wiring larger fan for Imhotep Osilator

[wwdotme]

I have a Imhotep fan wiring question.
I have brush less fan motor (out of a truck)I would like to rewind to use in place of the computer fan.
I have successfully rewound several computer fans but this one has me stumped because
their are 9 coils and 6 magnets. What I am asking is would I still use all nine coils or skip a couple
and run the same amount of coils to magnets. Or do I just need even number of coils?
ww

[Joit]

Hi,
you can use much Coils as you want.
There are 2 Parts of the Circuit, one is the Trigger Coil, the other the Power Coil.
They should have approx the same Impedance.
The Trigger fires the Power Coil at the N-Poles to repel. Maybe you look how much N poles are near the Coils, and use this one for the Powercircuit, and the other for Trigger.

[wwdotme]

I have .6 ohms on the coils
the rotor with the magnets has a metal band around the outside will this interfere with the magnets?
building another circuit hoping to get a test run before work today.
thanks for your answers.
ww

[wwdotme]

here is a link to a drawing of the motor.
hope it helps
link
just realized magnets are north, south alternating also..

[ren]

Hi.

You will probably find that at any given time three coils will be in phase together and all facing the same polarity of magnet. If your magnets are NSNSNS then it will be 120 degrees coils in phase for the same polarities.

This gives you the option of having three different phases which are separate from each other, each having its own triggering. Alternatively you could use all coils firing from one trigger, but some of the coils would need to be wound in reverse (or hooked up for opposite polarity) because when the master is triggered some of the coils will not be facing a north pole.

The easiest way would be to select three coils @ 120 degrees apart and wind them all the same and treat that as your drive and power coils (if you can wind bifilar).

Regards

[wwdotme]

Thank you ren and joit
I see what u are talking about I will just do the 3 120 degree coils and get it to work then maybe play with the others for multi phases. You both have been a big help.
I'm still worried a little about the metal around the outside of the magnets, but will work on winding the coils first.
thank again
ww

[Joit]

Hi,
The Metal does not matter, i got a small one, with a Metalcase and a lot of the Fan got Metal, hidden behind some Plastic

[ren]

my understanding is the metal is not ideal, but wont be too much of a problem.

[wwdotme]

Well I got the coils wound last night every third coil at 120 degrees. all wound in the same direction, tested them, they ohm'd out 2 separate coils. The wire that was on the motor may have
not been a good choice it measured out to awg 20. I hooked up my bedini ciruit, no luck
switched the trigger wires around still nothing. Now when ever I apply power my power supply trips. It is 12v 4a older pc supply that I have been using because of the low amps. Checked the diodes they check out only thing left is the transistor a 2n3055.
Looking up wire size to coil effects.
ww

[wwdotme]

tested my transistor it is now a 3 way connector.

[Joit]

tested my transistor it is now a 3 way connector.

Did you remove the Diode between E and B first before testing?
When you apply Current throught the circuit, and got a Resistor at Base, it should survive it.
The 2n3055 still can handle about 7 Amps at the Base.

And well, i tried the same with an Alternater with the same Wire Size,
but the Wires are to thick,
as to build up a good Magnetfield, what can repell the Magnets.
You would need very big Coils, that they make enough Strenght.
And at last 10 Ohms at the Coils are maybe the minimum, what you should have from windings.
Thick Wires give very less Resistance, only inductive one.
Maybe a Mix from thick and thin Wires would do it.

[wwdotme]

yes tested transistor out of the circuit

will try rewinding cols tonight with smaller wire for trigger

thanks

[wwdotme]

Well tried a smaller wire on the coils this time no luck.
Got the circuit fixed
will get some smaller wire for both and rewind with fresh wire.
till next time thank you for your input
ww

[wwdotme]

2-5-09
Well it worked for just a short period before the transistor burnt up.
used a TIP3055 transisor 4001 diode 680 resistor neon bulb and a 5k pot. using
the Imhotep schematic with these parts, works on my pc fan motor.
It spun up light flickering bright. pot was on high side 4.8k soon as I turned the knob
power supply went out and guessing transistor is now bad. I have current going
through the power coils all the time now. With the heavier wire on the
power side of motor is that spiking my transistor?
Oh transistor got VERY HOT!
bed time for me
ww

[wwdotme]

added some shots of this motor to my site
http://http://wwdotme.com/
enjoy