What is it about laser printers that causes UPS manufacturers to recommend
they not be powered by a "stepped approximation to sine" UPS? It's a SMSP,
isn't it? What makes it special such that it needs sine-only? No such caution
re. computers, etc...

Thanks.

notme wrote:
What is it about laser printers that causes UPS manufacturers to recommend
they not be powered by a "stepped approximation to sine" UPS? It's a SMSP,
isn't it? What makes it special such that it needs sine-only? No such caution
re. computers, etc...


Modified sine is often just full peak on, pause, full negative peak,
pause, and so on. That can mess with PFC circuitry and also stresses
rectifiers at the line input more than a sine. However, RVers and
traveling sales folks do sometimes use modified sine inverters.

What really wreaks havoc is a printer that has a powerful fuser which
draws short but huge bursts of current. That can cause the inverter
inside the UPS to choke.

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

Meat Plow wrote:
On Sun, 19 Jul 2009 08:55:05 -0700, Joerg
wrote:

What really wreaks havoc is a printer that has a powerful fuser which
draws short but huge bursts of current. That can cause the inverter
inside the UPS to choke.

chaCHING! Collect your prize at the door.


What did I win? Can one drink it?

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

Meat Plow wrote:
On Mon, 20 Jul 2009 10:11:37 -0700, Joerg
wrote:

Meat Plow wrote:
On Sun, 19 Jul 2009 08:55:05 -0700, Joerg
wrote:

What really wreaks havoc is a printer that has a powerful fuser which
draws short but huge bursts of current. That can cause the inverter
inside the UPS to choke.
chaCHING! Collect your prize at the door.

What did I win? Can one drink it?

How about a bottle of Macallan 1926 single malt?


Nice! But a 1978 Montrachet or a nice bottle of Chateau d'Yquem would
also do :-)

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

Joerg wrote:
Meat Plow wrote:
On Mon, 20 Jul 2009 10:11:37 -0700, Joerg
wrote:

Meat Plow wrote:
On Sun, 19 Jul 2009 08:55:05 -0700, Joerg
wrote:

What really wreaks havoc is a printer that has a powerful fuser
which draws short but huge bursts of current. That can cause the
inverter inside the UPS to choke.
chaCHING! Collect your prize at the door.

What did I win? Can one drink it?

How about a bottle of Macallan 1926 single malt?


Nice! But a 1978 Montrachet or a nice bottle of Chateau d'Yquem would
also do :-)

I'd prefer the Scotch, myself.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

On Mon, 20 Jul 2009 11:56:18 -0700, Joerg wrote:
Meat Plow wrote:
On Mon, 20 Jul 2009 10:11:37 -0700, Joerg
Meat Plow wrote:
On Sun, 19 Jul 2009 08:55:05 -0700, Joerg

What really wreaks havoc is a printer that has a powerful fuser which
draws short but huge bursts of current. That can cause the inverter
inside the UPS to choke.
chaCHING! Collect your prize at the door.

What did I win? Can one drink it?

How about a bottle of Macallan 1926 single malt?

Nice! But a 1978 Montrachet or a nice bottle of Chateau d'Yquem would
also do :-)

I can get an "almost half-gallon" (1.75L) of Prestige Vodka for $8.99 plus
tax. ;-)

Cheers!
Rich

On Tue, 21 Jul 2009 20:35:16 GMT, Rich Grise
wrote:

On Mon, 20 Jul 2009 11:56:18 -0700, Joerg wrote:
Meat Plow wrote:
On Mon, 20 Jul 2009 10:11:37 -0700, Joerg
Meat Plow wrote:
On Sun, 19 Jul 2009 08:55:05 -0700, Joerg

What really wreaks havoc is a printer that has a powerful fuser which
draws short but huge bursts of current. That can cause the inverter
inside the UPS to choke.
chaCHING! Collect your prize at the door.

What did I win? Can one drink it?

