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HELP:Dealing with Diabetes Project

Postby bahelan23 » Thu Dec 13, 2018 8:17 am

I have redid the breadboard several time and the pump will still not turn on
I have tried every solution posted: Rotating the potentiates, changing the resistors, troubleshooting etc....
we know that the pump works because we tried several times to turn the pump on using batteries.
Are there any other ways to get the pump working.
Also, when we turn the pump on with just batteries no liquid is being sucked in.

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Joined: Fri Feb 01, 2013 7:00 am
Occupation: Retired molecular biologist, university researcher and teacher

Re: HELP:Dealing with Diabetes Project

Postby SciB » Thu Dec 13, 2018 5:35 pm

Welcome to Scibuddies. Sorry you are having trouble with the diabetes demonstration project.
Troubleshooting the set-up through emails is really difficult and it sounds like you have tried most of the things that I would have suggested.

The pump not pulling up liquid is a fairly common problem with peristaltic pumps. The suction comes from rollers that compress silicone rubber tubing, and the pressure of the rollers on the tubing has to be strong enough to seal the sides of the tube air tight as it passes between the rollers. Your pump should have come with instructions on how to adjust the roller pressure and the tubing should have been the correct diameter and wall thickness to operate with your pump. Check the instructions and let me know if it starts working. With the right tubing and the right pressure, it should easily pump liquid.

The components of the circuit, particularly the MOSFETs and the potentiometers, are subject to failure and defects. If you are 100% certain that you have the circuit wired correctly and all the connections are tight, then component failure may be the cause. For troubleshooting, it helps to have a digital volt-ohm-amp multimeter. You can buy a decent one for around $20 and they are very useful around the home for testing batteries, lamp bulbs, wiring and appliances.

Try to get the pump working and hopefully you will succeed and can get the circuit set up again. If you buy the meter, you can test the leads to the pump to see if there's enough voltage to operate it. You can also troubleshoot the resistance in the circuit and test the batteries.

I hope this helps. Post again and let me know what happened.

Good luck!

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