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Dephy Actuator Package

The Dephy Actuator Package is a turn-key solution for people who want to test FlexSEA's capabilities or quickly design a prosthetic limb. The Package consists of a custom brushless motor integrated with a FlexSEA-Rigid circuit and a minimalist enclosure, pre-loaded embedded software, and a full suite of high-level software and test scripts.


  • Fully integrated brushless motor (BLDC), power electronics and control logic
  • Plug and play solution: no programming needed for most applications
  • Cross-platform graphical user interface and full suite of Python demo scripts
  • Built-in high-performance controllers: current, position, impedance, and voltage.
  • Built-in sensors and interfaces: 6-axis IMU, voltage, current, temperature, strain gauge amplifier, etc.
  • Communication: Bluetooth, USB, RS-485, SPI, UART and I2C
  • Safety features: battery I²t, motor I²t, voltage limits, temperature


Table 1. Motor

Mass 230 g
Terminal resistance 186 mΩ
Terminal Inductance 138 µH
Torque Constant 95 mNm/A
Diameter 87 mm
Length 17 mm
Rotor inertia 1E-4 kg m2

Table 2. Housing

Mass 50 g
Material 7075-T6 Aluminum
Finish Black anodization

Table 3. Embedded System

Mass 41 g
Voltage 20-50 V (5s-12s LiPo)
Commutation type 4-quadrant Field-Oriented control (4Q FOC)
PWM frequency 20 kHz
Max continuous current 10 A (Note 1)
Peak current 30 A (Note 1)
High level controller STM32F427 180 MHz Cortex-M4 with floating-point unit (FPU)
IMU MPU-9250 6-axis (3-axis accelerometer, 3-axis gyroscope) (Note 2)
Bluetooth RN-42 Class 2 EDR Bluetooth module
Strain-gauge amplifier One full-bridge channel, 5V excitation Gain = 203
Motor encoder Absolute magnetic encoder, 14-bits
Current sensing and control Motor: 3-ch 12-bits sensing, 20kHz PI controller
Battery: ±20A, 900Hz bandwidth, 12-bits
Safety protections (HW) 52V TVS, 10A slow-blow fuse
Intrinsic sensors Battery voltage, intermediate voltage, +5V bus, temperature, etc.

(1) Higher currents can be used with a heatsink. (2) Magnetometer disabled by software – overpowered by the motor’s magnetic field

Example Applications


dephyactpack.txt · Last modified: 2018/09/21 14:51 by jfduval