Re: Laser printer draws current in a spike, what for?

From: John Woodgate (jmw_at_jmwa.demon.contraspam.yuk)
Date: 08/30/04 

Date: Mon, 30 Aug 2004 09:34:55 +0100

I read in sci.electronics.design that Anthony Guzzi
<dukeofurl@sonic.net> wrote (in <maBYc.11003$54.150804@typhoon.sonic.net
>) about 'Laser printer draws current in a spike, what for?', on Mon, 30
Aug 2004:
>~Dude17~ wrote:
>
>> X-No-Archive: Yes
>>
>> I've got a laser printer that draws current in spikes and it
>> makes the lights flicker as well as causing a UPS on the same circuit
>> to switch over to battery due to excessive dV/dT. Unfortunately, I
>> don't have a way of putting the printer on its own circuit unless I
>> want to use a long extension cord.
>
>
>I have a Brother HL-1470N, at home, which exhibits the same symptoms.
>
>I too was thinking of posting about this. I am trying to figure out
>what to do about this. In my case, I simply moved it off of the UPS,
>but the lights flickering is still undesirable.
>
>Is there anything I can actually do about this?

You definitely did the right thing in moving it off the UPS. There is no
justification, normally, for running a printer off a UPS, and, as you
see, it is a very stressful load which could adversely affect the UPS
life or reliability.

A laser printer sold in Europe must conform to EN 61000-3-2 and -3. The
former is concerned (indirectly) with limiting the peak pulse current,
cycle by cycle, while the latter is concerned with limiting flicker. But
you'd need to run it from 240 V - either directly or with 120:240
transformer. The frequency doesn't matter.

According to US sources, problems such as you report never occur, and
they don't need to implement the IEC versions of those ENs as US
standards. So you are actually just imagining the flicker. (;-) 

-- 
Regards, John Woodgate, OOO - Own Opinions Only. 
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

Relevant Pages

  • Re: Laser printer draws current in a spike, what for?
    ... >> makes the lights flicker as well as causing a UPS on the same circuit ... In my case, I simply moved it off of the UPS, ... A laser printer sold in Europe must conform to EN 61000-3-2 and -3. ... The bad news is that everything is prohibited. ...
    (sci.electronics.design)
  • Re: Laser printer draws current in a spike, what for?
    ... > I've got a laser printer that draws current in spikes and it ... > makes the lights flicker as well as causing a UPS on the same circuit ... In my case, I simply moved it off of the UPS, ...
    (sci.electronics.basics)
  • Re: Laser printer draws current in a spike, what for?
    ... > I've got a laser printer that draws current in spikes and it ... > makes the lights flicker as well as causing a UPS on the same circuit ... In my case, I simply moved it off of the UPS, ...
    (sci.electronics.design)
  • Re: OT: surge protectors
    ... The maximum rated wattage of a laser printer is ... pretty high, too, often exceeding the capacity of a typical UPS. ... then dirty 'computer grade' electricity is not harmful. ... Do not power 'at risk' appliances such as a laser printer via UPS. ...
    (alt.sys.pc-clone.dell)
  • Re: OT: surge protectors
    ... recommends NOT attaching laser printers to their UPS's, ... The amount of current can be enough, even with a UPS having a ... First is the aforementioned effect of a surge in drawing power by the laser ... If Ben Myers grasped the 'reasons why', ...
    (alt.sys.pc-clone.dell)