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Sunday, September 5, 2010

Build Your Own BLDC Motor Controller for your e-Bike or e-Scooter

There is no greater satisfaction then completing a project you started and knowing you built the whole thing.
Introducing the most robust e-bike/e-scooter motor speed controller system available for the hobbyist market today.

Here is the ultimate do-it-yourself 3-phase brush-less DC motor speed controller you could ever sink your time and money into.

My home-made 3-phase BLDC motor controller is cheap and easy to build.

The idea behind this 9 month R&D project build was to design a simple but useful robust EV controller system that others would want to build and learn from.

I based my controller design on PIC16F87X series micro-controllers. The software I developed using a in-circuit programmer/in-circuit debugger.
This two controller system has one dedicated to motor control and the other a simple user interface and programming/diagnostic tool I called the "Dashboard".

The minimal system is designed to require just the motor controller. Any programming changes are done through the PC software interface.
With the optional "Dashboard" connected to the motor controller, programming changes can be done where ever you are.
While driving LCD Display will show battery voltage, discharge current, wattage, speed, throttle, RPM, ride-time and much more.
The "Dashboard" has a data-logging function that stores 4095 samples into a EEPROM chip. Logged data can be retrieved, saved and graphically display on the PC Interface software.
There is also a built-in hardware diagnostic screen that shows hall effect sensors, brake & reverse inputs and more for quick and easy hardware troubleshooting.

What was my design criteria?
1st of all it has to be easy to assemble so I did not use any surface mounted components. Anyone can put this together.
2nd must be made from off-the-shelf parts. All components are commonly available at Mouser or Digi-Key.
3rd have you learn more about this technology. If you build it then you can fix it right! All you problems solved in one project.
4th make it easy to modify for other battery and motor technologies.

What popular features did I include in my motor controller design?
3 Switch Selectable Throttle Control Limits
Programmable Battery Pack Low Voltage CutOff (LVC)
Adjustable Hardware DC Current Limiter
Programmable Software Phase Current Limiter
Regenerative Braking Recharge Voltage & Current Limiting
Programmable Cruise Control Options
Brake Switch & Reverse Commutation Switch Input
Reverse Throttle Limit
Open Throttle Protection
Hardwired 120°/60° Phase & Motor Direction jumpers
Hall Sensor Failure Detection
Data-Logger function with Programmable Interval Timer (4095 samples x 16 bytes)
Adjustable LCD Display Color & Brightness
RGB LED Back-lit 16x2 LCD Display with 4 Key User Interface
Dealer/Build/Owner Text Message Splashes in LCD every minute in standby
Built-In Hardware Diagnostics LED
Made for use with Hall Effect Sensor-ed 3-Phase BLDC motors
Multi-Wheeled Drive capabilities (1 to 4 BLDC controllers running on one throttle/brake wire thru digital link)

Specs: 12 MOSFET PC board, Battery Voltage Up to 102.3V, Current Sensing Up to 100A, Discharge/Regen Recharge Current sensing, Reverse Commutation, Regenerative Braking, Cruise Control Twist Throttle
Battery: Sealed-Lead Acid, VRLA, SLA, Up to 24S lipo (100V)
Most popular TO-220 MOSFET devices P75NF75, IRFB4110, IRFB4115, IRFB4310 to build with

In the Owner's Manual the schematic, parts list, component placement, printed circuit board layout are included. The end user can program the controller features through a simple software interface which connected to a serial or USB port.

This controller was developed and is intended to be an OPEN SOURCE HARDWARE project you can build at home.