Re: Remote Power Supply Connection

On Sun, 18 May 2008 09:04:49 +1000, "Trevor Wilson"
<trevor@[EMAIL PROTECTED]
> wrote:

>
>"flipper" <flipper@[EMAIL PROTECTED]
> wrote in message 
>news:oolu249l2p19arj95g2it4fhjag238ajfl@[EMAIL PROTECTED]
>> On Sun, 18 May 2008 07:36:56 +1000, "Trevor Wilson"
>> <trevor@[EMAIL PROTECTED]
> wrote:
>>
>>>
>>>"Ian Thompson-Bell" <ruffrecords@[EMAIL PROTECTED]
> wrote in message
>>>news:g0mu6g$2vgp$1@[EMAIL PROTECTED]
>>>> Trevor Wilson wrote:
>>>>> **Asked and answered. Use AC. Do not use DC.
>>>>>
>>>>
>>>> In practice that is perhaps not such a good idea as it sounds. It
means
>>>> the rectifiers will be at the end of a fairly long piece of cable.
The
>>>> large rate of changes of current caused by rectifiers (especially the
>>>> semiconductor type) combined with the series inductance of the cable
is 
>>>> a
>>>> recipe for noise, interference and possibly stability problems.
>>>
>>>**I fail to see how. In practice rectifiers are already at the end of
very
>>>long cables and are supplied by devices with prodigious inductance. In
any
>>>case, there are measures that can be taken to reduce the problems 
>>>associated
>>>with noise from diodes. There are even (easy) measures which can be
taken 
>>>to
>>>reduce the inductance of those connecting cables. What I am very
concerned
>>>about is the extreme ignorance displayed about the dangers associated
with
>>>DC arcs and connectors. This, as opposed to your hypothetical, is a
very
>>>real possibility. Read this:
>>>
>>>http://www.arcadvisor.com/faq/dc_direct_current_arc.html
>>>
>>>Trevor Wilson
>>>
>>
>> The connector isn't a switch, relay, or fuse.
>
>**Indeed. If it is unplugged, whilst 'hot' a disaster could result.

While I'm not particularly enamored with the idea of HVDC umbilicals
it doesn't take too much thought to come up with at least one means to
prevent manual disconnect while hot and I'm sure a few minutes more
could produce others.

> Using AC 
>eliminates any possibility of such a disaster.

So does preventing disconnect while hot and you seem to have
completely missed the entire discussion about how to ensure 'no touchy
hot pins'. And, if done right,  no 'touchy hot' could also mean no
'arcy disaster hot'.

> Using DC is just dumb.

You really should look for a more congenial means to salve your ego.


>Trevor Wilson 
>