[rescue] let's revisit the whole FC-AL thing

[nick at snowman.net]

Dude, he's getting paid 50$ on 10$ worth of parts.  Makeing a proffit is
fine, makeing a (minimum, after shipping) 500% proffit on investment is
absurd.  Course everyone else who sells t-cards wants more so...  I can
probably either borrow or create the power shareing circutry, but I'd like
someone to check my transmission lines & data lines.  Also I saw something
in the spec about not being able to just use stupid jumpers to ground on
the control pins, anyone able to confirm/deny/explain this?  They said
(and I'm probably misremembering this) that I needed to hook up an open
collector to each of the pins I wanted pulled to ground/enabled.
	Ncik

On Tue, 26 Feb 2002, George Adkins wrote:

> > > > I'm still looking into it, but the problem is 1. I'm not a competent
> > > > enough PCBer.
> > > is the PCB really even needed?  not really i don't think, it might be
> > > possibly to live without it.
> > It's not that simple.  For the design I was going for the PCB is required,
> > though if you'd like I can provide the pinout, it's a public spec, and you
> > can attach a total of ~10 wires.  4 tx/rx, a few power, and whatever ID
> > etc you require.  
> 
> This guy is getting paid for his work, it just happens that he's asking to 
> get paid well, that's all.
> I can fab PC boards (have done small production runs of 10 or 12 before.  And 
> was actually thinking of trying to get this particular project going myself.
> 
> > > > 3. the SCA connectors run 5$ a pop, 
> > >
> > There are minimal electronics required, (~30$ total) 
> I'm all for the idea myself, I don't have a source for the connectors though, 
> does anyone else here know where to get them?
> 
> > SCA connectors the next third, and the power supplies (my current thought
> > is three ATX power supplies on sleds to make them hotswap) the last.
> 
> The hotswap power supplies is the trickiest of them all, because you have to 
> load-balance them.  If you do not, then the weakest supply (voltage wise) 
> ends up supplying all the current, until it's maxed out, then the next one 
> starts taking load, etc.etc.  Burns out power supplies fast.
> 
> You'd need to engineer a load-balancing board (I started to look at doing 
> this, but stopped when I didn't have enough expertise to spec the proper 
> parts) and plug the supplies into that, although for drives, all you really 
> need is +12V and +5V, which simplifies things.
> 
> George
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