Can someone tell me about differences between them?
I started learning arduino using Jeremy Blume's book. It says that to control a dc motor you need an h-bridge and a separate source of power. Then goes the explanation of what exactly an h-bridge is, its circuit, etc., but all the sudden the book says 'but instead we gonna use a dc motor driver some letters and numbers' with no explanation or anything. And now I'm lost. Like, why would I want to search, choose, buy and wait for delivery of driver, when I can just go buy transistors and diodes and make ab h-bridge?
Generally speaking a motor driver contains a h-bridge circuit. A h-bridge is the electronic equivalent of a DPDT switch.
If you know how to make a suitable h-bridge with discrete components there is no reason not to.
Speaking personally it would be far too much trouble to do that and my design would not be nearly as good as a commerical product. Many of them have short circuit and overload protection.
And h-bridges using Mosfets are much more efficient than those using bipolar transistors - but mosfet circuits are more complex.
...R
So, that is it basically? A motor driver is just an improved h-bridge? Many circuits(i.e. attached one) I found on web do have protection (even though it's just a diode between battery and motor) and fairly easy to make.
My problem was that I could just go and by some transistors and make an h-bridge following those circuits, or I'd have to get into drivers, somehow choose the one I need and then buy it - which is another problem - should I go for cheap chinese bootlegs (cheap and quick to deliver, since I live near chinese border) or original ones (more expensive, probably more reliable, delivery time from 1 week ans up to eternity)?
While an H-Bridge can be easily built using four transistors and diodes, a modern motor driver may contain much more. Like the other poster said, it may have short circuit and overload protection. They will often include "shoot-through" current protection, high power gate drivers so they can be safely switched at high PWM rates, better power dissipation, etc.
All in all, unless you are very experienced and have unusual needs, you're probably better off buying an integrated driver chip
If you can get the chinese products quickly why not try them. How much do you stand to lose if some of them don't work?
You have not given us any indication of the voltage or current that you want to control with the motor driver.
The Pololu website is a good place to get an idea of the sort of things that are available.
...R
So, I kinda got a general idea about drivers from Pololu website, but also got another question - what is the difference between motor driver and motor driver carrier?
The driver is the microchip so the carrier is the board it is mounted on for your convenience. But the phrase "motor driver" usually means "motor driver carrrier" or "motor driver board" because few people have the capability to work with the surface mount chips.
...R
One advantage of making your own from components is that you will probably learn more about what not to do. But sometimes this comes at the expense of battering your head against a brick wall for a few days until you`ve figured out where you went wrong.