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Treadmill DC Motor Control Answered

Hi all,

I have been given a treadmill motor by a friend, sadly none of the control boards have come with it, just the motor and a transformer bolted to the same bracket.

I'm hoping someone can tell me the best way for a layman to hook this up for variable speed, as I would like to improve on my 1/4hp single phase motor currently attached to my lathe.

I don't know much about the motor and could not find a datasheet, but a pic is attached.

Is there any plug and play options that don't cost the earth, ideally i would like to be able to plug it into the mains (UK) and just control with a pot.

As always thanks in advance, you guys make this place a great resource for us noobs.



I have no idea how you found that, I must have spent 2 solid hours searching for info and found virtually nothing, I can barely stand the shame :)

More info would be great, I'm useless with electronics, safe and understand what not to touch etc, but useless.

But I can solder and screw wires into terminals with the best of them, so I looked at this: https://www.ebay.co.uk/itm/262608971745?ul_noapp=true

But was unsure about the amperage, I had no figures, but it felt a bit low, so I guess by fluke I was right.

Ideally for the lathe low speed and high torque is ideal but I guess you set me straight on that?

That triac control and DC bridge in the YouTube video is the way to go..

One may wonder why there is no need of a filter capacitor for smooth power as in an ordinary PowerSupp...
That is because the armature inductance and mechanical inertia which smooths out the torque pulsations in a rotary motor !

I did buy same rectifier and controller but can't seem to get it to work properly.

The standard potentiometer was 500k and worked, but at 50% the motor was tearing a hole in space and time and more would trip the breaker, i got a cheap 200k pot like the guy in the vid, this popped the breaker as soon as power was supplied even at 0% so then tried a 1m potentiometer with the same spec (2w 1a) as the original but that just trips the breaker as soon as power is supplied as well.

Do you have any ideas on what I'm doing wrong?

You need to add a 300k series resistor to the 200k pot so that the total resistance is still 500K ..
But which side, you must experiment... Trial and error !

I no longer get notice of someone responding, so it's hit or miss if you get answered ...

And I Can Not erase this also too

We may have to PM until they fix that too !

Hi I did try to email but not sure if you have revived it, so Ill post here to for the next guy.

I think I'm starting to grasp the concept and have got a 300k pot working
with the addition of 200k of resistors, so already 10 steps ahead of where
I was this time last week.

I have been thinking about fine control, at the moment it's about half a
turn to get the motor running and it still runs way to fast for the lathe
at 100%, could I add something like pre & post potentiometers to set the
range of the main speed control?

Maybe a 200k either side of a 100k and adjust untill the motor starts at
10% and stops near an acceptable high speed, or would I be constantly
chasing my tail and by changing the overall resistance keep changing the
point at which the motor starts to turn.

Or failing that maybe 2 in series for corse and fine control.

Either way, thank you again for your help.

And a very good class it is..

Thanks for the link, that's definitely my motor, I think I stumbles across that one while looking for the datasheet.

The DC controller page sums up pretty much what I am trying to achieve.

Thanks man, I did try something similar, same rectifier I think, but with a different speed controller.

Problem I had was the original potentiometer value was the wrong (500k) so I tried other values and everything just kept blowing fuses as soon as power was applied.

So it now rests in maybe try that again one day pile :)

Hope yours works out though, I followed this guide, maybe it will help?