While dealing with robotics, there may be some cases where L293D isn't quite a good option due to its current limitation. In those cases, we opt for more powerful drivers. Let's have a look at another product from robokits, which can pretty much drive powerful high torque motors:
The preceding motor driver is my personal favorite. It has multiple controls and can drive high torque motors. The driver has the following five control pins:
- Gnd: Ground.
- DIR: When low, the motor rotates in one direction; when high, it rotates in another direction.
- PWM: Pulse width modulation to control the speed of the motor. Recommended frequency range is 20 Hz - 400 Hz.
- BRK: When high, it halts the motor in operation.
- 5V: Regulated 5V output from the motor driver board.
From the description of the pins discussed here, it should be clear as to why this is a better choice.
The voltage and current specifications are as follows:
- Voltage range: 6V to 18V
- Max current: 20 A
The current and the voltage rating help us to drive motors with max load. We have used this motor driver for many of our applications, and it serves without fail. However, there are other motor drivers also on the market that can provide a similar functionality. The choice of which motor driver to use depends on certain factors, as discussed here:
- Power: It all depends on how much power the motor needs to run at full capacity. The current drawn at full load and at no load condition. If you are going to use a high torque motor driver with an L293D, you may end up frying your motor driver.
- Maneuvering: According to the use case of the problem, the choice of motor is yours and ultimately the choice of the motor driver. In high speed line following, we require PWM capability, thus we need a driver that is capable of handling PWM signals.
Ultimately based on your use case choose your motor driver.
The following is an image of a small yet high performance UGV powered using the previous motor driver that we developed:
Black-e-Track UGV. The UGV's motors are high torque 300 RPM and can climb steep slopes of up to 75 degrees.
Now we have a fairly good idea of how motor drivers work and how we can choose a good motor driver.