I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.

--
pyotr filipivich.
Discussing the decline in the US's tech edge, James Niccol once wrote
"It used to be that the USA was pretty good at producing stuff teenaged
boys could lose a finger or two playing with."

"pyotr filipivich" wrote in message
...
I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.

Typically, a device "pulls" what it needs for a lack of a better way of
describing it. For instance, a battery capable of powering the space
shuttle at 12V could also start my motorcycle, but not the other way around.
--


Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com
Production Tapping: http://Production-Tapping-Equipment.com/
Flagship Site: http://www.Drill-N-Tap.com
VIDEOS: http://www.youtube.com/user/AutoDrill
TWITTER: http://twitter.com/AutoDrill
FACEBOOK: http://www.facebook.com/AutoDrill

V8013-R

"Joe AutoDrill" on Tue, 26 Apr 2011 14:28:03
-0400 typed in rec.crafts.metalworking the following:
"pyotr filipivich" wrote in message
.. .
I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.

Typically, a device "pulls" what it needs for a lack of a better way of
describing it. For instance, a battery capable of powering the space
shuttle at 12V could also start my motorcycle, but not the other way around.

Ah, so "one way of thinking about it"is that - yes, the wall wart
can supply up to 1 amp at 12 VDC, but the router is only going to use
half an Amp.

Thanks.

Now to see if I let the magic smoke out. (I've been told by
Electrical Engineers, that electrical items run on smoke, and letting
the smoke out is what causes them to fail.)

tschus
pyotr

--
pyotr filipivich
"Hey, remember when gas was $2.20 a gallon and the unemployment rate
was 4.4%? What happened with that?
Oh, right, the Democrats won the 2006 Congressional elections." Moe Lane

pyotr filipivich fired this volley in
:

Ah, so "one way of thinking about it"is that - yes, the wall wart
can supply up to 1 amp at 12 VDC, but the router is only going to use
half an Amp.


But the other way of thinking about it is that some Wal Warts are not
regulated. If not, and you do not draw something near to their ratings,
they may damage the powered equipment by supplying too high a voltage.

The little lightweight switching supplies are almost always regulated,
but the heavier transformer-based units are often just a transformer,
bridge rectifier, and filter capacitor; Their outputs can vary 50% from
the rating at full load.

LLoyd

On Tue, 26 Apr 2011 11:24:08 -0700, pyotr filipivich
wrote:

I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.

Yes, more than likely. Make sure that the supply is regulated (just
stick a voltmeter across it without a load and read the voltage if
you're not sure- it should read 12V within a fraction of a volt).
If it weighs only a few ounces, it's a switching supply and they're
virtually always regulated.

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
pyotr filipivich fired this volley in
:

Ah, so "one way of thinking about it"is that - yes, the wall wart
can supply up to 1 amp at 12 VDC, but the router is only going to use
half an Amp.


But the other way of thinking about it is that some Wal Warts are not
regulated. If not, and you do not draw something near to their ratings,
they may damage the powered equipment by supplying too high a voltage.

The little lightweight switching supplies are almost always regulated,
but the heavier transformer-based units are often just a transformer,
bridge rectifier, and filter capacitor; Their outputs can vary 50% from
the rating at full load.

LLoyd

It's instructive to see what happens to a wall-wart when you abuse it. If
you short the output of one, most of them will fry themselves in an instant
from the current overload.

I've done that for entertainment when I no longer have use for them. I have
too many in my junk box as it is. g I have two of them that did not. The
transformers in them must be so pathetically underbuilt that they just
buzzed. Most of them are somewhat self-limiting by virtue of extreme
transformer inefficiency, but most in my limited experience will not
tolerate a direct short.

Regarding the motor, if you supply too much voltage, you probably will get a
surprise regarding that 1/2 Amp.

--
Ed Huntress

"Ed Huntress" wrote in message
...

It's instructive to see what happens to a wall-wart when you abuse it. If
you short the output of one, most of them will fry themselves in an
instant from the current overload.


That's because they are almost always with Underwriters Labs as being a
"current limiting device" and as such they are actually designed to fry in
an overcurrent situation--and the main reason they are so prevalent these
days is exactly because this...IE, in many situations it allows
manufacturers to circumvent agency certification so long as the device is
sold along with a "listed power supply"....essentially making it faster,
easier and less costly for manufacturers to bring new electronic items to
the marketplace..

