for a lot of free energy claims, you'll be
happy to note.)

In general, wall transformers aren't a big deal.

M Kinsler

"mm" wrote in message
...
On Wed, 13 Jun 2007 14:51:20 -0400, "Zephyr" an address @ some place
.com wrote:

Hey folks,

I'm curious about power consumption of things like the power supply for my
dell laptop
its and AC/DC adaptor, and when the unit is charging my laptop it gets
quite
warm.
from that I infer that its using a fair amount of power.

now, if I leave it plugged into the wall, but remove the laptop, it does
not heat up, but.
there is a little light on it that indicates it is receiving power.
aside from that little light, is it using any significant amount of
power?
The label on the unit says the input is 1.5a

same question goes for my cell phone chargers 0.2a

I understand that some of these things do use power constantly, but... how
much?

Good question. Not only the ones with wall warts, those black
"adaptor" boxes that plug into the wall with a cord coming out of
them, but many radios etc. with the transformers inside, have no
switch in the primary of the power transformer, and they are ON all
the time.

For electronic reasons I don't well understand, when there is no
current in the secondary of a transformer, there is higher impedance
in the primary of the transformer, so less current flows even through
the primary. The heat one can feel, that you feel, the waste heat
would be iiac the same percentage of energy used, as when the device
is running and there is current through the secondary.

From your touch, it sounds like the current is a lot lower, but otoh,
it's on all the time if the thing is plugged in, even for things that
are only used an hour a year.

Does anyone know what the percentage is, or how much these things use
when off?



You can pick up a gadget called a Kill A Watt and other similar devices for
under 30 bucks. It's a pretty impressive power analyzer, the wonders of
modern technology. Pick up one of those and you can find out how much power
anything in the house draws, as well as the power factor, cumulative
consumption, etc. I have one and love it.

Is vampire some in-joke conflation of V(olt) + amp that I'm out of the
inductive loop with (sorry Mr Churchill)

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

jmagerl wrote:
Heres a link to "kill-a-watt". It was very useful to slay my vampires
http://www.meritline.com/kilwateldet.html


Not really. I'm gonna share a tip that may save your life!

This business about about a wooden stake through the heart of a vampire is
pure Hollywood bull****! If you read Bram Stoker's book, you'll find that
the tool to use is a BOWIE KNIFE, not some ****ant tent-peg!

I'm in Texas. We have a LOT of Bowie knives here and almost no vampire
problem.

On Jun 14, 5:47 am, "N Cook" wrote:
Is vampire some in-joke conflation of V(olt) + amp that I'm out of the
inductive loop with (sorry Mr Churchill)

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list onhttp://home.graffiti.net/diverse:graffiti.net/

I believe that it has to do with the idea that a vampire is something
of a parasite, living as he or she does on the blood or electric
current of the host. It's one of those imprecise terms up with which
we all must put.

M Kinsler

okay, _you_ try to match wits with Winston Spencer C.

m kinsler wrote in message
ups.com...
On Jun 14, 5:47 am, "N Cook" wrote:
Is vampire some in-joke conflation of V(olt) + amp that I'm out of the
inductive loop with (sorry Mr Churchill)

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list
onhttp://home.graffiti.net/diverse:graffiti.net/

I believe that it has to do with the idea that a vampire is something
of a parasite, living as he or she does on the blood or electric
current of the host. It's one of those imprecise terms up with which
we all must put.

M Kinsler

okay, _you_ try to match wits with Winston Spencer C.


So is Vampire = Wall Wart another term to add to my USA/UK (2 nations
divided by a common language) file ?
http://www.divdev.fsnet.co.uk/tool_terms.htm
If anyone, reading this, is aware of any other tool/technical terms in US or
UK, my real email address is spelt out on the URL below

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

On Thu, 14 Jun 2007 16:27:12 +0100, "N Cook"
wrote:

So is Vampire = Wall Wart another term to add to my USA/UK (2 nations
divided by a common language) file ?
http://www.divdev.fsnet.co.uk/tool_terms.htm
If anyone, reading this, is aware of any other tool/technical terms in US or
UK, my real email address is spelt out on the URL below

From my understanding of the term, a vampire device is any one that
continues to draw power even when in the 'off' state. This would
include devices powered by a 'wall-wart', devices with a built-in
clock, devices that are powered on/off by a remote control (the
circuit that receives from the remote needs power all the time), etc.

So they would include most microwave ovens (the clock), TVs, VCRs,
DVD players/recorders, DVRs, personal computers, etc.

