David Walker

L6470: Watch the MIN_SPEED parameter

Discussion created by David Walker on Nov 27, 2017

When using the L6470 controller, watch out when using the MIN_SPEED parameter. The BEMF correction internally uses this parameter when computing the KVAL to set the duty cycle for driving the motor. The actual expression (I think) is:

 

 

This wasn't documented anywhere I could see unless I missed it.

 

This got me in trouble because I found I was really underdriving the motor when MIN_SPEED was set.

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