Hi guys, seems to be the right place for my problem:
i am using a 2.8V 1,6A -unipolar stepper motor and I'm thinking of using the DRV8834-Driver. Is this the right driver for my motor?
Thanks!
The DRV8834 is for bipolar motors.
Also, don't make the mistake in thinking that 2.8V is the limit that the motor can handle. 1.6A is a hard limit, but it's typical to use a voltage much higher than that -- (24V+) for common stepper motors, and that higher voltage gets you better speed and more torque at those higher speeds.
You may find some useful stuff in Stepper Motor Basics
As @Chagrin has said stepper motors work best with high voltages. The Pololu DRV8825 can handle up to 45v.
...R
hey guys, thank you so much!
my biggest problem is to understand the difference between motor power supply and logic power supply.
in my mind the logic power supply responsible for an operating driver (lower than the minimum leads to an not-operating driver and higher than the max. harms the driver)
and the motor power supply is that kind of voltage which is used for the motor. Is that right?
The Pololu web pages for the DRV8834 and DRV8825 have very clear wiring diagrams.
...R
hi robin, yes I just saw those nice diagrams.
can i only manage the speed by changing the motorsupply voltage or can i change it via code (just saw plenty of programs with "set.speed". What the right thing to do?
The speed depends on how often you "step" the motor, up to a limit.
The higher the supply voltage, the higher the speed limit.
ok so as long as i operate unde the speed limit...i can adjust the actual speed via set.speed?
I suggest to read the documentation for the software you intend to use.
technik_mario:
ok so as long as i operate unde the speed limit...i can adjust the actual speed via set.speed?
The speed limit is a physical one - it just won't go any faster. It won't do any harm to try making it go faster. If you increase the motor power voltage it will probably reach a higher maximum speed.
If you are using a higher voltage you MUST use a driver that is capable of limiting the current to protect the motor.
You could use this Simple Stepper Code to experiment with if you are using a driver that takes step and direction signals.
...R
Hi,
Can you post a link to the spec of your stepper motor please?
Thanks... Tom.... 
HI guys,
ok this is my motor: 42STH38-1684B - 1.8 Degree - 1.68A Stepper - 51:1 Gearbox - 3328_0 at Phidgets
I'm going to operate with the Pololu - DRV8825 Stepper Motor Driver Carrier, High Current.
technik_mario:
Hi guys, seems to be the right place for my problem:i am using a 2.8V 1,6A -unipolar stepper motor and I'm thinking of using the DRV8834-Driver. Is this the right driver for my motor?
Thanks!
I don't believe you have a 5 wire motor of that specification. Are you sure its
not bipolar?
technik_mario:
HI guys,
ok this is my motor: NEMA17 - 1.8 Degree - 1.68A Stepper - 51:1 Gearbox - 3328_0 - Phidgets
I'm going to operate with the Pololu - DRV8825 Stepper Motor Driver Carrier, High Current.
So why did you say you had a unipolar motor?
Hi,
12V 1.7A
Max Speed 63rpm.
Tom......
hi guys,
it's a bipolar motor. sorry typing mistake.
As far as I know, the 63rpm are the maximum speed of the motor at (recommended) 12V motor-supply, but without any load. Is there any way to get the maximum speed under load..or just test it?
I want to load the motor with different weights to lift them a predefined lifting height...if i set the speed via program will there be any recognicable difference in time, voltage, current?
technik_mario:
As far as I know, the 63rpm are the maximum speed of the motor at (recommended) 12V motor-supply, but without any load. Is there any way to get the maximum speed under load..or just test it?
Because your motor has a reduction gear head on it that's pretty hard to calculate without testing - friction in the gear head comes into play. But what you should be expecting is that the torque will drop off somewhat linearly between 0 RPM and the maximum RPM.
Regarding changes in time/voltage/current based on power output, no, you should not see any difference. Steppers are full power or zero power, or you could say they're either on or they're off.