Power Vampires are a significant problem. While each one
is (usually) not significant, altogether they can add up
to quite a bit. I have found that they can add up to
several hundred watts. "Kill-a-watt" can be quite useful
if you can guess where they all are and they are plug-in
devices. As you can see, not all plug in the wall. Here are some
idle power consumptions that I have measured:

Doorbell transformer 8 watts
cordless phones 4-9 watts
DirecTV receiver (off) 34 watts
TV (off) 17
Garage door opener 2.5
Fax machine 10
Gas furnace 20
Newer gas furnace 27
Central AC outdoor unit 20-40 watts (two different units)

Other devices to consider:
Any device with a remote control (stereo, DVD player, X-10, etc.)
Any portable device with a rechargeable battery:
(cordless phones, toothbrush, vacuum, drill, etc.;
cell phones)
Timers of any sort (irrigation, lights, etc.)
UPS for your computer.
DSL modem
motion activated lights

200 watts continuous is 144 KwH per month. That's hundreds $ per year!

Zephyr wrote:

Hey folks,

I'm curious about power consumption of things like the power supply for my
dell laptop
its and AC/DC adaptor, and when the unit is charging my laptop it gets quite
warm.
from that I infer that its using a fair amount of power.

now, if I leave it plugged into the wall, but remove the laptop, it does
not heat up, but.
there is a little light on it that indicates it is receiving power.
aside from that little light, is it using any significant amount of power?
The label on the unit says the input is 1.5a

same question goes for my cell phone chargers 0.2a

I understand that some of these things do use power constantly, but... how
much?

I found this link but it doesn't get into the Nitti gritty I was looking
for

http://gizmodo.com/gadgets/gadgets/c...act-181497.php

Dave

On Jun 14, 8:30 am, "HeyBub" wrote:
jmagerl wrote:
Heres a link to "kill-a-watt". It was very useful to slay my vampires
http://www.meritline.com/kilwateldet.html

Not really. I'm gonna share a tip that may save your life!

This business about about a wooden stake through the heart of a vampire is
pure Hollywood bull****! If you read Bram Stoker's book, you'll find that
the tool to use is a BOWIE KNIFE, not some ****ant tent-peg!

I'm in Texas. We have a LOT of Bowie knives here and almost no vampire
problem.

And as you know, it was someone from Texas who killed Dracula.

I suppose that Texas did the world a service killing Dracula, but you
guys also gave us TWO Bushes. Given my choice, I'd rather have
Dracula. The only thing he sucked try was blood.

Of course, I can't talk. I'm from NY. We have Hillary Clinton, Rudy
Guianni, AND Mike Bloomburg running for President ... and you thought
people hated New York BEFORE this ....

On Thu, 14 Jun 2007 17:05:06 GMT, M Q
wrote:

These are the sort of things that bother me.

Doorbell transformer 8 watts
cordless phones 4-9 watts
DirecTV receiver (off) 34 watts
TV (off) 17
Garage door opener 2.5
Fax machine 10
Gas furnace 20
Newer gas furnace 27
Central AC outdoor unit 20-40 watts (two different units)

I don't understand this one. Have AC's changed, or do all brands have
this, and what is outside that is using current when the AC isn't
running? Are we talking about 12 months a year?


Other devices to consider:
Any device with a remote control (stereo, DVD player, X-10, etc.)
Any portable device with a rechargeable battery:
(cordless phones, toothbrush, vacuum, drill, etc.;
cell phones)
Timers of any sort (irrigation, lights, etc.)
UPS for your computer.
DSL modem
motion activated lights

200 watts continuous is 144 KwH per month. That's hundreds $ per year!

Pat wrote:
On Jun 14, 8:30 am, "HeyBub" wrote:
jmagerl wrote:
Heres a link to "kill-a-watt". It was very useful to slay my
vampires http://www.meritline.com/kilwateldet.html

Not really. I'm gonna share a tip that may save your life!

This business about about a wooden stake through the heart of a
vampire is pure Hollywood bull****! If you read Bram Stoker's book,
you'll find that the tool to use is a BOWIE KNIFE, not some ****ant
tent-peg!

I'm in Texas. We have a LOT of Bowie knives here and almost no
vampire problem.

And as you know, it was someone from Texas who killed Dracula.

I suppose that Texas did the world a service killing Dracula, but you
guys also gave us TWO Bushes. Given my choice, I'd rather have
Dracula. The only thing he sucked try was blood.

We also gave the country Eisenhower and Lyndon Johnson. I admit, it's a
mixed bag. Fortunately, there's JEB Bush for eight years then that
good-looking Hispanic nephew. By then, the dynasty will be firmly
established. It's then but a small step to a monarchy.


Of course, I can't talk. I'm from NY. We have Hillary Clinton, Rudy
Guianni, AND Mike Bloomburg running for President ... and you thought
people hated New York BEFORE this ....

Nah, Clinton is everyman's ex-wife. She's a goner. Bloomburg is the
quintessential nanny-state leader. Guilianni isn't so bad. "A conservative
is a liberal New Yorker who realizes he hasn't been mugged in several weeks
now and attributes it to Guilianni."

I remember talking to one of my customers in Manhattan on 9/12. I told him:
"We're ALL New Yorkers today!" He was touched.

