How to Run a Stepper Motor Without a Driver

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Stepper motors need a driver in order to work, however there is a simple trick to make them run directly from a transformer. The speed will slow, equal to the frequency of the grid, but this can be in fact an advantage for some projetcs that do not need high speeds.

[@edifiedsquid8061]

Thx for keeping it simple and to the point and not wasting our time with useless info. Great work!

[@ramdhansaiidi4746]

Yeah i make it right now, printer stepper motor, 12v ac transformer, 220 micro farad cap, i folowed ur steps nd it's done . thumbs up for u Sir nd 5 stars for ur instructables. Thousand thanks from tunisia.

[@kengamble8595]

Thank you ! Very helpful ! I could never throw away those little motors but didn't know what to do with them, now I do !

[@rafsoc1613]

Thank you, that’s exactly what I was looking for. I will watch the add so you can make a little commission on this.

[@mikesaunders7667]

Very useful thank you and it works so well. For all those wondering, it is an 12VAC transformer he is using.

[@ludicscience]

Thanks

[@merlinmagnus873]

A 4 wire stepper motor requires 4 separate pulse sequences to run: 90 deg(+ - 0 0), 180 deg(0 0 + -), 270 deg(- + 0 0), 360 deg(0 0 - +). Notice that sequence 1&3 and 2&4 are basically AC pairs. All that switching is usually done with an array of transistors and a controller to time the pulses 90 Degrees apart. Using AC, you can mimic it. The capacitor is there to delay the one field by 90 degrees. If you have chatter, then the 2nd field is more or less than 90 degrees off the first. Get a bunch of small caps that are rated for at least the voltage of the motor and start connecting them in parallel. when the motor runs the smoothest, then add up the ferrads of all of them and get a capacitor that size. Make sure caps are rated for AC. Example: small 24v stepper used two CBB22 caps for smooth operation. Hope this helps. Great vid by the way.

[@pankajB66]

I have a 6 terminal motor. Can I add an inductor in the third coil to get the pulse another 90 deg? Will it work?

[@gscott69]

This is great. I just salvaged a stepper motor from an old printer and I'm now using it to open and close the blinds in my living room using this method. I'm using a DPDT toggle switch to switch the capacitor from one coil to the other to reverse the motor. A simple push button in-line with the power feed operates it.

[@ludicscience]

+gscott69 Glad you like it!

[@zaidhussain5206]

Thank you so much for sharing knowledge, that also mean you need AC supply to let motor operate .

[@da1cru1]

Thanks much for the correct and seemingly simple way to "bypass" the Stepper part. I couldn't bear to throw them out, especially the small ones from 3-1/2" drives, with the worm gear shaft. They look really useful just didn't know how to keep it steady running!

[@driveitbreakitfixit7496]

you just blow my mind...i didn't know how to run them before so i was going to get rid of them but thanks to you i know how to run them so for that i will subscribe

[@ludicscience]

+Matthew Lucyshyn Thanks

[@YuanLiuTheDoc]

Excellent idea to use inductive current to identify coil terminals! As you are using LED, polarity of terminals can also be detected. (Same if a DC voltmeter is used.) As such, wiring can be completely determined without trial and error.

[@chanakyasinha8046]

Use multimeter 😑

[@Ab-qv8zc]

The diode will light up either way because the stepper motor produces ac. Once you rectify the ac to DC it will only work if the polarity is correct

[@shawnlund]

Nice job on the tutorial. I learned a great deal thank you.

[@jasonstraurss6974]

this is exactly what I needed, thanks for the help!

[@juggernautsvaderdmunchkinland]

Thanks Ludic!! Always good stuff you teach!

[@ludicscience]

Brugga Jugga Thanks!

[@jovel2075]

salamat amigo! from Philippines.

[@jeffbeck6501]

This is a great explanation of stepper motors but what I really learned here is to be able to use just a 12v transformer with no H-bridge, so it is yielding 12AC power at 60 or 50Hz depending on country, and that you can take that pulse and put that with a capacitor, and get work done. Thanks for the video. It would be nice to see a video showing the cycles of how the capacitor is charged up and released.

