# How to use correctly a microstepping driver with a lower voltage stepper motor

I want to use a microstepping driver like Haitronic's HS2215 with a NEMA 17 stepper motor with rated voltage of 4.2V and rated current 1.5A.

The input voltage range of the microstepping driver is 9-40VDC.

From what I understand, I can use the switches to set the maximum current. In this particular case I would use SW4=On, SW5=On, SW6=Off.

TB6600 current settings You can adjust the current that goes to the motor when it is running by setting the dip switches S4, S5, and S6 on or off.

I've found this Maker's Guide which describes the settings for use with an arduino. However, I am not certain what voltage (VCC) should I supply to the mircrostepping driver? Should I provide, the minimum of 9VDC, should I provide less? Is this irrelevant?

• Look at electronics.stackexchange.com/questions/200324/… . My guess it that the stepper driver itself requires at least 9V to run, so it wouldn't even work (properly) with only 4.2V. PS I'd probably go with a bit lower current setting, as to not push the motor to it's max. Unless you really need the torque. Oct 10 '20 at 16:19
• what does this do? `SW4=On, SW5=On, SW6=Off` Oct 10 '20 at 16:40
• I think it set the maximum current to 1.5A and peak 1.7A, based on what I see on the label on the product. Oct 10 '20 at 16:53
• if the driver has current limiting, then the driver should automatically limit the output voltage, to keep the output current below a set threshold ... if the difference between the supply voltage and the output voltage is large, then the driver may generate extra heat, depending on design Oct 10 '20 at 17:02

That doesn't matter at all.

The voltage stepper motors are rated for is the voltage that, if applied to the motor coils, would create its rated current.

Stepper motor drivers monitor the current, and always use the full voltage available to them (9 - 40V in your case) to drive the stepper motor - using PWM. The stepper motors coils inductance slows down the change in current, allowing the driver to reach its set current.

Higher drive voltages simply mean that it's easier to overcome that inductance, allowing for faster stepper motor movements.

You'll want to set your driver at 1.0 or 1.5 A, and supply it with as much voltage (up to the rated 40 V) as you can.

• So, if I read your answer correctly, in stepper motor drivers (like the one I'm posting) the VCC voltage has to do with required voltage for the driver, and not the motor? Oct 12 '20 at 6:16
• Yes, basically. Only the rated current matters if you're using a stepper motor driver.
– towe
Oct 12 '20 at 6:21
• Do most modern stepper drivers work in this fashion (I mean using PWM to control the current)? In most datasheets I can't say I've found that information... I mean the L298 which is an older driver, did not seem to use this approach. Oct 12 '20 at 6:25
• They do, and it's usually somewhere at the top of the data sheets (e.g. A4988, DRV8825, TMC2209). The L298 is technically not a stepper driver - if you used that, yes, you should definitely not supply it with 40V, but only the rated voltage of the stepper motor - unless you manage current and PWM yourself on the MCU driving the L298. If it's called an "integrated" or "complete" stepper motor driver, it'll use PWM to drive the coils and regulate the current. Note: When stopped on a full step, you could measure the "rated" voltage across the coils too - it's just created via PWM from Vcc.
– towe
Oct 12 '20 at 6:33