Any suggestions, please?

[Christopher Chan]

On Friday, September 10, 2010 10:30 AM, Li Li wrote:
> On Fri, 2010-09-10 at 08:24 +0800, Christopher Chan wrote:
>> On Friday, September 10, 2010 03:40 AM, Li Li wrote:
>>    My experience in places like that was that PSUs died more
>>> often than in the lower voltage, higher amperage countries.
>>>
>>
>> Power supplies today are all of the switching type. I'd put it to heat
>> and humidity being the contributing factor rather than the voltage.
>>
> Yeah-but it's still winter and cool in the southern hemisphere.  The
> predicted high for Friday at Sydney is only 20 degrees C and this is
> almost exactly the average for the date.  I don't know where Basil
> lives, but unless he's way up north around Darwin he doesn't know what
> humidity is.   I remember all of the populous places in Oz as being
> mighty dry, and that was nearly 40 years ago; I'm told it is worse now
> and last (southern) summer's fires attest to that.
>
> I've seen lots and lots of switching power supplies die from
> over-voltage, spikes and the like.  They can arc spectacularly.  Their
> whole method of working is very high voltages (albeit at small
> amperages) and high frequencies: this stresses the cheap components
> found in most consumer grade PSUs.  Add in the usual house dust that
> clogs them (anybody else notice that home PCs, even in the cleanest
> houses, are far dirtier than office machines?), a thunderstorm or some
> idiot hitting a power pole with a car causing an inductive spike and
> pow!

Okay, I take back the part about high humidity and heat. However, low 
humidity is exactly what will contribute to them arcs you are talking 
about and of course, over-voltage. So it is not just the voltage alone.


>
> Now I'm interested: I'll ask people at my former employer if they have
> any stats on PSU replacement frequencies, say in 100 V Japan and 250 V
> Oz for comparable equipment.
>

Yeah, me too because we use 220V here in Hong Kong and I am somehow 
running at 310 (!!!) volts at home according to my digital multimeter. I 
hope that is not true and that something is amiss about my multimeter 
but then the previous occupier had recently had the mains replaced so...