[@ludicscience]

+Jeff Beck Yes! when I made the video i did not have an oscilloscope

[@singsingmei]

this is exactly what i was looking for. all other videos go straight to the theory and waste 10 minutes before anything happens

[@GregorKropotkin-qu2hp]

Excellent video with much very useful information for me with my current (no pun intended!) projects! Thanks very much for that- I will now subscribe to you and hope to learn more.

[@ludicscience]

+Gregor Kropotkin Glad you like it! I will be uploading more videos, thanks for subscribing.

[@azimrashed93]

Thanks for this video. My problem is slove. Thanks again.

[@kaleemkawish2776]

Hi

[@TheSeeparag]

Lovely as always!

[@cobbiesmith9267]

Thanks for another great video very useful information

[@rohandesigns]

wow..this really helped my problem.. thanks Ludic

[@hemashri]

excellent. I studied a lot. thanks.

[@wesaveukraine]

Simple and perfect explanation. Thank you

[@dgadstv3876]

Oh i like it very much. tnx, i just pulled out motors from junked printer LX-300. I will try it.

[@purushothamanarulprasath4956]

very simple & I learned a great deal thank you.

[@cw4608]

Recommended by Jeremy Fielding. Thank you for this tutorial.

[@OghamTheBold]

So clear - so concise

[@TheMinderEngineer]

Keep hustling, big things incoming! 🚀

[@walterbunn280]

Heh... good stuff. An easy way to test my stepper motors without having to build a driver circuit is nifty. I like the comments where people are alarmed about AC through a brushless DC motor. It's funny stuff.

[@winlwin9756]

Thanks you very much L S ,this is wonderful tutorial. i have waiting another tutorials and i will subscribe twice.

[@ludicscience]

+Win Lwin Thanks

[@andrewferg8737]

Very informative. Thanks for sharing

[@thiscommentwasposted262]

Sir, you are a very smart guy. THANK YOU FOR THIS VIDEO.

[@ludicscience]

This message was posted thanks

[@cmjangra6230]

Very nice work, easy idea for running stepper motor thanks

[@colinwarner7762]

Ludic, thank you very very much for this video, it is very good, I now have an idea of what to do. many regards , Colin U.K.

[@jeffbeck6501]

Beautiful, simple design. So educational this video.

[@ludicscience]

+Jeff Beck Thank you.

[@danielpuchta674]

Thanks for the video. But how do the control system knows if the set of instruction which is sent to the motor via driver, was done? Because usually stepper motors are connected without any measuring device like rotary encoder so the system itself doesnt have any feedback if the rotation defined by steps was done. But in some cases (like if I use them for powering the axis of 3D printer) the system needs to know if the motor completed the rotation or not, and then the system can sent the command to other stepper motor to move in other axe/axis... Do the drivers have a dedicated signal for this purpose? (Like - was lastly sent set of instruction completed?). Or does it work by the principle of knowing the speed of rotation and the desired position, so the system calculates the time and after the time is reached, the system assume that the desired position was reached?

[@stefenhall9919]

Excellent Video, very informative.

[@flickmew99]

from this video now I have a new knowledge about how to check the coil

[@eriko8307]

This is very helpfull! thanks a lot!

[@Bandicoot803]

In general: It's the exact same circuit like a 230V single phase ac asynchronous motor where you declare one coil as a primary coil and the other one as an auxilary coil. To achieve the best results, you have to use the following simple formula: Ut x √2 = Uc. In this example: Ut ( 12V~ ) x √2 = Uc ( 16.97V ~ ). You have to have 17V~ on the capacitor for a smooth run. Hope I could help with these informations.

[@mbunds]

+Bandicoot803+ Thanks! This formula works excellently, and has been helpful for determining voltages in a home-built driver that optimizes coil current using dynamic DSP, like the Gecko Drives do. I’m failing at this, so far, but having help from formulas like to one you provided is much appreciated!

