Re: Stepper Drivers

You are talking about different numbers of axis.

If you do a single, small, clean design for one axis one can just stack up side by side as many drivers that are needed. It is
a lot faster to do a one channel amplifier layout and service, repair, trouble shooting is also simplified.
Bertho Boman
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> From: stratton@...
>
> The ballscrew is on order, so it's time to worry about other parts of
> the system, principally how to push around 5 amps through a stepper.
>
> A couple of options:
>
> 1) If I limit the supply rail to below 20V it's comparatively easy to
> make a full H bridge using N and P channel MOSFET's. The 20volt
> limitation arrises from the maximum VGS of the P fet without
> complicated floating circuitry to drive it.
>
> 2) If I were to limit the system performance to 4 amps I could use an
> L6203 bridge IC.
>
> 3) I could use a pair of International Rectifier IR 2103 triple half
> bridge drivers ($11 each) [well, 4 chips gets 3 axis] and 8 power N
> channel mosfets per axis. The circuit looks simple, and it will
> handle any reasonable supply rail.
>
> 4) I could use a cheaper full bridge driver HIP4080 ($6) at moderately
> high supply rails (up to 80v) along with 8 N channel MOSFETS per axis.
> According to the data sheet, I would have to build extra circuit to
> prevent the bridges from shorting on power on. (Hm, tempting instead
> to put a relay latched "Motor Enable" button on the box to activate
> the motor supply rail - operater has to push after each power on,
> won't work until logic/bias power is good).
>
> 5) I could just run the motors unipolar at about 2/3 the torque using
> very simple electronics. 4 N FET's and something to boost the gate
> drive voltage per channel... It's very tempting to build such a
> unipolar system to start! Is there a reason I don't want to do this?
>
> What kind of supply rails are people running anyway?
>
> Chris