View Full Version : Powering a motor

outlawspeeder

06-15-2017, 04:15 PM

Ok I need someone smarter than me. That's everyone on this site.

I got a free geared motor that I need to power for a project.

Label reads:

Bodine Elec Co

Type 32D5BEPM-W2

Volts 130

HZ DC

AMP 1.0

HP 1/8

Torq 46

RPM 123

Ratio 20.4

I am looking for a power supply 130VDC at 1AMP? If it has a rheostat that can go CW/CCW would be great. Thoughts without busting the bank?

Mike Amick

06-15-2017, 04:29 PM

Do a search on this site for treadmill motor. Lots of posts on how to power your motor.

In short ... just look for a DC motor speed controller. Just make sure it is designed to plug

into your ac wall outlet ... and puts out DC. I only say this because there are controllers out

there where YOU have to come up with the 130v DC .. and it will vary it.

You don't say where you are from ... so I don't know what voltage comes out of your AC outlet.

outlawspeeder

06-15-2017, 04:30 PM

States 120. Thank you, that's a starting point.

danlb

06-15-2017, 04:33 PM

You have 120V DC if you attach a line cord with a 1 amp diode in series with the motor. Yeah, it's pulsating DC and would benefit from some filtering, but it is DC.

Dan

Paul Alciatore

06-15-2017, 04:42 PM

A full wave rectifier (bridge) directly connected to the 115V AC line plus a filter capacitor will give you about 160 V DC.

A rheostat by itself is not a good way to control the value or polarity of a DC Voltage. It will waste much of the power in the form of heat. But there are many DC to DC converters out there that can control the DC output. Most are switching type regulators and will operate with a high efficiency. If the one you choose does not have it, a DPDT (Double Pole, Double Throw) toggle switch can control the direction.

You can do a direct internet search, but purchasing from an established, electronic supplier is probably a safer bet. Yes, it will cost a bit more. Some that I would recommend:

DigiKey https://www.digikey.com/products/en

Jameco http://www.jameco.com/webapp/wcs/stores/servlet/StoreCatalogDisplay?storeId=10001&catalogId=10001&langId=-1

Mouser http://www.mouser.com/

Newark http://www.newark.com/

engineerd3d

06-15-2017, 04:54 PM

This guy did it nicely and it skips out on the motor controller problems associated with treadmill controller, especially the used ones etc. He uses off the shelf parts and easy schematic to have a controller that will run much larger motors.

https://www.youtube.com/watch?v=_NmAFZMAfH8

outlawspeeder

06-15-2017, 05:07 PM

And that my friends is call crowed sourcing. In the last 45 minute I went from knowing just enough to burn up the motor to knowing where to start looking

These KB units are by far the best (easy &reliable) bang for the buck.

They do require 1 interchangeable resistor to match the motor current.

Work with perm. magnet or DC excited , All in one enclosed package that you can just plug in. ;-)

http://www.ebay.com/itm/KB-Electronics-KBMD-240D-9370D-MultiDrive-Variable-Speed-DC-Motor-Control-/152583562052

MattiJ

06-15-2017, 05:42 PM

You have 120V DC if you attach a line cord with a 1 amp diode in series with the motor. Yeah, it's pulsating DC and would benefit from some filtering, but it is DC.

Dan

If you use only one diode then you have only half power, 82 volts rms "DC"

If you use full-bridge you get pulsating dc, abt 115 volts rms. Add smoothing capacitor and that would be close to 160vdc

outlawspeeder

06-15-2017, 06:00 PM

The one diode. I never thought of that. Half the sine wave.

MaxHeadRoom

06-15-2017, 11:28 PM

Full wave rectifier with no smoothing capacitor will give you around 90vdc.

The KB SCR bridge types uses this configuration for 90v T.M. motors.

Max.

RichR

06-16-2017, 12:12 AM

Full wave rectifier with no smoothing capacitor will give you around 90vdc.

Ignoring rectifier losses a full wave bridge will put out 120 volts RMS, it's just unipolar instead of bipolar. Since it's 120 volts RMS, the power is

the same as 120 volts DC.

