Hall Effect Sensor Board

Looking to add Hall Effect sensors to your brushless and sensorless outrunner? These Hall Effect sensor boards are designed to be used with 12-slot, 14-pole “R/C outrunner” motors for ground applications. They enable the use of a Hall-sensor equipped motor controller for consistent startup characteristics. You provide your own 5-pin Hall sensor wiring harness for matching with your motor controller. They mate with our Hall Effect Sensor Adapters, or you can mount them independently. They are designed only for 14-pole motors and cannot be used with any other pole count.

Motor Type


R/C type outrunners come in many styles and diameters. You must match the sensor board to your motor’s true outer diameter. Measure the motor with calipers and find the nearest size within 1 millimeter. Outside of this range, the sensor board will most likely be incompatible. These boards are currently available in 4 sizes:

  • 42mm: Generic “42xx” outrunners
  • 50mm: Generic “50xx” outrunners
  • 59mm: Hobbyking “SK3-63” series: These motors are actually 59mm in diameter, so we list them as 59mm!
  • 63mm: Most “63xx” outrunners that are not the SK3-63 series
  • 80mm: “C” style 80mm series, most other 80mm outrunners


These Hall Effect Sensor Boards feature 120° adjustability via the slotted mounts. This adjustability is critical for properly lining up the sensors with your controller’s commutation table, also known as “finding sensor combos”. Additionally, the adjustability allows you to adjust sensor timing to maximize efficiency for single-direction applications like vehicle propulsion, where reverse is generally slow and infrequently used. It also features open-collector digital bipolar latch Hall Effect sensors, the most commonly used for brushless motor commutation.

In the Kit

All of the Hall Effect Sensor Board kits come with the following:

  • 14-pole PCB with 120° adjustment slots
  • 4x AH3761 type low-hysteresis digital latch Hall Effect sensors
    (3 for use, 1 for a spare)
  • Mounting hardware compatible with the Hall Effect Sensor Adapters

You must supply:

  • 5 pin wiring harness
  • Non-conductive mounting method, such as standoffs.
  • Optionally, 0603 sized 0.1uF ceramic capacitors for power smoothing (advanced users only)

If you do not have a mounting solution or want a modular solution that travels “with the motor”, see the Hall Effect Sensor Adapters. See the Installation Guide for more details.

Why Sensored?

Using sensorless motors for inertial applications like drivetrains is very much hit-or-miss. Sensorless commutation relies on a brief “kick” of power applied to the motor to start it spinning, upon which the controller senses the voltages present at the motor wires to continue sequencing drive voltage properly. Unfortunately, the “kick” is often not powerful enough for heavy loads, resulting in high pulses of current being drawn and the motor twitching back and forth, which can damage or destroy motor and controller. Even sophisticated sensorless controllers will benefit from the zero- and low-speed information provided by Hall Effect sensors.

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