This board is intended to connect a chain of 48 VDC RS-485 motor controllers to the outside world.
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USB - RS485 conversion. This is accomplished via the FT232H and ADM2682E IC's. The combination of these chips should provide full electrical isolation to the USB host and allow ~10 Mbps throughput to/from RS485.
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Input power sanitizing. A LM5066 hotswap controller IC provides sane controlled voltage ramps when the device is hot-plugged, and cuts power to the system when it exceeds ~56 volts. An input TVS diode starts kicks in around 65 V.
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Backdrive surge supressing. Sometimes when motors are aggressively backdriven by an external power source, significant voltages are generated "back" onto the motor bus. The board is equipped to detect this condition and dump power through a 10-ohm power resistor. Hysteresis and timing is provided by a STM32L071 microcontroller.
- Schematics in PDF
- KiCAD design files are found in
hardware - fabrication files for rev.A are found in
hardware/fab
