Can I buffer the effects of inrush?

J

Jay Levitt

Guest
I have a relatively-ginormous Xerox 7750DN color laser printer, rated 12A.
I bought it when I was living in a large house, where it had its own closet
and its own 20A circuit; it worked great there.

Now I live in an apartment, and any time it powers up, any lights on the
same circuit will dim and flicker - even fluorescent ones, which I don't
get, but whatever. Worse, even in its "sleep mode", it powers up every few
minutes to do something - rotate the rollers to prevent flattening, or heat
the something to do the something, etc.

At first I assumed it was the typical "old apartments are not designed for
modern appliances" problem. But I've moved twice since then, and my latest
apartment was built last year to the new (2002) code. Everything's 20A.

A little searching reveals that this problem is called "inrush" and is
pretty common; appliances can draw more than their rated value as they kick
in. The usual answer is to run a dedicated circuit.

Since I'm renting, I'd prefer not to do that. Yet it would be very nice to
get my paperwork done by more than just the computer monitor's LCD
backlight. I've got to do *something* now that the sun goes down at 4:30.
(Yes, wait till spring, I know.)

Is there some battery-like device I could plug the printer into that would
store power and dole it out when needed, preventing the printer from
drawing more than its share? My first thought was a UPS, but from what I
read, they're actually lousy at dealing with inrush, let alone protecting
the upstream supply from it.

Ideally, I'd like to find an off-the-shelf device, rather than build one,
since (a) I'm lousy with electronics, (b) all my soldering gear is in
storage, and (c) the last thing I built was an Edison-to-phone-plug
converter, which I swear was absolutely necessary (I was digitizing the
power waveform) but should probably disqualify me from ever building
anything again.

Jay
--
Jay Levitt |
Boston, MA | My character doesn't like it when they
Faster: jay at jay dot fm | cry or shout or hit.
http://www.jay.fm | - Kristoffer
 
"Jay Levitt" <jay+news@jay.fm> wrote in message
news:kvz6qnnly20d.dlg@jay.fm...
I have a relatively-ginormous Xerox 7750DN color laser printer, rated 12A.
I bought it when I was living in a large house, where it had its own
closet
and its own 20A circuit; it worked great there.

Now I live in an apartment, and any time it powers up, any lights on the
same circuit will dim and flicker - even fluorescent ones, which I don't
get, but whatever. Worse, even in its "sleep mode", it powers up every few
minutes to do something - rotate the rollers to prevent flattening, or
heat
the something to do the something, etc.

At first I assumed it was the typical "old apartments are not designed for
modern appliances" problem. But I've moved twice since then, and my latest
apartment was built last year to the new (2002) code. Everything's 20A.

A little searching reveals that this problem is called "inrush" and is
pretty common; appliances can draw more than their rated value as they
kick
in. The usual answer is to run a dedicated circuit.

Since I'm renting, I'd prefer not to do that. Yet it would be very nice
to
get my paperwork done by more than just the computer monitor's LCD
backlight. I've got to do *something* now that the sun goes down at 4:30.
(Yes, wait till spring, I know.)

Is there some battery-like device I could plug the printer into that would
store power and dole it out when needed, preventing the printer from
drawing more than its share? My first thought was a UPS, but from what I
read, they're actually lousy at dealing with inrush, let alone protecting
the upstream supply from it.

Ideally, I'd like to find an off-the-shelf device, rather than build one,
since (a) I'm lousy with electronics, (b) all my soldering gear is in
storage, and (c) the last thing I built was an Edison-to-phone-plug
converter, which I swear was absolutely necessary (I was digitizing the
power waveform) but should probably disqualify me from ever building
anything again.

Jay
Click to expand...
Jay,

I have the same problem with a laser printer. I eventually put it on a
separate circuit so it wouldn't interfere with other stuff.

The UPS still may be a good solution, but keep in mind that there are (at
least) two types of UPSi.

The cheaper ones feed the output from the input until an undervoltage is
detected. Then, their outputs switch over to the internal supply. This type
won't help your problem.