"N Cook" wrote in message
...
m kinsler wrote in message
ups.com...
On Jun 14, 5:47 am, "N Cook" wrote:
Is vampire some in-joke conflation of V(olt) + amp that I'm out of the
inductive loop with (sorry Mr Churchill)

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list
onhttp://home.graffiti.net/diverse:graffiti.net/

I believe that it has to do with the idea that a vampire is something
of a parasite, living as he or she does on the blood or electric
current of the host. It's one of those imprecise terms up with which
we all must put.

M Kinsler

okay, _you_ try to match wits with Winston Spencer C.


So is Vampire = Wall Wart another term to add to my USA/UK (2 nations
divided by a common language) file ?
http://www.divdev.fsnet.co.uk/tool_terms.htm
If anyone, reading this, is aware of any other tool/technical terms in US
or
UK, my real email address is spelt out on the URL below



It's a term used mostly by the solar/wind guys running houses off-grid. It
refers to any device which draws power even in the off state, regardless of
the sort of power supply.

mm wrote:

On Thu, 14 Jun 2007 17:05:06 GMT, M Q
wrote:
....
Central AC outdoor unit 20-40 watts (two different units)


I don't understand this one. Have AC's changed, or do all brands have
this, and what is outside that is using current when the AC isn't
running? Are we talking about 12 months a year?
....
Yes, we are talking 12 months a year unless you turn off the breakers.

One of the ACs was a 4 Ton Carrier unit. The power was consumed
by a 40 watt "crankcase heater". These are more common in larger
(4, 5, or more ton) AC condensers (outdoor units), those that are a longer
distance from the indoor unit, those that use R-410a, and in heat pumps.
Sometimes they are thermostatically controlled. This one was not.

The other is a 3 Ton Trane 2-stage condenser. The 20 watts appeared
to be consumed by a variable speed fan controller. This one is
totally inexcusable, as an added relay would pay for itself in less
than 1/2 a year.

These are the sort of things that California's Vampire Slayer bill
(which appears to have not become law) that the OP referred to might
embarrass manufacturers into cleaning up.

Note: some of the power consumption figures that I mentioned were
apparent power (measured in "Volt-Amps" -- the vector sum of real
power and reactive power) because it was easier to measure, and
some were in real power (measured in Watts). Kill-A-Watt measures both.
Residential power meters generally measure real power. The cost to the utility
is somewhere in between.

M Q writes:

Note: some of the power consumption figures that I mentioned were
apparent power (measured in "Volt-Amps" -- the vector sum of real
power and reactive power) because it was easier to measure, and
some were in real power (measured in Watts). Kill-A-Watt measures both.
Residential power meters generally measure real power. The cost to the utility
is somewhere in between.

It's pretty bogus to add up VA power numbers as if they were watts, then
calculate how much you would pay per year. If your meter measures real
power (and as you say, it probably does), then the cost depends on the
real power consumed.

For things with resistive heaters, real and apparent power are about the
same and it doesn't matter. But for something like half of the loads
you listed, the power is probably almost all magnetising current in a
transformer, with a very low power factor. For these loads, the real
power is a fraction of the apparent power, and using apparent power will
produce a large error.

Dave

On Fri, 15 Jun 2007 00:07:59 GMT, M Q
wrote:

mm wrote:

On Thu, 14 Jun 2007 17:05:06 GMT, M Q
wrote:
...
Central AC outdoor unit 20-40 watts (two different units)


I don't understand this one. Have AC's changed, or do all brands have
this, and what is outside that is using current when the AC isn't
running? Are we talking about 12 months a year?
...
Yes, we are talking 12 months a year unless you turn off the breakers.

One of the ACs was a 4 Ton Carrier unit. The power was consumed
by a 40 watt "crankcase heater". These are more common in larger
(4, 5, or more ton) AC condensers (outdoor units), those that are a longer
distance from the indoor unit, those that use R-410a, and in heat pumps.

OK. It's not that my system is all that matters, but it's all that I
control, I would be upset if it were in my control to stop wasting
electricity and I didn't. None of these factors apply to me, except
maybe R-410a if that is the old stuff, and I'm pretty certain I don't
have a crankcase heater.

Sometimes they are thermostatically controlled. This one was not.

The other is a 3 Ton Trane 2-stage condenser. The 20 watts appeared
to be consumed by a variable speed fan controller. This one is

I don't have a variable speed fan controller either. My outdoor fan
has one speed, and my indoor fan has one of three speeds, set by
connecting wires.

But I'll have to upgrade someday and now I'll know to turn my AC off
at the breakers after that, for the 11 or 10 months a year I don't use
it.

totally inexcusable, as an added relay would pay for itself in less
than 1/2 a year.

Sounds inexcusable

These are the sort of things that California's Vampire Slayer bill
(which appears to have not become law) that the OP referred to might
embarrass manufacturers into cleaning up.

