Hello!

I am currently working on a first project, designing and implementing a Cruise Control Adaptive system for a toy car. I am having problems in getting the L298 to work.

I have measured the following inputs on the L298:
Pin 4 - Vs - 8.3V
Pin 9 - Vcc - 4.9V
Pin 11 - Enable B - 4.9V
Pin 10 - Input 3 - 0V
Pin 12 - Input 4 - 4.9 V

When measuring between pins 13 and 14 (Out 3 and Out 4) it reads 0V. I've connected both sense A and sense B directly to ground.

I've also changed the L298 once, thinking that I've installed a faulty chip. I am running out of ideas .

Alex

 

Hello,

Can you post the board and schematic as .png format?
Perhaps a screenshot will do.
I can not read the attachments as they are.

Bertus

 

I have modified my first post.

Alex

 

Hi Alex,

Did you install the L298 from the bottom of the board? I ask this because you used the mirror image function on the L298. If you inserted it from the top of the board, all of the pin connections will be reversed.

[eta]
Don't forget to look at the saturation voltage drop.

At 1A, you'll lose about 3.2v, at 2A you'll lose around 4.9v in the bridge itself.

 

I think you are a GENIUS! I installed the two L298s from the top of the board, forgetting (not noticing) that I mirrored the component when I designed the PCB.

Unfortunately, I have quite a workload these days so the closest day I could think of for testing the L298 is Thursday night. I don't see any reason for it not to work though.

Thank you again!
Alex

 

I have put the L298 from the bottom of the board and it works perfectly. After I'll complete my project I will post a few more details in the dedicated section.

Thank you for your help!
Alex