Advantages and disadvantages of DC Motors

Thomas Addison might be the greatest electrical engineer of all times, but he did not tell us about the various types of currents. Now, we all know that current is of two types, it will be either in alternative wave forms usually known as alternative current or direct current which is not going to change throughout the supply.

Before getting deeper I just want to clarify one thing, current’s type is modified inside our machines the electricity supply has not got any role in it. the utilization of any form of current is dependent upon the type and functions of machines.

So far, we have been catching some characteristic glimpses of currents and have not come up to our focused topic: motors. If you recall your 8th standard physics, you will come to know that these currents of electrons are capable of moving materials such as shafts and ores.

You may also remember that any form of energy can be converted to other forms, in electrical world they usually convert electrical energy into mechanical specifically in motors.

DC motors as the name shows works through Direct current, we do not get to see DC motors around us that much. They are usually found in huge industries and factories. They are made up of several other tools, performance of a DC motor depends very much upon the material used to built it different manufacturers contact various rotary union manufacturers for making a DC motor.

You may also think of starting a business comprising of a lot of electrical equipment, machines and motors. DC motors are pivotal for various tasks, you may need to get and study a number of types of DC motors in order to get the desired results.

In this article I have tried to mention some pros and cons of several types of DC motors. Some may be new for you while few of them are quite common.

Types of DC motors

a) Series DC motors

As the name implies these motors run with full armature current. It has got a single but large wire wounded around the center.

b) compound DC motors

these DC motors are with separate fields; thus, they do not require a larger torque to work. They are very common in a number of industries.

c) DC shunt motors

These motors are a bit different. They are connected in parallel, unlike series DC motors. It works in an over simplified fashion because the shunt and the field are not directly linked.

Advantages and disadvantages of DC motors

Each DC motor has got its own pros and cons. Some are quite common while a few are rarely used. In this section I have explain advantages and disadvantages of each type.

1. Advantages of series DC motor

● Suitable for traction

DC motors requires a specific torque for starting off. Series DC motors are a tough one. They need a high momentum and torque for working.

A high huge torque can help in traction process. The resistors of DC series motor is placed in series that is when a high torque is applied to tackle that resistance, the process of traction gets easier.

● Easy conversion of DC and AC

DC series motors can easily convert alternative current to direct current and vice versa. That is why these motors are known as universal motors.

Usually because of this characteristic DC series motors are suitable for various home appliances. DC fans and washing machines have got these motors.

● More power

DC motors are capable of creating more output than other motors. They can do it for the minimum constructional power.

That is why these motors are considered more economical than the shunt motors.

Disadvantages of DC series motors

● Requires load

In case you are looking for a motot for a process where there is minimum or no load, you can not use DC motors there.

DC motors require a hug load for starting.

● No speed controls

Controlling a DC motors’ speed in nearly impossible, otherwise you will have to apply some greater efforts which can be really expensive.

2. advantages of shunt motors

● Works on a planned speed

Shunt motors can be used at a planned speed, that is why when companies have got a small budget and decide to work through that they opt for shunt motors.

● Cheap

These motors do not require high voltage energy to start. This makes them very affordable. many toys, small machines rely on DC shunt motor for excellent working time.

● Wider torque and speed

Shunt motors can work in wider torque range. You can alter the power and speed range by changing the resistance in parallel series.

Disadvantages of shunt motors

● Cannot change speed

Once a shunt motor has started working on it will only work for that particular speed. In a number of process, we require variable speed. Thus, there shunt DC motors will be of no help.

● Can not work at low speed

If the torque power is not huge enough. Then there can be disruptions in the constant process.

3. advantages of compound DC motors

● Very fast

These motors do not take time to start. You can change the speed any time it will not stop the process.

● Easy reversing

Unlike other motors compound motors are capable of turning the game, just within seconds. These motors are designed for heavy machinery.

Disadvantages of Compound DC motors

● Expensive

These DC motors require a heavy investment for maintaining the motors. You will have to take care of the brushes because the motors do not support any kind of hazardous situations happening because of the damaged brushes.


Dc motors are not widely used, and we usually hear about AC processes which is usually because of the price and cost of DC motors. Before you buy any product relying on DC motors you must check the type of motor and the energy supply you are going to provide. This will help you in maintaining the machines.

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