How about a bottle of Macallan 1926 single malt?

Nice! But a 1978 Montrachet or a nice bottle of Chateau d'Yquem would
also do :-)

I can get an "almost half-gallon" (1.75L) of Prestige Vodka for $8.99 plus
tax. ;-)

Listerine is $5 at WallyWorld.

On Mon, 20 Jul 2009 11:56:18 -0700, Joerg
wrote:

Meat Plow wrote:
On Mon, 20 Jul 2009 10:11:37 -0700, Joerg
wrote:

Meat Plow wrote:
On Sun, 19 Jul 2009 08:55:05 -0700, Joerg
wrote:

What really wreaks havoc is a printer that has a powerful fuser which
draws short but huge bursts of current. That can cause the inverter
inside the UPS to choke.
chaCHING! Collect your prize at the door.

What did I win? Can one drink it?

How about a bottle of Macallan 1926 single malt?


Nice! But a 1978 Montrachet or a nice bottle of Chateau d'Yquem would
also do :-)

A couple bottles of Chimay Gold, properly handled and stored would
suffice just fine.

OK maybe a case.

Jupiter Jaq wrote:
On Mon, 20 Jul 2009 11:56:18 -0700, Joerg
wrote:

Meat Plow wrote:
On Mon, 20 Jul 2009 10:11:37 -0700, Joerg
wrote:

Meat Plow wrote:
On Sun, 19 Jul 2009 08:55:05 -0700, Joerg
wrote:

What really wreaks havoc is a printer that has a powerful fuser which
draws short but huge bursts of current. That can cause the inverter
inside the UPS to choke.
chaCHING! Collect your prize at the door.
What did I win? Can one drink it?
How about a bottle of Macallan 1926 single malt?

Nice! But a 1978 Montrachet or a nice bottle of Chateau d'Yquem would
also do :-)

A couple bottles of Chimay Gold, properly handled and stored would
suffice just fine.

OK maybe a case.


Yes!

Even though the bottle of Dos Equis I had while doing the tear-down
maintenance on our DE filter yesterday night just hit the spot :-)

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

On Tue, 21 Jul 2009 09:09:04 -0400, Meat Plow
wrote:

On Mon, 20 Jul 2009 11:56:18 -0700, Joerg
wrote:

Meat Plow wrote:
On Mon, 20 Jul 2009 10:11:37 -0700, Joerg
wrote:

Meat Plow wrote:
On Sun, 19 Jul 2009 08:55:05 -0700, Joerg
wrote:

What really wreaks havoc is a printer that has a powerful fuser which
draws short but huge bursts of current. That can cause the inverter
inside the UPS to choke.
chaCHING! Collect your prize at the door.

What did I win? Can one drink it?

How about a bottle of Macallan 1926 single malt?


Nice! But a 1978 Montrachet or a nice bottle of Chateau d'Yquem would
also do :-)

I prefer something more on the line of a Roederer Cristal.

Never heard of them before. Don't like the website either.

I have had some fabulous Tattenger bottles though.

Meat Plow wrote:
On Mon, 20 Jul 2009 10:11:37 -0700, Joerg
wrote:

Meat Plow wrote:
On Sun, 19 Jul 2009 08:55:05 -0700, Joerg
wrote:

What really wreaks havoc is a printer that has a powerful fuser which
draws short but huge bursts of current. That can cause the inverter
inside the UPS to choke.
chaCHING! Collect your prize at the door.

What did I win? Can one drink it?

How about a bottle of Macallan 1926 single malt?

Sounds good to me!

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

On Sun, 19 Jul 2009 08:21:20 -0700, notme wrote:

What is it about laser printers that causes UPS manufacturers to recommend
they not be powered by a "stepped approximation to sine" UPS? It's a SMSP,
isn't it? What makes it special such that it needs sine-only? No such caution
re. computers, etc...

Thanks.

