Re: [CAD_CAM_EDM_DRO] OT: sort of electronics info

archie road wrote:

>I am currently working on a retrofit of a lagun cnc mill. i was
>wondering where i might find large capicaters (sp) and info on test
>equipment. such as a way to mesure very low resistances as in the
>impedence of motors and what type of osillascope people are using.
> It seems that in these groups they dance all around this issue but
>in 2+ years of surfing this and other cnc boards i haven't seen much on
>this issue except maybe a referance to mouser or Digi-Key
>
>

Mouser is a good place for larger capacitors. What you want is
sometimes called
"computer grade" with the 10-32 screw terminals. But, they get quite
expensive.
I've used up my supply of suitable caps here and have had to start
buying some.
The best deal I found is some CDE solder-terminal caps such as the
Mouser part
# 5985-85-63V12000. They have a variety of voltages and capacitance
ratings,
that particular one was a good fit for my projects.

You can probably get a used Tektronix analog oscilloscope pretty cheaply on
eBay, but the kinds of measurements needed in working with servo systems
will often be one-shot events, so a digital storage scope can save a lot of
frustration.

I have a General Radio impedance bridge that can measure milliohm values and
inductance, but I really don't think you need such an instrument unless
you are
designing servo drives.

Jon