Water Agitator Pump Needed

Projects General Guidance
1

Hello there,

I would like to make a "sous vide" cooking device with a crock pot I have. More or less, the concept is to keep food cooking for long periods of time at a specific temperature, which will be regulated by a waterproof thermistor and an Atmega 2560. I have some experience setting such projects up and coding. However, I would like some sort of water agitator...I thought of using a small external air pump, with a tube to the bottom of the crock pot, to constantly blow a small stream of air into crock pot.

First of all, I had trouble finding a small enough air pump. I have settled on this one:

http://www.trossenrobotics.com/robotgeek-pump-small

However, it operates at 6 or 12V, neither of which can be supplied by the 2560.

Should I choose a different pump? Are them some amplifier configurations that will allow me to run this pump off of the 2560? Should I use a completely different method altogether to agitate the water?

Thank you in advance,

Arthur

2

Since the motor (pump) only needs to run in one direction (no forward and reverse) the driver for the pump can be a logic level MOSFET. To choose a proper MOSFET you will need to know the stall current of the pump motor.

For more information google "arduino mosfet motor driver".

dc motor driver.jpg
dc motor driver.jpg804×660 40.4 KB

3

student_cougar:
Should I choose a different pump? Are them some amplifier configurations that will allow me to run this pump off of the 2560? Should I use a completely different method altogether to agitate the water?

Even if you would get a 5V water pump (they do exist - I have a bag full of them) you can't power it off the Arduino board as its regulator just can't take the strain. You have to use a separate power supply for it - the power supply can be shared between the two but power to the pump must be split off before the Arduino board.

4

Thank you both! I will look into a transistor combination that would allow me to use the pump, and perhaps a separate power supply.