bigal_scorpio
Active Member
Hi to Eric, Nigel and all,
Before anyone gets the wrong idea about the post I don't mean the need for components that can handle the larger voltage.
What I can't understand is that I have used PWM to control small low voltage motors before and now that I come to need to make a controller for a larger PMDC motor I wondered if it would be cheaper just to buy a ready made unit, but to my surprise they don't seem to be easy to come by.
OK thinks me, they must not be very common these PMDC motors but I was wrong. Many things use them especially in industry and other things especially tread mills (which is where this motor comes from).
I then decided to check for any help in google to give me the confidence to build one myself. Again I seem to be having difficulty finding anything that applies to motors over about 90v.
Can I just make a controller as for a 12v motor and uprate the components as necessary? Is there something different in the way higher voltage controllers work? All I want to do is get this motor working as a variable speed for my Wood Lathe, which would mean I didn't have to keep changing the belt all the time. I have seen others who have done this on the web but they either don't mention how they control the motor or they get a commercial unit from ebay or somewhere.
So any help or suggestions would be welcome. Thanks, Al
Edit: The motor is a PMDC 180v 1.25Hp motor from a treadmill that was working ok but the frame was broken so scrapped.
Before anyone gets the wrong idea about the post I don't mean the need for components that can handle the larger voltage.
What I can't understand is that I have used PWM to control small low voltage motors before and now that I come to need to make a controller for a larger PMDC motor I wondered if it would be cheaper just to buy a ready made unit, but to my surprise they don't seem to be easy to come by.
OK thinks me, they must not be very common these PMDC motors but I was wrong. Many things use them especially in industry and other things especially tread mills (which is where this motor comes from).
I then decided to check for any help in google to give me the confidence to build one myself. Again I seem to be having difficulty finding anything that applies to motors over about 90v.
Can I just make a controller as for a 12v motor and uprate the components as necessary? Is there something different in the way higher voltage controllers work? All I want to do is get this motor working as a variable speed for my Wood Lathe, which would mean I didn't have to keep changing the belt all the time. I have seen others who have done this on the web but they either don't mention how they control the motor or they get a commercial unit from ebay or somewhere.
So any help or suggestions would be welcome. Thanks, Al
Edit: The motor is a PMDC 180v 1.25Hp motor from a treadmill that was working ok but the frame was broken so scrapped.