There is another type and I think it's referred to as an "online" UPS. It
always feeds its outputs from the internal supply and uses the input voltage
only to charge its batteries. This may provide the buffering you need, but
you'd have to try it to see if the results are acceptable.

Bob
 
Jay Levitt wrote:
I have a relatively-ginormous Xerox 7750DN color laser printer, rated 12A.
I bought it when I was living in a large house, where it had its own closet
and its own 20A circuit; it worked great there.

Now I live in an apartment, and any time it powers up, any lights on the
same circuit will dim and flicker - even fluorescent ones, which I don't
get, but whatever. Worse, even in its "sleep mode", it powers up every few
minutes to do something - rotate the rollers to prevent flattening, or heat
the something to do the something, etc.

At first I assumed it was the typical "old apartments are not designed for
modern appliances" problem. But I've moved twice since then, and my latest
apartment was built last year to the new (2002) code. Everything's 20A.

A little searching reveals that this problem is called "inrush" and is
pretty common; appliances can draw more than their rated value as they kick
in. The usual answer is to run a dedicated circuit.

Since I'm renting, I'd prefer not to do that. Yet it would be very nice to
get my paperwork done by more than just the computer monitor's LCD
backlight. I've got to do *something* now that the sun goes down at 4:30.
(Yes, wait till spring, I know.)

Is there some battery-like device I could plug the printer into that would
store power and dole it out when needed, preventing the printer from
drawing more than its share? My first thought was a UPS, but from what I
read, they're actually lousy at dealing with inrush, let alone protecting
the upstream supply from it.

Ideally, I'd like to find an off-the-shelf device, rather than build one,
since (a) I'm lousy with electronics, (b) all my soldering gear is in
storage, and (c) the last thing I built was an Edison-to-phone-plug
converter, which I swear was absolutely necessary (I was digitizing the
power waveform) but should probably disqualify me from ever building
anything again.

Jay
Click to expand...
Probably the simplest off the shelf solution:
a desk lamp plugged into a small UPS. The
other stuff will still dim each time the laser
printer's fuser heats, but your lamp will
work from the UPS.

Ed

desk lamp.
 
"Jay Levitt" <jay+news@jay.fm> wrote in message
news:kvz6qnnly20d.dlg@jay.fm...
I have a relatively-ginormous Xerox 7750DN color laser printer, rated 12A.
I bought it when I was living in a large house, where it had its own
closet
and its own 20A circuit; it worked great there.

Now I live in an apartment, and any time it powers up, any lights on the
same circuit will dim and flicker - even fluorescent ones, which I don't
get, but whatever. Worse, even in its "sleep mode", it powers up every few
minutes to do something - rotate the rollers to prevent flattening, or
heat
the something to do the something, etc.

At first I assumed it was the typical "old apartments are not designed for
modern appliances" problem. But I've moved twice since then, and my latest
apartment was built last year to the new (2002) code. Everything's 20A.

A little searching reveals that this problem is called "inrush" and is
pretty common; appliances can draw more than their rated value as they
kick
in. The usual answer is to run a dedicated circuit.

Since I'm renting, I'd prefer not to do that. Yet it would be very nice
to
get my paperwork done by more than just the computer monitor's LCD
backlight. I've got to do *something* now that the sun goes down at 4:30.
(Yes, wait till spring, I know.)

Is there some battery-like device I could plug the printer into that would
store power and dole it out when needed, preventing the printer from
drawing more than its share? My first thought was a UPS, but from what I
read, they're actually lousy at dealing with inrush, let alone protecting
the upstream supply from it.

Ideally, I'd like to find an off-the-shelf device, rather than build one,
since (a) I'm lousy with electronics, (b) all my soldering gear is in
storage, and (c) the last thing I built was an Edison-to-phone-plug
converter, which I swear was absolutely necessary (I was digitizing the
power waveform) but should probably disqualify me from ever building
anything again.

