Mailinglist Archive: opensuse (3139 mails)

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Re: [SLE] Voltages [Was: Need help diagnosing hardware problem]
  • From: Basil Chupin <blchupin@xxxxxxxxxx>
  • Date: Tue, 24 Oct 2006 14:34:22 +0000 (UTC)
  • Message-id: <453E2460.9030504@xxxxxxxxxx>
Dave Howorth wrote:
Carlos E. R. wrote:
The Tuesday 2006-10-24 at 07:37 -0400, James Knott wrote:

Where do they have 110 V~ ???
North America. Here we have a 240/120V distribution system. You'd use
120 for small appliances, lighting etc. and 240 for heavy appliances
such as stoves etc. The power feed to homes is 240V with a grounded
center tap or neutral, so there's 120V either side of neutral.
Dual phase? Curious.

Hope this ends the interesting OT discussion :)

Perhaps not that OT as you would imagine :-) .

Let me start with this: I have a darkroom set up and my friend asked if he could borrow for a few weeks my enlarger control unit (which determines the exposure time for enlargements and then switched off the lamp after the calculated period of seconds). I had to resort to the manual method of doing test strips to find the correct exposure time.

I soon discovered that I was wasting paper because what the test strip showed as the right time for an enlargement produced a useless actual print. Now, I am not *that* bad in the darkroom, and therefore started to do some testing.

I discovered that the power supply--we have 230v/50hz--was fluctuating very badly in the downward direction at certain times of the day and night and NOT--which really surprised me--during the normal times when households are cooking, showering, or watching TV. I am talking here even after midnight and in the early hours of the morning when people are asleep. Anyway, the point here is that the power supply drops well beyond the accepted 10% limit at which damage to electronic gizmos is (deemed) probable. (I even called our electricity provider; an inspector came out, stuck a gizmo on the power line for a week- and confirmed my findings. A transformer some 500 meters up the line was eventually replaced.)

From the computer point of view: how many people just buy a box at a shop with a prepackaged $15 power supply and then merrily run their computer for hours? Does the PSU regulate the voltage sufficiently to provide the safety needed for such a delicate and complex bit of equipment?

OK, over to you for an interesting discussion :-) .


"Our enemies are innovative and resourceful, and so are we.
They never stop thinking about new ways to harm our country
and our people, and neither do we."
George W Bush 5 August 2004.

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