How Universal Motors are Used
Author: steve Published Under: Home
Electric motors are used in many different applications, from everything from home appliances to automobiles. They provide very reliable and consistent service, allowing for dependable speed control and consistent torque.
In most cases, electric motors can be classified as either a DC motor or an AC motor, with DC Motors only working with DC Current and AC Motors only working with AC Current. However, there are some electric motors that can use both types of current. These motors are called universal motors and are much more efficient than most other motors. As a result, many types of household appliances and tools use Universal motors.
Hand Drills
Hand drills are incredibly common and use a universal electric motor, which means that it can be used with either AC power or DC power. Using a series motor, a gear reduction located at the Jacob's Chuck, which is where the drill bit is attached, is responsible for putting load on the electric motor.
In most cases when it comes to the maintenance and repair of electric drills, the problems usually is the result of misuse of the device. If the brushes spark too much, which can usually be seen without taking the drill apart, they can be removed, along with the armature, and smoothed back out with sand paper. In most cases the grease located in the gear box is sufficient for the life of the drill. Extreme changes in heat can also cause problems with electric drills.
In most cases, electric drills allow for speed control. This variable speed control is achieved by using a resistor in the switch, which uses a gear to change the electrical circuit. This results in faster speeds the harder the trigger switch is pressed.
Even though many electric drills use AC power, the power is converted by the SCR to DC power, which increases efficiency.
Portable Saws: Circular Saws
Another example of a power tool that uses a universal motor is the Portable Saw or Circular Saw. As with an electric drill, it is usually possible to see if excessive sparking is occurring in the electric motor. Too much sparking, along with stalling of the blade, can result in overheating and damage to the armature and coils. It is important to keep the saw free of dirt and saw dust.