RE: Hauppauge card giving me a shock

["Keith Doxey" <ukha@xxxxxxxxxxx>]

Hi John,

Connecting an earth to the screen of one of the plugs wont do any harm.
Best
place is probably to tie them all down to the same earth and the easiest
place is probably at the booster.

Keith

> -----Original Message-----
> From: John Andrews [mailto:groups@xxxxxxx]
> Sent: 02 November 2004 20:44
> To: ukha_d@xxxxxxx
> Subject: Re: [ukha_d] Hauppauge card giving me a shock
>
>
>
> Keith
>
> Cheers for this, makes sense.
>
> So can I connect the aerial to my house's earth? Or is there a
> better way to
> get rid of this voltage?
>
> And also, I *HAVE* blown a motherboard before by plugging a
> leaky(?) aerial
> into a PCI Hauppauge card, so be warned.
>
>
> ----- Original Message -----
> From: "Keith Doxey" <ukha@xxxxxxx>
> To: <ukha_d@xxxxxxx>
> Sent: Tuesday, November 02, 2004 8:33 PM
> Subject: RE: [ukha_d] Hauppauge card giving me a shock
>
>
> >
> > Hi Anthony
> >
> > A couple of posts amalgamated together below for ease of reply
:-)
> >
> > Shocks from Aerial leads is quite common. The cause is that the
majority
> of
> > domestic video kit eg TV's and VCR's/Satellite receivers are
double
> > insulated do not require an earth connection. However, they also
contain
> > switch mode power supplies and these almost always leak a small
> amount of
> > mains current to the accessable circuitry, this is not a fault,
just an
> > undesireable "feature". This leakage current is within
safe
> limits but can
> > at times give you a tingle.
> >
> > Where it causes problems is when you have multiple pieces of
equipment
> > connected together as it makes the total leakage current greater
thereby
> > giving a more noticeable shock. Chris commented that boosters
"cause"
> > shocks. Well sort of..... because the main reason for having a
> booster is
> to
> > drive multiple sets, it follows that there will be multiple
leakage
> currents
> > making the total leakage higher. Actually a booster can lessen or
> eliminate
> > the effect as many of them have an earth connected which kills
> the leakage
> > totally.
> >
> > The reason for the sparks is that the PC case is earthed and the
high
> > voltage (but extremely low current) on the aerial lead is arcing
across.
> >
> > It isnt really anything to worry about, just be aware of it and
> try not to
> > touch both sides of the the circuit (eg plug in one hand, other
> hand on PC
> > case) when inserting the plug.
> >
> > Of course, if the sparks are similar to the arc from a MIG
> welder then you
> > do have a bit of a problem :-)
> >
> > Hope that helps
> >
> > Keith
> >
> >
> > > -----Original Message-----
> > > From: anthony.kirrane@xxxxxxx
[mailto:anthony.kirrane@xxxxxxx]
> >
> > I began to notice that the TV picture on my kitchen PC would,
over time,
> > become worse and worse.  I went to check the aerial cable going
into the
> > Hauppauge PVR 350 card and I got a very noticeable electric
shock.  I
> > thought, oh well some static that had caught me by surprise. 
Then I got
> > another one.  I noticed that if I run the coaxial plug across the
metal
> > casing of my PC (I know - I know!) I can visibly see little blue
> > sparks.  I don't get this behaviour from any of the other aerial
leads
> > which are all coming from a single booster.
> >
>
> > From: christopher purves [mailto:CHRIS_PURVES@xxxxxxx]
> > I have found boosters cause the shocks - too much amplification
perhaps.
> > Certainly I used to get shocks all the time in my old house.
Different
> > ground levels perhaps.
>
>
>
>
>
>
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