wiki/ avionics/ generic-motor-driver

Generic Motor Driver (GMD)

PROBLEM: PSAS has a need for brushed and brushles DC (BLDC) motor drivers in various power ranges from 0.5 to 2 kW. These are needed for on-board control servos as well as ground stations and antenna pointers. A scalable and configurable driver board must be created to meet as many motor driver needs as possible.

Requirements

System Diagram:

Design

Features:

Deadtime control

FET drivers

FETs

Input isolation

Capacitors

Bus capacitance seems, at first glance, to be a nebulous subject on the web. Here are some thoughts on what sizes and values we should use.

Bus Capacitor Design

Final choices, based on cost and reasonable assembly time:

Schematic Diagram:

Page 1
Page 2
Page 3

Board Layout:

Layout Page 1

Configurations

The configurations below describe the GMD as populated and programmed for the individual projects.

High current DC brush motor driver for Rocket Tracks

Pin Number Purpose
1 U-half bridge PWM input
2 V-half bridge PWM input
4 Watchdog input
5 Common (GND)
6 Enable input

Connector Pins

The input connector pins described correspond to the 9 pin "serial" connector on the edge of the board opposite the FETs.

Photos:

Copper power supply bus-bars
Power bus attachment
Assembled PCB