[Gb-ccb] Information and advice on optic-fibre ethernet

[John Ford]

Martin Shepherd writes:
 > 
 > 
 > On Wed, 20 Aug 2003, Roger Norrod wrote:
 > > Info on the supplies is available off the GBT Electronics web page.  The
 > > direct URL is:
 > >
 > > http://www.gb.nrao.edu/electronics/GBTelectronics/RxInterface/index.html
 > 
 > Thanks. I hadn't seen this page.
 > 
 > > We probably cannot dedicate a supply set solely to the CCB, but why don't
 > > you tell me what voltages and currents you need and I'll look into the
 > > implications.
 > 
 > Unfortunately I won't know this for a while yet, but only having 3A
 > available at 5V is clearly going to be a problem. The single board
 > computer alone will probably draw about that much current at 5V, and I
 > don't know how much the other logic will draw yet.
 > 
 > I want to avoid having either a transformer or a switch-mode power
 > supply close to the CCB box, so if I do need more power than the
 > existing supplies can provide, will there be room to mount another
 > power supply alongside the existing ones?

There is room.  It'll have to be filtered and shielded, if it's a
switcher.  Since the computer itself makes *much* more noise than a
switching supply, I recommend you package the supplies needed for the
computer and digital login in the box with the digital stuff, and then
either use our supplies for +- 15 and 5 volt analog, or provide your
own linear analog supplies.

John