Voltage supply of a stepper motor control

Thread Starter

tommino

Joined Aug 31, 2023
2
Hi all,

I am trying to use an embedded controller on a 2 phase stepper motor with the followong specs
Basic Step Angle1.8°
Rated Current1.2A / Phase
Voltage4VDC
Winding Resistance3.3Ω / Phase
Mass: Motor0.35kg
The controller can implement position and current control
However my question is about the voltage supply of the controller which as far as i know should be the voltage supply of the H-bridges: can you tell me what happens if I use a voltage supply of 24V with a motor like this?
Will the current controller become impossible to implement since the nominal voltage of the motor should 4V?
 

MaxHeadRoom

Joined Jul 18, 2013
28,513
What is the H-bridge semi you are using?
Normally you use a translator IC between the H-bridge unit and whatever is used to for position control.
The typical one is L297 IC, this allows the max current to be monitored for the motor and cap it off at this limit, in a continuous fashion.
Vref sets the voltage measured at the neg (GND) end of the H-bridge FWD/REV devices.
See:
https://320volt.com/en/l297-l298-ile-step-motor-surucu-devresi/#google_vignette


1697224003020.png
 
Last edited:

Thread Starter

tommino

Joined Aug 31, 2023
2

MaxHeadRoom

Joined Jul 18, 2013
28,513
If it is an intelligent drive, then it should have means of setting a max current level for Steppers?
However I could not see anything on it in the manual?
Steppers should be operated at their max (rated) current in a constant fashion throughout the RPM range.
 
Last edited:

BobTPH

Joined Jun 5, 2013
8,664
The specs of steppers is very misleading. The 4V is the voltage needed to attain the desired current when the stepper is stopped. The faster you want to run it, the more voltage you need. This is because the coils are inductors. When you apply a voltage to the coil the current starts rising at a rate of:

dI/dt = V / L

For maximum torque you need the current to rise to the max in a fraction of the time of one step. Stepper controllers do this, then use PWM to keep the current there.
 
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