Note: some of the power consumption figures that I mentioned were
apparent power (measured in "Volt-Amps" -- the vector sum of real
power and reactive power) because it was easier to measure, and
some were in real power (measured in Watts). Kill-A-Watt measures both.
Residential power meters generally measure real power. The cost to the utility
is somewhere in between.

I'd like to better understand that and what Dave said. I once asked
about the difference between volt-amps and watts and didn't get a real
answer iirc. I haven't googled.

James Sweet wrote in message
news:Gbjci.13139$%H5.1612@trndny03...

"N Cook" wrote in message
...
m kinsler wrote in message
ups.com...
On Jun 14, 5:47 am, "N Cook" wrote:
Is vampire some in-joke conflation of V(olt) + amp that I'm out of
the
inductive loop with (sorry Mr Churchill)



It's a term used mostly by the solar/wind guys running houses off-grid. It
refers to any device which draws power even in the off state, regardless
of
the sort of power supply.



There does not seem to be an equivalent recognised UK term for this, any
limies/pomms know any different ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

In message , N Cook
writes
James Sweet wrote in message
news:Gbjci.13139$%H5.1612@trndny03...

"N Cook" wrote in message
...
m kinsler wrote in message
ups.com...
On Jun 14, 5:47 am, "N Cook" wrote:
Is vampire some in-joke conflation of V(olt) + amp that I'm out of
the
inductive loop with (sorry Mr Churchill)



It's a term used mostly by the solar/wind guys running houses off-grid. It
refers to any device which draws power even in the off state, regardless
of
the sort of power supply.



There does not seem to be an equivalent recognised UK term for this, any
limies/pomms know any different ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/



I'd never heard it until it appeared here (about a week ago?). If you
have to have a term to describe such power supplies, it's quite a good
one. However, it's just one more step down the road where words don't
actually mean what they say (most of which seem to originate in the
USA).
Ian.
--

Hi,

On some of these smaller power supplies there is no transformer at
all! I.E. no primary and secondary. They do have an inductor that is
used to step down the power and rely on a Thysistor (aka. electronic
switch) to turn on an off very fast. Usually 60 times a second (ac
mains frequency). The voltage regulation is dependent on the amount of
time the switch is on during the power cycle.


http://en.wikipedia.org/wiki/Switched_mode_power_supply

One nice thing about this is that they can adapt to many mains
voltages and mains frequency. Hence for laptop computers you only need
one "International" power brik like supply.

Warmest regards, Mike.

Ian Jackson wrote:
In message , N Cook
writes

James Sweet wrote in message
news:Gbjci.13139$%H5.1612@trndny03...


"N Cook" wrote in message
...
m kinsler wrote in message
ups.com...
On Jun 14, 5:47 am, "N Cook" wrote:
Is vampire some in-joke conflation of V(olt) + amp that I'm out of the
inductive loop with (sorry Mr Churchill)

snip
I had not heard of this usage regarding power consumption until this
thread, however 'vampire tap' in electronic parlance refers to
a piercing type of cable connector, most often a coaxial connector
used in Ethernet 10base5 wiring.


I'd never heard it until it appeared here (about a week ago?). If you
have to have a term to describe such power supplies, it's quite a good
one. However, it's just one more step down the road where words don't
actually mean what they say (most of which seem to originate in the USA).
Ian.

....hmmm, I never cease to be amazed by the Brits' continual misuse of
case in referring to companies (in usenet postings) in the plural instead
of the singular, e.g. "Hewlett Packard have a new line of servers" instead
of "Hewlett Packard has a new line of servers".

Regards,

Michael

In message , msg
writes
Ian Jackson wrote:

snip


I'd never heard it until it appeared here (about a week ago?). If you
have to have a term to describe such power supplies, it's quite a good
one. However, it's just one more step down the road where words don't
actually mean what they say (most of which seem to originate in the
USA).
Ian.

I had not heard of this usage regarding power consumption until this
thread, however 'vampire tap' in electronic parlance refers to
a piercing type of cable connector, most often a coaxial connector
used in Ethernet 10base5 wiring.

...hmmm, I never cease to be amazed by the Brits' continual misuse of
case in referring to companies (in usenet postings) in the plural instead
of the singular, e.g. "Hewlett Packard have a new line of servers" instead
of "Hewlett Packard has a new line of servers".

Regards,

Michael


Hey! You are right about the 'vampire tap'.

I'm in the CATV industry, and I've just remembered that, many years ago,
I did see reference to 'vampire taps' as being the latest and greatest
for coaxial ethernet. That took me back to the early 1960s, when similar
tap devices were manufactured in the UK (by Thorn, I think). I may still
have one somewhere. Nasty things!

Re the British incorrect use of plurals when referring to companies (or,
indeed, any group), yes, this is very common, eg the 'government are',
'the team are' etc. However, being grammatically correct does sometimes
grate a little. Maybe the Americans are not totally to blame for this
sad world we live in. But, of course, we always (correctly) say 'maths'
(for mathematics).