Possibly because some laser printers have 1000 watt fusing elements
and most home UPS units can't provide that much power?

John

wrote:

Possibly because some laser printers have 1000 watt fusing elements
and most home UPS units can't provide that much power?

They go out of their way to hide it. A friend of mine moved here with a 120
volt industrial strength HP laser printer. The specs said 325 watts, the
current draw was listed as 8 amps max on the last page of the manual.

My current small Samsung printer never actually says what it draws, but the
web page and manual made a big point about it drawing 6 watts in standby. Since
we print around 5 times a week, the standby current matters more than the
max draw, but I would not want to plug it into a UPS.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM

On Sun, 19 Jul 2009 16:19:04 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:

wrote:

Possibly because some laser printers have 1000 watt fusing elements
and most home UPS units can't provide that much power?

They go out of their way to hide it. A friend of mine moved here with a 120
volt industrial strength HP laser printer. The specs said 325 watts, the
current draw was listed as 8 amps max on the last page of the manual.

Nothing much hidden the 8 Amps, 120 volts, 960 watts. That's damned
close to a thousand watts, IMHO.


My current small Samsung printer never actually says what it draws, but the
web page and manual made a big point about it drawing 6 watts in standby. Since
we print around 5 times a week, the standby current matters more than the
max draw, but I would not want to plug it into a UPS.

Geoff.

I wrote:

They go out of their way to hide it. A friend of mine moved here with a 120
volt industrial strength HP laser printer. The specs said 325 watts, the
current draw was listed as 8 amps max on the last page of the manual.

PeterD wrote:

Nothing much hidden the 8 Amps, 120 volts, 960 watts. That's damned
close to a thousand watts, IMHO.

My point was that the 8 amps was only on the last page of the manual, not
anywhere else, including the web page, sticker on the printer, specs page
at the begining of the manual and so on.

Geoff.


--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM

On Sun, 19 Jul 2009 20:39:05 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:


I wrote:

They go out of their way to hide it. A friend of mine moved here with a 120
volt industrial strength HP laser printer. The specs said 325 watts, the
current draw was listed as 8 amps max on the last page of the manual.

PeterD wrote:

Nothing much hidden the 8 Amps, 120 volts, 960 watts. That's damned
close to a thousand watts, IMHO.

My point was that the 8 amps was only on the last page of the manual, not
anywhere else, including the web page, sticker on the printer, specs page
at the begining of the manual and so on.

Geoff.

Ah, I see your point.

On Sun, 19 Jul 2009 16:19:04 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:

wrote:

Possibly because some laser printers have 1000 watt fusing elements
and most home UPS units can't provide that much power?

They go out of their way to hide it. A friend of mine moved here with a 120
volt industrial strength HP laser printer. The specs said 325 watts, the
current draw was listed as 8 amps max on the last page of the manual.

Only 8 amps? HP is usually fairly good about supplying power
consumption specs. For example, for the HP LJ 3200 all in one, see:
http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=bpl08239&locale=en_US&taskId =101&prodSeriesId=24354&prodTypeId=18972#A8
Inrush Current: (Duration: significantly 1 second)
Model A (120V): 23 A peak (20 deg C, from cold start)
Model AB (240V): 40 A peak (20 deg C, from cold start)

With a 23A inrush current, the UPS is gonna go into shutdown, blow a
fuse, or somehow complain. (I haven't tried it).

What I find amusing is that in order to get an Energy Start rating,
the printer must reduce average consumption to below 50% of normal
power consumption. This is usually done with a power save shut down
and an "instant on" feature. However, to get reasonable startup time,
the initial inrush current is really high.

My current small Samsung printer never actually says what it draws, but the
web page and manual made a big point about it drawing 6 watts in standby. Since
we print around 5 times a week, the standby current matters more than the
max draw, but I would not want to plug it into a UPS.

My clamp-on amps guesser has a peak hold function. I'll try it out on
some of my LaserJet printers in the office and see what it shows.



