AnsweredAssumed Answered

Why is the L6470 getting hot?

Question asked by Nathan Coon on Jul 21, 2017
Latest reply on Aug 3, 2017 by Nathan Coon

I am using the X-NUCLEO-IHM20A1 board. The stepper motor that I am driving is a PK296A2A-SG36.

Resistance (Ω/phase) = .96 [Bipolar (Series)]

Inductance (mH/phase) = 6 [Bipolar (Series)]

Voltage (VDC) = 2 [Bipolar (Series)]

Current per Phase (A/Phase) = 2.1 per phase

I am using a 24V supply.

I used those values to get my Kval like this:

For full current:

Kval = (.96 * 2.1) / 24 = .084%

Kval is an 8 bit register so I found 20/255 = .08 so the register value should be 20 it I want to use the full 2.1 amps. When I use this value the L6470 gets really hot.

Currently I am only giving it the command run(1, 75) so it is quite low. It even gets hot when running at half kval = 10. I am not sure what is going on. Any help would be greatly appreciated.