Ian.

--

Ian Jackson wrote in message
...
In message , msg
writes
Ian Jackson wrote:

snip


I'd never heard it until it appeared here (about a week ago?). If you
have to have a term to describe such power supplies, it's quite a good
one. However, it's just one more step down the road where words don't
actually mean what they say (most of which seem to originate in the
USA).
Ian.

I had not heard of this usage regarding power consumption until this
thread, however 'vampire tap' in electronic parlance refers to
a piercing type of cable connector, most often a coaxial connector
used in Ethernet 10base5 wiring.

...hmmm, I never cease to be amazed by the Brits' continual misuse of
case in referring to companies (in usenet postings) in the plural instead
of the singular, e.g. "Hewlett Packard have a new line of servers"
instead
of "Hewlett Packard has a new line of servers".

Regards,

Michael


Hey! You are right about the 'vampire tap'.

I'm in the CATV industry, and I've just remembered that, many years ago,
I did see reference to 'vampire taps' as being the latest and greatest
for coaxial ethernet. That took me back to the early 1960s, when similar
tap devices were manufactured in the UK (by Thorn, I think). I may still
have one somewhere. Nasty things!

Re the British incorrect use of plurals when referring to companies (or,
indeed, any group), yes, this is very common, eg the 'government are',
'the team are' etc. However, being grammatically correct does sometimes
grate a little. Maybe the Americans are not totally to blame for this
sad world we live in. But, of course, we always (correctly) say 'maths'
(for mathematics).

Ian.

--


I never hear the royal "we" but I'm often forced to hear reference to the
football "we" all the time. As in "we were robbed" mouthed by people who
haven't kicked a ball since they were kids.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

In message , N Cook
writes


I never hear the royal "we" but I'm often forced to hear reference to the
football "we" all the time. As in "we were robbed" mouthed by people who
haven't kicked a ball since they were kids.

Nah. You've got it wrong. It's usually 'We WAS robbed!'
Ian.
--

On Jun 13, 11:25 pm, m kinsler wrote:
On Jun 13, 10:53 pm, mm wrote:





On Wed, 13 Jun 2007 14:51:20 -0400, "Zephyr" an address @ some place

.com wrote:
Hey folks,

I'm curious about power consumption of things like the power supply for my
dell laptop
its and AC/DC adaptor, and when the unit is charging my laptop it gets quite
warm.
from that I infer that its using a fair amount of power.

now, if I leave it plugged into the wall, but remove the laptop, it does
not heat up, but.
there is a little light on it that indicates it is receiving power.
aside from that little light, is it using any significant amount of power?
The label on the unit says the input is 1.5a

same question goes for my cell phone chargers 0.2a

I understand that some of these things do use power constantly, but... how
much?

Good question. Not only the ones with wall warts, those black
"adaptor" boxes that plug into the wall with a cord coming out of
them, but many radios etc. with the transformers inside, have no
switch in the primary of the power transformer, and they are ON all
the time.

For electronic reasons I don't well understand, when there is no
current in the secondary of a transformer, there is higher impedance
in the primary of the transformer, so less current flows even through
the primary. The heat one can feel, that you feel, the waste heat
would be iiac the same percentage of energy used, as when the device
is running and there is current through the secondary.

From your touch, it sounds like the current is a lot lower, but otoh,
it's on all the time if the thing is plugged in, even for things that
are only used an hour a year.

Does anyone know what the percentage is, or how much these things use
when off?

xposted to sci.electronics.repair

I found this link but it doesn't get into the Nitti gritty I was looking
for

http://gizmodo.com/gadgets/gadgets/c...mpire-slayer-a...

Dave- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

Well, there's been a lot of discussion on this. Essentially, when
there's no load on the phone charger or other appliance, it's like
having an inductance across the power line of your house. There will
be some very small current flow, but only because it's not a perfect
inductance. All of the energy used in these wall transformers when
they're just idling is dissipated in the form of heat in their black
plastic case, so you can get an idea of how much power they're using
by just feeling them. It's not really very much. Note that you'll
have a tough time measuring the power drain with a multimeter, because
both current and voltage will show rather high readings. But since
they're almost 1/4 cycle out of phase, there's almost no power being
dissipated, and only a good power meter will take this into account.
(This problem is the basis for a lot of free energy claims, you'll be
happy to note.)

In general, wall transformers aren't a big deal.

And don't forget, in winter you don't mind a little heat radiating, so
there really is no waste, unless you have them plugged in the attic or
something.

On Jun 14, 11:27 am, "N Cook" wrote:
m kinsler wrote in message

ups.com... On Jun 14, 5:47 am, "N Cook" wrote:
Is vampire some in-joke conflation of V(olt) + amp that I'm out of the
inductive loop with (sorry Mr Churchill)

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list

onhttp://home.graffiti.net/diverse:graffiti.net/



I believe that it has to do with the idea that a vampire is something
of a parasite, living as he or she does on the blood or electric
current of the host. It's one of those imprecise terms up with which
we all must put.

