Brake vs. Coast in the Drive

[Ether]

Originally Posted by Jared341

I did not realize that the speed controllers brake during every PWM cycle. I had assumed that they were only shorted when the signal was at/near the "neutral" pulse width.

Shorted but not necessarily braking. In fact, for a black jag at high PWM and low rpm the shorting actually allows the current to keep flowing and providing motive (not braking) torque during the brief PWM "off" portion of the cycle. There's a thread somewhere that goes into details and explains this.

link:
http://www.chiefdelphi.com/forums/at...2&d=1295820836

[EricVanWyk]

I'd really love to see a graph of the effect of this hybrid use-case, with feet per second on the X axis and power consumption on the Y axis. Repeat the test for all coast, all brake, and half and half.

[jspatz1]

We ran exactly the hybrid combination you described in our 2-motors-per-transmission drive train this year, and it worked well all year with no problems. We like the moderate braking it provides without being too severe.

[Hawiian Cadder]

We did this in 2011 with black jags on CAN bus with no ill effects, our motors were 2 cims per side in tough-boxes(2 motors per gearbox) chained at 14.4 fps.

Originally Posted by jspatz1

We ran exactly the hybrid combination you described in our 2-motors-per-transmission drive train this year, and it worked well all year with no problems. We like the moderate braking it provides without being too severe.

Would you do it again?

What were the advantages/disadvantages of it?

Did it do exactly what you want, or were there some things you wished it could do, but didn't? If so, what?

Did it put any strain on the motors? By that, I mean did your motors get broken/overheated really quickly?

Thanks!

[jspatz1]

Originally Posted by SuperNerd256

Would you do it again?

What were the advantages/disadvantages of it?

Did it do exactly what you want, or were there some things you wished it could do, but didn't? If so, what?

Did it put any strain on the motors? By that, I mean did your motors get broken/overheated really quickly?

Thanks!

No ill effects. Moderated the braking exactly as we wished. Motors ran cool, no problems. Would do again.

Originally Posted by jspatz1

No ill effects. Moderated the braking exactly as we wished. Motors ran cool, no problems. Would do again.

Thanks!