Re: Why does laptop PSU have an earth wire?

On Tue, 21 Mar 2006 14:07:59 +0100, "John of Aix"
<j.murphy@xxxxxxxxxxxxxx> wrote:

Spiny Norman wrote:
On Tue, 21 Mar 2006 10:16:19 +0100, "John of Aix"
<j.murphy@xxxxxxxxxxxxxx> wrote:



All the french plugs I've ever had were 2 pin with an earth strip on
the edge of the plug to connect to the earth on the socket. The two
I've had for laptops were the same with a three hole connector to the
PSU. I'd assumed the earth was connected to a screen in the psu but
I've not had reason to have one stripped to find out.

There are two (or in fact three, but the third is for high amperage
things like cookers and ovens) and one has an earth connector,

I used to get kit from our french and italian sites and all the plugs
had earth strips on. Never actually seen one without it except some
travel adapters they sell over here for continental travel.

but all
the portables and almost every other low powered equipmenet has two and
there are no more electrocutions in France than anywhere else. This
three pin (fused) giant plugs for equipment that is usually smaller than
the plug itself is absolutely needless.

Once had a health and safety officer doing a lecture on H/S. He
started waffling on about how UK plugs were safer than continental
stuff so I asked him what tests he could cite and pointed out the
design was certified for use in a lot more countries than the UK
design. Though I don't know how that hangs now since I've been out the
business over ten years.. I actually prefer the UK plugs just for the
ability to fit a fuse. It tends to give warning that something is
wrong before major damage occurs.

Anything that goes through a
transformer is not earthed as the transformation is done by induction.

Lots of PSUs these days use a voltage regulator on a heatsink. No
transformer though quite scary for some users as to how hot they get
when they aren't expecting it. Had a couple brought to me to check
because of that.

The convertor may be earthed but the equipement isn't, it usually runs
at 9-20 volts and a few milliamps, the danger is zilch.


However the OP was getting problems when powered off a mains supply. I
would be tempted to get a new PSU and cables. Only £30
.

Relevant Pages

  • Re: Why does laptop PSU have an earth wire?
    ... where the earth connection may not be readily seen. ... My sister and a few friends have laptops from the US, ... All the french plugs I've ever had were 2 pin with an earth strip on ... I've had for laptops were the same with a three hole connector to the ...
    (uk.comp.misc)
  • Re: Why does laptop PSU have an earth wire?
    ... where the earth connection may not be readily seen. ... France and not one single one of them has a three pin plug therefore ... All the french plugs I've ever had were 2 pin with an earth strip on ... I've had for laptops were the same with a three hole connector to the ...
    (uk.comp.misc)
  • Re: Two cables in one plug ?
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  • Re: Why does laptop PSU have an earth wire?
    ... the edge of the plug to connect to the earth on the socket. ... I'd assumed the earth was connected to a screen in the psu ... I used to get kit from our french and italian sites and all the plugs ... This three pin giant plugs for equipment that is usually ...
    (uk.comp.misc)
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