A small BLDC motor is a powerful alternative to traditional brushed DC motors. They offer better efficiency, lower maintenance costs, and longer lifespans, without the brushes and commutator that wear down over time and produce electrical noise.
Using advanced commutation techniques like field-oriented control (FOC), these motors deliver minimal torque ripples and high speed range performance. Let’s explore the key advantages of these motors in more detail:
Miniaturization
Small BLDC motors are ideal for handheld devices with high power demands. They provide a high torque / weight ratio and are suitable for applications such as cordless tools, RC vehicles, heating and cooling systems, and drones.
Unlike traditional AC induction motors that utilize brushes to commutate, the rotor of a BLDC motor is powered by permanent magnets showcasing north and south poles alternately positioned. This arrangement allows a much smaller stator coil, which in turn can be designed with less copper and higher density. The result is a compact motor that can be used in tight spaces, such as an aerospace actuator or portable medical pump.
Precise speed control is another benefit of a small BLDC motor. This capability enables optimal energy efficiency in HVAC systems, allowing for more consistent and accurate airflow. It also helps reduce energy usage in electric vehicles, enabling higher range and better user comfort.
The lack of brushes in a BLDC motor means that feedback technologies such as Hall effect sensors and incremental encoders are required to ensure precise commutation and rotation. Since these sensors do not produce a direct analog voltage corresponding to the rotor’s position, they must be combined with an Small BLDC motor MCU or controller that is specifically configured for BLDC motor control and has optimized comparator circuits. However, this can add complexity and cost. To simplify the design, many encoder manufacturers now offer a single IC with both a Hall element and signal processing circuit that can output digital signals that match the MCU or controller’s U/V/W commutation outputs. This eliminates the need for a separate amplifier, AD converter, and comparator, reducing both the total component count and cost.
High Torque Density
BLDC motors can deliver very high torque density in a small package. They are used in power tools such as screwdrivers, nail guns, and pruning shears where the ability to generate high torque within a limited space is critical. They are also used in industrial applications such as positioning, servo, and actuation.
In order to achieve high torque, BLDC motors utilize techniques that allow the current flows in the motor to be controlled precisely. The current in the windings is induced by the magnets and then controlled to match the speed of the rotor magnets. When the rotor magnets align themselves with the currents in the motor, they create a magnetic field that chases the current flow in the windings and maintains rotation.
Currently, the highest level of control accuracy is achieved using so-called “observer tracking” methods. This involves constructing a very precise model of the motor and reproducing values that are not directly measured, such as speed and back-EMF, from other measurements made by the current controller.
This approach to the design of BLDC motors has enabled the size of the magnets and the number of turns in the windings to be reduced while maintaining the torque output. The resulting small motors are able to deliver the performance needed by customers, while at the same time supporting device miniaturization and a wide range of operating conditions.
Flexibility
BLDC motors can be used with a variety of position sensors to achieve precise position control. This flexibility makes them ideal for dynamic applications such as collaborative robots and exoskeletons, where the speed of rotation can change rapidly. In addition, they can also be used in applications that require a constant torque output such as servo drives.
For example, a maxon flat motor can be combined with an encoder to provide feedback and position control. The sensor can be configured as either (Type 1), which detects the absolute angle of the rotor, or (Type 2), which detects the rotational position of the rotor relative to the stator.
Moreover, a BLDC motor can be controlled with a microprocessor or an integrated circuit. In contrast to brushed DC motors, which have brushes and commutator, BLDC motors have no moving parts, meaning they are more maintenance-free. This reduces wear and tear, which extends the lifespan of a motor and lowers operating costs for users.
Moreover, a BLDC motor’s electronic commutation system allows for accurate and repeatable speeds. This feature is important for many applications, including industrial automation, HVAC systems and medical devices. For instance, precise speed control in medical devices ensures consistent movement and minimizes patient risk. It can also increase energy efficiency in HVAC systems and improve user comfort.
Efficiency
BLDC motors require less electrical power to produce the same mechanical power as other types of motors, which reduces energy consumption and operational costs. This makes them ideal Small BLDC motor wholesale for applications that demand long battery life, such as electric vehicles and drones.
Brushless DC motors also provide better efficiency than brushed motors, due to the absence of brushes and commutator. This eliminates the need for constant contact between metal components and eliminates arcing which generates electrical noise that can cause interference with other circuits.
In order to accurately measure core losses, you need to take several readings at various speeds and under different load conditions. This can be done using a multimeter and a drill, by connecting the multimeter to the positive and negative leads of the motor and spinning it at a constant speed. You can then measure the current draw and voltage to get an estimate of core loss.
The control systems of BLDC motors are complex, and they depend on encoders or hall sensors to monitor the position of the rotor. Since these systems are difficult to program and troubleshoot, dependency on them increases operational risk for many applications. For example, in medical devices dependency on sensors raises concerns because any failure in the system could affect patient safety. In industrial automation, any failure in sensors or encoders may lead to expensive downtime.
