P
Peter Kiproff
Guest
Is comparator switching, or resistor current limiting better?
I'm using Maxnc on some home brew stepping motors drivers for lathe & mill
work.
I've been satisfied that it works as well as it does however I'm seeing the
need for more speed/pwr
My setup is a Fet with a .1 ohm current detect applied to a comparator that
naturally oscillates @
approx 1 kHz, I adj the ref so I average 1.4 amp per phase as per mfg
recommendations.
My motors are rated 5V @ 1.4A, the raw pwr supply is approx 15 V, I'm
running half steps.
There are 4 per Axis X, Y, Z * 4 machines so I would like to modify what I
have.
The currant drops of if I try to go faster, so this is my limitation.
If I was to use say a 10 ohm 25 W resistor on each leg limiting the currant
to the same 1.4 A
Is it any better?
If I put a cap in parallel with each resistor would this improve
performance? what value?
Double the drive voltage? any currant derating?
Thank you for responding
Peter
I'm using Maxnc on some home brew stepping motors drivers for lathe & mill
work.
I've been satisfied that it works as well as it does however I'm seeing the
need for more speed/pwr
My setup is a Fet with a .1 ohm current detect applied to a comparator that
naturally oscillates @
approx 1 kHz, I adj the ref so I average 1.4 amp per phase as per mfg
recommendations.
My motors are rated 5V @ 1.4A, the raw pwr supply is approx 15 V, I'm
running half steps.
There are 4 per Axis X, Y, Z * 4 machines so I would like to modify what I
have.
The currant drops of if I try to go faster, so this is my limitation.
If I was to use say a 10 ohm 25 W resistor on each leg limiting the currant
to the same 1.4 A
Is it any better?
If I put a cap in parallel with each resistor would this improve
performance? what value?
Double the drive voltage? any currant derating?
Thank you for responding
Peter