Open Source PM Brushed Controller for LEV

[FrankG]

Hey All,

I'm new to this forum, but have been following Brad & Kat's work for a few years...

Below are a set of links to an "Open Source" Motor Controller that was designed for Permenant Magnet Brushed DC motors, aiming specifically at the 1Kw to 2.4Kw range.

In brief the PicOx is a PicAxe 08M based digital Controller that performs an ADC of a Hall-effect throttle and an ADC of a Hall-based current sensor. These two parameters determine the “Mark” value of a 15Khz PWM signal that does the switching to the Output stage.


http://www.theworkshop.ca/energy/picox/picox.htm (http://www.theworkshop.ca/energy/picox/picox.htm)

The link above details the general Design specification, and introduces the tools required, parts list, and some basics about the PicAxe family of processors.

http://www.theworkshop.ca/energy/picox/2/picox2.htm (http://www.theworkshop.ca/energy/picox/2/picox2.htm)

The link above details the proto-typing process, development of a current sensor with recycled parts, and trouble shooting techniques when problems arise.

http://www.theworkshop.ca/energy/picox/3/picox3.htm (http://www.theworkshop.ca/energy/picox/3/picox3.htm)

Part # 3 details the PCB fabrication process, and acts as an illustration of how to “Maximize” the ill-effects of Ground Noise to a sensitive digital circuit and how to diagnose the problem.

http://www.theworkshop.ca/energy/picox/4/picox4.htm (http://www.theworkshop.ca/energy/picox/4/picox4.htm)

Part #4 is the complete revision of the PCB design to mitigate the Noise issues identified in Part # 3 as well as how to “Patch” a simple PCB Modification to the PCB design without scrapping the entire brd when proto-typing.

At the end of the project the Controller can sustain 48V @ 75 Amps repeatedly for approx 5 second bursts and is really only limited by the In-Line breaker that cuts the supply voltage, though the entire system’s overall design objective is met reliably at 48V 50Amp operation…


All the Best!

FrankG
www.theworkshop.ca (http://www.theworkshop.ca)
frank@theworkshop.ca

[AtomicZombie]

Great work! That is a perfect controller for the Scott 1HP motor.

Are you thinking about mass producing some boards? The only other MC like that I know of is the OSMC, but it is more geared towards differentially steered robotics.

Cheers.
Brad

[FrankG]

Hey Brad,

No plans to produce it, but rather hope that a few builders take it under thier wing so to speak and refine the firmware that is in the PicAxe with features that I would never have thought of...

On that model it still has 1 lone input pin available that could easily be used as a "Brake" sesnor to cut the output to the motor or as a "Lock" feature...

The PicOx 2.xx is done proto-typing and can handle a full 4.8Kw load, as well as features an Infra Red "Security" feature similar to keyless entry and Brake-Motor Cut-out...

I'll post a link once the PCB design is done and no issues arise when bench testing.

FrankG
www.theworkshop.ca (http://www.theworkshop.ca)
frank@theworkshop.ca

[AtomicZombie]

Cool, I bet a few EV builders here will be interested in the final design.

If I fry the Alltrax I plan on using for Kat's security robot, I might have to build one myself.

Brad

[FrankG]

The link below is to Part #4 in the Suzuk-E RM125 project...

It deals entirely with a complete MY1020 refurb, comprised of a full rewind with MORE turns of HEAVIER copper... Sound impossible??? NOT!!!

As well as a Brush-Plate Upgrade and creating an access port for Active Cooling (to be covered in Part #5)...

http://www.theworkshop.ca/energy/suzuk_e/4/4.htm