M Kinsler

okay, _you_ try to match wits with Winston Spencer C.

So is Vampire = Wall Wart another term to add to my USA/UK (2 nations
divided by a common language) file ?http://www.divdev.fsnet.co.uk/tool_terms.htm
If anyone, reading this, is aware of any other tool/technical terms in US or
UK, my real email address is spelt out on the URL below

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list onhttp://home.graffiti.net/diverse:graffiti.net/

"A vampire is a-a cell deal you can plug in th' wall to charge your
cell phone."
-George Bush, Denver, Aug. 14, 2001

On Jun 13, 4:51 pm, "Zephyr" an address @ some place .com wrote:
Hey folks,

I'm curious about power consumption of things like the power supply for my
dell laptop
its and AC/DC adaptor, and when the unit is charging my laptop it gets quite
warm.
from that I infer that its using a fair amount of power.

now, if I leave it plugged into the wall, but remove the laptop, it does
not heat up, but.
there is a little light on it that indicates it is receiving power.
aside from that little light, is it using any significant amount of power?
The label on the unit says the input is 1.5a

same question goes for my cell phone chargers 0.2a

I understand that some of these things do use power constantly, but... how
much?

I found this link but it doesn't get into the Nitti gritty I was looking
for

http://gizmodo.com/gadgets/gadgets/c...mpire-slayer-a...

Dave

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxx

Dave: There is not really enough info/numbers in the original posted
question to calculate; but here is an attempt.

Answer: Very little.

Here's an assumption. If it use 100 watts while lap-top charging it
probably uses less than 10% of that while not charging. That is less
than 10 watts. And 10 watts is probably a bit of an overestimation any
way.

Any more than that the charger alone would get slightly warm all the
time! Something like the amount of heat from one of those on-all-the
time night lights which IIRC are often 7.5 watts.

10 watts for one hour is one, one hundredth of a kilowatt hour. Using
my cost of electricity (yours may be more or less) of about 9 cents
(all charges included) per kilowatt hour, it will cost about 0.09
cents for every hour that it is plugged in but not charging anything.

Make that say one tenth of a cent; in other words it will cost around
2 to 2.5 cents per 24 hour day that it is plugged in and not charging.
Hardly worth bothering about?

A 100 watt light bulb left on for the same 24 hours would cost about
20 to 25 cents. Again depending on you electricity cost.

In regard to the cell phone charger.

You do not specify if the 0.2 amps is the input or the output.
Assuming it is the input:
Approx 120 x 0.2 = 24 watts. But again that would while charging.
That's probably less than one quarter of what the laptop charger
needs, cell phone is much smaller isn't it? While not charging; again
it probably uses less than one cent per 24 hour day.

This sort of question by those who are ignorant of electricity,
although the info. is usually on the label somewhere, and most of us
'did it in science class in school?"; reminds one of the little old
lady who used to go round plugging up her electric outlets "To stop
the electricity from leaking out"!

One item that doesn't seem to be realized with all this saving energy/
conservation business is that any lost heat from using less efficient
devices helps heat the house. We live in a cool area of North America
where every month of the year requires some heating, in our case
electric heating. We don't need or use air conditioning at all. So the
lost heat from much cheaper (about 25 cents each) non CFL light bulbs
etc. merely reduces electric heating! Our bathroom, for example, is
heated almost entirely by the six 40 watt bulbs above the vanity. Only
in coldest winter does the 500 watt baseboard electric heater operate!

z wrote:
On Jun 14, 11:27 am, "N Cook" wrote:
m kinsler wrote in message

ups.com... On Jun 14, 5:47 am, "N Cook" wrote:
Is vampire some in-joke conflation of V(olt) + amp that I'm out of the
inductive loop with (sorry Mr Churchill)
--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list
onhttp://home.graffiti.net/diverse:graffiti.net/



I believe that it has to do with the idea that a vampire is something
of a parasite, living as he or she does on the blood or electric
current of the host. It's one of those imprecise terms up with which
we all must put.
M Kinsler
okay, _you_ try to match wits with Winston Spencer C.
So is Vampire = Wall Wart another term to add to my USA/UK (2 nations
divided by a common language) file ?http://www.divdev.fsnet.co.uk/tool_terms.htm
If anyone, reading this, is aware of any other tool/technical terms in US or
UK, my real email address is spelt out on the URL below

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list onhttp://home.graffiti.net/diverse:graffiti.net/

"A vampire is a-a cell deal you can plug in th' wall to charge your
cell phone."
-George Bush, Denver, Aug. 14, 2001


Could the vampire thing relating to cable piercing connectors originally
have come from festoon lighting lamp holders as used on fairgrounds etc.
where two sharp spikes (fangs) pierce the insulation of flat twin cable
to provide power to the lamp holder?

