Ma 25 September 2017, 14:17

File #384
Overview
- Yellow XT60 power connector (battery connection).
- Blue/black/red wire: 3 phases going to the brushless motor itself.
- STM32 SWD-Link programming connector (Vcc-CLK-GND-DIO)
All wires are made of nice and flexible silicon insulation which has a lot of fine copper strands inside.

File #382
Close up of the front with several IC's
- STM32F103 Cortex-M3 microcontroller, the PWM inputs of the 3 gate drivers are connected to Ch1-Ch3 outputs of Timer1 enabling hardware PWM control of the 3 half bridges.
- 3,3V Linear regulator
- CAN Transceiver
- High-Side current sensing amplifier
- 3 Half bridge drivers, delivering gate charging and discharging currents of 3.5A with cross conduction prevention. A gate resistor is required to limit ringing due to the high charge and discharge currents. Each driver is accompanied by a large ceramic capacitor to deliver the required gate charge currents. It would have been better to also place a small ceramic cap (100n) very close, but there was no space left to place those, so these caps were omitted. Ceramic caps are known to have very low impedance, even at higher frequencies. Regular electrolytic caps become inductors at high frequencies
- Resistor dividers are also provided for Back EMF measurement to enable sensorless commutation of the brushless motor. (Top row of resistors and caps)


File #383
Close up of the back showing the main 6 N-channel mosfets and a current sensing resistor.
- An 12V LDO is also provide so the input voltage isn't limited to 12V (Maximum of the gate drivers)

Current handling capability is mostly limited by the mosfet selection, if very large currents are required: multiple mosfets should be placed in parallel. The traces on the PCB also need to be able to handle the current.
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Laatste wijziging: Ma 29 April 2013, 13:52