Power supply for NEMA8 Stepper Motor and L298

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Hi everyone!

What would be the recommended power supply to power a single NEMA8 stepper motor connected to a L298.

Thanks everyone.

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What are the specs of your Nema8 motor? Nema8 motors come with various specs.

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This one specifically

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If you’re using the L298 now and want a quick, safe setup: use a 5 V 2 A supply, mount a heatsink on the L298, and test at low speeds/loads. If you want better performance and reliability, swap the L298 for a DRV8825 or TMC2209 and use a 12 V 2 A supply. Set the driver current limit to approx 0.6 A.

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You can also consider A4988. It is cheap, adjustable current limit, up to ~2 A peak (with cooling). It’s a good basic choice. The A4988 is a micro-striding driver for governing the stepper motors, it is incorporated with the interpreter (translator) for the tranquil process. By this controller stepper motor can control by 2 pinouts, one pin is to regulate the direction of motor revolutions and other is for steps regulation of motor.

Introduction to A4988 - The Engineering Projects

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Hey @BellAmi223613,

Welcome to the forum!

Ahsrab gives some solid advice in regards to powering the L298.

I agree with the suggestion to move away from the L298 if possible, it’s really not efficient for driving steppers compared to modern drivers like DRV8825, A4988, or TMCs.

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Thanks so much for the info! And thanks @Ryan!
If I was to stick with the L298 (for now), could I combine this power supply with that stepper motor I linked above?

Also, If I was to try either the TMC2209 or A4988, can I still use that power supply and stepper motor?
Thank you!

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Hi @BellAmi223613,

Yes, that voltage supply should work, although it might not work to peak performance.

The L298 has a pretty significant voltage dropout even at 1A and since the Nema8 needs 3.7V to drive, you might not be able to get the motor to max speed.

image

Even if you switch to the TMC2209 or A4988, it will probably be better to go for a 12V 2A DC PSU.

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Hi Jane,

Awesome thank so much.

This i what I am thinking of getting as it will keep my options open in case I decide to switch drivers..

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Iv been trying to find the matching pairs using a small light but can’t and iv tried all the combinations.

I thought maybe the light could be faulty but it works fine for the other stepper motor I have and I can’t understand the datasheet.

The wires are green yellow black and red.

Can anyone help?

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Hi BellAmi
This copied from Adafruit web site for that motor.
If you have a motor with Green/Black/Yellow/Red color wires, to connect to our shield/hat/featherwing, put the wires in this order: Black, Red, skip ground if there is one, Green, Yellow.

If you have a motor with Yellow/Red/Orange/Blue color wires, to connect to our shield/hat/featherwing, put the wires in this order: Red, Blue, skip ground if there is one, Yellow, Orange.

The Adafruit article for that motor is here

Cheers Bob

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Hi Bob,

Thanks for the quick reply! I tried red and black but no light from the bulb. Am I missing something here?

I’m trying to connect to the l298 to run some tests.

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Hi BellAmi
If you get a result with Green and Yellow then Red and Black are the only 2 wires left. It would not be impossible to have a faulty stepper with no connection on one of the wires or an open circuit coil.

I note the motor is rated at 3.9V. You haven’t perchance applied 12V to this winding (without the bulb) have you and burned it out??

I also note that this cable has a connector fitted. You could do a continuity check (with your bulb) between the wire ends and the connector contacts. Bad crimps are not unknown either.
A bad contact in the connector could be the culprit also.
You will have to do the testing as you have the device in front of you, I haven’t

Do you have a basic multimeter. When you embark on a project or find a problem such as this you are not going far without one. Your voltage source and lamp bulb will only do so much.
Cheers Bob

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Hi Bob,

Tried that combination too and the same result.

I haven’t applied any power to the motor yet, just tested by rotating the shaft. I initially suspected i either inserted the connector the wrong way or that I didn’t plug it in all the way but this isn’t the case. I found it weird actually that the wires aren’t fixed to the motor as is the case with my other motor.

I do have a feeling though that either the motor could be faulty or there might be an issue with the wire termination inside the connector.

I don’t have a multimeter on hand unfortunately I am wondering if there is another way to test to confirm what the issue might be.

Thanks Bob.

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Hi BellAmi

Don’t quite see what that would achieve.If you connected a multimeter the motor might act as a generator

You should not be able to do that without going to a lot of trouble or just using brute force. It should be keyed.

I noted both possibilities above

If you remove the connector you might be able to get at the contacts inside to check the coil continuity directly without the cable. Or fit a known good cable.

You just might have to get one.
trouble shooting without even a basic multimeter or a known good set of bits will be next to impossible. For this sort of basic measurement you only need Volts, Amps and resistance with possibly the associated Diode test and this sort of thing is available for a very few dollars. As you add more capability of course the price will go up but if you are not even sure of basic use these add on functions will only confuse the issue.

Your light bulb for instance will not tell you if there is actually a complete open circuit or only a resistance that is high enough to prevent the bulb coming on. The difference could be quite important when trying to figure out remotely what the problem might be.
Cheers Bob

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Hi Jane

Naughty Naughty
That stepper is quoted at 3.9V. 12V might be a bit much ???
Cheers Bob
Must be slipping, I missed that bit.