Re: Turn off laser printer with power strip?

• From: "John Smith" <someone@xxxxxxxxxxxxx>
• Date: Wed, 1 Feb 2006 03:00:18 -0500

w_tom:

You seem to like the phrase, "junk science reasoning without numbers." 
Other than to use that phrase a few times to describe EMI/RFI filtering in 
surge protectors, you offer nothing to back up your argument.

I'm looking at a new-in-the-box APC surge protector, Model SurgeArrest 
Essential P6B.  It took me about 5 seconds to find the following technical 
specification numbers on the box:

    >20-55dB EMI/RFI Filtering

A quick check of APC's web site found the surge protector section.  Partial 
specs for one device 
(http://www.apc.com/resource/include/techspec_index.cfm?base_sku=PF11VNT3) 
include:

    Surge energy rating:  2030 Joules
    eP Joule Rating:  3400
    EMI/RFI Noise rejection (100 kHz to 10 MHz):  70 dB

So your claim that EMI/RFI filtering is promoted "without numbers" is 
groundless.  In fact, in light of your claim that "[i]n reality, a power 
strip protector [sic] does nothing useful for a consumer," I realize you are 
confusing the terms "power strip" and "surge protector."  Though you may 
have seen the insides of a common power strip, I suspect you have never seen 
the insides of a surge protector.  (Whatever you wish to call it, I also 
dispute your claim that for a consumer the power strip / surge protector 
device is useless.)

> Meanwhile your logic is that if a fan in a printer or a car runs
> after power off, then if fan does not run, damage will result.
> Nonsense.  Spin that only a politician could love.  Does the laser
> printer or car get hotter when powered off?  Of course not.  If a fan
> does not spin, the laser printer and car still cool - just slower.

I did not say that damage will result after power off if a fan does not run. 
I said that you may shorten the product's life by repeatedly letting it bake 
in its own heat.  If you had experience with leaky electrolytic capacitors 
you would know that.

Your ad hominem attack is out of place in this technical debate.

Finally, I never said that the printer gets hotter when it's powered off. 
(Although a car's engine block may get hotter immediately after the water 
pump stops circulating cooling water, that's a discussion for another 
forum.)  I said exactly what you wrote:  After being turned off, without 
benefit of a fan the printer or car eventually gets cooler, but it takes 
more time.  Since heat can damage electronics by shortening its useful life, 
it's advantageous to get rid of that heat whenever possible.  That's why 
most electronic equipment cases contain air vents.  Thus, if an engineer has 
designed a product so that its cooling fan continues running after the 
product is turned off, turning off that cooling fan before it has finished 
ridding the electronics of heat is counterproductive.

I mentioned overhead projectors earlier.  After most models are turned off 
with their switch, the fan continues to run for a few minutes to cool the 
bulb.  Unplugging the projector before the fan automatically turns off 
defeats the cooling mechanism.  The same principle applies to printers.  See 
http://www.modernsoundpictures.com/neumade-overhead-2002.html

This being a free country, you are of course free to cool or not cool your 
own laser printer in any manner you so choose.  Heck, if you don't think 
they're important you can even disconnect the fans if you feel like it!  But 
I question the wisdom of second-guessing the engineering team that designed 
the printer's fan cooling system in the first place:  If they didn't think 
it was necessary, they wouldn't have chosen a circuit that keeps the fan 
running after power off.



"w_tom" <w_tom1@xxxxxxx> wrote in message 
news:1138754388.359225.130000@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> John Smith wrote:
>> A surge protector also offers EMI/RFI filtering.  Why purposely inject
>> trouble directly into your safety device?
>
>   EMI/RFI filtering in power strip protectors is just another example
> of junk science.  Promoted without numbers in order to deceive.  In
> reality, a power strip protector does nothing useful for a consumer.
> However, because it is so grossly overpriced, a power strip protector
> vastly enriches its manufacturer.  A manufacturer who conveniently
> forgets to mention the most critical component for protection - earth
> ground.  Why mention missing earth ground when being honest will only
> destroy those profits?  Same with the EMI/RFI filter.  Another myth
> promoted by junk science reasoning - without numbers.
>
>  Meanwhile your logic is that if a fan in a printer or a car runs
> after power off, then if fan does not run, damage will result.
> Nonsense.  Spin that only a politician could love.  Does the laser
> printer or car get hotter when powered off?  Of course not.  If a fan
> does not spin, the laser printer and car still cool - just slower.
>
>  If removing power from a laser printer was so destructive, then the
> laser printer would have warning IN BIG LETTERS in the owner's manual.
>
>  Makes no difference whether power is removed by printer switch, power
> strip, or wall switch.
> 


.

• Follow-Ups:
  • Re: Turn off laser printer with power strip?
    • From: w_tom

• References:
  • Re: Turn off laser printer with power strip?
    • From: w_tom

• Prev by Date: Re: Turn off laser printer with power strip?
• Next by Date: Epson dot-matrix printer
• Previous by thread: Re: Turn off laser printer with power strip?
• Next by thread: Re: Turn off laser printer with power strip?
• Index(es):
  • Date
  • Thread

• Security
• UNIX
• Linux
• Coding
• Usenet

• Archive
• About
• Privacy
• Search
• Imprint