Re: [CAD_CAM_EDM_DRO] Need help with O-scope

Ed wrote:

> I am having a problem with a mill set up with Gecko drives. There seems
> to be a noise problem that has cropped up on the Z axis and I would like
> to look at it with a scope. I have the use of a scope but have not used
> one for several years and have forgotten a few things. The part I worry
> about is; do I have to use an isolation transformer to keep from popping
> an IC do to different ground potentials? The scope is a B K Precision
> model 1570A with API 1X and 10X probes. Any help appreciated. Ed.

The only this is to not ground the scope to the motor output
terminals, as both of them switch between ground and the motor
supply voltage. In general, you should have no worry of popping
something by grounding the scope probe to the DC supply ground
or computer ground. You MAY get false readings due to the high
di/dt of the switching transistors in the Gecko. That is the
nature of trying to track down noise/interference though.
When looking at the step/dir pulses out of the computer, ground
the scope to the computer, such as the housing of the parport
connector, as it has its ground isolated from the Gecko's DC
supply.

Jon