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Detected Output Not Reading Correctly

Submitted by maa10 on Tue, 07/06/2010 - 14:54

Hi everyone,

So I am having trouble getting the electronics box to work. My output test does not match my set bias. That is when I set the bias to +0.5V I will get a negative voltage, and when I set it to -0.5V I will get a positive voltage. I have the red electrode clipped to the glass and the black electrode clipped to the graphite rod, so I don't know what's going on. Does anyone know what's going on?

Thanks,
Michael Albano
ALbion College

Detected Output

Submitted by PoLi_TeCHNiCa on Thu, 07/08/2010 - 12:17.

Dear Mr. Albano,
Hi! We are the Polytechnic High School branch of the SHArK project, and we had the exact same problem. We realized that the voltage marked on the box was the reverse of the actual sign. We simply switched the stickers on the box marked "Positive" and "Negative" and continued testing.
Hope this helps!
Sincerely,
The Polytechnic School Chapter

Polytechnic School

Polytech, How high is your

Submitted by maa10 on Fri, 07/09/2010 - 08:01.

Polytech,

How high is your dectected output reading? Because ours reads +.7V for a -.5V bias and -.4V for a +.5V bias. Aren't the decteded voltages suppose to be between -4V and -2V for a -.5V bias and +4V and +2 V for a +.5V bias? If so our values aren't clsoe to those ones. We think that the elctronics box might have a grounding problem, and that might have blown a chip. But maybe it is as simple as you say. Were not sure yet.

Thanks for the help,
Michael Albano
Albion College

MAA

Detected Output Not Reading Correctly

Submitted by PoLi_TeCHNiCa on Fri, 07/09/2010 - 15:16.

Mr. Albano,

Our detected output readings for a +0.5 V bias usually settle somewhere between +0.8 V and +0.3 V but a detected output reading under 1.0 V should suffice. For a negative bias, the detected output reading should be somewhere between 0.0 V and -1.0 V. It would seem that simply switching the labels would work just fine.

I just checked the SHArK Manual that we have and they claim that "as long as the output is below +/- 3 V (the sign of the current should match the sign of the potential), the scan should run successfully."

Good luck!

John, Simone, Chris, Dylan, and Claire
Polytechnic School

Polytechnic School