Re: Proper size of capacitors for transient suppression?

Jon:

Just looked up the chip. VERY impressive. I think I'm going to do a
little tweaking and then run with my current design. I'm about a
week from seeing if everything goes up in a puff of smoke and, while
I'm looking for every possible way to procrastinate, sooner or later
I've got to see how close everything comes to design expectations.

BTW, I mis-wired the first power supply in my new pendant and during
testing about a month ago, I not only let the smoke out of it, but
the flames and the noise as well <G>

Hopefully I've learned my lessons.

Jeff

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:
>
>
> washcomp wrote:
>
> >Except for the MPG leads (not yet installed), the longest distance
of
> >any line is less than 10 feet (3 meters). I used #18 wire for
> >everything to keep the resistance to a minimum.
> >
> >The pendant also has the keyboard emulator embedded. I have heard
of
> >people connecting each terminal through a capacitor to ground (56
> >terminals? Ee Gads!)
> >
> >
> For digital lines, especially where you can't suppress the higher
> frequencies
> with a big capacitor, a real transient suppressor is the way to
go. MOV
> devices have very high capacitance, too. LittelFuse came out with
a line
> of devices that are sold through Digi-Key. I am using the SP720AB,
> which Digi-Key sells under the order code of F2163. This is an SO-
16
> packaged device that protects up to 14 signal lines. The other 2
pins are
> connected to ground and +5 V. Any signal outside the voltage on
these
> 2 lines will be clamped to one of those supply rails. The
capacitance is
> very low.
>
> Jon