Help me understand??

[Elias lector]

I'm sorry if this is a stupid or already discussed subject.

Can anyone help me understand how vesc controllers can be so small but output so much?
I mean if you look at the monster sized controller on a surron compared to every vesc I've seen you could stack like 10 of them in the same box.
My kelly kvd7212nx isn't very large but can put out 200amps. But I've seen some vesc controllers that are just slightly larger than a stamp claim to do the same. I'm in no way an electronics genius, I would say just slightly beyond basic knowledge so if possible can this be dumbed down for me lol thanks.

 

[neptronix]

Minimalist design and virtually no heatsinking because in an RC application you don't really need it - you have short, intense bursts of power and lots of low amp cruising.. on a bike, you have much more prolonged periods of drawing in a lot of amps.

Also, the higher quality/lower resistance the mosfet, the smaller those mosfets can get and the less heatsinking you need.

Grin's phaserunner controller is a good example of miniaturization also, sort of a midway point between the postage stamp sized RC controller and the brick sized ebike controller.

 

[Elias lector]

Minimalist design and virtually no heatsinking because in an RC application you don't really need it - you have short, intense bursts of power and lots of low amp cruising.. on a bike, you have much more prolonged periods of drawing in a lot of amps.

Also, the higher quality/lower resistance the mosfet, the smaller those mosfets can get and the less heatsinking you need.

Grin's phaserunner controller is a good example of miniaturization also, sort of a midway point between the postage stamp sized RC controller and the brick sized ebike controller.

OK that all makes perfect sense to me but maybe im just not looking at the correct vesc controllers because I keep reading that people are using them on ebikes as well. And I think that's where I'm losing my understanding because as you said no heatsiking and all I see is tiny caps on the vesc units. So I just can't grasp how it would reliably last for more than a few minutes on a bike. Again maybe I'm missing something or just looking at the wrong units. I'm asking because I plan to build another bike after I finish the current one. I'm still shopping around for parts but I'm leaning towards a qs190 or atleast a 138. So a controller will be the next thing I get and seeing all the open source possibilities with a vesc I'm interested but skeptical.

 

[neptronix]

I think a big ol' QS would be too much for a VESC. I would search around for some builds with VESCs and see how far other members have gone with them in a high power ebike application. Hopefully you get some experience in this thread.

 

[Elias lector]

I think a big ol' QS would be too much for a VESC. I would search around for some builds with VESCs and see how far other members have gone with them in a high power ebike application. Hopefully you get some experience in this thread.

Awesome thank you

 

[A-DamW]

Short list of of larger VESC based controllers you can buy now(in no particular order):

Powervelocity Nextgen(California based):
24F NextGen PV Controller 144v
ES thread:
PV NextGen FOC 100-180v 36kw max - $799

3shul/Hackey(India based):
Shop - 3ShulMotors
ES thread:
HESC V1 150v 600Amp VESC based motor controller

Trampa/Benjamin Vedder, Creator of the VESC ecosystem(UK based):
VESC STR-500 100V 500A
ES thread:
VESC STR-500 100V 500A Launched
VESC origin story:
Benjamin's robotics | A site about some of my projects, some tutorials and anything else I feel like publishing

Masinaelectrica/joulemotors(Netherlands based)
100-200kW continuous:
Joule Motors
Brushless motors, 3Phase inverters, schematics. Joulemotors.com
https://www.youtube.com/channel/UCKWHbUOPVhMy1DsFZlZWLMw