[@kiisofttech618]

Thank you for This simple technique

[@scottydntno]

2 questions, Where can i buy a 12v transformer and how did you power the transformer?

[@amrali4410]

excellent tut

[@crate8134]

Hi, Great solution! Could you please give me some tips on how many volts/amps AC I would need to use for a standard Nema 17 stepper motor, also what would be the best capacitor type / voltage / uF? thanks!

[@jereryder394]

Great tutorial. I'm attempting with a 4 wire, 6vlt micro stepper w/100mF cap with no motor action. Should I increase mF cap value until its running, & smoothly?

[@jasonmare33]

thank you! can you slow motor down with different capacitor or adding resistor?

[@davidbolha]

Hello, What about using an RC ESC on these type of motors ? Could they be used to drive them ? 🤔 Thanks.

[@ianosf]

Excellent video, thank you

[@ludicscience]

:)

[@dariencharlton4773]

I have a Nema23 stepper motor that takes 24V,48V. Seeing this video is telling me to wire in series the 48V is the correct voltage however, how would I calculate the capacitance considering I know resistance of coils and amperage of coils? Are there any formulas I can use?

[@chivainmanfoumbi9026]

That's hyper GREAT!!! thanks a lot bro'

[@rafenwulf]

That's really helpful, thanks!

[@martonhegedus2684]

Simple and clear..., magnifique!!! :)

[@AliRaza-po3yj]

great effort Sir :)

[@ludicscience]

:)

[@JzoneMD]

Very nice idea.. Good job..👍👍👍

[@johnpantig8447]

Good day Sir, May ask what exact value of the capasitor you have used in the video... Thanks...

[@dantudichoi1091]

simple but effective. explaination....đơn giản nhưng sâu sắc giải trình

[@houlaperes]

hola, este proceso lo podemos controlar desde una consola dmx? que hardware, sofware necesiramos?

[@conversationwithgod272]

Nice video that you should mention that it must be alternative current otherwise it will never work with continuous current

[@gabrielciliagallegos8962]

Muchas gracias!

[@cphVlwYa]

should the cap value form a resonant circuit with the induction of the coil an the frequency of tge transformer?

[@tandroid8633]

Thanks for the video.

[@diamony123]

Your a genius Manuel

[@elidari60]

It’s all sounds good how do you know which capacitor do you need you are saying that the motor supposed to be ran smoothly do I have to buy several different capacitor or does it say on the motor which capacitor do I need thank you

[@carivoj]

Do you think it is a good idea to use polarized capacitor in an AC circuit?

[@offgrid2010]

Great info. Years ago i played around with using stepper motors as generators so I'm surprised i hadn't thought of spinning the motor to test the leads. I have several SAS drives that are too much trouble to set up RAID. I managed to alter a SATA plug to get past the block on the SAS drive. All the contacts r supposed 2b the same but, unlike SATA drives, it does not spin. Maybe this will help me get there. Thank you for doing this video.

[@danieliusb2234]

Just check continuity with a multimeter, no need to invent a generator

[@grumyoseph]

Very good and thanks!

[@TaxilunarTM]

Hey friend, thank you for the valuable information! For a Brazilian, the way you speak English is very good, it is perfectly understandable. Also the way you explain it very didactic! Please answer me if the engine loses power in this type of use. I wonder if you allow me to do a similar video for Brazilian friends who do not understand English. Thanks again, please go on!

[@ludicscience]

Thanks so much!

[@DillonGaming036]

I am Brazilian and Portuguese

[@e1hak]

useful... thx for uploading...

[@tonymak9213]

Ukhgvhkgvkhgvhkgv

[@Bianchi77]

thanks for the info :) does capacitor directly connected to AC supply? no polarity ?

[@GustaveNDAYIZEYE]

Good work! I'm your subscriber!

[@rmarsh9997]

I hve several from an old server cassette drive..however they have 9 wires ..does this hack work the same on the 9 wires?

