Hello! First post here.
I've been working on a niche project, and would appreciate input from more experienced hardware designers, and some guidance for customizing the firmware for my design (probably start with 75/300 config files as they seem closest to my design).
Some background on the scooter:
- Single 8" motor. 1000W peak, 500W nominal
- 48V 10.5Ah battery (Samsung 35E)
- Rear drum brake wheel, with emergency fender brake
- 13kg
- Dual suspension
- Stock controller leaves a lot to be desired (touchy throttle curve, on/off regen control)
- Stock controller uses 6 x SKD502T MOSFETs (85V, 120A, 4.6mΩ) (Stock controller photos for your curiosity)
I like this small scooter a lot. Quality is decent. Nothing touches it at this weight. Dual motors and variable regen would improve it in many aspects, especially for heavier riders and hills.
Others have strapped two stock controllers together to make dual-motor versions, and you can fit a 13S3P 15Ah (Samsung 50S) battery with some small modification.
I have so far designed the power PCB to fit the original heatsink, and am designing the MCU PCB to attach to the top of this.
I'm using Vishay SQJQ184ER MOSFETs (80V, 430A, 1.4mΩ). They look like oversized SOIC-8, and have a drain-connected top side for heatsinking with 0.25°C/W. I'll likely use a thermal pad for isolation.
Here's the schematic and some PCB pics for now. Let me know if there are changes you'd make and why. TVS diodes necessary for these specs? What about the V and C filter values?
Right click - open image in new tab to see full size.
I also plan on designing a new dashboard based on VESC-Express firmware. That'll be a learning experience.
Thanks!