wiring larger fan for Imhotep Osilator

[Joit]

Usual the Circuit between C and E should not touch the Base.
But the Current goes still at Emitter side through the second Coil.
Maybe you measure, how much Volt is at the Base.
Youi can put some Alloy at the Backside from the Transistor, or get a Case for it, for cooling.
The Temperatur comes from either high Amps or high Frequency, when hes switching.
But so far you can keep it cool, it should survive.
And btw, when you turn the Pot higher, your Frequency goes up too.

[wwdotme]

ok so the pot was at about max and that would have been on the high side of the frequency so either that or high amps burnt out my transistor. Going to run a few test on the coils by spinning them up and see what I get for amps and voltage out of curiousity.

test using slow cordless drill
trigger coil is at 3.5 ohms putting out 1.8 volts & 125 mA wire size small doubled
power coil side is .5 ohms putting out 1.4 volts & 150 mA wire size awg 20

[wwdotme]

JOIT!!
It lives!!!!!!
no neon light though??
Smoked my 5k pot but runs on my 25 ohm pot or hooked straight up...
well my gets a little hot I did notice so shut it down for the night.

[Inquorate]

Try more than one transistor

I was using 3 Tip35c's connected together in parallel, and found that they were pretty indestructible running an ignition coil; my wall plug 2.5amp 15v transformer 'blew up' before they did. Actually I've sent them to dmonarch.

I saw a blue flash everywhere out of the corner of my eye (that's not where source transformer was in my vision) and a snap/ crack noise, and everything stopped. Everything was working except the transformer.

Ps my joule thief circuit chews up potentiometers in short order; flames and sizzling etc. I have to use several 1w resistors in parallel or they burn up too. Or a 12v lightbulb seems to handle amps, I've got some small 10w xenon bulbs and car tail lights. Different ohms.

[Joit]

Congrats wwdotme
The Neon is not really needed, i never use one.
But it is once something, that you got a Indication, what the best Spot is,
and other is, it helps to switch the Transistor, when the Circuit still has Current left.
But put a 10 Ohm Resistor in Serie with a Pot.
It takes some of the Ampere away from the Pot.
And connect the Base to the outer Pin of the Pot.
When the main current runs over the Middle Pin, and then to the outer, the Pot can handle it better.
You measure the Voltage between C and E, after the Diode.
That is, what you usual get out.
You can measure your Ohms at the Coils too, then you can see, how high the Base resistor can be. It should not be more, then one Coil have.
With the Pot you can adjust the Output better, because it makes a different,
which Spot you have, and this you can adjust with the Frequency/Pot.
What part of it is now still hot?

[wwdotme]

joit this thing self oscilates as soon as u hook up power
out is little over 14 volts no battery.
out put running is 12.5 no battery

[Joit]

Thats a good sign.
My Coild do not oscillate, depends, how i did wind them
Maybe you still can get a Pot at it, to adjust it some better, maybe even get a stronger one.
The RPM there can make a big different at last too.

[wwdotme]

I got a 25 ohm pot on it. can adjust it some up and down. will look around and see if I got any small resistors 100 ohm or so. see what happens then
thanks

[Joit]

Yep, you have just to have to find they right Spot, the range is not to far, where the Rotor dont speed up anymore.
I usual turn it there, where it has close highest Rpm, and turn it then some back into the 'Amp range' lower.
When you turn the Pot high, you get more Voltage from it, and lower, it gives more Amps at the charge.
But the other thing is, when you change the Source Power, you have to adjust the Pot new. It variies there all time.

I looked on your Page at your Fan, it looks great, a nice XXL Thing
And still some Spots left, where you could put Coils on it.
But that is experimenting, how good they would work there.
But you did do a good Job so far

[wwdotme]

Thanks on the motor got 4 or 5 of these to play with so when I get some new wire will rewire one of the other coil packs they are easy to switchout.

well I almost got this one all hard wired up.
Have had pc problems the other half's pc it blue screening on windows start so been working on that.
did get a few readings off the motor it is pulling almost 1 amp!! guessing the 20 guage wire on power coils.
was measuring the out put on b and c a/c i was getting about 10 volts and on d/c i was getting 12.4 but when i hooked meter up backwards it was reading -16 volts for a high. Is this normal to get a higher reading backwards?
Well sat. I move out to the garage and hook up some car batteries to see what I get. I think I got 2 that are good enough to use.

forgot before i hard wired the motor u could get it to self oscilate by starting it till it was talkin then stop it by hand and it will self oscilte but the amp draw is higher and the output is less. no real data yet.