Jay
--
Jay Levitt |
Boston, MA | My character doesn't like it when they
Faster: jay at jay dot fm | cry or shout or hit.
http://www.jay.fm | - Kristoffer
Click to expand...
 
"Jay Levitt" <jay+news@jay.fm> wrote in message
news:kvz6qnnly20d.dlg@jay.fm...
I have a relatively-ginormous Xerox 7750DN color laser printer, rated 12A.
I bought it when I was living in a large house, where it had its own
closet
and its own 20A circuit; it worked great there.

Now I live in an apartment, and any time it powers up, any lights on the
same circuit will dim and flicker - even fluorescent ones, which I don't
get, but whatever. Worse, even in its "sleep mode", it powers up every few
minutes to do something - rotate the rollers to prevent flattening, or
heat
the something to do the something, etc.
Click to expand...
There is a device called an Inrush Current Limiter.
It is inserted in series with the input line. The common use is to limit
surge current to power supply capacitors.
The device starts at a high resistance; as an example 5 ohms, then as it
heats up the resistance drops down to .2 ohms. They come in many different
values.
I don't know if it will work for your application, but they are very cheap
and worth a try.
See;
http://www.ametherm.com/Inrush_Current/welcome.html?gclid=CP_PqZ_Mm5ACFQGdPAod9XCv6w
Check out the FAQ.
Mike
 
"Jay Levitt" <jay+news@jay.fm> wrote in message
news:kvz6qnnly20d.dlg@jay.fm...
I have a relatively-ginormous Xerox 7750DN color laser printer, rated 12A.
I bought it when I was living in a large house, where it had its own
closet
and its own 20A circuit; it worked great there.

Now I live in an apartment, and any time it powers up, any lights on the
same circuit will dim and flicker - even fluorescent ones, which I don't
get, but whatever. Worse, even in its "sleep mode", it powers up every few
minutes to do something - rotate the rollers to prevent flattening, or
heat
the something to do the something, etc.
Click to expand...
See the last item on this list of parts. # SL32 10015
http://www.ametherm.com/Inrush_Current/Bigamp_datasheet.htm
 
amdx wrote:
"Jay Levitt" <jay+news@jay.fm> wrote in message
news:kvz6qnnly20d.dlg@jay.fm...

I have a relatively-ginormous Xerox 7750DN color laser printer, rated 12A.
I bought it when I was living in a large house, where it had its own
closet
and its own 20A circuit; it worked great there.

Now I live in an apartment, and any time it powers up, any lights on the
same circuit will dim and flicker - even fluorescent ones, which I don't
get, but whatever. Worse, even in its "sleep mode", it powers up every few
minutes to do something - rotate the rollers to prevent flattening, or
heat
the something to do the something, etc.


There is a device called an Inrush Current Limiter.
It is inserted in series with the input line. The common use is to limit
surge current to power supply capacitors.
The device starts at a high resistance; as an example 5 ohms, then as it
heats up the resistance drops down to .2 ohms. They come in many different
values.
I don't know if it will work for your application, but they are very cheap
and worth a try.
See;
http://www.ametherm.com/Inrush_Current/welcome.html?gclid=CP_PqZ_Mm5ACFQGdPAod9XCv6w
Check out the FAQ.
Mike

Those are NTC's and react slowly... His line or service to his complex
Click to expand...
is under rated for the load. Putting in soft start circuits would most
likely cause the printer to malfunction.



--
"I'd rather have a bottle in front of me than a frontal lobotomy"
http://webpages.charter.net/jamie_5
 
"Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in message
news:iOW6j.27$cD.9@newsfe05.lga...
amdx wrote:
"Jay Levitt" <jay+news@jay.fm> wrote in message
news:kvz6qnnly20d.dlg@jay.fm...

I have a relatively-ginormous Xerox 7750DN color laser printer, rated
12A.
I bought it when I was living in a large house, where it had its own
closet
and its own 20A circuit; it worked great there.