That said, beware of "counterfiet UL stickers", items imported from
Communist China being notorious for this particular consumer fraud.

--

On Apr 26, 3:17*pm, "Ed Huntress" wrote:
"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in messagenews:Xns9ED399F9754E7lloydspmindspringcom@2 16.168.3.70...





pyotr filipivich fired this volley in
:

* * *Ah, so "one way of thinking about it"is that - yes, the wall wart
can supply up to 1 amp at 12 VDC, but the router is only going to use
half an Amp.

But the other way of thinking about it is that some Wal Warts are not
regulated. *If not, and you do not draw something near to their ratings,
they may damage the powered equipment by supplying too high a voltage.

The little lightweight switching supplies are almost always regulated,
but the heavier transformer-based units are often just a transformer,
bridge rectifier, and filter capacitor; *Their outputs can vary 50% from
the rating at full load.

LLoyd

It's instructive to see what happens to a wall-wart when you abuse it. If
you short the output of one, most of them will fry themselves in an instant
from the current overload.

I've done that for entertainment when I no longer have use for them. I have
too many in my junk box as it is. g I have two of them that did not. The
transformers in them must be so pathetically underbuilt that they just
buzzed. Most of them are somewhat self-limiting by virtue of extreme
transformer inefficiency, but most in my limited experience will not
tolerate a direct short.

Regarding the motor, if you supply too much voltage, you probably will get a
surprise regarding that 1/2 Amp.

--
Ed Huntress-

Boy, Ed, you sure are easily entertained.

Many of these things have fusible links under the first layer of tape
in the transformer, others have "polyfuse" type circuit interruptors.
Would you prefer, perhaps, that they supply unlimited current and just
catch fire when you short them?

BTW, regarding the original question: Yes, a properly working device
will draw only what current it needs from your 12V supply (assuming
it's putting out something near 12V), but the designers sometimes rely
on the overcurrent protection built into the supply rather than
spending the extra $0.25 to put a fuse in the router. So, if you had a
fault situation in the device and it was connected to a larger than
expected supply, you *could* have a fire. In reality, it's unlikely;
at the currents your talking about (0.5A vs 1.0A) it's virtually
impossible, but I've seen installations which have large numbers of
consumer-grade devices connected to a single large supply, and that
sort of thing could be a problem.

"rangerssuck" wrote in message
...
On Apr 26, 3:17 pm, "Ed Huntress" wrote:
"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in
messagenews:Xns9ED399F9754E7lloydspmindspringcom@2 16.168.3.70...





pyotr filipivich fired this volley in
:

Ah, so "one way of thinking about it"is that - yes, the wall wart
can supply up to 1 amp at 12 VDC, but the router is only going to use
half an Amp.

But the other way of thinking about it is that some Wal Warts are not
regulated. If not, and you do not draw something near to their ratings,
they may damage the powered equipment by supplying too high a voltage.

The little lightweight switching supplies are almost always regulated,
but the heavier transformer-based units are often just a transformer,
bridge rectifier, and filter capacitor; Their outputs can vary 50% from
the rating at full load.

LLoyd

It's instructive to see what happens to a wall-wart when you abuse it. If
you short the output of one, most of them will fry themselves in an
instant
from the current overload.

I've done that for entertainment when I no longer have use for them. I
have
too many in my junk box as it is. g I have two of them that did not. The
transformers in them must be so pathetically underbuilt that they just
buzzed. Most of them are somewhat self-limiting by virtue of extreme
transformer inefficiency, but most in my limited experience will not
tolerate a direct short.

Regarding the motor, if you supply too much voltage, you probably will get
a
surprise regarding that 1/2 Amp.

--
Ed Huntress-

Boy, Ed, you sure are easily entertained.

I used to tear the wings off of flies, until I discovered RCM.


Many of these things have fusible links under the first layer of tape
in the transformer, others have "polyfuse" type circuit interruptors.
Would you prefer, perhaps, that they supply unlimited current and just
catch fire when you short them?