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

On Sun, 19 Jul 2009 19:35:22 -0700, Jeff Liebermann
wrote:


My clamp-on amps guesser has a peak hold function. I'll try it out on
some of my LaserJet printers in the office and see what it shows.

Wont you have to open up the IEC power cord and clamp only a single
path?

I also notice that many of these are powered with standard 10A IEC line
cords. How can that be right for a device with such high usage
declarations?

On Wed, 22 Jul 2009 10:05:27 -0700, FatBytestard
wrote:

On Sun, 19 Jul 2009 19:35:22 -0700, Jeff Liebermann
wrote:


My clamp-on amps guesser has a peak hold function. I'll try it out on
some of my LaserJet printers in the office and see what it shows.

Wont you have to open up the IEC power cord and clamp only a single
path?

Nope. I have an adapter that came with a Radio Shock clamp on
Amps-guesser. 22-161 multiplier.
http://support.radioshack.com/support_meters/doc21/21584.htm
It's the device on the right. It's a double loop, with 10 turns in
one loop, and one turn in the other. With the clamp-on ammeter in the
10x loop, the current readings are 10 times larger, making low current
readings much easier. In the 1x loop, it effectively splits the line.
Very handy.

Incidentally, the clamp-on meter is a Honeytek A902 that I bought on
eBay many years ago. Not great, but it has the features I wanted. 2A
full scale, temperature probe, and peak hold. The peak hold is handy
for measuring laser printer inrush current, but I was more interested
in the peak current at a remote radio site, where transmitters are
constantly and randomly drawing current.

I also notice that many of these are powered with standard 10A IEC line
cords. How can that be right for a device with such high usage
declarations?

Dunno, but I can guess. Current capacity standards for device cords
are tested for maximum wire heating. While the 23A inrush current
might seem rather high, it only appears for perhaps a second, when the
fuser initially warms up. After that, the operating current of the
laserjet is well withing the current limitations of a common #14AWG
power cord. Try it. Does the cord get warm when furiously printing?
Probably not.

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

On Sun, 19 Jul 2009 19:35:22 -0700, Jeff Liebermann
wrote:

My clamp-on amps guesser has a peak hold function. I'll try it out on
some of my LaserJet printers in the office and see what it shows.

Well, I just tried it at home. 46A peak on startup for my HP LaserJet
2100 printer (at US standard 117VAC/60Hz). Ouch. I did it several
different ways and came up with roughly the same result. I couldn't
have done it without the "max hold" function on the Honeytek A902
clamp on ammeter because the inrush current doesn't last very long.
46A peak will certainly cause problems for any UPS running in backup
mode.



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

On Sun, 19 Jul 2009 16:19:04 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:

Since
we print around 5 times a week, the standby current matters more than the
max draw, but I would not want to plug it into a UPS.

Geoff.

If all you print is 5 times a week, and idle current matters that much,
burning a few calories by forcing anyone wanting to do a print job to
walk over and turn on the printer's main switch (zero idle current) and
wait a few minutes for the printer to boot up to its ready point would be
the right way to go.

Then again, it matters not what printer you buy, and you can plug it in
directly since you do not need "protection" for a device you only use 5
times a week, which has no need to be plugged into a UPS to begin with.
Any normal power strip would protect it, and many have RJ45 network
isolation ports as well. If you are using the USB interface, it IS 100%
plug and play and would not need to be plugged in until runtime either.

FatBytestard wrote:

burning a few calories by forcing anyone wanting to do a print job to
walk over and turn on the printer's main switch (zero idle current) and
wait a few minutes for the printer to boot up to its ready point would be
the right way to go.

In this case the printer is next to the server, the computers are spread over
two floors and several rooms. And to top it off, I'm partially disabled, so
just getting up and walking over the printer, even if I were next to it,
is difficult.

