knowltonm
Well-Known Member
I have built my stir plate with a the minimal setup of switch, potentiometer, and 12VDC computer fan. I was previously using a 9V 300mA power supply but I have stepped up to a 12V 800mA supply because I had issues getting the thing to start every time. I now get a nice big vortex with 900mL in the 1L flask, but at the lowest setting it was still creating a vortex that went down to the magnet. Though it was smaller, I don't think I want that fast of a stir after I run high for initial oxygenation. Has anybody put in a low/high button or switch on their stirrer for this reason? I thought it would only require a switch between the on/off and potentiometer, basically running without a resistor or with a resistor to cut down the input to the potentiometer. Anybody try this? Thanks.