I have basic electric knowledge but feel stuck on a few issues regarding this process. I have a 130VDC motor that I am attempting to control through a basic off/low/med/hi ceiling fan control knob. I have a properly rated rectifier for converting the ac to a dc current and understand that I also need a capacitor in parallel with the motor to smooth the current.

1)My basic understanding of electric motors tells me the draw from the 130VDC is going to be greater than 130V when initially starting the motor therefore my first thought is that I need to amplify to the voltage to the motor.

2)What rating should I be using for the capacitor in parallel.

3)I was given some advice on this subject before and was told I could use EITHER a start or a run capacitor for this purpose however it is my understanding that start capacitors are only for starting and will explode if left live in a continual system.

Thank you very much ahead of time for taking time to respond.

 

Are you using a bridge rectifier after the Triac controller?
Unless you absolutely want full rpm from the motor, you may not need the cap. if you do, it can be a 200vdc electrolytic, a motor run cap should not be needed and also they do not come in very high values needed for what you need, especially if the motor is fairly high current.
Max.

 

... I have a 130VDC motor that I am attempting to control through a basic off/low/med/hi ceiling fan control knob. I have a properly rated rectifier for converting the ac to a dc current and understand that I also need a capacitor in parallel with the motor to smooth the current.

Unlikely that the switch will work. It is made to work with a motor that has multiple windings; your likely does not.

1)My basic understanding of electric motors tells me the draw from the 130VDC is going to be greater than 130V when initially starting the motor therefore my first thought is that I need to amplify to the voltage to the motor.

It takes a higher initial current to start a motor.

2)What rating should I be using for the capacitor in parallel.

Depends on the current that the motor requires. What is the motor rating? Watts? HP? Current?

3)I was given some advice on this subject before and was told I could use EITHER a start or a run capacitor for this purpose however it is my understanding that start capacitors are only for starting and will explode if left live in a continual system.

A capacitor used for motor starting is a special AC capacitor. You should use a DC capacitor like an electrolytic with appropriate voltage rating.

 

I am using a bridge rectifier rated up to 600V, and yes full rpm is the goal.

 

I bought the motor used these are the stats I am aware of Bodine, 1/17 HP, 417 RPM, 7 in-lbs torque, 130 VDC

 

I am using a similar 130Vdc Bodine gearmotor on an airplane mover I built. I think mine was more like a 1/4HP. I used 150uF at 250Vdc electrolytic capacitor as a filter across the motor.

 

Are you using a bridge rectifier after the Triac controller?
Unless you absolutely want full rpm from the motor, you may not need the cap. if you do, it can be a 200vdc electrolytic, a motor run cap should not be needed and also they do not come in very high values needed for what you need, especially if the motor is fairly high current.
Max.

I am using a bridge rectifier rated up to 600V, and yes full rpm is the goal.

Unlikely that the switch will work. It is made to work with a motor that has multiple windings; your likely does not.



It takes a higher initial current to start a motor.



Depends on the current that the motor requires. What is the motor rating? Watts? HP? Current?



A capacitor used for motor starting is a special AC capacitor. You should use a DC capacitor like an electrolytic with appropriate voltage rating.

I bought the motor used these are the stats I am aware of Bodine, 1/17 HP, 417 RPM, 7 in-lbs torque, 130 VDC

 

How much do I need to amplify the voltage to start the motor or will the 250Vdc electrolytic capacitor take care of that?

 

This must be a Bodine motor with G.B. they usually run fine straight off of 120vac with full wave rectifier.
But for that size of motor I would estimate a 1000μf 200vdc cap if you need a little more rpm..
The motor run caps are usually just oil filled paper and do not go up that high, otherwise they would be fine.
The start caps could also be used which are larger uf and are back to back electrolytic, as you are not subjecting it to AC it should be fine to use on DC.
It would pay to remember to zero the pot at the end of use, but if you use the one/of switch built in, it should not be a problem for soft starting.
Max.

 

How much do I need to amplify the voltage to start the motor or will the 250Vdc electrolytic capacitor take care of that?

You don't have to "amplify" anything to start a motor, just connect a more-or-less steady DC voltage to it and get out of the way.

 

Thank you very much for the help I wish I had more information on the motor however the bodine site told me the serial # was a oem sale and could not give me any other information

 

What other info do you need? they are straight forward DC motors and it seems you have the important info.
Max.

 

I was asked about watts and so forth but I think I have everything I need again thank you very much.