How Do You Choose a Motor Driver for a DC Motor?

In the world of robotics, we get to see that there are various different types of motors that are available in the market. These are in the form of motors like; DC brushed motor Driver, brushless motors, stepper motors, and servo motors. These are the type of motors that can be controlled by various different methods. Some of the motors can be directly connected to the power supply, whereas the other types of motors, like servo motors, require a signal from the controller to operate them. This is the part where we need a motor driver, as when we need to control the motor, we need a controller too. 

What is a DC Motor?

A dc motor or a motor driver circuit is a type of motor that takes the low-current signals that are applied by the controller and turns them into a signal that is used to drive the motor. Motor drivers work in a way that they act as a surface between the motor and the control circuit, as it allows you to have much larger loads, even from a small signal. They can handle high voltages and currents where some of the motors work the best. This is the type of circuit that consists of an IC or discrete JFETs that are capable of handling high power. These are the motor driver ICs that are the current amplifiers. However, different chips offer different interfaces. Some well-known motor driver ICs include the L293D and the L298N.


H-Bridge Circuit

The H-bridge is a form of a circuit that allows a DC motor to go backward or even forward. In simpler words, these are this circuit switches the polarity of a voltage applied over a load. When Q1 and Q4 are closed, it is usually connected to the left terminal of the motor, and the GND is connected to the right terminal, which usually moves the motor in a single direction. In the case hen Q2 and Q3 are closed, Vbat is then applied towards the right terminal of the motor, and the GND is applied to the left side, which moves the motor in a single direction. However, an H-bridge can be easily built using 4 transistors, two PNP, and two NPN. The PNP transistors are used for the purpose of switching Vcc, and NPN is used for the purpose of switching the GND connections. 


The Most Compatible Motor

Among the availability of the type of motors that exist, we get to see that it becomes tough to select the best type of motor that goes exactly according to your requirement. However, the first thing that you look for when you are looking for a motor driver is a list of the most compatible motors. In the case of most of the motor drivers, we get to see that they are brushless DC motors that are geared and the stepper motors too, but some motor drivers are compatible for angle-based motors; thus, it is necessary to choose the driver based on the type of motor that you need according to your usage. 



The motor driver and the interface that you choose should be exactly according to your application. In the case of most of the motor drivers, we get to see that they are usually compatible with Arduino and other types of TTL inputs, but in case if you want to make sure that you control the motor wirelessly, the way it is done in Bluetooth control boards, then one needs to consider the use of remote controllers. Moreover, the number of channels should also be considered. In case you want to control multiple motors, then you need multiple external signals. In this case, a multiple-channel motor driver must be chosen to keep in mind that the current and voltage are right. 


Voltage and Current

The next thing that one needs to pay attention to is the voltage and current handling capacity. One needs to find a suitable voltage range based on your application. However, finding the right range of voltage is not anything difficult. Along with that, to find the right type of voltage but one also needs to find the right current. Finding a driver with enough voltage handling capacity is a comparatively easier task as the drivers that are available in the market are equipped with current handling technology and capacity. 


On State Resistance

The current that is in the motor driver flows in a way that it flows through on-state resistance, and heat is released for power dissipation. The driver IC operates at its peak, and the current capacity leads to an increase in the internal temperature, which can lead to a thermal shutdown. Keeping this thing, one needs to select a type of IC with the current handling capacity, and the IC might sometimes heat too.

When we talk about the applications of motor drivers, we get to see that Motor drivers have got various applications already. Their use is plenty in industries and applications such as:

Incandescent displays and LED

Stepping motor

Solenoid and relay switching

Automotive applications

PC peripherals


Car navigational systems

As mentioned above, motor drivers are seen to be used in a variety of applications/fields. Their applicability is vast and varied as they are versatile products. 

Our Thought

Motor drivers form a type of ‘bridge’ or interface, usually between the motor and the microcontroller. This is then used in several industries and applications, are as PC peripherals, car navigational systems, and robotics. Their main function is to take or convert a low-current signal to a higher-current signal in order to drive a motor according to the requirement. While out there shopping for a motor driver. There are a few more things that must be considered too. Some of these important things are to consider its weight, speed, velocity, current, and various other factors too.