Re: Remote Power Supply Connection

"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.

-- 
Trevor Wilson
www.rageaudio.com.au