It would be fun to watch. d8-)


BTW, regarding the original question: Yes, a properly working device
will draw only what current it needs from your 12V supply (assuming
it's putting out something near 12V), but the designers sometimes rely
on the overcurrent protection built into the supply rather than
spending the extra $0.25 to put a fuse in the router. So, if you had a
fault situation in the device and it was connected to a larger than
expected supply, you *could* have a fire. In reality, it's unlikely;
at the currents your talking about (0.5A vs 1.0A) it's virtually
impossible, but I've seen installations which have large numbers of
consumer-grade devices connected to a single large supply, and that
sort of thing could be a problem.

pyotr filipivich wrote:
I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.

--
pyotr filipivich.

More or less correct. However I'm betting that the router doesn't even
need 12 volts. Probably that has a LOT of overhead in it. Most
electronics out there use around 5-6 volts. The extra allows for voltage
sags, spikes due to other items starting up.
If you opened the router the first items in the power feed will likely
be a couple of capacitors and a couple of regulators. Likely a 7805 type
with maybe a 7905 if it also has a negative rail.


--
Steve W.

On Tue, 26 Apr 2011 11:24:08 -0700, pyotr filipivich
wrote:

I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.

--
pyotr filipivich.
Discussing the decline in the US's tech edge, James Niccol once wrote
"It used to be that the USA was pretty good at producing stuff teenaged
boys could lose a finger or two playing with."

Corret. It will draw what it needs up to the capacity of the wall warts
maximum rating.

Gunner

--
"If I say two plus two is four and a Democrat says two plus two is eight,
it's not a partial victory for me when we agree that two plus two is
six. " Jonah Goldberg (modified)

On Tue, 26 Apr 2011 18:13:33 -0400, the renowned "Steve W."
wrote:

pyotr filipivich wrote:
I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.

--
pyotr filipivich.

More or less correct. However I'm betting that the router doesn't even
need 12 volts. Probably that has a LOT of overhead in it. Most
electronics out there use around 5-6 volts. The extra allows for voltage
sags, spikes due to other items starting up.
If you opened the router the first items in the power feed will likely
be a couple of capacitors and a couple of regulators. Likely a 7805 type
with maybe a 7905 if it also has a negative rail.

Most routers that I've seen use a switching power supply to knock down
an input voltage (5 or 12VDC) to 3.3VDC and lower for most of the
juice.

Here's a typical one-chip switch (not router)
http://www.marvell.com/products/swit..._datasheet.pdf
Page 138 has the current requirements..

up to 22mA typical at 3.3V = 73mW
up to 330 or so mA typical at 2.5V = 825mW
up to 150mA typical at 1.5V = 225mW

plus more for power supply losses, LEDs etc.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

On 2011-04-26, Steve W. wrote:
pyotr filipivich wrote:
I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.


More or less correct. However I'm betting that the router doesn't even
need 12 volts. Probably that has a LOT of overhead in it. Most
electronics out there use around 5-6 volts. The extra allows for voltage
sags, spikes due to other items starting up.
If you opened the router the first items in the power feed will likely
be a couple of capacitors and a couple of regulators. Likely a 7805 type
with maybe a 7905 if it also has a negative rail.



Most wall warts are not regulated and are meant to produce proper
voltage at the operating current. They may supply higher voltage at
lower current.

i

Ignoramus7326 fired this volley in
:

Most wall warts are not regulated and are meant to produce proper


That may have been true in the past, but more and more we're seeing the
switching variety, now that they've included the switching transistors on
the control chips.

Usually, now, you'll see electronics powered by switchers, and DC motor-
driven appliances by the dumb type. But with the cost and manual labor
associated with assembling a transformer, I expect more will become
switchers, even for the motor devices.

LLoyd

"Steve W." on Tue, 26 Apr 2011 18:13:33 -0400
typed in rec.crafts.metalworking the following:
pyotr filipivich wrote:
I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.

--
pyotr filipivich.

More or less correct. However I'm betting that the router doesn't even
need 12 volts. Probably

"Probably" - but all I know is what I can decipher off the
sticker. B-)

...that has a LOT of overhead in it. Most
electronics out there use around 5-6 volts. The extra allows for voltage
sags, spikes due to other items starting up.
If you opened the router the first items in the power feed will likely
be a couple of capacitors and a couple of regulators. Likely a 7805 type
with maybe a 7905 if it also has a negative rail.
--
pyotr filipivich
We will drink no whiskey before its nine.
It's eight fifty eight. Close enough!

