Artificial Pancreas

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marybunster
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Joined: Sun Feb 14, 2016 2:42 pm
Occupation: Parent

Artificial Pancreas

Post by marybunster »

We are trying to do this project for my daughter's science fair project. We have everything connected and the potentiometer doesn't seem to adjust when we turn the white knob. Our pump runs even when the sensor is not in any solution. From what we've read, it seems that the sensor needs an acidic environment as the conductor.

Thanks for your help.
Mary
norman40
Former Expert
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Joined: Mon Jul 14, 2014 1:49 pm
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Re: Artificial Pancreas

Post by norman40 »

Hi Mary,

Sorry that you’re having problems with your artificial pancreas circuit. The pump should not run if the conductance sensor is not in a solution. Are the bare wires of the conductance sensor touching each other? If the wires touch the conductance sensor would have a low resistance (as it would if immersed in an acidic solution) and would make the pump run.

If your conductance sensor is OK you should check to make sure the MOSFET is connected properly as this device acts as the on/off switch for the pump. And it’s a good idea to check all of the connections in the circuit. There’s a help section for this project that might be useful as well:

https://www.sciencebuddies.org/science- ... shtml#help


I hope this helps. Please ask again if you have more questions.

A. Norman
robotz
Posts: 5
Joined: Wed Feb 17, 2016 7:48 am
Occupation: Student

Re: Artificial Pancreas

Post by robotz »

I tried this experiment last fall and never got it to work until I asked the teacher in shop and electronics. He said the transister in that circuit is one you can't touch without damaging it. It hates static electricity. He showed me how to use it safely (which takes alot of special equipment) and then it sort of worked. Teaher designed a circuit with better parts that don't break when you touch them. The new circuit worked a lot better but the project still doesn't show very much.

Ask at your school if someone can help you design a better circuit.

Your science friend, Scott
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