🚀 go-pugleaf

On 2008-11-11, Arfa Daily <arfa.daily@ntlworld.com> wrote:
>
> "Whiskers" <catwheezel@operamail.com> wrote in message 
> news:slrnghja8j.e5j.catwheezel@ID-107770.user.individual.net...
>> On 2008-11-10, Dave Plowman (News) <dave@davenoise.co.uk> wrote:
>>> In article <slrnghhb1o.bes.catwheezel@ID-107770.user.individual.net>,
>>>    Whiskers <catwheezel@operamail.com> wrote:

[...]

> A system carrying a lot of amps to the load that's drawing it, is no more or 
> less dangerous than one that's only carrying a small current, except in as 
> much as there is a greater potential for heat failure at connection points 
> within that system. A high voltage system, irrespective of how many amps it 
> is capable of carrying above a few milliamps, is far more dangerous to a 
> human, than a low voltage system good for a few hundred amps. Given the 
> (reasonably) constant resistance of any described path through the human 
> body, a voltage of a hundred volts with a current availability of as little 
> as 50mA, may be enough to kill under the right (wrong!) circumstances. 

So a charge of 10kV from walking across a carpet (DC) , or a "non-lethal"
50kV "Tazer" (AC), are more dangerous than a 1kV power line?  The danger 
from 'High Voltage' power lines comes from the vast amount of current they 
can deliver.

> On 
> the other hand, a low voltage welding supply, will not have enough voltage 
> behind it to push enough current through that same path to kill you, even 
> though that supply is good for 200 amps or more.

What voltage does a 'low voltage' welder operate at?  Don't they use 
capacitors to raise the supply voltage to at least 40kV?  Or can welding 
really happen at 12V?

> As far as your contention that a transformer isolated supply is only safe 
> with double insulated equipment, that simply isn't true. The only way that 
> you can drive current through the body from such an isolation transformer, 
> is to hang yourself across both output terminals. Either terminal to ground 
> will present no electric shock hazard at all.
>
> Arfa 

Sounds too good to be true. 

-- 
-- ^^^^^^^^^^
--  Whiskers 
-- ~~~~~~~~~~