DC motor start curve

[minigran]

Has anyone built a program to plot the start up curve of a DC motors current draw over a shunt or similar device. I need to self teach 30 parts, add a tolerance to the upper and lower extremes and check 100% of our production. 

[Kalin_T]

Dear minigram,

Could you please be more specific in what you are trying to do? What kind of hardware are you using for:

1. Controlling your motor

2. Acquiring data from your motor

Do you need to acquire voltage or current with your data acquisition device?

What version of LabVIEW, DAQ are you using?

Are you using any additional modules or toolkits?

What do you mean by "self-teaching 30 parts"? What parts? Teach them to do what?

What uppper and lower limits are you talking about?

In general try to be as detailed as possible in the description of your problem, so that we can figure out what team we need to assign your question to, as well as to give you a quicker reply.

Thank you!

[minigran]

Please excuse my newness to Lab View and the Forum; I have the responsibility of creating a Lab View program that will test a DC fractional Hp motor for resistance to acceleration of the armature, ARS,  by measuring the current applied to the first seconds of the start of the motor. The screen shot I attached is the actual curve measured using a Burster Digiforce 9310 Data logger. This unit sets an envelop that is created by sampling 30 known good motors current signature, adds a tolerance to the least and greatest curve. The motors then have a pass or fail based on staying within the envelop.

I have just ordered the Lab View 8.20 Pro. Dev. to do this project and will be using the Ni Compaq DAQ USB system with the plug in modules for my I/O. MY power supply will be GPIB controled 55/55 unit. All this will be housed in a 3 rack system.

My intent is to have the Lab View drive the power supply using the GPIB interface, control the test sequence and operation of at least 1 air slide controler. My local Ni Sales application engineer has said no problem with what we want to do using Lab View.

My background is that of a manufacturing engineer specializing in the CNC machine tool field. This is all new to me and my background is week in the electrical discipline so any help os appreciated as I get this going.

Bob

[Kalin_T]

Hi Bob,

Welcome to the LabVIEW world! Thank you very much for the detailed explanation! It seems like it would be better if you contact us over the phone (I suppose you participate in the Standard Support Program) once you get all of your hardware and software.

Most measurement devices can measure voltages within a certain range. With a resistor, you also can measure the current through an analog input connector. To do so, you must place a known resistance in series with the load and the voltage.

You can measure voltage dropped across the resistor and convert it to current using Ohm's Law:

I_(A) = V_(V) / R_(Ω)

where I is the current, V is the voltage, and R is the resistance.

You can get a head start with your LabVIEW experience by reading the "Learn LabVIEW in 3 Hours" Tutorial. 

Your testing set can be done in LabVIEW without a problem. You will have more specific questions once you start working on your project with the real hardware and software. Let us know if we can help with anything else in the meantime.

Best regards,