What is the difference between the PmodHB3 and the PmodHB5

[JColvin]

I noticed the PmodHB3 and the PmodHB5 seem to be really similar in both their schematics and reference manuals, so I wanted to know what the difference between them was.

[JColvin]

What I found is that while both of these Pmods support motor feedback from Hall Effect sensors (or some other kind of feedback), the PmodHB3 presumes that the feedback sensor is not incorporated into the motor itself but is rather an external sensor. So, the two motor feedback pins, SA and SB, are on their own header (J5) on the Pmod.

 

On the other hand, the PmodHB5 presumes that the feedback sensors are incorporated into the motor itself and have their signal wires on the same wire header as the motor outputs present on the J2 header.

 

Otherwise, the two Pmods are functionally the same.

[ricardo_lara_gomez]

I have a question, I have the PmodHB3 my pmod could withstand the power consumption of my engine starting 12v 2A starting consumption is 4A

[JColvin]

Hi ricardo_lara_gomez,

The PmodHB3 will for sure be able to handle the 12v 2A that you motor continuously runs at.

As for the starting consumption of 4A, I personally don't know what the transistors on the PmodHB3 are rated for, so I do not know if they would burn out if you applied 4A to them for a brief amount of time. I would suspect that because they are only labeled for 2A that running double the current would damage them, but again, I do not know this for certain.

Thanks,
JColvin

[ricardo_lara_gomez]

Diligent has another pmodHB with greater capacity, or some circuit to support the inrush current.

[JColvin]

Hi,

Digilent does not offer another H-Bridge that can withstand a higher current rating. What I would probably do is instead "recreate" an H-Bridge using the PmodOD1 since each of it's outputs can handle up to 4.1 amps (for under 5 seconds) and can then each comfortably run at 3.0 A. 

What you would need to do is appropriately wire Pmod to the motor and then write the code so that a short never occurs between two of the transistors in the PmodOD1 and that current only ever runs through the motor, since the Pmod does not have both "enable" and "direction" pins -- just the four transistors that can be "switched on".

Let me know if you have any questions.

Thanks,
JColvin