BLDC Fan Controller Circuit Diagram and PCB Design

Designing a Brushless DC (BLDC) ceiling fan controller circuit and PCB can be a complex task requiring knowledge of electronics, microcontrollers, and PCB design software. Here’s a general overview of the process:

BLDC Fan PCB Design Steps

  1. Requirements and Specifications: Begin by defining the requirements and specifications of your BLDC ceiling fan controller. Determine the input voltage, current rating, speed control options, and any additional features you want to incorporate.
  2. Microcontroller Selection: Choose a microcontroller that meets your requirements and has sufficient processing power and peripherals to control the BLDC motor. Popular choices include microcontrollers from the STM32 series or Arduino boards with compatible shields.
  3. Motor Driver Selection: Select a suitable motor driver that can handle the voltage and current requirements of your BLDC motor. Common choices include dedicated BLDC motor driver ICs like the DRV830x series from Texas Instruments or integrated modules like the L6234 from STMicroelectronics.
  4. Circuit Design: Design the control circuitry for the BLDC motor. This typically involves interfacing the microcontroller with the motor driver and adding additional components like Hall effect sensors for rotor position detection and voltage regulation circuitry. Create your circuit design using a schematic capture tool like EAGLE, KiCad, or Altium Designer.
  5. PCB Layout Design: Transfer your circuit schematic to PCB design software and start laying out the components on the board. Ensure proper separation of high-power traces from low-power traces to minimize noise interference. Follow standard PCB design guidelines for component placement, and trace routing, and keep in mind the mechanical constraints of the ceiling fan enclosure.
  6. Gerber Files and Manufacturing: Once the PCB layout is complete, generate Gerber files from your PCB design software. These files contain the necessary information for the PCB manufacturer to produce the physical board. Choose a reputable PCB manufacturer and submit your Gerber files for manufacturing.
  7. Assembly and Testing: Once you receive the manufactured PCB, assemble the components onto the board following the Bill of Materials (BOM). Ensure correct polarity and soldering quality. Perform thorough testing to verify the functionality and safety of the BLDC ceiling fan controller circuit.

Ceiling fan controller based on STM32 and SLLIMM-nano

The STEVAL-IHM038V1 system evaluation board implements a BLDC/PMSM fan controller board which is based on the SLLIMM™-nano (small low-loss intelligent molded module) STGIPN3H60 and STM32F100C6T6B microcontroller. The STEVAL-IHM038V1 incorporates a complete inverter stage and a control stage to drive a 3-phase BLDC fan motor with a power range of 30-35 W with FOC (field-oriented control) sensorless mode for ceiling fan applications. Specifically for the Indian market, a passive PFC stage is implemented for power factor correction to reach a power factor greater than 0.90. To set the speed by remote control, an onboard IR demodulator is available.

BLDC Ceiling Fan Controller Circuit Diagram and PCB Design
PCB of BLDC Ceiling Fan Controller

The inverter stage is implemented using the intelligent power module SLLIMM™-nano STGIPN3H60 which embeds 600 V IGBTs with gate drivers, op-amp for current sensing, and a comparator in a single NDIP-26L package, resulting in a reliable and compact system design.

The control part includes field-oriented control with a sensorless control algorithm, fault detection, and speed setting via remote control (IR receiver), all handled by the STM32F100C6T6B microcontroller from ST’s ARM®Cortex™-M3 core-based low-density STM32™ MCU family.

Circuit Diagram of BLDC Ceiling Fan Controller

Features and Specifications of the Controller

  • Maximum input voltage: 265 V AC or 375 V DC
  • Minimum input voltage: 90 V AC or 128 V DC
  • Output power for applied motor: up to 50 W
  • +15 V auxiliary power supply based on the VIPER16 in a non-isolated buck configuration
  • Compact design using the SLLIMM™-nano STGIPN3H60 consisting of 600 V IGBTs with gate drivers, op-amp for current sensing, and comparator
  • Passive PFC circuit for power factor correction
  • On-board infrared (IR) receiver/demodulator for speed and on/off control using IR remote
  • External EEPROM M24C01 for recovery of last speed setting
  • Hardware overcurrent protection
  • Overtemperature protection with NTC thermistor
  • Overvoltage and undervoltage detection
  • Based on 32-bit ARM®Cortex™-M3 core-based microcontroller STM32F100C6T6B
  • Firmware based on STM32 PMSM FOC SDK 3.0 motor control firmware library and fully customized for the ceiling fan application
  • FOC (field-oriented control) sensorless algorithm
  • PCB size customized for ceiling fan design
  • PCB diameter: 105 mm
  • Double-sided layout
  • RoHS compliant

It’s important to note that designing a BLDC fan controller circuit and PCB requires electronics knowledge and PCB design expertise. If you’re not familiar with these processes, it’s recommended to consult an experienced electrical/electronics engineer or seek professional assistance to ensure a safe and reliable design.


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