help

[raoof]

hello

i understood that i can use ohm´s law ....and also i have 10 ohm resister which is attach to my laser diode driver ...but my question is how to volatge vs current graph ...with step of 0,1 V....using usb6009  here you can see my graph which i am trying to get.....

thanks

[raoof]

hello

i am sending picture ,,please telll me how to get ouput graph

thanks

[GerdW]

Hi raoof,

my question is how to volatge vs current graph

These steps are required:

1 output a voltage

2 read the corresponding voltage across your resistor and calculate the current

3 back to step 1 for all voltage steps

4 display all current vs voltage values in a XY graph

[raoof]

hello

i got 001.5 mv as ouput...?is that right??

how i can get corresponding  volatge valuses  across resistor  sir????

so plot currnet vs voltage

thanks

[crossrulz]

You have to vary some voltage source as an input.  You measure the current by measuring the voltage drop across the resistor.  So for each set voltage, you have a current.  Build those numbers into two arrays (one for voltage and one for current) and use an XY graph to create your plots.

1.5mV across a 10 Ohm resistor would be 150uA.  How much current are you expecting?

[raoof]

hello sir

how i can vary volatge ....?because i given 5V FROM POWER SUPPLY ,,how can i vary it..and where i should  read volatge drop ...as i am not able to see my multi meter please send me 2 array program sir.

thanks

[crossrulz]

How do you expect to do an IV curve when you can't set the voltage?  How do you tell the driver what voltage to put out?

[billko]

I really think you have to back to square one and define your requirements before attempting anything else.  From what I've read, you don't really know what you want to do, how to do it, or with what instrumentation.

[raoof]

hello

sir i am cofused ...i have 5 v ..but i am not able to vary please tell me how i can vary this 5 v which is constant ......

and can i get  your skype id ..which will be more more easy to tell you and get my solution please help me out...as i am new to labview this is my frist time using labview ......hope for the best

thanks

[crossrulz]

billko is right here:  the help you actually need right now has nothing to do with LabVIEW.  Your problem is you don't even know what you are trying to test.

So from I have been able to gather here, the goal is to perform an IV curve.  What device is this curve supposed to be done on?  If you are doing an IV curve, you need a supply that you can vary, preferably via serial port or USB (so that we can control it in software).  The measure current, you will have a 10 Ohm resistor in series that you can measure the voltage drop and derive the current.

So let's try to get that setup before we start doing anything with code.