Re: Remote Power Supply Connection

"Trevor Wilson" <trevor@[EMAIL PROTECTED]
> wrote in message
news:69fijqF336p9iU1@[EMAIL PROTECTED]
>
>
> "keithr" <keithr@[EMAIL PROTECTED]
> wrote in message
> news:4832585c$1@[EMAIL PROTECTED]
>>
>> "Trevor Wilson" <trevor@[EMAIL PROTECTED]
> wrote in message
>> news:69c1qjF320bo4U1@[EMAIL PROTECTED]
>>>
>>>
>>> -- 
>>> Trevor Wilson
>>> www.rageaudio.com.au
>>> "keithr" <keithr@[EMAIL PROTECTED]
> wrote in message
>>> news:4830ce5f$1@[EMAIL PROTECTED]
>>>>
>>>> "Trevor Wilson" <trevor@[EMAIL PROTECTED]
> wrote in message
>>>> news:69bqsaF321ke3U1@[EMAIL PROTECTED]
>>>>>> Lets face it the whole safety thing can be fixed. You put the
>>>>>> connectors at each end under covers. The covers can only be lifted
by
>>>>>> removing a screw (or two), under the cover is a micro switch. Long
>>>>>> before anybody can access the actual connectors, the power is
>>>>>> switched off by the microswitch. I have seen this on a number of
>>>>>> pieces of professional equipment, for the safety of both the
operator
>>>>>> and the equipment itself.
>>>>>
>>>>> **Except that such a solution only works with AC. DC power requires
>>>>> that capacitors be discharged as well (I need not remind you that
>>>>> microswitches are spectacularly unsuited for high Voltage DC).
>>>>>
>>>>> AC power cables make far more sense. Using DC is dumb.
>>>>
>>>> Use some sense Trevor, you do not switch the power with the
>>>> micro-switch, you use it to energise a relay or relays.
>>>
>>> **I *am* using sense. Find me a relay which can switch (say) 500 Volts
>>> DC. I'll wait.
>>>
>>>>
>>>> Let me spell it out for you - you supply an unswitched low voltage
from
>>>> the power supply to the amp. That pulls in a relay that connects the
B+
>>>> input pin(s) to the B+ line in the amp. This voltage is fed back
>>>> through the cable to a similar switch in the power supply. When both
>>>> switches are made (optionally after a delay) a relay is pulled in in
>>>> the power supply which applies B+ to the cable. If either micro-witch
>>>> is opened then power is dropped isntantly to both relays. Simple
>>>> enough?
>>>
>>> **It SOUNDS simple. Find me a realy rated for (say) 500 Volts DC. I'll
>>> wait.
>>
>> If that is a problem then you can switch the mains to the B+
transformer
>> and short the B+ both in the supply and the amp to ground through a
>> suitable resistor using a couple more relays (at the earthy end of the
>> resistor of course). Of course in that case you would need a separate
low
>> voltage transformer and you'd need to get the sequencing between the
>> shorting relays and the mains relay right.
>
> **You COULD go to such heroic lengths. Or you could just use AC in the
> first place. You would save yourself a bunch of money, time and increase
> safety.
>
You would also totally defeat the object of the exercise.....
to keep AC (except for the signal) out of the amp chassis.

Iain