[sdiy] dare I say - decoupling?

[Peter Grenader]

Guys...please.  WHAT does all this have to do with the flight velocity of an
unladen swallow?  Can we please keep this on-topic.

- P



harrybissell wrote:

> James Patchell wrote:
> 
>> Harry likes to use the analogy of "Ground == Ocean"....very important
>> here...In general, you do not need a ground plane.  But when things don't
>> seem to be working they way they should...well...
>> 
> 
> Yes... I do.   If you pour a cup of water into the North Atlantic Ocean...
> does the water level rise ?   Of COURSE it does... but probably not enough to
> notice or care.   Does the water level rise in England (I'm going to pour from
> Boston in this case :^) ?  Yes it does... but it takes time for the change in
> sea
> level to even out. They will notice the rise much later.
> 
> What about if I pour the cup of water into a shotglass ??? Does the water
> level
> rise ?
> Yes. Do I notice ???  Probably... unless I had been using that shotglass for
> hours
> :^P
> 
> You think of supply rails like pipes carrying current to the circuit... well
> ground
> is
> like sewer pipes draining that current.  If any of the pipes are too small,
> the
> water
> pressure drops when you open a valve.  AND it takes time for the water to flow
> from
> 
> the source to where that pressure drop is.
> 
> Decoupling caps will act as local sources of 'water'... helping to hold the
> pressure
> steady with changing demand AND acting as a reservoir ... until the rains come
> again
> (from the main filter caps, through the resistance and inductance of the
> supply
> 'pipes')
> 
> This is why some "Harley Engineers" like myself and twin-separated-at-birth
> Jim
> Patchell use LOTS of decoupling caps, probably MUCH more than we really need
> to.
> They are not real expensive... cheap insurance.
> 
> A Harley Davidson engineer was quoted as saying "At Harley-Davidson... if we
> need
> to make something stronger, we make it BIGGER. If that makes it ugly...we
> CHROME
> it"
> 
> H^) harry
>