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The Basics Of Working With Brushless Motors

Working with brushless motors offers a lot of flexibility due to their wide ranges of use. There are plenty of different types of DC brushless motors available these days, including sensored brushless motors. Additionally, these types of units come in a variety of sizes for different applications. Small brushless motors and large brushless motors alike provide more efficiency in terms of torque per watt compared to certain other motor options, and they can also operate under variable power conditions for long periods of time.

When it comes to purchasing motors, many engineers choose to source brushless motors from ARC Systems Inc. Likewise, some choose to work with ARC Systems Inc. to design custom brushless motor solutions. In any case, it’s generally recommended to partner with a motor manufacturer to get the components you need for your facility instead of trying to engineer a solution on your own. Even if you go the DIY route, a motor manufacturer can offer advice and guidance to help you avoid pitfalls.

Understanding Three-Phase Current

If you’ve worked with brushless motor designs, you likely already know that they typically rely on a three-phase current design. In a nutshell, a permanent magnet rings an inner core lined with electromagnets. When current is supplied to the electromagnets, they attempt to align themselves according to the permanent magnet’s polarity. This causes the core to spin, but this action only lasts a short time.

Power is then switched to different electromagnets of the opposite polarity which causes the core to continue spinning to the next alignment interval. This process repeats on and on depending on the power supplied and ultimately results in energy generation.

When working with brushless motors, understanding the basic process of movement within the magnet’s interaction is crucial. Without this knowledge, misuse can occur, and you may have a hard time diagnosing problems.

Troubleshooting Brushless Motors

Speaking of diagnosing problems, troubleshooting brushless motors can be done by following a few simple steps. First, check the manufacturer’s specs to determine what is considered normal operation. Note the values for things like torque, thrust, voltage, current and rotations per minute. Next, use benchmark testing software and hardware to examine the values provided by your motor under different operating conditions.

For motors utilized in things like drones, you can use the RCbenchmark Series 1585 test stand. This will allow you to safely and effectively monitor performance. Once you have your own values, compare these to the values provided by the motor’s manufacturer. If the numbers don’t align, you may need to have a repair professional examine the components for things like short-circuited wires. For larger DC brushless motors, other testing standards and equipment may be needed.

How Much Power Do You Need?

Finally, most brushless motors operate according to the values derived from Kv. This is the measurement of rotations per minute per volt supplied to the electromagnets. Higher torque is often the result of a wider motor, but these components will require lower Kv. In some cases, these types of motors will also include the use of a propeller or similar additional component.

There are other factors that can affect Kv, and Kv is not always the same across similar motors from different manufacturers. This is why it’s once again handy to have your manufacturer’s specifications available during performance testing so that you are checking values according to the standards laid out by your manufacturer.

Power needs will differ according to the application as some motors will need to run for long periods of time while others will be used at varying currents. If you’re not sure about your current or future power consumption needs, talk to your manufacturer prior to making a purchase to ensure that the brushless motor you receive will meet your needs.