Re: Remote Power Supply Connection

On Fri, 16 May 2008 12:22:33 GMT, Patrick Turner
<info@[EMAIL PROTECTED]
> wrote:

>
>
>flipper wrote:
>> 
>> On Fri, 16 May 2008 20:40:33 +1000, "Trevor Wilson"
>> <trevor@[EMAIL PROTECTED]
> wrote:
>> 
>> >
>> >"Iain Churches" <IainNG@[EMAIL PROTECTED]
> wrote in message
>> >news:yy9Xj.1624$_03.705@[EMAIL PROTECTED]
>> >>
>> >>
>> >> "Trevor Wilson" <trevor@[EMAIL PROTECTED]
> wrote in
message
>> >> news:694fk9F30lh2sU1@[EMAIL PROTECTED]
>> >>>
>> >>> "BretLudwig" <bratzirules@[EMAIL PROTECTED]
> wrote in message
>> >>>
news:7a2f6434985dd93af0ad7ca24683b83c@[EMAIL PROTECTED]
>> >>>> "BretLudwig" <bratzirules@[EMAIL PROTECTED]
> wrote in message
>> >>>>
news:6889949c0f7376f69fcc9ea26ef19be9@[EMAIL PROTECTED]
>> >>>>> **** Brussels.
>> >>>>>
>> >>>>> Do it yourself and who will know?
>> >>>>>
>> >>>>> Put simply the use of an outboard power supply chassis is the
OPTIMUM
>> >>>> way
>> >>>>> to achieve the BEST possible performance.
>> >>>>
>> >>>> **Nonsense. Whilst an external power supply *may* have some
advantages,
>> >>>> transferring large amounts of DC is a dumb thing to do. Using AC
is far
>> >>>> more
>> >>>> sensible. Capacitors need to be placed close to output devices,
not many
>> >>>> cm away"
>> >>>>
>> >>>> That defeats the purpose of having the PS outboard. You want the
AC OFF
>> >>>> the signal chassis!
>> >>>
>> >>> ******elding is cheap and simple. By all means, keep the power
transformer
>> >>> off the signal chassis, but rectifying and smoothing, THEN trying
to
>> >>> couple the result to the signal chassis is a recipe for disaster.
>> >>
>> >> Please elaborate. What kind of "disaster" ?
>> >
>> >**Google: 'Welder'. Welders operate on DC current. It is for this
reason
>> >that commonly available relays have a maximum working Voltage of 27
VDC.
>> >Much higher and the arc created can be self-sustaining. Damage can be
>> >considerable.
>> >
>> >> My own 50W amp now five years old, has been running
>> >> several hours per day without any problems.  It meets my
>> >> objective for a very low level of hum and noise.  To build
>> >> the same amplifier in a single chassis with the required
>> >> physical separation between critical components
>> >> would have required a footprint the size of a desktop.
>> >>>
>> >>>>
>> >>>> You want the primary filter caps on the PS chassis and some more
on the
>> >>>> signal chassis, with a choke before them that sees only the ripple
for
>> >>>> AC.
>> >>>
>> >>> **Nope. You *only* want to transfer AC between chassis. Not DC.
Unless
>> >>> you are a fool, of course.
>> >>
>> >> The idea, Trevor, is to build an audio chassis in which the
>> >> only AC is the signal.  It is a very good solution if it can be
>> >> implemented in a safe way.
>> >
>> >**Trying to use connectors for DC (with appreciable current and
Voltage) is
>> >dumb design. Much smarter to use AC.
>> 
>> Seems to me the 'disaster' is easily avoided by using the power switch
>> to turn the unit on and off instead of trying to do so by plugging and
>> unplugging the DC connector.
>
>Disasters await those who for for whatever reason tinker or tamper
>with gear, or use it in some way that is a result of permanent 
>or tem****ary stupidity.
>
>Manufacturers have to ensure that nothing bad is anle to happen.
>
>Including say a todler poking a metal knitting needle into a hole
>through
>a chassis, or a finger into a hole in which the finger becomes jammed,
>and the child struggles to remove it while contacting mains or +500V. 
>One doesn't want to main customer's child, OK.
>
>Disasters are easily avoided by common sense, but not everyone 
>has the same degree of common sense, so despite all the rules,
>disasters keep happening simply because its possible that disaster is
>possible.
>
>I once had a client who bought his friend's Leak monoblocs with KT66.
>No bottom covers were fitted to the chassis. No lifting handles.
>He tries to pick an amp up and forgets to turn it off.
>He reaches casually around the bottom of the chassis and makes contact
>with B+.
>He hurls the amp with great gusto at the ceiling where a couple of tubes
>smash, and rain down
>broken glass and toxic junk, then the amp does a somersault on the way
>to the floor
>where the remaining tibes are smashed.
>
>He was lucky a cup of tea and good lie down were all he needed to get
>over the experience.
>
>His pocket recovered later.

Ok, You convinced me you shouldn't be using HVDC umbilicals.

>
>Patrick Turner.
>
>
>> 
>> >
>> >Trevor Wilson
>> >