Choosing the Right Type of Motor Driver for Your Project

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Are you planning to work on a project which includes using a motor? Is the thought of using a motor giving you chills? Well, you don’t need to worry about it anymore! This post will take you through all the necessary information and guidelines to follow while working with motors in your next project.

Motors are essential when it comes to converting electrical energy into mechanical energy. Basically, they allow you to perform mechanical tasks using electricity. There are a number of types of motors including DC motors, servo motors and stepper motors which have different characteristics based on their working principles.

To allow the motors to work perfectly with your choice of microcontroller, it is important to choose the right type of motor driver. Let’s take a look at the different types of motor drivers and see how they work.

What Is a Motor Driver?

A motor driver essentially “drives” a motor i.e. it allows the motor to be controlled using the microcontroller. It acts as an interface between the motor and the microcontroller mainly because they work on different levels of currents.

A motor requires a high amount of current whereas a microcontroller needs less amount of current. Two devices requiring different amounts of current simply cannot be connected together without a third device which steps up or steps down the current. A motor driver is what you need to serve the purpose.

A motor driver takes the low-current signal from the controller circuit and amps it up into a high-current signal, to correctly drive the motor. It basically controls a high-current signal using a low-current signal. There are different types of motor drivers available in the market, in the form of ICs. They have different characteristics and serve the purpose of driving different types of motors.

The motor driver ICs are connected to microcontrollers via a circuit called the “H-bridge”. Let’s understand what an H-bridge is and how it works.

What Are the Key Characteristics of Motor Drivers?

When it comes to selecting a motor driver for your project, you must keep in mind the following standards and judge the motor driver considering the following four aspects:

Voltage and Current

It is important to select a motor driver for your project by first looking at the voltage and current ratings of it. If you are sure of the application for which you need the motor driver, then you would know what supply voltage is required for the project and what amount of operating current is required for each of the project’s components. Make sure that the motor driver you’re planning to buy fulfills the voltage and current requirements of your project.

Compatible Motors

“One size fits all” isn’t true for motor drivers. Not all motor drivers can be used with every type of motor. There are certain motors which are compatible with different types of motor drivers. Generally, most motor drivers are compatible with DC motors, stepper motors and geared motors. But if you’re looking for a motor driver for a servomotor then, you need to be a bit more cautious while choosing the motor driver.

Every motor driver comes with a list of compatible motors so you don’t need to worry about it. All you need to do is go through that list before buying the driver.

Interface

Before you choose a motor driver for your project, you need to be sure about its application. Generally, most motor drivers work fine with Arduino boards but, if you’re going for a different application like building a wireless project then you need to opt for a wireless motor driver. A common type of wireless motor driver is the Bluetooth controller board which is widely used in many wireless motor projects.

What Are the Different Types of Motor Drivers?

Motor drivers are differentiated based on the type of motor control they offer. Some motor drivers provide speed control while others are non-speed controlling. A single motor driver can be used for more than one type of motor. Likewise, there are some drivers which specifically work for a single type of motor. 

Here is a list of some common motor drivers used with different types of motors:

Motor

Motor Driver

DC Motor

A4988, DRV8833, L293

Stepper Motor

A4988, DRV8833, L293, ULN2003

Servomotor

L293

 

The L293 motor driver can be used to drive two DC motors simultaneously. The following schematic shows how this can be done.

An examplary motor paso a paso connection

Hopefully, now you know how to choose the right type of motor driver for your project and what key factors need to be kept in mind while buying a motor driver which best suits your application. So, what are you waiting for? Go ahead and grab that motor driver you think is best for your project!

If you want to learn more about how the controllers work and how they are constructed the below passage is just for you.

What Is an H-Bridge?

An H-bridge is a circuit usually made using two pairs of transistors working as switches. They allow the motor to either go backwards or forwards, depending on how the switches are controlled. Most of the controllers are based on such a circuit.

An H-bridge controls the direction in which your motor spins i.e. either forward or backward. This is controlled by switching the polarity of the input voltage of the motor. If a positive voltage is applied via the H-bridge, the motor spins in a certain direction and when the polarity is reversed, I.e. a negative voltage is applied, the motor starts spinning in the opposite direction. The direction of spin of the motor plays an essential part in robotics projects as it allows the robots to move in different directions and perform various tasks.

An H-bridge is made up of two pairs of transistors which are connected to the motor and supplied with an input voltage. Each of the pairs of transistors are connected on the opposite ends of the motor and one is supplied with the input voltage while the other transistor is grounded. As one pair of transistors is switched on at a time, the current flows from the source voltage to the positive terminal of the motor, then to the negative terminal of the motor, and then finally to the ground. This is the case of a positive polarity.

Similarly, when the other two transistors are switched on, the current flows from the voltage source to the negative terminal of the motor, then to the positive terminal of the motor, and finally to the ground. This is the case of a negative polarity since the current enters the motor through its negative terminal.  

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