Oh and BTW, the power switch is behind the printer, which would have to
be pulled out from the shelf it is on with one hand while the other reaches
behind it feeling around. For most of us, this would require an extra person,
sort of like the LED watch from Saturday Night Live that required you to push
3 buttons.

Geoff.


--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM

On Wed, 22 Jul 2009 18:34:03 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:

FatBytestard wrote:

burning a few calories by forcing anyone wanting to do a print job to
walk over and turn on the printer's main switch (zero idle current) and
wait a few minutes for the printer to boot up to its ready point would be
the right way to go.

In this case the printer is next to the server, the computers are spread over
two floors and several rooms. And to top it off, I'm partially disabled, so
just getting up and walking over the printer, even if I were next to it,
is difficult.

Oh and BTW, the power switch is behind the printer, which would have to
be pulled out from the shelf it is on with one hand while the other reaches
behind it feeling around. For most of us, this would require an extra person,
sort of like the LED watch from Saturday Night Live that required you to push
3 buttons.

Geoff.

The main power switch on the printer itself makes its off current zero.
You can build a small bluetooth device that fires a solenoid and a rod to
turn it on via network call if you want, and have someone else turn it
off for you. That could be lower consumption. :-)

wrote:
On Sun, 19 Jul 2009 08:21:20 -0700, notme wrote:

What is it about laser printers that causes UPS manufacturers to recommend
they not be powered by a "stepped approximation to sine" UPS? It's a SMSP,
isn't it? What makes it special such that it needs sine-only? No such caution
re. computers, etc...

Thanks.

Possibly because some laser printers have 1000 watt fusing elements
and most home UPS units can't provide that much power?

IIRC, the fusing lamps are closer to 250W, but the element will draw a
lot more than that when it's cold.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

On Jul 19, 11:21*am, notme wrote:
What is it about laser printers that causes UPS manufacturers to recommend
they not be powered by a "stepped approximation to sine" UPS? It's a SMSP,
isn't it? What makes it special such that it needs sine-only

The main heater (the one that fuses the toner so it sticks to the
paper) is usually run on a thermostat, using a big SCR (triac, to
be more specific). Those SCRs can trigger on fast-rising spikes
on the power line, by capacitive coupling from cathode to gate,
so steps in the power-in voltage are contraindicated.

Items like a computer PS, which converts AC to DC before
using the power, aren't picky.

"whit3rd" wrote in message
...
On Jul 19, 11:21 am, notme wrote:
What is it about laser printers that causes UPS manufacturers to recommend
they not be powered by a "stepped approximation to sine" UPS? It's a SMSP,
isn't it? What makes it special such that it needs sine-only

The main heater (the one that fuses the toner so it sticks to the
paper) is usually run on a thermostat, using a big SCR (triac, to
be more specific). Those SCRs can trigger on fast-rising spikes
on the power line, by capacitive coupling from cathode to gate,
so steps in the power-in voltage are contraindicated.

So a heater of that sort takes its power directly from the line?

On Jul 19, 1:19*pm, "Michael Robinson" wrote:
"whit3rd" wrote in message

...
On Jul 19, 11:21 am, notme wrote:

What is it about laser printers that causes UPS manufacturers to recommend
they not be powered by a "stepped approximation to sine" UPS? It's a SMSP,
isn't it? What makes it special such that it needs sine-only

The main heater (the one that fuses the toner so it sticks to the
paper) is usually run on a thermostat, using a big SCR (triac, to
be more specific). *Those SCRs can trigger on fast-rising spikes
on the power line, by capacitive coupling from cathode to gate,
so steps in the power-in voltage are contraindicated.

So a heater of that sort takes its power directly from the line?

Do inkjet printers handle the simily waveform well?

Greegor wrote:
Do inkjet printers handle the simily waveform well?

Inkjet printers use very low power stepper motors to move the head and paper,
and very tiny heaters to make the ink bubble up. They run off of low power DC.
The power supply in the printer (or external on most of my inkjets) very happily
converts the output of a UPS to the DC that it needs.