On Tue, 26 Apr 2011 15:17:33 -0400, "Ed Huntress"
wrote:


"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
.3.70...
pyotr filipivich fired this volley in
:

Ah, so "one way of thinking about it"is that - yes, the wall wart
can supply up to 1 amp at 12 VDC, but the router is only going to use
half an Amp.


But the other way of thinking about it is that some Wal Warts are not
regulated. If not, and you do not draw something near to their ratings,
they may damage the powered equipment by supplying too high a voltage.

The little lightweight switching supplies are almost always regulated,
but the heavier transformer-based units are often just a transformer,
bridge rectifier, and filter capacitor; Their outputs can vary 50% from
the rating at full load.

LLoyd

It's instructive to see what happens to a wall-wart when you abuse it. If
you short the output of one, most of them will fry themselves in an instant
from the current overload.

I've done that for entertainment when I no longer have use for them. I have
too many in my junk box as it is. g I have two of them that did not. The
transformers in them must be so pathetically underbuilt that they just
buzzed. Most of them are somewhat self-limiting by virtue of extreme
transformer inefficiency, but most in my limited experience will not
tolerate a direct short.

Regarding the motor, if you supply too much voltage, you probably will get a
surprise regarding that 1/2 Amp.
No motor in a router - not in the computer type anyway - and a 12
volt 1/2 amp Motor type router is only 6 watts, or roughly 1/100 hp.

pyotr filipivich wrote:
I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.

--
pyotr filipivich.
Discussing the decline in the US's tech edge, James Niccol once wrote
"It used to be that the USA was pretty good at producing stuff teenaged
boys could lose a finger or two playing with."


Supply verses demand.

The wart can supply an amp.
The router only draws 1/2 amp.
Live is good.

If the draw approaches the supply's capability things get if-ier.
At some point the draw will pull the voltage down below spec.
At some other point that will really suck.


--

Richard Lamb
http://www.home.earthlink.net/~cavelamb
http://www.home.earthlink.net/~sv_temptress

Ed Huntress wrote:

It's instructive to see what happens to a wall-wart when you abuse it. If
you short the output of one, most of them will fry themselves in an instant
from the current overload.

I've done that for entertainment when I no longer have use for them. I have
too many in my junk box as it is. g I have two of them that did not. The
transformers in them must be so pathetically underbuilt that they just
buzzed. Most of them are somewhat self-limiting by virtue of extreme
transformer inefficiency, but most in my limited experience will not
tolerate a direct short.

Regarding the motor, if you supply too much voltage, you probably will get a
surprise regarding that 1/2 Amp.



Letting the magic smpke out causes the house to smell bad!
--

Richard Lamb
http://www.home.earthlink.net/~cavelamb
http://www.home.earthlink.net/~sv_temptress

Think of voltage as the Pressure.

Current is the flow based on the pressure and the resistance to that
pressure.

In other words - the voltage sets the current flow on a load.
The router uses 12v and has a resistance (simple terms here) that
draws 1/2 an amp - so the wall wort runs in idle.

you might have a faster starting speed - that might not be good.
It might not matter. Start current is higher than run current.

The wart can handle the higher currents when starting and when loaded.

Martin

On 4/26/2011 1:24 PM, pyotr filipivich wrote:
I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.

--
pyotr filipivich.
Discussing the decline in the US's tech edge, James Niccol once wrote
"It used to be that the USA was pretty good at producing stuff teenaged
boys could lose a finger or two playing with."

pyotr filipivich writes:

I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.

Yes, that's correct.
--
It's time to try defying gravity

On Tue, 26 Apr 2011 17:22:19 -0700, pyotr filipivich
wrote:

"Steve W." on Tue, 26 Apr 2011 18:13:33 -0400
typed in rec.crafts.metalworking the following:
pyotr filipivich wrote:
I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.

--
pyotr filipivich.

