Re: testing steppers

--- In CAD_CAM_EDM_DRO@y..., Steve Ross <sross@m...> wrote:

> Hello All
>
> Recently I had a brand new driver box go up in smoke. It turns out

a

> stepper motor was the problem. How can you test a stepper motor

before you

> smoke the box?
>
> Steve Ross

An ohmmeter test to determine the windings followed by checking for
shorts between windings and a winding shorted to the case should root
out most of the destructive overloads. An open winding won't
overload the card but will case the motor to just sit and vibrate.
If you are still concerned put a power resistor in series with the +
side of the motor DC power that will limit the current to within the
rating of the driver. Use the age old formula of R = E/I where R
equals the value of the resistor in ohms, E is your applied voltage
and I is the max current rating of the driver card. Power is
calculated by using the formula Wattage = current(I) squared times
the resistor you just calculated.

IMHO It should be difficult to destroy a well designed driver card
with pulse by pulse current limiting that is being run within the
voltage specs of the card.