Aquaticus ROV

Homebuilt underwater robot
 
Home » Research » BLDC

BLDC controller

After examining BLDC controllers available on the net (mostly for RC airplanes), I decided to design and build my own controller for robots.

Requirements

  1. Sensorless
  2. Max voltage: 12V
  3. Max current: 10A
  4. I²C for control
  5. RS232 (5V) for diagnostic and configuration
  6. No SMD parts
  7. Minimum additional elements
  8. ISP connector for programming

Controller is based on Atmel ATmega8 chip with limited number of external components. Preliminary design is finished. I will publish here all schematics, board and software.

Schematic

BLDC controller schematic: Initial revision.BLDC controller schematic: Initial revision.

EFT zero cross detection

Voltage divider with low pass filter connected to ADC inputs. ADC reference voltage equal to power voltage.

Current sensor

Voltage divider with low pass filter connected to ADC input. Designed to use with internal reference voltage 2.56V.

Low voltage sensor

Voltage divide with low pass filter connected to analog comparator. Input is compared with internal reference voltage 2.56V.

Power bridge

IRL2703 MOSFETs (TO-220AB package) controlled by IR2101 chips.

Power

7805 to provide 5V.

Other

ISP connector, RS232 (5V) connector, I2C connector. Power, program and user function LEDs.

PCB

Early prototype version of PCB, only one piece was made. Size 10x8cm. Needs to be optimized.

BLDC PCB prototype design: Early version.BLDC PCB prototype design: Early version.

BLDC controller PCB: Partially assembledBLDC controller PCB: Partially assembled

Assembled BLDC controller: Modified version of PCBAssembled BLDC controller: Modified version of PCB

Links

Application notes

  1. Sensorless control of 3-phase brushless DC motors from Atmel
  2. Sensor-based control of three phase Brushless DC motor from Atmel
  3. Board Size & System Cost Advantages of the Hitachi Integrated ECN303x BLDC Solution
    versus A MicroController (Discrete) BLDC Solution     from Tech Tips from Hitachi
  4. Sensorless Brushless DC Motor Control: made easy with Motorola’s 68HC908MR32

Semiconductors

  1. BTS 7710 GP Infineon driver
  2. FDS8880 30V N-Channel PowerTrench MOSFET
  3. IRF7455 30V Single N-Channel HEXFET Power MOSFET

Other Controllers

  1. BLMC controller
  2. Speedy BL
  3. SBL Micro V2
  4. Tornado controller (German only)
  5. List of BLDC controller projects



add new comment

Project status
Submitted by admin on Tue, 2008-04-22 12:31.

This project was never finished
I have no time to finish it nor update schematics.

Version of the schematic visible on the page has some small bugs, e.g. +5V instead of +12V for IRF2101.
Please use this BLDC controller as reference but not working unit!

For working device check links section, especially Atmel links -- Atmel provides schematics and source code for their sensorless application.


reply