More or less correct. However I'm betting that the router doesn't even
need 12 volts. Probably

"Probably" - but all I know is what I can decipher off the
sticker. B-)

...that has a LOT of overhead in it. Most
electronics out there use around 5-6 volts. The extra allows for voltage
sags, spikes due to other items starting up.
If you opened the router the first items in the power feed will likely
be a couple of capacitors and a couple of regulators. Likely a 7805 type
with maybe a 7905 if it also has a negative rail.
I've tried a 9 volt power supply on the odd one, and they did NOT
work. On others they would likely work.

If you have + and - 5 volt rails, from a DC source, a minimum of about
10.7 volts is required..

On Tue, 26 Apr 2011 21:52:47 -0500, Martin Eastburn
wrote:

Think of voltage as the Pressure.

Current is the flow based on the pressure and the resistance to that
pressure.

In other words - the voltage sets the current flow on a load.
The router uses 12v and has a resistance (simple terms here) that
draws 1/2 an amp - so the wall wort runs in idle.

you might have a faster starting speed - that might not be good.
It might not matter. Start current is higher than run current.

The wart can handle the higher currents when starting and when loaded.

Martin

On 4/26/2011 1:24 PM, pyotr filipivich wrote:
I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.

--
pyotr filipivich.
Discussing the decline in the US's tech edge, James Niccol once wrote
"It used to be that the USA was pretty good at producing stuff teenaged
boys could lose a finger or two playing with."
Martin - this router is not a rotary tool - it is a data device.

Letting the magic smpke out causes the house to smell bad!

Not as bad as the piece of Tupperware my wife "cooked" in the electric oven
last night...
--


Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com
Production Tapping: http://Production-Tapping-Equipment.com/
Flagship Site: http://www.Drill-N-Tap.com
VIDEOS: http://www.youtube.com/user/AutoDrill
TWITTER: http://twitter.com/AutoDrill
FACEBOOK: http://www.facebook.com/AutoDrill

V8013-R

On Tue, 26 Apr 2011 23:48:29 -0400, wrote:

On Tue, 26 Apr 2011 21:52:47 -0500, Martin Eastburn
wrote:

Think of voltage as the Pressure.

Current is the flow based on the pressure and the resistance to that
pressure.

In other words - the voltage sets the current flow on a load.
The router uses 12v and has a resistance (simple terms here) that
draws 1/2 an amp - so the wall wort runs in idle.

you might have a faster starting speed - that might not be good.
It might not matter. Start current is higher than run current.

The wart can handle the higher currents when starting and when loaded.

Martin

On 4/26/2011 1:24 PM, pyotr filipivich wrote:
I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.

--
pyotr filipivich.
Discussing the decline in the US's tech edge, James Niccol once wrote
"It used to be that the USA was pretty good at producing stuff teenaged
boys could lose a finger or two playing with."
Martin - this router is not a rotary tool - it is a data device.

I was wondering about that in the initial stages of reading the OP's
message. g would hardly power a HF mini-Dremel, let alone
a real MAN'S router. giggle

--
Age is always advancing, and I'm pretty sure it's up to no good.
--Harry Dresden

On Tue, 26 Apr 2011 11:24:08 -0700, pyotr filipivich
wrote:

I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.

--
pyotr filipivich.
Discussing the decline in the US's tech edge, James Niccol once wrote
"It used to be that the USA was pretty good at producing stuff teenaged
boys could lose a finger or two playing with."

Think of voltage as pressure and current (amps) as flow rate. The
flow rate depends on the load or current conducting path available,
just as it depends on pipe size, valve setting, etc in a water supply
system. A short presents no resistance to flow, like an open water
main, so flow rate will be the capacity of the source. Your half-amp
load presents resistance to flow such that when supplied with 12 VDC
it will draw about 1/2 amp even if the 12 volt source were capable of
supplying thousands of amps, just as a faucet might draw one gallon
per minute from an 80 psi water main capable of delivering hundreds of
GPM to a hydrant.

On Apr 27, 12:45*pm, Don Foreman
wrote:

... Your half-amp
load presents resistance to flow such that when supplied with 12 VDC
it will draw about 1/2 amp even if the 12 volt source were capable of
supplying thousands of amps, *...