The difference with laser printers is that the toner only sticks to the paper
as long as there is an electrical charge. To keep it falling off of the paper
after a few minutes, it has to be melted onto the paper.

The technical term used is "fused" and the part of the printer is called
a "fuser". They could of as easily called it "ironing" and an "iron", (as in
an iron-on T shirt pattern) but that would have been too simple and
not sound important enough. :-)

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM

On a sunny day (Mon, 20 Jul 2009 11:14:04 +0000 (UTC)) it happened "Geoffrey
S. Mendelson" wrote in
:

Greegor wrote:
Do inkjet printers handle the simily waveform well?

Inkjet printers use very low power stepper motors to move the head and paper,
and very tiny heaters to make the ink bubble up.

Epson inkjets do not use heat at all, but piezo elements to push the ink out.
Better, allows more more types if ink, and is faster, and allows for better control
of the droplets.
Yes I have couple of Epsons:-)
But their service sucks as it is non-existing.

"Geoffrey S. Mendelson" wrote in message
...
Greegor wrote:
Do inkjet printers handle the simily waveform well?

Inkjet printers use very low power stepper motors to move the head and
paper,
and very tiny heaters to make the ink bubble up. They run off of low power
DC.
The power supply in the printer (or external on most of my inkjets) very
happily
converts the output of a UPS to the DC that it needs.

The difference with laser printers is that the toner only sticks to the
paper
as long as there is an electrical charge. To keep it falling off of the
paper
after a few minutes, it has to be melted onto the paper.

The technical term used is "fused" and the part of the printer is called
a "fuser". They could of as easily called it "ironing" and an "iron", (as
in
an iron-on T shirt pattern) but that would have been too simple and
not sound important enough. :-)

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM

Not quite their fault for using that terminology, though. It's borrowed from
the photocopier industry, where the same principle is used in exactly the
same way. I doubt that iron-on T-shirt patterns were around - certainly not
to the general public - when the toner / fuser technique was first
established by Xerox or whoever it was ... :-)
Arfa

On Mon, 20 Jul 2009 11:14:04 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:

Greegor wrote:
Do inkjet printers handle the simily waveform well?

Inkjet printers use very low power stepper motors to move the head and paper,
and very tiny heaters to make the ink bubble up. They run off of low power DC.
The power supply in the printer (or external on most of my inkjets) very happily
converts the output of a UPS to the DC that it needs.

The difference with laser printers is that the toner only sticks to the paper
as long as there is an electrical charge. To keep it falling off of the paper
after a few minutes, it has to be melted onto the paper.

The technical term used is "fused" and the part of the printer is called
a "fuser". They could of as easily called it "ironing" and an "iron", (as in
an iron-on T shirt pattern) but that would have been too simple and
not sound important enough. :-)

Geoff.

Thermal Embedding... wait!

Vulcanization...

Makes the print job live long and prosper, as opposed to...

http://www.funnyordie.com/videos/5d0...ulcan-greeting

Greegor wrote:
On Jul 19, 1:19 pm, "Michael Robinson" wrote:
"whit3rd" wrote in message

...
On Jul 19, 11:21 am, notme wrote:

What is it about laser printers that causes UPS manufacturers to recommend
they not be powered by a "stepped approximation to sine" UPS? It's a SMSP,
isn't it? What makes it special such that it needs sine-only
The main heater (the one that fuses the toner so it sticks to the
paper) is usually run on a thermostat, using a big SCR (triac, to
be more specific). Those SCRs can trigger on fast-rising spikes
on the power line, by capacitive coupling from cathode to gate,
so steps in the power-in voltage are contraindicated.

So a heater of that sort takes its power directly from the line?

Do inkjet printers handle the simily waveform well?

