DC motor speed control

[kabi]

Hi, I am trying to control the speed of a 36V 2.5Amp 3000 rpm max speed DC Motor using LabVIEW. I need someone to guide me what are the hardware required to do this. 1) Which DAQ is most suited for controlling the DC motor ? 2) Any other hardware required such as a controller, etc ? 3) Any example programs for DC motor speed control ? 4) Any circuit diagrams explaining the connections to be made. I wil be grateful if someone helps me with the above said things

[johnsold]

No DAQ device can generate the kind of voltages and currents you need for that motor. So you will need some kind of controller.  

Controllers come in many styles and configurations. To select one you will need to have information on the range of speeds and how fast you will be changing the speed. If you have limitations on acceleration and deceleration, those will affect the choice of controller as well. Once you have a group of controllers which meet the requirements for the motor side, you can consider how to drive the controller from the computer.  The control inputs may be a control voltage (0 - 10 V for example), current (4-20 mA), or communications via RS-232/422/485, Ethernet, or USB.

Lynn

[kabi]

Hi Lyn,

Thanks for your reply 🙂
There is no limit on acceleration and decelaration on the motor speed. We have decided to go with a controller which can vary speeds by chaning 0 -10 V using a pot.
How to control this controller using a DAQ ?

With reagrads,
Kabilan

[johnsold]

Kabilan,

In principle you can simply feed 0-10 V from your DAQ to the input where the pot would be connected. You need to verify that the negative side of that input is connected to ground. If it is not, some kind of isolation or level shifting circuit will be required.  I have seen some controllers in the past which used non-grounded inputs. With a pot it is not a problem, but connecting a DAQ to such a controller usually releases smoke and foul odors!

Lynn