Antwort: [sdiy] construction of simple power bus for newmodul ar?

[Tim Parkhurst]

Some interesting results from the "PCB Trace Width Calculator" found at

http://www.geocities.com/CapeCanaveral/Lab/9643/TraceWidth.htm

If I want to put 2A current though a power trace 17 inches long (made on a
PCB with 1oz copper), this can be handled with a trace that is .027"
(0.69mm) wide. This also assumes a 10°C max temp rise above ambient (a
fairly safe temp rise limit).

Basically, I would think that a power buss PCB with traces about a third of
an inch wide would EASILY handle the current for a single row of modules.
YMMV, but I thought the calculator listed above was a pretty nifty tool. I
think Harry's idea about a four layer PCB with interleaved ground planes is
a great one, but a little beyond most DIY board makers. Note that the above
numbers are for external traces. If you had power traces on inner layers,
they need to be wider to handle the same current.


Cheers!


Tim (nifty tool) Servo

"Imagination is more important than knowledge." - Albert Einstein




> -----Original Message-----
> From: harrybissell [mailto:harrybissell at prodigy.net]
> Sent: Thursday, August 05, 2004 2:51 PM
> To: Paul Perry
> Cc: synth-diy at dropmix.xs4all.nl
> Subject: Re: Antwort: [sdiy] construction of simple power bus for
newmodular?
> 
> Of course I don't believe that we've ever discussed this... but the ideal
> bus might
> consist of a four layer PCB with the voltage planes interleaved to get
> really, really
> low inductance and high capacitance (all good things).
> 
> Multiple, parallel twisted pairs might go up to the individual modules to
> keep the benefit
> of this construction.   Are you listening MOTM ???     :^P
> 
> But SERIOUSLY folks... you might consider commercial PCB suppliers for a
> power bus.
> I have indeed done this !!!   If you are careful about labeling the
> components, a large PCB
> 'might' be bandsawed into smaller strips after manufacture, without
running
> afoul of the
> "no step and repeat" rules.
> 
> H^) harry
> 
> Paul Perry wrote:
> 
> > Christian wrote:
> > >You could thicken the stripboard traces by soldering solid wire on the
> > >heavily loaded traces.
> >
> > This works, I rescued a poorly laid out board
> > that way, there was enough resistance in the traces around
> > a power supply to generate a grounding hum.
> >
> > Before running into current carrying problems, leakages from LFO
> > switching etc via power line resistance might be a problem.
> >
> > paul perry Melbourne Australia
> 
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