02-07-2014 06:20 PM
I purchased a myDAQ a few weeks ago for an online course I'm taking. Using DMM tool in Elvis I've never been able to measure current through the Digital Multimeter. I can measure voltage but when I switch the position of the red lead to the A position and try to measure current I get all zeros. Nothing. I have the DMM setting to Specific range and set to 20mA. My circuit consists of a single 9V battery and a 2.2kohm resistor. I can't get any simpler than that.
02-07-2014 06:27 PM
02-07-2014 07:22 PM
Electrical Engineering 101. Voltage is measured in parallel of the circuit. Current is measured in series of the circuit.
02-07-2014 09:13 PM
No I had it in series. I actually Skyped with an assistant to my Professor and he watch me build the circuit and made sure everything was setup correctly and I still got no value at all on the ELVIS DMM.
It appears from the logic diagram on the top of the myDAQ that the DMM may be a separate circuit that feeds inputs into a controller. I'm think that there is something wrong with the A port of my myDAQ that is not allowing the signal to go through. Like I said I have no trouble reading voltage
02-08-2014 06:13 PM
Sorry but I DID describe my issue. My issue is this: when using the myDAQ red and black probes to read current I get no current reading. Yes I have placed the probes in series with the one 9V battery and one 2.2k ohm resistor. No reading. It's the simplest circuit I could make to test my equipment. I even had an assistant to my Professor watch me build the circuit on Skype to verify I was had everything setup right and using the probe correctly. Is there an internal fuse that could have been blown if I hooked it up incorrectly?? Something I can replace?
02-10-2014 10:07 AM
The "A" port of my myDAQ says"1 A MAX". Does that mean that inside there is a 1A fuse protecting that circuit? If so can I open the back up and replace it? What kind of warranty (if any) comes with my myDAQ and would it be void if I open up the back to replace it the fuse? I assume that because the my DAQ is used by students for learning purposes that the fuses would be replaceable and NOT board mounted for obvious reasons.
Let me know! Thanks!
02-10-2014 02:54 PM
Glnd,
Here are a couple of things that will help you out.
1) There is a video demonstration on how to check to see if the fuse is good on your device.
https://decibel.ni.com/content/docs/DOC-12879
2) If you look at the Safety and User Guide for myDAQ then you will find the instructions on removing the fuse. (Bottom of Page 2)
www.ni.com/pdf/manuals/375745.pdf#page=2
Hope this helps.
02-11-2014 06:24 AM
THANK YOU! I ran the test to check the internal fuse and it indicates that indeed the fuse is blown! I will buy one and replace it today!