DMC60 REGEN PATH??

[Wrencher]

Does the DMC60 require a reverse diode across the power switch to limit brake-regen voltage levels?

On page 5 of the reference manual for the DMC60 it indicates that the braking function is done by internally shorting the motor leads together when brake mode is enabled.
Does the DMC60 speed controller perform regenerative braking when brake mode is enabled or just burn it off as heat?

Is there any concern if the power supply is turned Off, (power switch opened), while the motor is spinning down?
Some controllers are sensitive to this because if they regen back to the battery the voltage can rise to unsafe levels and damage them.

I see diode D6 on sheet 4 of the schematic, is this zener used to limit this voltage level?  

Thanks,

Brian

[JColvin]

Hi @Wrencher,

I have asked the engineer who is much more familiar about the DMC 60 about this; they are out of the office though, so it may be a few days until I get a response for you.

Thanks,
JColvin

[JColvin]

Hi @Wrencher,

I apologize for the delay. This is what I heard back from our engineer about your questions:

Quote

The brake mode described in DMC60 reference manual is describing the behavior when the neutral throttle is applied. In coast mode all 4 mosfets (the entire H-bridge) are turned off. Any current is circulated through the intrinsic catch diodes. In brake mode both the lower left and lower right mosfets are turned on, which essentially shorts the motor leads together through the ground polygon. If the voltage gets too high then D6 will conduct, or the varistors between + and GND and – and GND will turn on and conduct. Regenerative braking can occur during normal use and I don’t think it’s safe to use the DMC60 with a power supply that can’t handle some amount of reverse current. It was designed to be used with lead acid batteries… the same ones used by FIRST robotics. We’ve done no testing with LIPO’s or other battery chemistries.

Thank you,
JColvin