True, but as I said above, only if there is no fault in the device.
There are some devices that rely on the overcurrent protection in the
wall wart. If such a device was powered by an unlimited supply and
there was a fault in its circuitry that caused ot to draw lots more
current, there could be an exciting event - Ed might find it
amusing ;-)

On Wed, 27 Apr 2011 08:40:30 -0400, "Joe AutoDrill"
wrote:

Letting the magic smpke out causes the house to smell bad!

Not as bad as the piece of Tupperware my wife "cooked" in the electric oven
last night...


GAAACKKK!!!!

My wife used to use the broiler to store extra pots and pan..and she
stuffed in some plastic stuff and not thinking ...turned the oven on to
warm it up to baking temps.

Fortunately..I keep fire extinguishers everywhere around the house.
With a nice BIG CO2 extinguisher near the stove.

Nasty nasty nasty smell that took months to go away.

Gunner

--
"If I say two plus two is four and a Democrat says two plus two is eight,
it's not a partial victory for me when we agree that two plus two is
six. " Jonah Goldberg (modified)

Larry Jaques on Wed, 27 Apr 2011
07:01:00 -0700 typed in rec.crafts.metalworking the following:
On Tue, 26 Apr 2011 23:48:29 -0400, wrote:

On Tue, 26 Apr 2011 21:52:47 -0500, Martin Eastburn
wrote:

Think of voltage as the Pressure.

Current is the flow based on the pressure and the resistance to that
pressure.

In other words - the voltage sets the current flow on a load.
The router uses 12v and has a resistance (simple terms here) that
draws 1/2 an amp - so the wall wort runs in idle.

you might have a faster starting speed - that might not be good.
It might not matter. Start current is higher than run current.

The wart can handle the higher currents when starting and when loaded.

Martin

On 4/26/2011 1:24 PM, pyotr filipivich wrote:
I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.

--
pyotr filipivich.
Discussing the decline in the US's tech edge, James Niccol once wrote
"It used to be that the USA was pretty good at producing stuff teenaged
boys could lose a finger or two playing with."
Martin - this router is not a rotary tool - it is a data device.

I was wondering about that in the initial stages of reading the OP's
message. g would hardly power a HF mini-Dremel, let alone
a real MAN'S router. giggle

No, I've got power supplies for those things. Thanks to everybody
for the advice.

The router "worked" for some values of "worked". But trying to
set up an home network which did not kill off the WiFi access in the
process ... I had to go back to he restore point.

(What I'm trying to do is use the WiFi connection on a laptop for
Internet access - to neighbor's WiFi router - and then hook the desk
top to the Laptop, so that the Desktop can log-on through the WiFi.
Microsoft has no clue as to how that might work, so it figures I must
mean I want to set up a wireless router connection and the wizard then
blithely completely screws things up. But that is a different rant.)
--
pyotr filipivich
We will drink no whiskey before its nine.
It's eight fifty eight. Close enough!

Don Foreman on Wed, 27 Apr 2011
11:45:24 -0500 typed in rec.crafts.metalworking the following:
On Tue, 26 Apr 2011 11:24:08 -0700, pyotr filipivich
wrote:

I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.

--
pyotr filipivich.
Discussing the decline in the US's tech edge, James Niccol once wrote
"It used to be that the USA was pretty good at producing stuff teenaged
boys could lose a finger or two playing with."

Think of voltage as pressure and current (amps) as flow rate. The
flow rate depends on the load or current conducting path available,
just as it depends on pipe size, valve setting, etc in a water supply
system. A short presents no resistance to flow, like an open water
main, so flow rate will be the capacity of the source. Your half-amp
load presents resistance to flow such that when supplied with 12 VDC
it will draw about 1/2 amp even if the 12 volt source were capable of
supplying thousands of amps, just as a faucet might draw one gallon
per minute from an 80 psi water main capable of delivering hundreds of
GPM to a hydrant.

Electricity is like water - it has to have a 'flow' out in order
for it to 'flow' in. Hence the number of electricians who will work
with one hand in their pocket.
--
pyotr filipivich
We will drink no whiskey before its nine.
It's eight fifty eight. Close enough!

