[hpsdr] Demeter = HPSDR power supply(?)

[Chris Albertson]

--- peter at gehughes.us wrote:

> Just a thought
> 
> While you are thinking about adding another card to the bus you might
> want to look at how this might limit you in your choice of
> cards..With
> only 6 slots and upwards of 11 possible choices without even
> considering a slot mounted Power Supply.

If the PS is to have the ability to be shut down on command then
somehow Ozy and Sasquatch need a way to communicate with the PS
either by setting a voltage on a line or by sending a
command over a serial interface.  The ability of the PS to send
status information such as voltages and current implies the
serial interface.  On a backplane-centric system
it seems natural to use the backplane for communications.

Some other interface could be used to send the data but it
would have to use the current Ozy hardware design

So there is a decision to be made:  (1) Will the PS exchange
data with the rest of the system and (2) if so over
what interface.

Will people really be placing 6 cards in an Atlas?  Would it
even make sense to have a Mercury and a Janus in the same system?
and if you did have both of these would you want to power them both
up at the same time.  I could imagine interaction due to EMI

On this other system that uses a ribbon cable as the backplane,
the ribbon cable may be made quite long.  So being "on the buss"
did not have to mean being one inch away from an analog card.
The PS could be some inches away inside it's own metal box.

With HPSDR I guess it does make sense to keep the hight power, noisy
parts of the PS off any plug-in card.  But if the PS is to be "smart"
commands and status information needs some kind of data path so 
you either use the buss or point to point cabling or simply
design a "dumb" linear supply that is controlled by a simple
On-off toggle switch.


Chris Albertson
  Home:   310-376-1029  chrisalbertson90278 at yahoo.com
  Office: 310-336-5189  Christopher.J.Albertson at aero.org


       
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