Re: Stepper Power Supply

Wash my mouth! I ought to know better!
I am used to thinking in servos and peak loads and I forgot about stepper supplies although I have built a few over the years.
With the steppers the load is much more constant, specially if there are series resistors with the windings.

Sorry about that.
Bertho
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> From: Bertho Boman <boman@...>
>
> Please remember that a transformer is commonly rated for continuous use, normally on a resistive load. That completely changes
> the rating once you have a capacitive input rectifier. After the capacitor, you can talk about DC current and DC voltage
> ratings.
>
> Your typical servos or stepper motors will only draw peak currents during full torque accelerations. Once they are up to speed,
> the current will drop quickly.
>
> What this boils down to in practice is:
> If the transformer runs at reasonable temperature when used to run your CNC, it is fine from power over load consideration.
>
> A "weak" transformer might drop the output voltage too much under temporary peak load and be unacceptable because of the reason.
>
> Hopefully this will add some practical "feel" for the problem.
>
> Bertho Boman