It shouldn't be an issue at all for inkjets, only lasers.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

On Sun, 19 Jul 2009 14:19:10 -0400, Michael Robinson wrote:

The main heater (the one that fuses the toner so it sticks to the
paper) is usually run on a thermostat, using a big SCR (triac, to
be more specific). Those SCRs can trigger on fast-rising spikes
on the power line, by capacitive coupling from cathode to gate,
so steps in the power-in voltage are contraindicated.

So a heater of that sort takes its power directly from the line?

There's no reason to use DC, particularly if it means that you need a
1kW PSU instead of 200W.

notme wrote:
What is it about laser printers that causes UPS manufacturers to recommend
they not be powered by a "stepped approximation to sine" UPS? It's a SMSP,
isn't it? What makes it special such that it needs sine-only? No such caution
re. computers, etc...

The big difference is that lasers usually have a mains powered quartz
lamp inside the fuser assembly to cook the toner onto the paper. My
guess would be that the lamp puts a huge current spike on the mains each
time it powers up, which is every minute or so. If so, that spike might
overload the UPS.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

Meat Plow wrote:
On Tue, 21 Jul 2009 17:37:46 +1000, Bob Larter
wrote:

notme wrote:
What is it about laser printers that causes UPS manufacturers to recommend
they not be powered by a "stepped approximation to sine" UPS? It's a SMSP,
isn't it? What makes it special such that it needs sine-only? No such caution
re. computers, etc...
The big difference is that lasers usually have a mains powered quartz
lamp inside the fuser assembly to cook the toner onto the paper. My
guess would be that the lamp puts a huge current spike on the mains each
time it powers up, which is every minute or so. If so, that spike might
overload the UPS.

The fuser in the older HP lasers was on even waiting for a print job.
There was a thermostat on the lamp strip inside the roller to keep the
fuser roller at a constant temp.

Yes, that's correct. (Fixed hundreds of them, back in the days.)

The warnings on UPS date back to
those times.


--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

Meat Plow wrote:
On Sat, 25 Jul 2009 23:07:18 +1000, Bob Larter
wrote:

Meat Plow wrote:
On Tue, 21 Jul 2009 17:37:46 +1000, Bob Larter
wrote:

notme wrote:
What is it about laser printers that causes UPS manufacturers to recommend
they not be powered by a "stepped approximation to sine" UPS? It's a SMSP,
isn't it? What makes it special such that it needs sine-only? No such caution
re. computers, etc...
The big difference is that lasers usually have a mains powered quartz
lamp inside the fuser assembly to cook the toner onto the paper. My
guess would be that the lamp puts a huge current spike on the mains each
time it powers up, which is every minute or so. If so, that spike might
overload the UPS.
The fuser in the older HP lasers was on even waiting for a print job.
There was a thermostat on the lamp strip inside the roller to keep the
fuser roller at a constant temp.
Yes, that's correct. (Fixed hundreds of them, back in the days.)

First Laserjet printer I owned was a 4+. Snagged it from a client who
was going to dumpster it after I installed a LJ 6p. The 4 had a high
print count maybe upawards of 50k but after a good cleaning including
inside the laser assembly prism and spreader lens it worked perfect
and I've been using it for 7 years now

The older engines are by far the best. I've seen Canon SX engine
printers (eg; the HP Series 2) still going strong at half a million
prints. Dust 'em out every now & then, scrub the rollers with acetone
every couple of years, & they last forever. I heard of one unit (in a
police department) that was still going strong at 1.5 million prints.
The MX engines are pretty good too, but the SX engine is still the king.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

On Sun, 19 Jul 2009 08:21:20 -0700, notme wrote:

What is it about laser printers that causes UPS manufacturers to recommend
they not be powered by a "stepped approximation to sine" UPS? It's a SMSP,
isn't it? What makes it special such that it needs sine-only? No such caution
re. computers, etc...


"Do not look into laser beam with remaining eye." ;-)

Cheers!
Rich