Electric question

[Hawk]

A question for the electricians out there. I have an electric motor I took off a treadmill

My question is this; it's rated for 2400 rpm at 115 VDC. Could I connect directly to a 12 V battery and cut down the rpm's?

I know when the motor was on the treadmill it went thru a electronic speed control. Wasn't sure if I could directly conect to the battery.

Chris

Edited January 16, 2020 by Hawk

[JimErn]

If it runs it will definitely run slower.  Typically a dc motor has that nominal voltage, and a range of voltages it operates in, do you see something like that on the motor data plate?

Load is also an issue as part of rpm's

Nothing bad will happen if you connect it to the battery give it a try

[Hawk]

38 minutes ago, JimErn said:

If it runs it will definitely run slower.  Typically a dc motor has that nominal voltage, and a range of voltages it operates in, do you see something like that on the motor data plate?

Load is also an issue as part of rpm's

Nothing bad will happen if you connect it to the battery give it a try

 

[JimErn]

Don't see it on there, but is a continuous duty motor.  not sure what you plan on using if for but keep that in mind

go for it

[Hawk]

Plan to put a flexible sanding drum on it

Chris

[spirithorse]

Hi, Hawk,
Just out of my curiosity, please let us know how this works.
With a rating of 115vdc, I would never have imagined a 12v battery
would even be an option.

God Bless! Spirithorse

[Hawk]

On 1/16/2020 at 6:16 PM, spirithorse said:

Just out of my curiosity, please let us know how this works.

Well, tried with a 12V battery, didn't get near enough RPM's and I could slow it way down just by putting my fingers on it. Then I tried hooking (2) 12V batteries together, 24V, still a fail!!! My conclusion, this is not going to work!

Back to the drawing board...

Chris

[spirithorse]

Sorry to hear it didn't work.

Do you have access to the wiring that was on the tread-mill to hook the motor back to
the original wiring?

God Bless! Spirithorse

[tgiro]

The treadmill had a controller board to control the speed of the motor. Somewhere on that board is a rectifier circuit which converts the 110 Volt AC to DC voltage. The board also has an impedance circuit on it which controls the amount of voltage to the motor to set the speed. 

A 12 volt battery will not get you any kind of speed or power from the motor - and - you will rapidly kill the battery. To get any speed or power you'll have to run at the rated voltage.

The best thing to do, if you aren't into electronic circuits, is just rig the controller board back on to the motor an control it with that. With a careful use of pulley sizes. you can probably get drums to spin at around 1750 rpm. 

What ever you do, be sure to protect yourself from bare wires and circuit traces. Find a plastic box or something to put that circuit board to protect is from sawdust and sanding dust.

Edited January 18, 2020 by tgiro

[Hawk]

I have shelved this project, all the parts of the treadmill are long gone. I'm going back to plan A, get a motor ment for this...

Thanks all for your help

Chris

[amazingkevin]

If,be been saving lots of power supplys from various things.so far the best one is a computer power supply. Plenty,watts and volts and voltages to try.

[Hawk]

10 hours ago, amazingkevin said:

computer power supply

Thanks amazingkevin... never crossed my mind, when I pursued electric model airplanes I used one for recharging flight batteries. I'll have to check this out.

Chris

[tgiro]

12 hours ago, amazingkevin said:

If,be been saving lots of power supplys from various things.so far the best one is a computer power supply. Plenty,watts and volts and voltages to try.

Note that the maximum voltage output from this supply is only +12 volts at 24 AMPS. This would be the same as connecting to a 12 volt battery.

If you shop around you can find power supplies that will give you the 115DC volts, but watch your current (amperage).