Brushed DC motors are powerful, versatile tools built for a wide range of vehicles, heavy machinery, industrial equipment, and other applications. Because there are so many options available on the market, it can be difficult to know exactly which brushed DC motor is the right fit for your operational needs and equipment demands. This five-step decision-making guide details the most important factors that go into choosing the right motor:
- Voltage
- Speed
- Torque
- Size
- Duty cycle
1. Determine Voltage Requirements
Start narrowing down your selection by determining the voltage requirements your system has. DC motors operate at voltages ranging from 1.5V to 48V depending on exactly how much power and performance you need. For example, remote and portable devices may be battery-powered and require a relatively low voltage, but rack-mounted devices will need more, such as 24V. The electrical power source itself, whether it's a 12V battery or a wired power supply, will also dictate how high of a voltage your motor can be. Generally, most DC motors provide 12 or 24VDC (direct current voltage).
2. Decide Speed Requirements
Once you know your voltage requirements, calculate how fast the rotational speed of the motor should be. See what rotational speed requirements are the norm for your motion control system, including the constant and maximum speeds. Then, you can look for the rated motor speed or on-load motor speed specification—this number represents the speed a DC motor can reach once it has a load.
3. Figure Out Torque Requirements
Your chosen brushed DC motor must also satisfy your torque requirements. Closely related to speed, torque is the load that the output shaft of the motor can withstand. In general, motor speed decreases as torque increases, and vice versa. On-load or rated torque, as well as peak or stall torque, must be able to handle anticipated loads at startup, throughout operations, and during acceleration and deceleration.
To determine peak and rated torque, read through the motor's specifications. These documents will typically include the motor's performance curve so you can see the relationship between speed and torque at different stages of operation.
4. Size vs. Performance Considerations
The three factors above—voltage, speed, and torque—will help you find a range of acceptable brushed DC motors. Now, you need to narrow down the list of options to just motors that can physically fit within your system.
As a general rule, bigger motors are more powerful and can deliver more torque. Motors range in size from 8 to 25 mm in diameter and 16.6 to 67.2 mm in length. However, your system may not have room for the biggest possible motor. Carefully measure the allotted space or research the required specifications in your equipment manual. Size requirements can overrule power preferences, so you may need to adjust your torque and speed requirements or your budget to find the right motor.
5. Establish Your Duty Cycle
Consider the lifespan of the motor and the type of duty cycle you need. Intermittent duty cycles can make motors last longer and extend their lifespans compared to continuous-use motors. If you need a continuous-duty motor, make sure it works at optimal efficiency by inspecting it regularly. The necessary duty cycle of your device or application will determine the best type of motor after you’ve narrowed down the options by specification.
Learn More at Pelonis Technologies
Choosing the right motors for equipment and devices will significantly impact the performance of the system—and the cost of using it. When you're looking for new or replacement motors, always consider the voltage, speed, torque, size, and required duty cycle before purchasing your final selection.
At Pelonis Technologies, we provide our clients with a wide range of brushed DC motor controllers and other motor systems to provide reliable, efficient, and high-performance power for everything from small devices to large equipment. Reach out to us today to learn more about our inventory or for professional assistance determining what type of motor you need. You can also request a quote to start your order.
