How to add diodes for Bidirectional motor with L298N module

Other Hardware Motors, Mechanics, Power and CNC
1

Recently, I bought L298N module to control 2 DC motors. I followed the according to the instruction in the video here:

It worked well.

After researching more about DC motor, if you suddenly stop the motor, there will be back EMF that can hurt the power source. As I checked online, the L298N module does not have diode protection for back EMF. How do I add the diodes externally with L298N if I use 2 motors? I checked and found this circuit diagram in the link: http://www.instructables.com/file/FT8ERG4GYVDJSP8

In the circuit diagram, the motor has its own power source, Vmotor and ground. Is it right to just add the diode according to the circuit diagram in the link and no need to add the power source?

2

Which L298N module? They should all have 8 diodes, if not they add 8 as per that link or the L298N datasheet application circuit.

3

You could use a full wave bridge instead of 4 separate diodes;
l298_fwb.png

l298_fwb.png

4

bori02082014:
After researching more about DC motor, if you suddenly stop the motor, there will be back EMF that can hurt the power source.

Ah, no, that's wrong - suddenly stopping the motor drops the back EMF to zero, leading to a high current
demand (stall current levels can be 10 times maximum continuous rating).

Back-driving the motor so it spins faster than the power source can spin it unloaded will mean there's
too much back EMF for the power source.

back EMF is basically proportional to speed of rotation, the constant is called the motor constant.