On Wed, 27 Apr 2011 10:27:51 -0700, pyotr filipivich
wrote:


(What I'm trying to do is use the WiFi connection on a laptop for
Internet access - to neighbor's WiFi router - and then hook the desk
top to the Laptop, so that the Desktop can log-on through the WiFi.
Microsoft has no clue as to how that might work, so it figures I must
mean I want to set up a wireless router connection and the wizard then
blithely completely screws things up. But that is a different rant.)
--

http://www.ehow.com/how_2308651_use-...-repeater.html

http://reviews.pricegrabber.com/wire...ing/m/2932693/


--
"If I say two plus two is four and a Democrat says two plus two is eight,
it's not a partial victory for me when we agree that two plus two is
six. " Jonah Goldberg (modified)

On Wed, 27 Apr 2011 10:27:51 -0700, pyotr filipivich
wrote:

Don Foreman on Wed, 27 Apr 2011
11:45:24 -0500 typed in rec.crafts.metalworking the following:
On Tue, 26 Apr 2011 11:24:08 -0700, pyotr filipivich
wrote:

I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.

--
pyotr filipivich.
Discussing the decline in the US's tech edge, James Niccol once wrote
"It used to be that the USA was pretty good at producing stuff teenaged
boys could lose a finger or two playing with."

Think of voltage as pressure and current (amps) as flow rate. The
flow rate depends on the load or current conducting path available,
just as it depends on pipe size, valve setting, etc in a water supply
system. A short presents no resistance to flow, like an open water
main, so flow rate will be the capacity of the source. Your half-amp
load presents resistance to flow such that when supplied with 12 VDC
it will draw about 1/2 amp even if the 12 volt source were capable of
supplying thousands of amps, just as a faucet might draw one gallon
per minute from an 80 psi water main capable of delivering hundreds of
GPM to a hydrant.

Electricity is like water - it has to have a 'flow' out in order
for it to 'flow' in. Hence the number of electricians who will work
with one hand in their pocket.

And power Engineers with both hands in their pockets..

pyotr filipivich wrote:

Electricity is like water - it has to have a 'flow' out in order
for it to 'flow' in. Hence the number of electricians who will work
with one hand in their pocket.


Wouldn't that be "hand in YOUR pocket"?
--

Richard Lamb
http://www.home.earthlink.net/~cavelamb
http://www.home.earthlink.net/~sv_temptress

pyotr filipivich wrote:

Electricity is like water - it has to have a 'flow' out in order
for it to 'flow' in. Hence the number of electricians who will work
with one hand in their pocket.

I like the water pipe analogy, until it comes to "short" circuits and "open"
circuits. ;-D

Cheers!
Rich

Spehro Pefhany wrote:
On Wed, 27 Apr 2011 10:27:51 -0700, pyotr filipivich

Electricity is like water - it has to have a 'flow' out in order
for it to 'flow' in. Hence the number of electricians who will work
with one hand in their pocket.

And power Engineers with both hands in their pockets..

When I was in the USAF, if you were caught wearing any jewelry while
working on electronics, even freakin' DOG TAGS, you were subject to
disciplinary action.

Actually, I was kind of astonished when I learned that a welding arc
drops about 20-30 volts. Consequently, I wouldn't even wear a wris****ch
while, say, jump-starting a car.

I was once helping a buddy jump-start his car - I put the cables on my
battery, and he proceeded to start to apply the clamps to his battery -
red to black and black to red. I shrieked, "NO!NO!NO!NO!NO!NO!NO!NO!NO!"
and luckily stopped him in time. Whew!

Cheers!
Rich

rangerssuck wrote:
On Apr 27, 12:45*pm, Don Foreman
wrote:

... Your half-amp
load presents resistance to flow such that when supplied with 12 VDC
it will draw about 1/2 amp even if the 12 volt source were capable of
supplying thousands of amps, *...

True, but as I said above, only if there is no fault in the device.
There are some devices that rely on the overcurrent protection in the
wall wart. If such a device was powered by an unlimited supply and
there was a fault in its circuitry that caused ot to draw lots more
current, there could be an exciting event - Ed might find it
amusing ;-)

I was kind of surprised to learn that the fuse in the equipment isn't
there for the purpose of protecting the equipment - it's there to
protect the supply and its wiring from when the equipment fails short.

