Motor vs mech brakes Info

[Shark413]

I have seen a lot of posts about mech vs motor braking and I am not here to debate one being better than the other, but I was able to capture some Eagle Tree info that was kind of interesting. May be some of you who are more technically inclined can comment. Anyways I have two brushless 1/8 scale buggies, an SH Z-Car with mech brakes front and rear, and a Losi 8ight with motor brakes and a Smart diff (center). I bascially made two runs, one at about 3/4 throttle then brake, and then another at full throttle then brake. As you can see in the graphs the first one (Losi) shows the pack voltage dropping when accelerating, then when the brakes come on there is a slight amount of positive voltage, something BrianG has mention (regenerative braking). Then the second graph shows the mech braked buggy, and there is no positive spike (no motor braking = no regenerative effect), it's pretty flat. Yeah I know, too much time on my hands.

[tom255]

Actualy no regen braking in any of ESC's its just error that related with fet switching and motor parasitic inductance. Regen effect much less than one sec.
I remember that GriffinRu put Trancient Voltage Suppressors on his modded ESC's to prevent voltage spikes.

[E-Revonut]

Originally Posted by tom255

Actualy no regen braking in any of ESC's its just error that related with fet switching and motor parasitic inductance. Regen effect much less than one sec.
I remember that GriffinRu put Trancient Voltage Suppressors on his modded ESC's to prevent voltage spikes.

So are you another one saying that there is no regen braking and therfor calling Patrick a liar? I assure you that there is as there is no other way to disipate all that energy.

[tom255]

Originally Posted by E-Revonut

So are you another one saying that there is no regen braking and therfor calling Patrick a liar? I assure you that there is as there is no other way to disipate all that energy.

Ofcource not!
Test what Brian made not truly shows real numbers first he made test on unloaded motor that means motor stoped and you cant see constant regeneration.
One guy made similar test but motor spinned by other that simulated a kinetic energy and constat braking aplied, motor under test didnt stoped other motor still spinn it. And he noticed too regen effect but its not constant just spikes. That is not regeneration in my understanding.
He noticed some funny effect too when ESC not connected and you spinn connected motor FETs acts as Diodes (Driver not drive them) and you can see true regeneration effect.
I anybody understands russian can read this:
http://rc-auto.ru/forum/index.php?showtopic=6645&st=40
All energy dispates by heat on fets and windings.

[SpEEdyBL]

Well my graphs show a constant regeneration effect between 0 and 4 amps for to the duration of breaking. The battery voltage increases as the current increases in that part of the graph.

http://www.rc-monster.com/forum/showthread.php?t=18458