motor shield and high torque stepper

[ingstroem]

hi there,

i'm using the motor shield with a high torque stepper at 2.8volt, requesting 1.68ampère. as the shield delivers only 0.6ampère per bridge ... is there a way to fix this?

thanks in advance!

[adafruit_support_bill]

See "I need more power" in this post: viewtopic.php?f=31&t=26873

[ingstroem]

thanks a lot! - very helpful post.

[Quentinbri]

Hello,
I'm in same problem, i bought a motor with the same caracteristics and a motor : 3.2V an 2.8A.
Can i control it with the motor shield (3* SN754410 in Piggy Back ?) or i have to create other h-bridge ?

Thanks

[adafruit_support_bill]

2.8A is too much for this shield. Even with the piggybacked H-bridges, you will be exceeding the contact ratings of the chip sockets.

[Quentinbri]

Do you think in can control other transistor connected like a motor ?

[adafruit_support_bill]

At that point you are essentially building your own H-bridge. If you want to go that route, there are a lot of resources on the web with H-bridge circuit designs. If you prefer something off-the-shelf, Pololu has a nice range of moduler stepper controllers.

Another approach is to just use a different motor. A low voltage motor like that (3.2v) needs high current to develop torque. If you double the voltage, you can get the same torque with half the current. An 18v motor with a 0.5A/phase rating should have similar torque and will comfortably run on an un-modified shield.

[Quentinbri]

Thank you for your help but i ve already bought my motors.
I think I will do a h-bridge