RonUK

Ian Jackson wrote:


I'm in the CATV industry, and I've just remembered that, many years ago,
I did see reference to 'vampire taps' as being the latest and greatest
for coaxial ethernet. That took me back to the early 1960s, when similar
tap devices were manufactured in the UK (by Thorn, I think). I may still
have one somewhere. Nasty things!


They were real low grade ****. They were replaced by backmatched
taps when systems were extended past the original 12 channel systems in
the US. They caused mismatch problems, and wasted a lot of the signal
on the trunklines or feeders. They worked, more or less on systems with
just a few channels, and very few customers, but them, those people were
already used to ghosting and snow. They had all been pulled from the 17
systems around Ft Rucker by 1972, including a couple short haul feeds
that only had a couple channels.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

In message , Michael A. Terrell
writes
Ian Jackson wrote:


I'm in the CATV industry, and I've just remembered that, many years ago,
I did see reference to 'vampire taps' as being the latest and greatest
for coaxial ethernet. That took me back to the early 1960s, when similar
tap devices were manufactured in the UK (by Thorn, I think). I may still
have one somewhere. Nasty things!


They were real low grade ****. They were replaced by backmatched
taps when systems were extended past the original 12 channel systems in
the US. They caused mismatch problems, and wasted a lot of the signal
on the trunklines or feeders. They worked, more or less on systems with
just a few channels, and very few customers, but them, those people were
already used to ghosting and snow. They had all been pulled from the 17
systems around Ft Rucker by 1972, including a couple short haul feeds
that only had a couple channels.


Equally bad on ethernet I expect? Also, does ethernet require them to be
non-directional (ie just resistive tap-offs, with no directional
coupler)?
Ian.
--

On Fri, 15 Jun 2007 09:00:18 +0100, Ian Jackson
wrote:



I'd never heard it until it appeared here (about a week ago?). If you
have to have a term to describe such power supplies, it's quite a good
one. However, it's just one more step down the road where words don't
actually mean what they say (most of which seem to originate in the
USA).

England has loads of slang that the USA doesn't use. Most of which
we've never heard. Ask about this on alt.english.usage and the
English posters there can give you lots of stuff.

I think you are in the position I'm in in our respective countries,
knowing few or no people who recent slang. Old slang doesn't capture
our attention because we know what it means.

Ian.
--

On Wed, 13 Jun 2007 14:51:20 -0400, Zephyr wrote:

Hey folks,

I'm curious about power consumption of things like the power supply for
my dell laptop
its and AC/DC adaptor, and when the unit is charging my laptop it gets
quite warm.
from that I infer that its using a fair amount of power.


traditionally, transformers do use power even when their device is not on.
There is loss in the field. But more modern electronic ones do not
require anywhere near as much. Recent cell phones I think are electronic
transformers. Those I tend to just leave plugged in, LED and all!!

mm writes:

I'd like to better understand that and what Dave said. I once asked
about the difference between volt-amps and watts and didn't get a real
answer iirc. I haven't googled.

To calculate watts, you take instantaneous measurements of voltage and
current and multiply them together, then integrate (average) the result
over some time period. You can do this in analog circuitry using an
analog multiplier device, or you can do it digitally by making many
measurements of voltage and current per cycle and multiplying them
digitally before filtering. Either way, you need a special meter that
measures and multiplies two quantities instant by instant.

To calculate volt-amps, you measure and integrate voltage and current
separately, then multiply the two numbers together. This can be done
with two independent ordinary multimeters.

If the load is resistive (e.g. an oven, baseboard heater, etc) there is
no difference between watts and VA. The current is always in phase with
the voltage, the product of the two is always positive, and the two
different calculation methods give the same answer.

But that's not true of capacitive and inductive loads. In capacitive
loads, the current waveform is up to 90 degrees in phase ahead of the
voltage waveform (i.e. peak current happens as voltage passes through
zero, where its rate of change is greatest). If the phase shift is
exactly 90 degrees (pure capacitance), then for half of the cycle the
sign of the current and voltage are actually different, and the product
of the two is negative for that portion of the cycle. The same is true
for inductive loads (e.g. transformer with no load on it, unloaded
motor) except the current waveform lags the voltage one by up to 90
degrees.

Whenever there is a phase shift between current and voltage, the VA
remains the same, but the watts measured are reduced. Effectively, for
one portion of the AC cycle the circuit accepts power from the utility,
and for another portion of the cycle it feeds some of that power back to
the utility. If the phase shift is a full 90 degrees (either ahead or
behind), the net power is zero!

Both measures are important. Watts is the amount of actual power
consumed by your device and converted into heat, light, or mechanical
motion. Voltage determines the amount of insulation needed on wires and
the number of turns of wire in a transformer, while amps determine the
size of wire needed to carry the current and the resistive losses in
that wire resulting from current flow.

So VA is generally the right measure to use when sizing transformers and
wiring, not watts.

