Re: Gecko Stepper on Bridgeport

> For Mariss
>
> There has been a lot of interest in your drives for these larger 42

series

> motors.
> You have also been good enough to answer some of my queries my

email.

> One that hasn't been addressed and from what I can see a few

people would

> like to know is
> [1] Can the 210 driver run these M112 steppers like fitted to the
> Bridgeports given a change of transformer ?
>
> [2] Will the new 160v drive be able to run these ?
>
> [3] What will be the max amperage of the new 160V drive.
>
> I have some specs on the M112's and depending on the number of

wires and

> the suffix numbers they can draw from 3.5 to 15.2 Amp
> --
>
> Regards,
> John Stevenson
> Nottingham, England

Hi,

1 and 2) Yes. They can run them now. At 160VDC they will run 2 to 3
times faster.

The amperage will stay the same if I'm lucky. The "on" resistance of
a MOSFET goes up as the square of its rated voltage. The present
drives use 100V rated MOSFETS, the new one will need 200V rated
MOSFETS. This means the size of the silicon die must be 4 times
bigger to keep the same "on" resistance. The MOSFET package used in
the present drive is called a "TO220AB". Beyond a certain die size a
bigger package must be used, and I mean much bigger (TO247).

MOSFET cost hinges on die size and package. Since 8 are used per
unit, this adds up rapidly.

Mariss