Current Source

[Hernar]

Hello,

I want to build a current source controlled by LabVIEW. I was looking at some information and I found that you can make a voltage controlled current source, which we can control with the 0-10 v analog output of my DAQ card. The problem is that I need to generate currents of about 30 A, so these circuits dont work for my needs.

Do you have any ideas of how to build this current source?  

PXI 6229, PXI 6232

LabVIEW 8.2

[johnsold]

Hernar,

A 30 A current source can be built using the same kinds of circuits that are used for 3 mA.  You just need to add power transistors, heat sinking, protection circuits, and so forth.   If you are not an engineer or technician experienced with working with power electronics, you should hire someone or buy a product.  Otherwise you will very likely blow up some things while trying to learn how to do it right.

What is the maximum compliance voltage required?  What is the load impedance? How fast do you need to change the current?  What kinds of safety and protection requirements must be met?

Lynn 

[waldemar.hersacher]

You can buy a off the shelf power supply which is able to be controlled by an analog voltage for current limit. Set the power supply to the max. allowed voltage and the anlaog control to current limit. Sometimes you need an isolated analog amplifier between the DAQ-card and the power supply to get them work correctly.

Take a look a the specifications fo the power supply to meet all requirements johnsold was talking in his questions.

[Hernar]

Yep, I dont have much experience in electronics, so I think the easiest solution will be to control a power supply with LabVIEW to set the current limit.

Anyway thanks for your replies.

Best Regards,

Hernar