ESC Carrier Board

Outline

This is the MUREX ESC Carrier Board, the world's first open source modular motion control system. In the event of a speed controller failure, the ESC Carrier Board allows for rapid replacement of the components through a hotswap interface. In addition, the board offers inrush current protection for the ESCs. It has a footprint of 146.7 mm x 85.6 mm (5.78 in x 3.37 in).

Current Status

• V2.0 tested and functional

Detailed Description

The MUREX ESC Carrier board is a two-layer carrier board that can hold up to 6 ESCs. The ESCs are protected from inrush current by Ametherm's AS32_1R030 NTC thermistor, which provides a resistance of 1Ω at 25°C. The board receives 12V and 3.3V input from the MUREX Power Board (opens in a new tab) via the 8-channel Molex 43045-0821 Micro-Fit connector, and data is exchanged via the 2-wire UART protocol with the MUREX Carrier Board (opens in a new tab) through the 5-channel Molex 53047-0510 PicoBlade. The TE 5530843-7 connector is used to connect the ESCs to the ESC Carrier Board. The Molex 43045-0627 Micro-Fit connector is used to output the ESC phases to the brushless DC motors.

Connectors and ICs

• Ametherm AS32_1R030 (opens in a new tab) (NTC Thermistor)

  • 12V input and output
  • 30A maximum stable current
  • 1Ω resistance at 25°C
  • 0.03Ω resistance at 15A
  • 0.01Ω resistance at 30A

• Molex 43045-0821 Micro-Fit (opens in a new tab) (to MUREX Power Board (opens in a new tab))

  • 8.5A maximum current per position
  • Right-angle mating
  • 8 positions (2 x 4)
  • 12V input to ESCs (through NTC thermistor)
    • 3 positions
  • 3.3V input for RP2040 on ESCs
    • 1 positions
  • Remaining 4 positions used for grounding

• Molex 53047-0510 PicoBlade (opens in a new tab) (to MUREX Carrier Board (opens in a new tab))

  • 1.0A maximum current per position
  • Vertical mating
  • 5 positions (1 x 5)
  • 2 UART channels (1 primary and 1 backup)
    • 4 position
  • Remaining position used for grounding

• TE 5530843-7 (opens in a new tab) (to ESCs)

  • Application Specification (opens in a new tab)
  • 3.0A maximum current per position
  • Vertical mating
  • 60 positions (2 x 30)
  • Sends power to ESCs
    • Protected 12V (18 positions)
    • 3.3V (2 positions)
  • Sends UART data from MUREX Carrier Board to ESCs (2 positions per channel, 4 positions total)
  • Sends ESC phases to BLDC motors (through Molex 43045-0627 Micro-Fit connector)
    • 6 positions per phase, 18 total
  • Remaining 18 positions used for grounding

• Molex 43045-0627 Micro-Fit (opens in a new tab) (to BLDC Motors)

  • 8.5A maximum current per contact
  • Vertical mating
  • 6 positions (2 x 3)
  • Sends ESC phases to BLDC motors (2 positions per phase, 6 positions total)

Schematic (PDF)

To Do

• V2.0 testing

Changelog

V1.0:

• Initial design

V2.0:

• Refactored pinout of the TE 5530843-7 connector to bring 12V and GND next to phases
  • Refactored placement of the components on the right side of the board to accommodate new pinout and decrease the size of the board
• Decreased spacing between ESCs to give the board a smaller footprint
• Thickened 12V traces on the Molex 43045-0821 Micro-Fit connector
• Removed connectors for 2 ESCs to decrease the size of the board