Now I live in an apartment, and any time it powers up, any lights on the
same circuit will dim and flicker - even fluorescent ones, which I don't
get, but whatever. Worse, even in its "sleep mode", it powers up every
few
minutes to do something - rotate the rollers to prevent flattening, or
heat
the something to do the something, etc.


There is a device called an Inrush Current Limiter.
It is inserted in series with the input line. The common use is to limit
surge current to power supply capacitors.
The device starts at a high resistance; as an example 5 ohms, then as
it heats up the resistance drops down to .2 ohms. They come in many
different values.
I don't know if it will work for your application, but they are very
cheap and worth a try.
See;
http://www.ametherm.com/Inrush_Current/welcome.html?gclid=CP_PqZ_Mm5ACFQGdPAod9XCv6w
Check out the FAQ.
Mike

Those are NTC's and react slowly... His line or service to his complex is
under rated for the load. Putting in soft start circuits would most likely
cause the printer to malfunction.
Click to expand...
Check the info on the website, a quote from one page,

" Typical resistance ranges are from 0.25 ohm to 220 ohm, depending on the
amount of protection desired. As current flows through to the Surge Limiter,
the resistance drops in milliseconds to as low as 0.01 ohm, which
functionally removes it from the circuit."

I'm sure this depends on the particular part, But I think these devices
react quickly.
Mike
 
On Sun, 09 Dec 2007 13:53:21 -0500, Jamie wrote:

See;
http://www.ametherm.com/Inrush_Current/welcome.html?gclid=CP_PqZ_Mm5ACFQGdPAod9XCv6w
Check out the FAQ.
Mike

Those are NTC's and react slowly... His line or service to his complex
is under rated for the load. Putting in soft start circuits would most
likely cause the printer to malfunction.
Click to expand...
Even if they worked quickly, wouldn't it still cause problems with the
printer? I'm assuming that, whatever the printer's doing - and let's call
it "heating the fuser" just so we have something less abstract to talk
about - it actually needs the current it's drawing. So limiting its
current draw would just cause it to not be able to heat the fuser, right?
Kinda like preventing a diabetic from finishing the orange juice by locking
the fridge. Yeah, it preserves the OJ, but...

All of the "inrush protectors" I've seen, including this one, are designed
to protect a given device *from* inrushing current. In my case, though,
the printer (according to Xerox) is operating correctly - when it's heating
up, it draws a higher-than-average current, because it needs it. (Kinda
like "locked rotor amps" on a motor.) So I don't want to protect it from
itself; I just want everything else to not notice it.

I'm assuming what I need is a clever device that detects the large current
draw, goes back in time, and builds up enough reserve power to amortize
that current draw over time, so the upstream circuit doesn't see it. But,
since we can't do that, it'd have to be something that's online all the
time, drawing slightly more current than it really needs, and storing it
up.

In essence, it's an online UPS, but from what I read about UPS's, they
aren't good at this particular task for whatever reason (and here's where
it would help if I understood electricity).


--
Jay Levitt |
Boston, MA | My character doesn't like it when they
Faster: jay at jay dot fm | cry or shout or hit.
http://www.jay.fm | - Kristoffer
 
Jay Levitt wrote:

On Sun, 09 Dec 2007 13:53:21 -0500, Jamie wrote:


See;
http://www.ametherm.com/Inrush_Current/welcome.html?gclid=CP_PqZ_Mm5ACFQGdPAod9XCv6w
Check out the FAQ.
Mike


Those are NTC's and react slowly... His line or service to his complex
is under rated for the load. Putting in soft start circuits would most
likely cause the printer to malfunction.


Even if they worked quickly, wouldn't it still cause problems with the
printer? I'm assuming that, whatever the printer's doing - and let's call
it "heating the fuser" just so we have something less abstract to talk
about - it actually needs the current it's drawing. So limiting its
current draw would just cause it to not be able to heat the fuser, right?
Kinda like preventing a diabetic from finishing the orange juice by locking
the fridge. Yeah, it preserves the OJ, but...

