HELP PLEASE!

Thread Starter

Petergombasek92

Joined Dec 3, 2014
6
I'm currently undertaking a D.I.Y project of making a magnetic stirrer capable of stirring liquid quantities in excess of 20L +
By trade km a plumber and electrical doesn't scare me, not at all its the fact that I'm clueless within regards to component capability, and I don't even know were to start when trying to study a wiring diagram or circuit drawings..... I thought I could work it out but im sick of buying replacement components as I keep blowing then over and over and over.....

My supply list is as followed,
-Standard high power DC motor @ 9700RPM

- my mains power is 240V AC, Electric motor is DC.... Ive been trying to make it work with something like a laptop charger... to achieve AC TO DC
Specs:
Input: 240V-50Hz 15W
Output: 15V d.c.500mA

-potentiometer (Motor speed controller)

CAN SOMEONE PLEASE SHOW ME HOW TO WIRE THIS THING !
 

ISB123

Joined May 21, 2014
1,236
That charger cant supply 1A needed for motor to work at full power and potentiometer cant handle that kind of power.Cheap pots are under 0.5W.
You should use PWM.
 

GopherT

Joined Nov 23, 2012
8,009
Do you have a spec for the motor?
Voltage at max RPM..
Current draw at stall (max current draw).

Desired RPM when stirring your flask.

Also, why magnetic and not an overhead stirrer?
Large flasks are not normally stirred magnetically because the stir bars would be too long and fat for that much torque and do not have enough magnetic strength. Therefore, they keep spinning off-axis (inefficient mixing).
 

MaxHeadRoom

Joined Jul 18, 2013
28,619
.... I thought I could work it out but im sick of buying replacement components as I keep blowing then over and over and over.....

!
Not really surprising noting the specs you have supplied so far, as already mentioned the complete specifications of the motor are needed.
240vac 50Hz, I assume you could be in UK?
Max.
 

Thread Starter

Petergombasek92

Joined Dec 3, 2014
6
I live in Australia, full motor specs are quoted with the link I pasted the link shows these specs as followed bellow;

Operating Range (V) 6-18


No load
• Voltage (V): 12
• Speed (rpm) 9700
• Current (A) 1.3

At Stall
• Torque (kg.cm) 6.0
• Current (A) 57

At Max Efficiency
• Efficiency (%) 73
• Power (W) 52
• Speed (rpm) 8490
• Torque (kg.cm) .60
• Current (A) 6.0

Dimensions
• Diameter (mm) 42
• Total Length (mm) 85
• Shaft Length (mm) 19
• Shaft Diameter (mm) 5.0
• Mounting Thread M4
 

MaxHeadRoom

Joined Jul 18, 2013
28,619
I'm currently undertaking a D.I.Y project of making a magnetic stirrer capable of stirring liquid quantities in excess of 20L +
-Standard high power DC motor @ 9700RPM

Input: 240V-50Hz 15W
Output: 15V d.c.500mA

!
Are you sure of the torque demands for the motor?
It appears without some kind of gearing you may have a torque miss match?
Do you need 9700rpm?
Max.
 

wayneh

Joined Sep 9, 2010
17,496
You do know that large magnetic stir plates are commercially available? I used one for stirring 5-gllon pails and 20L glass carboys.
 

wayneh

Joined Sep 9, 2010
17,496
Me too, but I choose my battles carefully. I build as a last resort, after first ruling out buying, followed by hacking something similar.

9700 rpm sounds WAY too high. I would guess a couple hundred rpm is as fast as a magnetic stir bar can go.

How are you going to spin the magnetic field, to drive the stir bar?
 
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