Hey, as the title says, I have little experience with boards and IC's.
I plan on making a mecanum drive train using 350w motors @ 24vdc.
I have not yet been able to test the stall current, the only info i received for the motors was continuous current: 13.4A.
Ive had trouble finding a similar H bridge design within that power range and voltage.
My questions were:
Can i ballpark stall current off the data i have, or does someone with experience have a good estimate?
What PFETS would be best, ideally logic driven? I have some P30N06LE on the way but i may have jumped the gun.
What P channel PFETS would couple nicely with the former mentioned in a H bridge? Or would it be easy enough to use all N channel if they are login driven?
I also was thinking about buying some V40DL45-M3/I if i need circuit protection. Also ideally the system would use dynamic braking.
If anyone can answer any of these, it would be much appreciate.
Stall current of 50 Amperes would be a reasonable guess, could be higher. You can estimate it by carefully measuring the winding resistance with a multimeter capable of accurately measuring resistances in the milliOhm range. Rotate the shaft very slowly, and divide the lowest value you get into 24V.
There are a number of H-bridges on the hobby market that can handle that current. It is out of the question for a novice to design and construct an H-bridge in that high-current category that works, and is safe to use.
Thanks for the reply. I was going off 13.4A stall current. When i re checked the info for the motors i bought i realised it was continuous. I will need to do a an actual load test on them for accurate data.
I realise i can purchase the whole driver or a full h bridge ic at the least. But i was hoping to build from scratch and learn.
Thanks for the input. I'll do an actual load test on them for an accurate number i suppose and go from there.
I appreciate your concern, but its at least low voltage. I have experience with DC circuits and protection. Just not with ICs etc. So i will probably just be letting out magic smoke in the worst scenario. Im ok with burning up some components and boards. I will just prototype untill i get it right.
Save yourself a lot of grief, purchase a BTS7960 H bridge. they can be gotten for a lot less then your hardware design. I got them for less then $5 US from my favorite china supplier last year.
I believe it will run fine as the stall current if for a short time and they do have current limit capabilities as well. You can try it but you may have to match the modules and use fast clock edges. The modules have some logic which will also help shape the signal. I think the big problem will being able to get the power to the bridge. I use them for high side PWM on LEDs, upwards to thirty amps and they stay cool. Yep you can wire them to get two independent drivers that will both sink and source current.