All of the "inrush protectors" I've seen, including this one, are designed
to protect a given device *from* inrushing current. In my case, though,
the printer (according to Xerox) is operating correctly - when it's heating
up, it draws a higher-than-average current, because it needs it. (Kinda
like "locked rotor amps" on a motor.) So I don't want to protect it from
itself; I just want everything else to not notice it.

I'm assuming what I need is a clever device that detects the large current
draw, goes back in time, and builds up enough reserve power to amortize
that current draw over time, so the upstream circuit doesn't see it. But,
since we can't do that, it'd have to be something that's online all the
time, drawing slightly more current than it really needs, and storing it
up.

In essence, it's an online UPS, but from what I read about UPS's, they
aren't good at this particular task for whatever reason (and here's where
it would help if I understood electricity).


You need a better service for the printer.
Click to expand...


--
"I'd rather have a bottle in front of me than a frontal lobotomy"
http://webpages.charter.net/jamie_5
 
"Jay Levitt" <jay+news@jay.fm> wrote in message
news:13qrz8gptj9hy$.dlg@jay.fm...
On Sun, 09 Dec 2007 13:53:21 -0500, Jamie wrote:

See;
http://www.ametherm.com/Inrush_Current/welcome.html?gclid=CP_PqZ_Mm5ACFQGdPAod9XCv6w
Check out the FAQ.
Mike

Those are NTC's and react slowly... His line or service to his complex
is under rated for the load. Putting in soft start circuits would most
likely cause the printer to malfunction.

Even if they worked quickly, wouldn't it still cause problems with the
printer? I'm assuming that, whatever the printer's doing - and let's call
it "heating the fuser" just so we have something less abstract to talk
about - it actually needs the current it's drawing. So limiting its
current draw would just cause it to not be able to heat the fuser, right?
Kinda like preventing a diabetic from finishing the orange juice by
locking
the fridge. Yeah, it preserves the OJ, but...

Ok, sounds like the lights dim and stay dimmed until the printer shuts
Click to expand...
down, not just dimmed during printer startup.
Find the outlet closest to the circuit breaker and plug your printer into
that outlet. See if that helps.
Mike
 
On Sun, 09 Dec 2007 15:34:11 -0500, Jamie wrote:

In essence, it's an online UPS, but from what I read about UPS's, they
aren't good at this particular task for whatever reason (and here's where
it would help if I understood electricity).

You need a better service for the printer.
Click to expand...
Yeah, I think you're right. I did a little more searching - funny how you
can find different things on different days - and I found an article:

http://powerelectronics.com/mag/power_power_supply_system/index.html

It may be a little dated, but the upshot is:

* An online UPS *can* buffer the effects of inrush
* But it's not very efficient in general (due to the constant rectification
and re-inversion)
* And even less efficient in dealing with surges
* So it needs to be majorly oversized
* And thus costs a few thousand bucks.
* Ferroresonant models are more efficient
* But are freaking huge and also expensive.

So even if my apartment manager wants to charge me $500 for what ought to
be a $200 job to run a new circuit, I'd have to move 5-10 times for a UPS
to pay for itself, not including any electricity costs from the
inefficiency, plus noise and heat...

I guess I'll talk to the apartment manager.

--
Jay Levitt |
Boston, MA | My character doesn't like it when they
Faster: jay at jay dot fm | cry or shout or hit.
http://www.jay.fm | - Kristoffer
 
Jay Levitt wrote:
On Sun, 09 Dec 2007 15:34:11 -0500, Jamie wrote:


In essence, it's an online UPS, but from what I read about UPS's, they
aren't good at this particular task for whatever reason (and here's where
it would help if I understood electricity).


You need a better service for the printer.


Yeah, I think you're right. I did a little more searching - funny how you
can find different things on different days - and I found an article:

http://powerelectronics.com/mag/power_power_supply_system/index.html

It may be a little dated, but the upshot is:

* An online UPS *can* buffer the effects of inrush
* But it's not very efficient in general (due to the constant rectification
and re-inversion)
* And even less efficient in dealing with surges
* So it needs to be majorly oversized
* And thus costs a few thousand bucks.
* Ferroresonant models are more efficient
* But are freaking huge and also expensive.

