Thread: Bedini SG
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Old 02-16-2008, 02:31 PM
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Sephiroth Sephiroth is offline
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Originally Posted by ren View Post
you would be changing the inductional qualitites of your trigger circuit Sep. I see it acting like a choke of sorts. Its actually a cool little experiment. Good work! If you want to play around with your trigger circuit I suggest winding a single trigger coil and using it as a pickup coil. You could wind a small one to see if it gives a faster switching time, and you can play around with the angles of pickup.

I was also thinking of a way you could use a pickup coil in place of a hall device.
thanks ren! After reading up on chokes it appears that is excatly what it is doing!

What I was trying to do was see if the trigger coil could generate enough electricity to power the relay (it cant!) but i noticed the motor behaved in a much different way with the relay in the circuit...

first I thought it was just the added resistance of the coil (which is about 67 ohms) so I took it out and increased my pot 67 ohms higher but it didn't behave the same way...

with the relay in, I have to turn my pot down (not all the way down) to get it to fire the coils but here are the wierd effects:

No self resonance

Reduced amp draw - you might remember this motor used to draw almost an amp at one point. Then rewired it to the "ring circuit" and that dropped to 470ma. But now (with the choke) it is drawing 300ma. Which is insanly low thinking about how much it used to draw!!! I can get it to operate at less then 200ma but not as high rpm.

very very slow acceleration - takes a few minutes to reach top speed.

RPM - RPM is at least equal to the top speed without the choke. possibly faster but can't be sure. I have a Tach in the post so I can confirm speed in the next week or two.

Just as a note I am using a standard superpole at the moment. I don't think my magnets are strong enough to get Aaron's superpole to work.

I also tried hooking another relay in series so that there were two relays in series but it didn't perform as well.

I also tried bridging the relay with a diode (tried it in both directions) amp draw increased (nearly doubled) but not rpm.

Will have to read a bit more about chokes and try out a few of different values on the trigger to see if there is an optimal one...
"Theory guides. Experiment decides."

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