DIY Stir Plate speed control - high/low switch

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
K

knowltonm

Well-Known Member
Joined
Feb 10, 2008
Messages
137
Reaction score
1
Location
Hudsonville, MI
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.
 
knowltonm said:
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.
Click to expand...

I built mine using a 9v 300mA wall wart and the same circuit as you did. I have no issue getting 2l of starter to get a great vortex. However, I do have the same issue you do with the vortex touching down in smaller volumes. I like your idea of a resistor inline with a high low switch. I thought about that, but I'm concerned about heat issues. I was going to experiment with lower voltage power supplies and/or a more resistant rheostat. I'll let you know my results when I do.
 
Yeah, my only real issue with the 9V 300mA supply was startup...it wouldn't start up, just a high pitched squeal until I held another strong magnet on top for a split second and took it away...starts right up after that. Maybe I didn't need a stronger supply but instead a different fan? I've got a new brushless computer fan that has only been used for this purpose...have you had issues starting yours up?
 

Similar threads

Nagorg
Stir Bar Size for Maelstrom Stir Plate
Replies
17
Views
2K
wepeeler
wepeeler
B
DIY 5KW Induction Heater
Replies
2
Views
5K
Spivey24
S
OpenSights
Starter and stir plate questions, a few anyway
Replies
3
Views
750
CodeSection
CodeSection
F
Stir plate doesn't have enough control
Replies
11
Views
1K
forgetaboudit
F
piojo
Stir plate: what kind of DC motor has high torque at low speed?
Replies
6
Views
2K
piojo
piojo
Yakima 300

Latest posts

Back
Top