What is a Sensored BLDC Motor and What Brushless Motor Controller (brushless ESC) Can I Use With Them?

So, what is a sensored BLDC motor?

A sensored BLDC motor is a brushless DC motor with inbuilt positional sensors (called hall effect sensors). These sensors can be used by a brushless motor controller (brushless ESC) to monitor the exact position of the rotor and are therefore a useful method of maintaining speed of the brushless motor. These sensors are also particularly useful during the start up phase as it enables an optimised sequence to be applied depending on the exact position of the rotor.

A sensored brushless DC motor operates in closed loop as its standard operating method

The advantages of using sensored brushless DC motors

There are several major advantages of using sensored brushless DC motors. The core advantage of the sensored system over other similar systems is that they can reach much higher speeds and last much longer than most other types of motors (with the exception of sensorless brushless motors).

The second of these advantages is that they tend to be easier to setup and run than sensorless brushless motors. This is largely due to the sensors enabling the controller to know exactly where the rotor is and therefore to be able to operate accordingly. This initial knowledge of the rotor position removes many of the potential hurdles associated with sensorless brushless systems such as problems at startup and can also be used as a safety feature if required

The disadvantages of using sensored brushless motors

There are however, disadvantages to such motors.

Firstly, they are (generally speaking) more expensive than sensorless BLDC motors due to the added components and the additional complexity involved in construction. As a result of the additional complexity they are also more prone to problems, especially in applications where there are potential issues with humidity or dirt as any interference with the sensor’s performance will ultimately jeopardise the entire control of the motor.

What is the best controller to use with a sensored brushless motor?

Not surprisingly – a sensored BLDC motor controller! To browse our existing stock range please see our sensored brushless DC motor controllers here. We have several models which vary depending on the power requirement you have but also have features such as four quadrant motor control as optional extras.

Depending on your application it is also possible to drive your motor using a sensorless brushless motor controller.

I have a sensored brushless DC motor, can I use a sensorless brushless motor controller?

The simple answer is yes, although the sensorless brushless motor controller will clearly not be able to make use of the hall effect sensors.

A sensorless BLDC ESC or brushless motor driver such as the ZDBL10 will not be able to make use of the inbuilt sensors within the motor but it will still be able to drive the motor using a sensorless brushless drive. Speed can be accurately maintained by using the back-EMF generated by the motor to read and determine the speed of the motor (in the same way the hall sensors would do in a sensored bldc motor). This can then be used to maintain a fixed speed even under a variable or changing load.

If you are not sure about how this might impact on performance please contact us to discuss.

Category: Brushless Motor Controller FAQs
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