On a market is a lot of magnetic stirrer for chemistry and they are quite expensive. The prices are starting around 80 € and higher. By my opinion, they are very overrated and this was a reason that I have built my own cheap one.
I had two ideas how the magnetic stirrer should work:
- Completely magnetic stirrer is as electric motor, what means that chemistry bow is inserted into coil, which rotate magnetic field and with-it metal stick in a bowl.
- Second idea was, that right under surface is mounted electric motor with strong magnet that rotate magnetic field. The chemistry bowl is on stirrer and the metal stick is rotating with magnetic field.
I choosed second idea because it is easier to do it.
Motor regulator scheme
First we have to design motor regulator for adjustable speed of stirrer.
PCB Layout
Here you can found an PCB layout design and assembled PCB.
Case preparation
In next step we have to prepare plastic box to install previous PCB and all other necessary components. In front side I attached potentiometer for speed regulation, LED that indicate the power and power switch. On back side is power outlet.
Electro-motor & magnet
As plastic box I used standard electrical box dimension 190 x 150 mm. As electro-motor I've used standard 12 V computer fan and attach on a strong magnet from an old hard drive. Fan is attached with threaded screws, firs nut is as spacer from box cover and the second one is for mounting.
Circuit and connections
Regulation board, potentiometer, LED, switch and power outlet is mounted in a box and connected together.
Finishing
For better view and to inform user I have mount all information on front panel. Front panel is drawn in Visio program.
How it works
On video you can see how magnetic stirrer works in practice. Don't forget to subscribe on my YouTube channel!