So even if my apartment manager wants to charge me $500 for what ought to
be a $200 job to run a new circuit, I'd have to move 5-10 times for a UPS
to pay for itself, not including any electricity costs from the
inefficiency, plus noise and heat...

I guess I'll talk to the apartment manager.

all that will do is correct for what the printer will see, you'll still
Click to expand...
see your lights dipping.
What you need to do is measure the voltage at the panel before and
after the printer is working. If you don't see any significant drop then
you'll do fine with a new line to your printer how ever, if a drop is
at the panel, you have bigger issues i'm sure your landlord will not
want to deal with.


--
"I'd rather have a bottle in front of me than a frontal lobotomy"
http://webpages.charter.net/jamie_5
 
On Wed, 5 Dec 2007 14:32:15 -0500, Jay Levitt <jay+news@jay.fm>
wrote:

I have a relatively-ginormous Xerox 7750DN color laser printer, rated 12A.
I bought it when I was living in a large house, where it had its own closet
and its own 20A circuit; it worked great there.

Now I live in an apartment, and any time it powers up, any lights on the
same circuit will dim and flicker - even fluorescent ones, which I don't
get, but whatever. Worse, even in its "sleep mode", it powers up every few
minutes to do something - rotate the rollers to prevent flattening, or heat
the something to do the something, etc.

At first I assumed it was the typical "old apartments are not designed for
modern appliances" problem. But I've moved twice since then, and my latest
apartment was built last year to the new (2002) code. Everything's 20A.

A little searching reveals that this problem is called "inrush" and is
pretty common; appliances can draw more than their rated value as they kick
in. The usual answer is to run a dedicated circuit.

Since I'm renting, I'd prefer not to do that. Yet it would be very nice to
get my paperwork done by more than just the computer monitor's LCD
backlight. I've got to do *something* now that the sun goes down at 4:30.
(Yes, wait till spring, I know.)

Is there some battery-like device I could plug the printer into that would
store power and dole it out when needed, preventing the printer from
drawing more than its share? My first thought was a UPS, but from what I
read, they're actually lousy at dealing with inrush, let alone protecting
the upstream supply from it.

Ideally, I'd like to find an off-the-shelf device, rather than build one,
since (a) I'm lousy with electronics, (b) all my soldering gear is in
storage, and (c) the last thing I built was an Edison-to-phone-plug
converter, which I swear was absolutely necessary (I was digitizing the
power waveform) but should probably disqualify me from ever building
anything again.
Click to expand...
---
How about if you made a mains "Y" adapter which necked down to a
single receptacle and you plugged the male ends into different
circuits on the same phase?



--
JF
 
On Wed, 5 Dec 2007 14:32:15 -0500, Jay Levitt <jay+news@jay.fm>
wrote:

I have a relatively-ginormous Xerox 7750DN color laser printer, rated 12A.
I bought it when I was living in a large house, where it had its own closet
and its own 20A circuit; it worked great there.

Now I live in an apartment, and any time it powers up, any lights on the
same circuit will dim and flicker - even fluorescent ones, which I don't
get, but whatever. Worse, even in its "sleep mode", it powers up every few
minutes to do something - rotate the rollers to prevent flattening, or heat
the something to do the something, etc.

At first I assumed it was the typical "old apartments are not designed for
modern appliances" problem. But I've moved twice since then, and my latest
apartment was built last year to the new (2002) code. Everything's 20A.

A little searching reveals that this problem is called "inrush" and is
pretty common; appliances can draw more than their rated value as they kick
in. The usual answer is to run a dedicated circuit.

