The ability to control the speed of a DC motor is an invaluable feature. It allows for the adjustment of the motor’s speed to meet specific operational requirements, enabling both speed increases and decreases. In this context, we have detailed four methods to effectively reduce the speed of a DC motor.
Understanding the functionality of a DC motor reveals 4 key principles:
1. The speed of the motor is governed by the speed controller.
2. The motor speed is directly proportional to the supply voltage.
3. The motor speed is inversely proportional to the armature voltage drop.
4. The motor speed is inversely proportional to the flux as influenced by the field findings.
The speed of a DC motor can be regulated through 4 primary methods:
1. By incorporating a DC motor controller
2. By modifying the supply voltage
3. By adjusting the armature voltage, and by altering the armature resistance
4. By controlling the flux, and by regulating the current through the field winding
Check out these 4 ways to tweak the speed of your DC motor:
1. Incorporating a DC Speed Controller
A gearbox, which you might also hear called a gear reducer or speed reducer, is just a bunch of gears that you can add to your motor to really slow it down and/or give it more power. How much it slows down depends on the gear ratio and how well the gearbox works, which is kind of like a DC motor controller.
How to achieve DC motor control?
Sinbad drives, which are equipped with an integrated speed controller, harmonize the advantages of DC motors with sophisticated electronic control systems. The parameters of the controller and the operating mode can be fine-tuned using a motion manager. Depending on the required speed range, the rotor position can be tracked digitally or with optionally available analog Hall sensors. This enables the configuration of speed control settings in conjunction with the motion manager and programming adapters. For micro electric motors, a variety of DC motor controllers are available on the market, which can adjust the motor speed according to the voltage supply. These include models such as the 12V DC motor speed controller, 24V DC motor speed controller, and 6V DC motor speed controller.
2. Controlling Speed with Voltage
Electric motors encompass a diverse spectrum, from fractional horsepower models suited for small appliances to high-power units with thousands of horsepower for heavy industrial operations. The operational speed of an electric motor is influenced by its design and the frequency of the applied voltage. When load is held constant, the motor’s speed is directly proportional to the supply voltage. Consequently, a reduction in voltage will lead to a decrease in motor speed. Electrical engineers determine the appropriate motor speed based on the specific requirements of each application, analogous to specifying horsepower in relation to the mechanical load.
3. Controlling Speed with Armature Voltage
This method is specifically for small motors. The field winding gets power from a constant source, while the armature winding is powered by a separate, variable DC source. By controlling the armature voltage, you can adjust the motor’s speed by changing the armature resistance, which affects the voltage drop across the armature. A variable resistor is used in series with the armature for this purpose. When the variable resistor is at its lowest setting, the armature resistance is normal, and the armature voltage decreases. As the resistance increases, the voltage across the armature further drops, slowing down the motor and keeping its speed below the usual level. However, a major drawback of this method is the significant power loss caused by the resistor in series with the armature.
4. Controlling Speed with Flux
This approach modulates the magnetic flux generated by the field windings to regulate the speed of the motor. The magnetic flux is contingent upon the current passing through the field winding, which can be altered by adjusting the current. This adjustment is accomplished by incorporating a variable resistor in series with the field winding resistor. Initially, with the variable resistor at its minimum setting, the rated current flows through the field winding due to the rated supply voltage, thus sustaining the speed. As the resistance is progressively decreased, the current through the field winding intensifies, resulting in an augmented flux and a subsequent reduction in the motor’s speed below its standard value. While this method is effective for DC motor speed control, it may influence the commutation process.
Conclusion
The methods we’ve looked at are just a handful of ways to control the speed of a DC motor. By thinking about them, it’s pretty clear that adding a micro gearbox to act as the motor controller and picking a motor with the perfect voltage supply is a really smart and budget-friendly move.
Editor : Carina
Post time: May-17-2024