6PTsocket

06-16-2017, 12:25 AM

You have 120V DC if you attach a line cord with a 1 amp diode in series with the motor. Yeah, it's pulsating DC and would benefit from some filtering, but it is DC.

Dan

Not quite. One diode is a half wave rectifier and passes current during one half of the sine wave and blocks during the other half. You lose half of the AC. with a big enough filter capacitor it can be made to work but half wave is usually only used for very low current demand. You want to use a bridge rectifier of four diodes that gets all the AC flowing in the same direction so the power is not off half the time and requires much less filtering for smooth DC. Also, a filtered supply like that will charge up to the peak AC voltage of around 180 volts under light load and is best followed with voltage regulation.

Sent from my SM-G900V using Tapatalk

6PTsocket

06-16-2017, 12:28 AM

The one diode. I never thought of that. Half the sine wave.

And half the voltage. The RMS value is only 60 volts. He has a 130 volt DC motor. Some of the other posts explain it quite well.

Sent from my SM-G900V using Tapatalk

Certainly you do not intend to use a DC motor at full rated voltage constantly.

Pick your environment and choose accordingly.

6PTsocket

06-16-2017, 12:33 AM

If you use only one diode then you have only half power, 82 volts rms "DC"

If you use full-bridge you get pulsating dc, abt 115 volts rms. Add smoothing capacitor and that would be close to 160vdc

Depending on the load. Under no load the caps charge up to 12O x 1.414= close to 170 volts

Sent from my SM-G900V using Tapatalk

JRouche

06-16-2017, 12:36 AM

I was in a kinda gearmotor buying frenzy. I was in that CNC phase of wanting to motorize many tasks.

And Bodine is top of the line.

I also had no way of powering these units up. More complicated is the varying power requirements my selection has. Always DC.

I bought a bunch of power units next. Another frenzy. KB supplies always seemed to work well. And mine are older that what was shown in the other gentleman's post. Maybe 80's?? They work well and are fully protected and controllable.

The KB controllers are top notch. Solid the type I have, heat sinks in the body. Old 1980s tech... JR

MattiJ

06-16-2017, 05:42 AM

And half the voltage. The RMS value is only 60 volts. He has a 130 volt DC motor. Some of the other posts explain it quite well.

Sent from my SM-G900V using Tapatalk

Half the power(on resistive load), but not half RMS voltage. Skip every second half-cycle and the rms voltage will be 120/sqrt2 = 85 volts

Average reading volt meter would show abt 60 volts.

mattthegamer463

06-16-2017, 09:05 AM

You could use a variac (autotransformer) for speed control, just rectify the output, put on a DC volt meter to monitor the output value. Unregulated though so it will fluctuate under motor load to some extent.

Use a simple DPDT switch to reverse motor direction.

RichR

06-16-2017, 09:07 AM

Half the power(on resistive load), but not half RMS voltage.

Wrong. It will be 1/2 the voltage and 1/4 the power.

Skip every second half-cycle and the rms voltage will be 120/sqrt2 = 85 volts

120 is already in RMS and SQRT2 is used to convert between RMS and peak (sinewave). A repetitive waveform that is present half the time

will appear to produce half the voltage.

If you switch a load 1 cycle on, 1 cycle off, 1 cycle on, 1 cycle off, etc, etc, etc, it will appear as 60 volts RMS.

If you switch a load 5 cycles on, 5 cycles off, 5 cycles on, 5 cycles off, etc, etc, etc, it will appear as 60 volts RMS.

If you switch a load 1/2 cycle on, 1/2 cycle off, 1/2 cycle on, 1/2 cycle off, etc, etc, etc, it will appear as 60 volts RMS.

MattiJ

06-16-2017, 10:25 AM

Wrong. It will be 1/2 the voltage and 1/4 the power.

120 is already in RMS and SQRT2 is used to convert between RMS and peak (sinewave). A repetitive waveform that is present half the time

will appear to produce half the voltage.

If you switch a load 1 cycle on, 1 cycle off, 1 cycle on, 1 cycle off, etc, etc, etc, it will appear as 60 volts RMS.

If you switch a load 5 cycles on, 5 cycles off, 5 cycles on, 5 cycles off, etc, etc, etc, it will appear as 60 volts RMS.

