Aux Power

[Tony Duell]

> 
> Hi people,
> 
> on my PDP11/23+ there is that key called "AUX POWER". But it doesn't do 
> anything on my machine. The only power switch is at the back of my 
> machine. And there is an unused connector at the back of the front 
> panel. From that little panel goes a cable to the back of the PDP which 
> ends in an unused connector, too.
> 
> Somebody said something about a power bus?? I have not found the posting...
> 
> Does a fancy power switching (everything in the rack at once) system 
> exist? If yes, what do I need to get my rack complete?


There is a power bus, it used 3 pin mate-n-lock connectors with the 3 
pins being groond-for-on, and ground-for-off (with the 'off' taking 
priority over the 'on'). The idea was that the system on/off switch would 
be wired between ground and ground-for-on (so that said switch would 
control the enitre system) and overheating-protection thermal switches 
would be connected between ground and ground-for-off (so that if anything 
got too hot, the whole lot would get powered down).

What uyou need is a 'power controller'. There were many types, the 861, 
the 872, etc. They are all pretty similar to use. Each one came in 115V 
and 230V versions (and had the appropriate type of US mains sockets on 
it, obviously there were internal changes too). 

-tony