Science Buddies: "Ask an Expert"

hi scibuddy,

first I was planning to do planaria project as per our last communication, but I could not do it.

can you please help me with my artificial pancreas questions....which I have asked in other post named artificial pancreas.

Dhruv

Hi i really need help with my science fair project, artificial pancreas on the road to curing diabetes. my problem is that even though everything is plugged in the conductivity sensor isn't interacting with the circuit. i can unplug it and it wont change a thing. i also cannot make the pump turn off even by turning the potentiometer to either extremities of its rotations. please answer fast, thank you

kevin

Hi Kevin,

Sorry you are having a problem with the circuit. It will be hard for me to trouble-shoot without being able to see your breadboard with the components. Check all your connections again to make sure you have all components and the battery in the right holes. Make sure none of the wires are touching. Make sure the alligator clips are making good contact with the wires.

Try removing the potentiometer ('pot') from the circuit. Does the pump stop? Try reinserting the pot in the opposite direction. Did that make any difference? The pot may be defective.

Did you put the MOSFET in the correct holes with the black side facing right?

I'm not sure I understand what you mean by "the conductivity sensor isn't interacting with the circuit". Do you mean that the pump is running even when the sensor is not placed in liquid? If that is the case then something is wired wrong because the conductivity is what completes the circuit and makes the pump run.

One last thing--don't post your questions on another student's thread. This causes problems for the experts who are looking for specific names to go with specific projects and questions. Start your own thread and put ALL your posts in that thread.

Good luck!

Sybee