Is a Brushless DC (BLDC) Motor and Controller Right for my Application?

What do I need to think about when considering which brushless DC (BLDC) motor and controller to use?

In order to know whether or not a Brushless DC motor is right for your application you need to think about several factors, some mechanical, some commercial and some of which will be down to your choice of brushless motor controller (sometimes also know as a brushless ESC or BLDC motor driver). Brushless applications tend to be higher speed, longer life applications but that doesn’t mean there aren’t alternative uses.

Mechanical factors when considering brushless DC motors

BLDC Motors offer the highest speeds possible from any motor and have exceptional life. This is due quite simply to the absence of brushes within the motor which reduces friction (and therefore enables higher speeds) but also improves lifespan by removing the one part a brushed DC motor which will wear out with time and use. Bear in mind that the performance you can get from a brushless DC motor will also strongly be dictated by the brushless motor controller you choose to use. A low end BLDC ESC will deliver basic speed controls but may not be energy efficient or able to use advanced features such as back-EMF monitoring and constant speed adjustment whereas a more advanced industrial type BLDC Motor Driver such as the ZDBL15 can be optimised to be hugely energy efficient and also to maximise the mechanical performance of the motor.

An important point to consider if you are looking for specific qualities in a BLDC motor is that they are not generally known for positional accuracy or torque. If you need high torque you could add a gearbox but if positional accuracy is important you would be best looking at stepper motors

Commercial factors - Does using a brushless motor AND BLDC motor controller make financial sense for my application?

Brushless motors are not the lowest cost motors on the planet but they are invariably the longest lasting. However, if your project is very price sensitive then a BLDC motor could still be achievable but it is likely that you would save money by using a brushed DC motor. If financial considerations are a major part of your considerations it is worth thinking about the lifespan of the project that you have as a brushless motor controller will last an average 5 times longer than a standard DC motor. If the cost of a brushless system is four times the brushed system but you need solid performance over a long lifespan then it is likely that the brushless motor system will be the most cost effective over the project lifetime.

A useful rule of thumb when selecting a motor for your project is that a brushed DC motor will typically operate well for 2000 hours whereas a brushless DC motor will operate well for 10000 hours. This obviously varies by manufacturer and motor type but if your application is likely to require regular and sustained use then a brushless DC motor and controller could actually be the most cost effective in the long run.

Conclusion - Think about the things which are the most important for your application

Motor choice is rarely simple! The trade offs between life, performance and cost are something that needs to be taken into account when making the decision as well as the importance or value attached to key features such as constant speed under variable load. Think about which of these factors is most important to you before making a decision and if you require any advice at all please contact us and we will be more than happy to help.

Category: Brushless Motor Controller FAQs
Did you find this FAQ helpful?