110VAC to 130VDC motor

[MidwestExpress]

Hey Everyone,

I have a project where I am building a 2x72" belt grinder. I have a perfectly good 130VDC, 4.25HP, 3170w motor to use. It came from a treadmill. My problem... how to power and then how to control.

What I want is to power it as well as control the speed of it. I could buy an $800 electronic power converter with variable speed capabilities, but one... that is more than I am willing to spend, and two... what is the fun of just buying something when you can build something! :-D

I have been out of major electronic projects such as this for a long while and I am looking for some ideas of how I can run this motor safely and for 45 min to an 1 hour at a time.

All ideas are greatly appreciated!

 

[Minder]

That is a fairly hefty motor, if running off of 120vac you will need a 30amp outlet.
One cheap way may be a Triac controller similar to used on Universal motor power tools, but with a 30a min. bridge on the output,
Remove the flywheel if fitted.
Ensure the rpm pot is at zero when first powering up.
M.

 

[MidwestExpress]

That is a fairly hefty motor, if running off of 120vac you will need a 30amp outlet.
One cheap way may be a Triac controller similar to used on Universal motor power tools, but with a 30a min. bridge on the output,
Remove the flywheel if fitted.
Ensure the rpm pot is at zero when first powering up.
M.

Is this what you are referring to?

https://www.digikey.com/product-detail/en/stmicroelectronics/T3050H-6I/497-10584-5-ND/2294982

What would the schematic look like?

 

[duke37]

The motor is labelled P.M.D.C so is likely to be a permanent magnet DC motor.The only way of controlling the speed is by controlling the voltage.

The speed is not given and could be very fast ot very slow. I doubt if the speed of a belt grinder is critical. Try the motor on 12V and see what speed you get, then work out a voltage to get the speed you want.

A transformer with a bridge rectifier is about the minimum circuit possible. A slow start with a resistor and relay shorting it out will do this or a thermistor of suitable rating.

 

[Minder]

Is this what you are referring to?
What would the schematic look like?

There are many if you Google, look for Triac controller with bridge.
With this type of control I would ensure no flywheel and always start with pot at zero.
In the DWG size the power components accordingly.
M.

 

[Harald Kapp]

May I add that you should add an EMI suppression filter on the mains side? A triac controlled circuit in that power range is sure to create a lot of EMI otherwise.