Dave

terry writes:

Make that say one tenth of a cent; in other words it will cost around
2 to 2.5 cents per 24 hour day that it is plugged in and not charging.
Hardly worth bothering about?

For anyone connected to the North American power grid. On the other
hand, it might be worth unplugging for off-grid people who generate
their electricity by solar panels or windmill and store it in batteries,
since their per-kwh cost is likely to be many times higher.

Dave

Ian Jackson writes:

Equally bad on ethernet I expect? Also, does ethernet require them to be
non-directional (ie just resistive tap-offs, with no directional
coupler)?

Ethernet required a direct connection to the conductor of the cable, if
I remember correctly. The receiver side was high impedance, so it
didn't present a significant load to the signal, and the vampire tap was
designed to create only a small hole through the shield and inner
dielectric so it wouldn't produce much of an impedance bump. Plus the
cable was marked with rings to indicate where you could put a tap
without having multiple taps end up a multiple of a wavelength apart.

When transmitting, an Ethernet transceiver acted as a current source,
putting a fair bit of current into the 25 ohm load (50 ohm cable heading
off in each of 2 directions). If two transceivers decided to transmit
at the same time, the high DC level on the cable was used to detect a
collision.

Original Ethernet used a baseband signal, and on a moderate-sized
network every station listened to every other one directly. There's no
"head end" to echo upstream signals back downstream again. There's no
notion of "upstream" and "downstream".

Dave

Ian Jackson wrote:

In message , Michael A. Terrell
writes
Ian Jackson wrote:


I'm in the CATV industry, and I've just remembered that, many years ago,
I did see reference to 'vampire taps' as being the latest and greatest
for coaxial ethernet. That took me back to the early 1960s, when similar
tap devices were manufactured in the UK (by Thorn, I think). I may still
have one somewhere. Nasty things!


Here, they were called "Stinger taps" and I had an unused tap block and
stinger, along with the strand clamp and drop hook in my toolbox, until
at least 2001. It might still be around, but I haven't used that toolbox
in so many years that i don't remember. I brought it home the day i was
laid off, then I was declared disabled, and unable to work, so it has
been under one of my benches here at home, ever since.


They were real low grade ****. They were replaced by backmatched
taps when systems were extended past the original 12 channel systems in
the US. They caused mismatch problems, and wasted a lot of the signal
on the trunklines or feeders. They worked, more or less on systems with
just a few channels, and very few customers, but them, those people were
already used to ghosting and snow. They had all been pulled from the 17
systems around Ft Rucker by 1972, including a couple short haul feeds
that only had a couple channels.


Equally bad on ethernet I expect? Also, does ethernet require them to be
non-directional (ie just resistive tap-offs, with no directional
coupler)?


Actually, there are two types of coaxial networking that used 75 ohm
cable. The simple, small network like Dave describes below witch were
non directional, and one that is usually part of a community loop where
pairs of one forward channel, and one return channel are used for data,
with a heterodyne signal processor at the headend to upconvert the
return channel to a forward channel witch is built with back matched
taps.

This system predates the current cable modems, but used standard, off
the shelf CATV components to build a private WAN along with the RF
modems. Some were mixed systems, of RF fed to clusters of the simpler
coaxial networking. The first system like that I heard about was the
Ohio State University campus in the '70s or early '80s. Their private
CATV system connected all the buildings, then tied the existing, smaller
networks together. I met two of their IT people at a hamfest, and they
were bragging about their design, till I told them about the systems I
maintained for the US army, years earlier. There was no return channel
equipment on the market, so we had a pair of 12 channel 'Vicoa' (Later
called Coral) systems set up as forward and return to carry the weather
data from an airfield to the main base where it added to the other nine
forward channels that fed the classrooms and airfield ready rooms.

We also built the first emergency alert system into a CATV system
that took control of the civilian CATV service to the barracks and on
base housing. A custom made coaxial relay was added to the existing
system to seize control of the private system. The ETV studio was 12
channel, like the civilian system. A toggle switch (with a hinged cover
and a lead seal) would feed the same audio and video to all 12
modulators, and switch the remote relay so an alert could be spread, no
matter what channel a TV was on. After we proved the concept, it
quickly spread to other bases, and new builds of civilian systems. The
last system I maintained was a 36 channel RCA headend, in the early
'80s. It had the optional IF loop through and auxiliary IF input for
the alert system. The Audio and video was fed through a separate
modulator with a IF output amp, instead of a channel module. I rewired
the rack by strapping the loss of signal output to the relay control,
and connected diodes to isolate each channel from the emergency control
system. I also looped the emergency video through the local access
control room so I could flip one switch and feed the same signal to all
36 channels in an emergency.

The loss of signal mod caused a message to appear a half second after
the carrier dropped out from a TV station, or satellite feed. That let
the tech on night shift check the alignment of the converters after
stations signed off, at night.

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida