I wanted to make this circuit in order to drive one bipolar stepper motor with an Arduino Uno :
Circuit :
Schematic :
As asked in the hardware required list on the tutorial here : http://arduino.cc/en/Tutorial/MotorKnob, I used one SN754410 H-Bridge (datasheet here : http://www.ti.com/lit/ds/symlink/sn754410.pdf) to drive one stepper motor (17PM-K304-06V, I'm sorry, but I couldn't find any datasheet concerning the stepper I am using, and neither did the teacher who gave them to me ...). Then, I did exactly the same circuit as on the schematic, but my H-Bridge started to heat ... but I don't know if it is really normal : my teacher said that it may not work at the end because the motor is only running idle for the moment, but the final aim of my project is to drive four motors (with one H-Bridge for each of them) with the Arduino Uno (we'll have to change our Arduino Uno for an Arduino Mega in the end, because there are not enough digital outputs on the Uno), placed on a Lego-made body with four legs, each being controled by one stepper that will need a certain couple to support the weigh of all the Lego-made body plus the four motors and also the whole circuit. I also used an external 5V power supply, which is placed as asked on the schematic for the motor.
Does someone know why the H-bridge is heating so much and would you have a solution for it ?
My teacher also talked to me about another H-bridge (L298 Multiwatt 15H : https://www.sparkfun.com/datasheets/Robotics/L298_H_Bridge.pdf), which, he says, would evacuate the heat more easily than the SN754410. However, the datasheet shows an application to drive a stepper motor with another CI (L297 : ST Microelectronics 0g0gh362kxwx30o7xi4x2i4jzffy datasheet pdf), but in this case, I won't be able to use the stepper library because the inputs used by the L297 are different (the teacher told me that the L297 was controled by two signals : a clock signal to say "ok, the motor can turn" and the other one says "you have to turn this way or the other"). Do you know if I can use the L298 on its own (without the L297), exactly like the SN754410 (just finding the right way to wire it) with the stepper library ?
this one can drive one stepper (at 2Amps), or two motors
....
If you can live with less torqe, power only one coil at a time.
Use only 4 of theese 8 stages
Normal pattern for stepper are:
1001
0001
0101
0100
0110
0010
1010
1000
..repeat
Without details of the motor it is hard to give advice. One possibility is that the motor draws more current than the SN754410 can provide. Or there may be a wiring fault. Or there may be a coding fault. Or ...
It would probably be much easier to drive the stepper with a proper stepper motor driver board such as the Pololu A4988. It only needs two Arduino pins for step and direction and it can limit the motor current so that the motor can be driven at higher voltages for better torque at higher speeds.
@knut_ny : my teacher already ordered the "simple" L298 for us last Tuesday =S I don't know if he'll accept to buy other stuff for us again ... and I was using an example of code that was given in the Arduino software that enabled me to choose the speed and the steps per revolution parameter for my stepper.
@Robin2 : I sent a mail to the company who makes the motor yesterday evening to ask them to send me the datasheet, I am still waiting for their answer =/ I read a topic a few days ago saying that the heating may be due to the current drawn by the motor as you also suggested, but I couldn't make sure if it is because of that yet, I'll try and see that once I have an answer from the company.
Or, I can also see if they don't have other steppers at school, with specifications I can find this time ^^ but I don't know if the motors will be able to support the full structure (and make it move) if the current isn't high enough =S
I'm going to try again tomorrow during my project session and see if any of your solutions help =)
Thank you a lot for your answers !
Without knowing the type of motor I must be careful not to criticize your teacher's choice of stepper driver.
If you are genuinely interested in the subject I would suggest, however, that you study the extra capabilities of the Pololu A4988 (for example) type of stepper motor driver.
The all-important characteristics of the motor are the size, number wires and winding-resistance, all of which can be measured and together give a reasonable estimate
of winding current (similar sized motors have similar power dissipation).
For a low-resistance winding motor a chopper-drive is required, not two H-bridges.