Cheers!
Rich

Gunner Asch wrote:
On Wed, 27 Apr 2011 08:40:30 -0400, "Joe AutoDrill"

Letting the magic smpke out causes the house to smell bad!

Not as bad as the piece of Tupperware my wife "cooked" in the electric
oven
last night...

GAAACKKK!!!!

My wife used to use the broiler to store extra pots and pan..and she
stuffed in some plastic stuff and not thinking ...turned the oven on to
warm it up to baking temps.

Fortunately..I keep fire extinguishers everywhere around the house.
With a nice BIG CO2 extinguisher near the stove.

Nasty nasty nasty smell that took months to go away.

One of the things I worked on when in the USAF was a jamming transmitter
with a separate power supply. The power supply was pressurized, to maintain
breakdown voltage so that it didn't arc over internally. One day, we got
one of the pressurized power supplies in the shop that had blown its
selenium rectifiers. Hoo Boy! It cleared the whole building for the rest
of the day!

Cheers!
Rich

pyotr filipivich wrote:
[question about volts/amps]

The only "dumb" question is the one you don't ask.

(Unless you ask Mr. Garrison - he says, "There are no stupid questions,
only stupid people.")

Cheers!
Rich the Philosophizer

pyotr filipivich wrote:

Larry Jaques on Wed, 27 Apr 2011
07:01:00 -0700 typed in rec.crafts.metalworking the following:
On Tue, 26 Apr 2011 23:48:29 -0400, wrote:

On Tue, 26 Apr 2011 21:52:47 -0500, Martin Eastburn
wrote:

Think of voltage as the Pressure.

Current is the flow based on the pressure and the resistance to that
pressure.

In other words - the voltage sets the current flow on a load.
The router uses 12v and has a resistance (simple terms here) that
draws 1/2 an amp - so the wall wort runs in idle.

you might have a faster starting speed - that might not be good.
It might not matter. Start current is higher than run current.

The wart can handle the higher currents when starting and when loaded.

Martin

On 4/26/2011 1:24 PM, pyotr filipivich wrote:
I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.

--
pyotr filipivich.
Discussing the decline in the US's tech edge, James Niccol once wrote
"It used to be that the USA was pretty good at producing stuff
teenaged boys could lose a finger or two playing with."
Martin - this router is not a rotary tool - it is a data device.

I was wondering about that in the initial stages of reading the OP's
message. g would hardly power a HF mini-Dremel, let alone
a real MAN'S router. giggle

No, I've got power supplies for those things. Thanks to everybody
for the advice.

The router "worked" for some values of "worked". But trying to
set up an home network which did not kill off the WiFi access in the
process ... I had to go back to he restore point.

(What I'm trying to do is use the WiFi connection on a laptop for
Internet access - to neighbor's WiFi router - and then hook the desk
top to the Laptop, so that the Desktop can log-on through the WiFi.
Microsoft has no clue as to how that might work, so it figures I must
mean I want to set up a wireless router connection and the wizard then
blithely completely screws things up. But that is a different rant.)

Install Linux; it'll be almost trivial.

Good Luck!
Rich

Should have been "stupid listeners" on Usenet...LOL

-----------------
"Rich Grise" wrote in message ...

pyotr filipivich wrote:
[question about volts/amps]

The only "dumb" question is the one you don't ask.

(Unless you ask Mr. Garrison - he says, "There are no stupid questions,
only stupid people.")

Cheers!
Rich the Philosopher

"pyotr filipivich" wrote in message
...
I've a wall wart which is rated 12 V DC at 1 amp output

The router is (I think) expecting 12 VCD at .5 amp.

And I correct in assuming that the wall wart will not "over supply"
the device - that its rating is essentially the max amperage it will
output, while the router is the amount it will draw to function?

That seems to make sense, to me. At this hour of the morning.

--
pyotr filipivich.
Discussing the decline in the US's tech edge, James Niccol once
wrote
"It used to be that the USA was pretty good at producing stuff
teenaged
boys could lose a finger or two playing with."

Let me guess that you have a D-Link router? My D-links have eaten a
number of power supplies until I got a good non-OEM one rated at 2
amps. It'll only draw what it needs but I think it sometimes needs
more than the OEM supply can reliably deliver.