multiple power supplies in a modular

[The Dark force of dance]

Y-ellow Merlin 'n' all.

At 10:59 PM 2/3/98 +1100, Merlin Zener wrote:

>One approach I've used (er - copied... :) is to have a standard
>power supply of, say, +/-15V or 18V and the first thing on each
>board is a pair of 100 ohm resistors and then 100uF caps to
>ground. Works for me.

Well I don't do this. And in as sense I go one better. Every op-amp and
every analogue IC and active circuit block is decoupled by a 50 to 100 ohm
resistor (metal film) whith a capacitor across it. Usually an electro of
about 1 - 10 mikes. Whatever it's not that important. The thing is that it
smooths the hell out of the powersuply feeding each op-amp. You can also use
2 capacitors from the respecitve supplys to ground on the IC side of the 100
ohm resistors. But in practice a single capacitor across the pair will suffice.

I would not use it on the input to each board though, or even if the supply
from there was feeding several major circuit blocks. This would only
localize any supply glitches. For example, if two VCOs were supplied like
this you could still experience the coupling effect.

But the resitor/capacitor trick is standard with me. I never just jack
circuits straight across the power suply.

Hope this helps.

Be absoltuely Icebox.
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