DIY magnetic stirrer

[Terryz_]

Hi all, Diying a magnetic stirrer, So sourcing for some materials..

1) Any spoilt Hard Drive, Require the Earth Magnet in the Hard Drive.

The other things, I am able to get...

And I need add advice on what to do if I want to control the speed of a CPU fan? Is it very simple to do or very complicated?

THanks and Regards

[LaW]

Simple. Go get a motor controller kit.

[Terryz_]

Simple. Go get a motor controller kit.

Not engineer person, where can get that..

[CFOh]

Terry,

if u dun need advance PWM control... just add one variable resistor to positive side of power supply... alter the resistance, u should observed the dc fan speed change. Cheers..

[Terryz_]

Terry,

if u dun need advance PWM control... just add one variable resistor to positive side of power supply... alter the resistance, u should observed the dc fan speed change. Cheers..

I know about the variable resistor, but what Ohm or what Volt and etc? I just need to attach the resistor to a Dial right?

[CFOh]

I know about the variable resistor, but what Ohm or what Volt and etc? I just need to attach the resistor to a Dial right?

ok.. your DC fan should be 12volt in general.. u should get variable resistor ~20ohm (Variable range around 20-50ohm).. you need do some soldering or attach them in Circuit bread board.. Cheers

[CFOh]

ok.. your DC fan should be 12volt in general.. u should get variable resistor ~20ohm (Variable range around 20-50ohm).. you need do some soldering or attach them in Circuit bread board.. Cheers

Pls find below the draft circuit... or try search book or web on Rheostat motor speed control method. I also almost 20year never play this leo..

[Thexder]

I have done a DIY thread for magnetic stirrer before.

[Terryz_]

ok.. your DC fan should be 12volt in general.. u should get variable resistor ~20ohm (Variable range around 20-50ohm).. you need do some soldering or attach them in Circuit bread board.. Cheers

Pls find below the draft circuit... or try search book or web on Rheostat motor speed control method. I also almost 20year never play this leo..

Thanks bro, If I got to Sim Lim Tower, will they help me connect if I show them this?

[Terryz_]

I have done a DIY thread for magnetic stirrer before.

THANKS BRO!! COOL!!! I know the basics behind it... Just that the controlling is problematic as I dun have engineering background... Unless I do without the controller...

Edited February 13, 2011 by Terryz_

[CFOh]

Thanks bro, If I got to Sim Lim Tower, will they help me connect if I show them this?

If soldering work involve, I believe they might some cost involve.

or you try electrical screw Terminal connector below, should be very easy...

and crocodile clips..

Connect your part according below, makesure your read the variable resistor layout before connect them..

Cheers...

[Terryz_]

If soldering work involve, I believe they might some cost involve.

or you try electrical screw Terminal connector below, should be very easy...

and crocodile clips..

Connect your part according below, makesure your read the variable resistor layout before connect them..

Cheers...

Thanks, I think I under this diagram a bit more...

[CFOh]

Terry, this suit yr application? Cheers.

[Terryz_]

Terry, this suit yr application? Cheers.

YES!!! THANKS BRO...

[LaW]

actually i have got lots of dead motor from car's radiator fan.

strong and heavy magnet, if you want. let me know.

i will ask my guys to dig it out for you.

[Terryz_]

actually i have got lots of dead motor from car's radiator fan.

strong and heavy magnet, if you want. let me know.

i will ask my guys to dig it out for you.

Thanks bro, I will try with the rare earth magnet first...

[Terryz_]

Anyone know knows how much would a variable resistor with dial cost in Sim Lim Tower... Ebay is selling quite ex... LOL..

[CFOh]

Anyone know knows how much would a variable resistor with dial cost in Sim Lim Tower... Ebay is selling quite ex... LOL..

How much is Ebay charge? shld be few dollar max? Cheers.

[Thexder]

Anyone know knows how much would a variable resistor with dial cost in Sim Lim Tower... Ebay is selling quite ex... LOL..

Variable resistor - $2-$5 depending on the resistance and quality

Knob - $0.50-$2 depending on bling factor

[Terryz_]

Is pontentiometer the same? LOL.. Sorry ah? Very limited in my knowledge of these stuffs..

[Terryz_]

Would these two work?

Potentiometer

Knob

[CFOh]

Would these two work?

Potentiometer

Knob

dun need so high resistance, 20-50ohm range will do...

[Terryz_]

Cant find leh..

LOL...

[Terryz_]

How about this?

Potentiometer

[Thexder]

Is pontentiometer the same? LOL.. Sorry ah? Very limited in my knowledge of these stuffs..

To me its the same thing.