High Voltage/Current Measurement

[LabDoggy]

I'm a new Labview user trying to take voltage and current measurements to compute the power produced by a photovoltaic array. the array can produce 68 volts and 35 amps in full sun shine. I'm using a PCMCIA DAQ-6036E. How should I go about taking the measurements without damaging the hardware?

[Ken_S]

Hello,

You will definitely need some form of signal conditioning to allow the 6036E to measure these signals.

1) To measure the voltage you will first need to convert the voltage to a lower voltage which is within the allowable range of the 6036E (+/- 10V). This signal can be attenuated as simply as using a voltage divider circuit. Another solution would be to use one of our signal conditioning products such as the SCC-A10 to attenuate the voltage by a factor of 10 before reading it using the 6036E. I have included a link to the product page for this module:

SCC-A10

2) To measure the large current you mentioned you will also need some signal conditioning, as the 6036E cannot read current
s directly. The general idea here is to route the current signal through a resistor and then use the 6036E to read the voltage across the resistor. After you read this voltage you can use the value of the resistor to calculate the current flowing through the resistor. One important thing to remember here is to pick a resistor that has a sufficient power rating to handle the current range your array provides.

I hope this helps! Let me know if there is anything I can help with or clarify.

Ken S.
Applications Engineering
National Instruments