Small DC motors can deliver a lot of oomph for their size. They’re commonly found in toys, hand-held power tools and appliances.
They can develop constant torque over a wide speed range and have good starting and stopping capabilities. This makes them ideal for driving heavy loads like elevators, ski lifts or conveyor belts.
Brushed DC Motor
Brushed DC motors are very common and can be found in all sorts of applications. They deliver good starting torque and can operate at high speeds, making them suitable for a variety of industrial applications as well as consumer electronics. They are simple to use, being able to work without any additional control circuits if speed control is not required.
When current passes through the armature coil, it causes the poles to repel Small DC motor each other and rotate in a fixed direction (depending on whether the polarity is set to positive or negative). To keep this rotation constant, the commutator reverses current flow every half-cycle by energizing different sections of the copper wiring.
As a result, the brushes and commutator are in continuous contact with each other as they rotate, which creates friction-induced wear that reduces their life expectancy. The constant contact also results in electrical and acoustic noise.
Eventually, the motor will reach a position where the commutator brushes touch both commutator plates at once, which shorts the coil current through both brushes. This wastes a large amount of power as it destroys the brushes and causes the commutator to overheat. It can also short the supply leads if the motor is connected to an external power source and shorts through the battery. This is called a dead-short and it kills batteries rapidly and drains the power source in a short period of time.
Permanent Magnet DC Motor
A permanent magnet DC motor utilizes a permanent magnet and an electromagnet to achieve motion. The permanent magnet, also known as a stator, does not move while the electromagnet, referred to as the rotor, rotates inside of the magnetic field. When the rotor is powered by an electrical current, it interacts with the magnet’s field and is repelled or attracted until the polarity of the armature’s coils aligns with those of the magnetic field.
The rotor is made up of a core consisting of slotted circular steel sheet laminations that are varnish insulated. Each of these slots holds a winding called an armature core. This core is connected to a brush through the commutator, which converts the current from the brushes into the rotating motion of the rotor. When the commutator is linked to a DC power supply, current is alternately directed through the armature and field windings.
Unlike other DC motors, permanent magnet motors are not controlled by changing the strength of their magnetic fields. This leads to more stability and simpler control, making them ideal for applications where speed and torque are critical for performance. In addition, the permanent magnet design reduces energy loss due to heat and friction, decreasing operating costs over the lifespan of the motor. These benefits make them an excellent choice for applications such as mobility, patient care, and industrial equipment.
Geared DC Motor
A DC motor converts direct current electrical energy into mechanical energy through a system of stationary magnetic fields, called a stator, and a moving magnetic field, called Small DC motor wholesale a rotor. When the rotor is energized, it interacts with the stationary magnetic fields to induce rotation. This motion is then converted into torque, which enables the device to perform its intended function.
However, sometimes the force required to power certain devices exceeds what a DC motor can produce on its own. In such cases, a gear motor can be utilized to increase the amount of torque that the device can utilize.
The operation of a geared motor is similar to that of a classic electric motor, but it uses a mechanical gear unit to reduce the speed of its drive shaft and increase the amount of torque it can provide. This is accomplished using a series of gears that can be configured into different combinations to achieve various output speeds and forces.
The use of a gear motor to deliver high torque at low output shaft rotation speed is beneficial for a wide range of applications. Whether it’s for security purposes (orientation of cameras), beverage dispensing and distribution systems, or even coffee machines, these motors are essential in many industries. Understanding the differences between this class of motors and other types that specialize in rotary actuation empowers designers and engineers to select the ideal motor for specific projects.
Combined Power Solutions
In addition to selecting the type of motor you want for your project, consider the voltage it runs on and its stall current. The higher the stall current, the more torque it has at a low speed. You also need to know if the motor has an operating current and what its rated RPM is. You may also be able to find these details on the product page.
Some hobbyists use servo motors for remote control devices like robots and RC toy vehicles. These motors can be AC or DC, but they provide position control rather than speed. They have a potentiometer and a control circuit, which receives electrical pulses to change the direction of the motor shaft.
These small motors are great for students and teachers who are using a maker space, classroom or summer camp to design projects and learn about the science of motion. They’re easy to mount on dowels and project sticks and can be powered by a pair of alligator clip leads connected to AA batteries (not included). These motors are also a great choice for Maker Faire, after school clubs, scout troops and kitchen table innovators. You can also pair them with gears and pulleys to create propellers, fans and transmissions in mechatronics projects. Many of these motors are available with optional enclosures, which help keep the motor protected from dust and moisture.