i do have a question about a program that runs three stepper motors, each of them one step at time on the loop, so they apparently move all togheter..
The question is.. Can i energize it like it were only one stepper?
or do this will draw the sum of three of them?
I'm using 3v 1.7a steppers from sparkfun, with the drv8825 from polou who permits to "sleep" the motor (2 motors sleeping when 1 stepping). But this runs a lot of times every second.
PS: Sorry for my poor english and for not posting the code, it is loooong and have some several mix between spanish and english (Bad habit )
Sorry, im using worm gears, so i can de-power them whitout that risk.. and for now, im using a laptop charger (19v, 3.5a) that seems to work great with two steppers, but im looking to energize them with li-ion or lipo batteries.
LiPo cells can generally provide a very high short-term current so I doubt if you would have a problem while the batteries are charged. The problem is that stepper motors are very inefficient. But if you can energize the driver, move a few steps and then de-energize the driver you will reduce the wastage.
Even though the worm prevents the load from moving the motor you may find that when the motor is re-energized it jumps to a different step from where it was when it was de-energized. Something for experiment.
Having said all that I am not sure what you want advice about.
Even though the worm prevents the load from moving the motor you may find that when the motor is re-energized it jumps to a different step from where it was when it was de-energized. Something for experiment.
i didn't know that, thanks for the advice, i will check it.
Having said all that I am not sure what you want advice about.
Are you planning to use 5 cells to get 19v?
Since im using "chopper drives" i can adjust the current flowing trought the motors with the built-in variable resistances.. this drivers work from 8 to 45 volts, so im using 19v because it is the power supply that i have by the hand to prove them, but im wanting to energize them with the lowest voltage possible (so i can save cells and budget)..
Maybe i didnt make it clear at first, but my code works like this:
-Loop begins and checks the info provided by BT and counters, then
-Motor 1 Steps once, then stop, de-energize and increase the counter for that motor (if had steps to make)
-Motor 2 Steps once, then stop de-energize and increase the counter for that motor (if had steps to make)
-Motor 3 steps once, then stop de-energize and increase the counter for that motor (if had steps to make)... then start again,
So, with this, the motors seems to move all togheter, but they're really moving one by one...
The really (and maybe stupid) question is if i can energize all the circuit, like if i were using only 1 motor (since them step one by one), and i could maybe use 9 - 12v batteries with a max drawing of 2amps (since they need 1.7) and get only more mAh's...
alexmt92:
but im wanting to energize them with the lowest voltage possible (so i can save cells and budget)..
Unfortunately stepper motors work better with higher voltages. The chopper drive limits the current so the motor is not damaged but it uses the high voltage to get up to the current limit as quickly as possible.
You will need to do some experiments to find the lowest voltage at which your system works satisfactorily.
And, sorry, but I don't understand this - maybe a diagram of what you have in mind would clarify things.
The really (and maybe stupid) question is if i can energize all the circuit, like if i were using only 1 motor (since them step one by one), and i could maybe use 9 - 12v batteries with a max drawing of 2amps (since they need 1.7) and get only more mAh's...
Or maybe you can explain the alternative that is in your mind.
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