Since I'm renting, I'd prefer not to do that. Yet it would be very nice to
get my paperwork done by more than just the computer monitor's LCD
backlight. I've got to do *something* now that the sun goes down at 4:30.
(Yes, wait till spring, I know.)
Click to expand...
http://www.solaheviduty.com/products/powerconditioning/cvs.htm


--
JF
 
On Sun, 09 Dec 2007 16:17:21 -0600, John Fields wrote:

http://www.solaheviduty.com/products/powerconditioning/cvs.htm
Click to expand...
Yeah, that (a ferroresonant transformer) might work, but then I'd have to
rent another apartment to keep the transformer in :)

How about if you made a mains "Y" adapter which necked down to a
single receptacle and you plugged the male ends into different
circuits on the same phase?
Click to expand...
Interesting idea. Actually, in a previous apartment, I solved the problem
by just running a 20A extension cord for the printer, plugged into the
kitchen outlets. It may well have caused a voltage drop in the kitchen,
but when I'm printing, I'm not in the kitchen. Therefore, I didn't care.

If the landlord doesn't want to run a new circuit - and now that I look at
it, the printer's about 6 feet from the panel, with only a closet between
them, so that's good - I could look into drawing power from a different
circuit, either with said Y adapter or said "shift the problem" approach.



--
Jay Levitt |
Boston, MA | My character doesn't like it when they
Faster: jay at jay dot fm | cry or shout or hit.
http://www.jay.fm | - Kristoffer
 
On Sun, 09 Dec 2007 15:55:26 -0500, Jamie wrote:

What you need to do is measure the voltage at the panel before and
after the printer is working. If you don't see any significant drop then
you'll do fine with a new line to your printer how ever, if a drop is
at the panel, you have bigger issues i'm sure your landlord will not
want to deal with.
Click to expand...
You're right, of course. I did that at my last apartment (built in 2000,
so decent-but-not-totally-modern code) and it wasn't affecting other
circuits, so I'm taking a wild guess that it won't here (2002 code) either.
In fact, last time, my "office" bedroom had outlets on two different
circuits, so I was able to arrange things so the printer was on one side
and all the lights plugged into the other. Not so lucky here.

Unfortunately, my Fluke and my scope are buried in storage, my cheapo Home
Depot meter can't show brief AC drops, and it'd be cheaper to add the
circuit than to buy a proper meter to test it. But I should try the
extension-cord test to see if the lights still dim when the printer's on a
different circuit. Thanks for the idea.

--
Jay Levitt |
Boston, MA | My character doesn't like it when they
Faster: jay at jay dot fm | cry or shout or hit.
http://www.jay.fm | - Kristoffer
 
"John Fields"
How about if you made a mains "Y" adapter which necked down to a
single receptacle and you plugged the male ends into different
circuits on the same phase?
Click to expand...

** Extremely dangerous suggestion !!

When one plug is removed from the outlet - it has LIVE pins.

Makes the parallel connected AC wall warts idea look tame.




........ Phil
 
"Jay Levitt"
Now I live in an apartment, and any time it powers up, any lights on the
same circuit will dim and flicker - even fluorescent ones, which I don't
get, but whatever.
Click to expand...

** The light output from a CFL ( compact fluoro) is FAR less affected by a
drop in the AC supply voltage than incandescent or normal fluoros - so
try using them.

Your other idea is plain nuts.



........ Phil
 
Phil Allison wrote:
"Jay Levitt"
Now I live in an apartment, and any time it powers up, any lights on the
same circuit will dim and flicker - even fluorescent ones, which I don't
get, but whatever.


** The light output from a CFL ( compact fluoro) is FAR less affected by a
drop in the AC supply voltage than incandescent or normal fluoros - so
try using them.

cut
Click to expand...
There is a very nice industrial unit,(timer+relay), which
is intended to limit inrush current, it puts a small resistor
(1-10ohms)in series with the mains power when you switch
on, and shorting that resistor out after about 100 milliseconds.
That gives the powersupply a chance to slowly load the supply
caps,(those are often the main reason for the powerdip), and
avoid blowing fast fuses.
It solved my problem, when about 6 computers were connected to
a 500 Watts 12Vdc--->230Vac convertor.
Even though total load was only about 250Watts, the convertor
signaled overload.
Adding the timer/relay solved all problems.
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top