If you switch a load 1/2 cycle on, 1/2 cycle off, 1/2 cycle on, 1/2 cycle off, etc, etc, etc, it will appear as 60 volts RMS.

No no, please no!

Please check the definition of RMS voltage and average voltage. I am exceptionally lazy electrical engineer so I am not going to start heavy maths here. :p

1 cycle of, 1 cycle on or 50% dyty cycle reduces POWER to half. Do we agree untils this point? To get half power there has to be 1/sqrt(2) rms voltage.

https://masteringelectronicsdesign.com/how-to-derive-the-rms-value-of-pulse-and-square-waveforms/

brian Rupnow

06-16-2017, 11:31 AM

My electrical background is rather vague, however I want to power a 12 volt motor from an automobile using 110 volt house current. I just called Sayal Electric in Barrie and he has a unit that will plug into 120 volt house current and put out 12 volt d.c. at 5 amps, for $29. That doesn't give you any flexibility in motor RPM but for this particular job, (The rotating trophy) that's okay.---Brian

flylo

06-16-2017, 12:21 PM

Brian, I've used these for 12v under $3/shipped eBay item number:252833442454

This on is variable speed 2 amp for $9. eBay item number:eBay item number:252796982454

RichR

06-16-2017, 01:28 PM

1 cycle of, 1 cycle on or 50% dyty cycle reduces POWER to half. Do we agree untils this point?

No, because if you plot the waveforms, the Y axis is measured in Volts, not Watts. A half cycle over the time period of a half cycle still has

an RMS value of 120 Volts. Over a full cycle time period that 120 Volts RMS half cycle will average to 60 Volts RMS.

MattiJ

06-16-2017, 01:46 PM

You cant average rms voltage :p

RichR

06-16-2017, 02:04 PM

MattiJ, I take it back. You are correct, the power is half so the voltage is 0.707 the original. I just needed to lie down a little while and think it through.

brian Rupnow

06-16-2017, 02:42 PM

Brian, I've used these for 12v under $3/shipped eBay item number:252833442454

This on is variable speed 2 amp for $9. eBay item number:eBay item number:252796982454

I don't deal with ebay. I did pick up the 12 volt 5 amp output from Sayal today, and it works really well. It plus the jack which the motor wires plug into cost me a grand total of $30, but I was able to see it first, and if it hadn't worked I could have returned it.

outlawspeeder

06-16-2017, 03:11 PM

This guy did it nicely and it skips out on the motor controller problems associated with treadmill controller, especially the used ones etc. He uses off the shelf parts and easy schematic to have a controller that will run much larger motors.

https://www.youtube.com/watch?v=_NmAFZMAfH8

So has anyone build and put this to use? This looks like what I am looking for. The motor maxed out at 130 Volt. This would be 120max meaning I will not hit full speed which I don't need.

Looking for Pros and Cons too.

MaxHeadRoom

06-16-2017, 03:58 PM

So has anyone build and put this to use? This looks like what I am looking for. The motor maxed out at 130 Volt. This would be 120max meaning I will not hit full speed which I don't need.

Looking for Pros and Cons too.

The only (or just one) problem is there is no features such as current limit, accel/decel adjustment, reset for reversing etc, as the original T.M. boards or the KB's offer, using one of those on a T.M. motor especially if leaving the flywheel on is going to be very tricky and risky if you want decent control.

You Might get away with it for the original Bodine motor with G.B. in the OP.

Anything else I would be very Leary, having implemented a few T.M. motors for spindles etc.

Max.

MattiJ

06-16-2017, 07:15 PM

MattiJ, I take it back. You are correct, the power is half so the voltage is 0.707 the original. I just needed to lie down a little while and think it through

Thanks, my faith in humanity is restored (thumbs up smiley)

wierdscience

06-16-2017, 09:37 PM

+1 for a KB controller,or if you want cheap-

http://www.ebay.com/itm/AC-110V-Rotary-Knob-Voltage-Speed-Controller-DC-Motor-Variable-DC0-90V-/182280105804?hash=item2a70bdaf4c:g:sFsAAOSwFe5X17F k

$30ish