[@da1cru1]

Ok, I dug out a 4 wire step motor and tried the led test and it worked, so I came back to re-watch how to get it going, before I do I'm curious bout 3 main things. First is that "power" to both sides, as both output leads shown here are red, if so what grounds it? Then you said a fairly low (compared to other caps I've recovered), and recommended 25V min. I am a total novice to electronics, but some want to learn. Any help thanks..

[@mojtabaazhar6957]

ok tank you , is the output of the transformotor , dc? or shoul be is AC? & spead of rotation the motor is very low , is able to increase spead of rotary to eg:3000rpm?

[@bandido7994]

Tienes un transformer de 12v, son 12v de entrada o de salida? Gracias por compartir tus conocimientos.

[@craignehring]

Stepper motors are cool... thanks for this video

[@ludicscience]

I love'em.!

[@Nestor11962]

what is the capacity of the capacitor? specifically for this engine.

[@JustFun-iz9rf]

that was useful thanks

[@brucewayne-px4lv]

Excellent.

[@hiksiol6306]

Thanks for this information. Can I use a 1000 mF capacitator, and what kind of stepper motor driver controller do you recommend?

[@charlesw4160]

Excellent!

[@rameshpatel-kw3xb]

many thanks 🙏🙇simple solution

[@Jeffrey314159]

Could these motors and the circuit you've demonstrated here been used in the tabletop electromechanical adding machines of the 1960's. These simple adding machines were driven directly by a 110VAC solenoid or an AC motor, which lead for a hot chassis.

[@ludicscience]

I really don't know, have no experience with those machines

[@arunavasarkar1000]

Sir, I have taken out the motors from a old Cannon IP 1980 printer and found there are two wires. Kindly tell whether these are 24V or 12V motors. Power supply module is 24V for this printer.

[@nx7640]

thank you great info

[@fourfourfoureightyfour23]

.. always loved this video

[@rwatson2609]

Very clever my friend!

[@ludicscience]

Thank you!

[@mikeoco1850]

That's a cool little trick to identify which wires are which.

[@8bit_coder]

Now think about it, the two wires that you can connect the cap to make it forwards and backwards, you could use an NPN transistor and an arduino and switch it on and off, therefore having variable speed.

[@shhhjj2769]

Hi Sir How if i am using a 12VDC power source? As yours is 12VAC how do u adapt your circuit to my 12vdc battery 1.3Ah source?

[@ISO07ISO]

Very very good. Thanks you.

[@eCitizen1]

Thanks for this information. Do you know if the stepper motor wired this way runs at a different speed, or at the same speed you would get from it when driven by a stepper motor controller? Also, is there a scientific way to determine the best capacitor to use?

[@daryooshshirvan7878]

I think the speed of the motor depends on frequency of the outlet power. Either 50 or 60 Hz.

[@yeri5882]

great good information

[@DarienCharlton]

How does the voltage of the motor affect capacitor value?

[@anthonytanner3461]

Great tutorial - thank you - I learned a lot . My question relates to power output when running step motors in this way . How does the power output compare to running the motor with driver and or controller .Is this a viable way of using the motor to carry out practical tasks for example turning a lead screw and nut to create linear motion .? Thank you

[@Enigma758]

Probably not, because the motor is now frequency controlled and without a variable frequency controller you they can only really run at constant speed and start/stop. When you do this, you lose the ability to precisely step the motor from computer control which is probably what's needed in your application. Although if you just want to move back and forth and stop/reverse with limit switches, it might be OK for that.

[@TanvirKabir0461]

Dear Sir, Could you please tell me,how can I run a 3 phase BLDC Generator Motor without a driver? If it is possible or not? thanks!!

[@seanzacharyuy7647]

does it have to run on ac power? and does the polarity of the capacitor mater?

[@denishdenish]

You mentioned the "frequency of the grid" description, which means you are running stepper on AC current and DC, is this correct? Wouldn't the AMPS in AC current burn the motor coiling, even if it is stepped down at 12volts?

[@PetrasL_1976]

Any ideas how to run asynchronous (5 wire) stepper without driver?

[@tsaboupamela]

I enjoyed the video explanation. Could you please help with the testing of a dvd motor? Thank you