PDA

View Full Version : Bedini SG Trigger


Mark
01-09-2009, 01:23 PM
If you make a traditional Bedini SG set up with a rotor that has 8 north facing magnets the transistor would "fire" 8 times a revolution. If you turned 4 of your magnets around and faced them south out and keeping everything else the same, would it still work but only "fire" 4 times a rotation? I assume that it would but only turn slower and not be as efficient. Then if you wanted it to "fire" on the south pole magnets couldn't you just reverse the trigger and power wires around so in is now out and out is now in?

dambit
01-09-2009, 04:10 PM
The wheel might spin a couple of time due to inertia, but when the transistor fires the electromagnet(s), depending on which way they are wound, it would pull in one pole but repell the other. This would cause the wheel to stop. I'm pretty sure anyway, I know it still works a little if you have all of the magnets the wrong way, but I'm not sure about your way. I haven't actually built one like that. :thumbsup:

Cheers,

Steve.

Mark
01-09-2009, 04:26 PM
I just looked the the Panacea Bedini file where it shows Ricks Self Runner and he is basically using the n-s-n-s magnet configuration with the standard SG. Wouldn't that set up only power the coil when the north facing magnet goes over the coil? And if so to get the coil to work on the south facing magnets would you turn the coil upside down or reverse the wires?

dambit
01-10-2009, 01:39 AM
Hi Mark,

I think the magnets in either setup will still induce a current in the trigger winding, but weather or not the rotors motion will be maintained I'm not sure. The way I see it at the moment I would say no, but I could be wrong. That happens a lot.:rofl:

As far as the wiring of the coil goes, I have wound several of my coils the "wrong" way (top is south) and each time I try to reverse the wires nothing works. I have not tried turning it upside down. The guy who I get to wind my coils always winds them for south (don't know why), so all of my chargers use south poles instead of north poles. I have not seen any difference in performance. Having said that, they still work with north facing magnets, but I get a tripple peak h-wave on the scope and the charging is pretty crap.

Cheers,

Steve.

ren
01-10-2009, 02:41 AM
Hi Mark,

Your reasonably correct in your assumptions. The south facing magnets wont trigger the transistor to fire unless your trigger wire is configured to pick up souths. Thus there will be attraction to the core, but no coil pulse on the souths. This will slow the wheel somewhat, but if it has any significant inertia this wont matter too much once it gets up to speed.

For firing on both the north and souths you should look into the Bipolar circuit, as used on the window motor. This will give you a general understanding of "switching polarities"

@ Dambit, a coil wound one way need only be flipped for opposite polarities.

kick-bak
01-10-2009, 09:54 AM
Hi

The fastest sg i've built had the magnets south out by mistake.It was really hard to start and I felt it ran slow till I turned my pot all the way up. The sg took off and started chewing about 2amps and got to over 7000rpm before I chickened out and pulled the plug on it. :eek: This setup for me would normally only use about 500ma but I had rebuilt the rotor and put the neo's in backwards.
It had a single pent-filiar(5 winds ) coil, vcr rotor with neo magnets running on a 12v car battery.
I still have the rotor, with north side out, and coil on my bench if anyone would like me to try this setup again.

BinzerBob
01-10-2009, 02:27 PM
I just looked the the Panacea Bedini file where it shows Ricks Self Runner and he is basically using the n-s-n-s magnet configuration with the standard SG. Wouldn't that set up only power the coil when the north facing magnet goes over the coil? And if so to get the coil to work on the south facing magnets would you turn the coil upside down or reverse the wires?

I believe if you look at the wave form of the bedini coil at the time that one unplugs the power battery, you will see a sine wave. That is the bedini coil will produce say +5 volts then -5 volts. And this is with North Facing magnets only...

Please look at my You Tube movie that shows this...

YouTube - 2008-11-20.wmv (http://www.youtube.com/watch?v=363H_XK-tPc)

So if you have a North South North South configuration it is pretty clear that the wave form one would get when the bedini motor is spun or it is switched off while running will produce a sine wave... only a better sine wave than with the N N N N configuration.

So I believe the NSNSNS bedini motor will work based on this deduction

So in practice when the NNNNN configuration motor is rotated by hand or say you turn off the bedini motor so say it was spinning at 2000 or so RPM, As the magnet approaches the coil it induces a say positive voltage and when the same magnet moves away from the coil a negative voltage is induced. This is my understanding of electromagnetic stuff (not really sure what polarity will be induced you have to use the right hand rule and stuff but assume I am correct for now).

Also between the N-N magnets there is a weak S magnetic pole that might exist. And if so this would amplify the positive negative induced voltage that is produced as I explained above. But overall, when the bedini coil core sees an increasing N magnetic flux a positive voltage is induced and when the magnetic N flux starts to decrease the polarity of the induced voltage reverses. ultimately if one introduces the S magnetic pole as the north is moving away the effect is amplified.

This is my guess and understanding, and so I believe that the NSNSNS configuration is good to go.

Best regards,

Mark
01-10-2009, 05:39 PM
OK, so from what I understand I wonder if you could run a SG set up with NSNS magnets charge a cap with the back EMF instead of charging a 2nd battery and even add some air core coils and dump that into the same cap, building up a little current. Then dump it back into the run battery using the south pole magnet and an air core coil to trigger a transistor. It would be dumping the cap into the run battery when no power was being extracted from it. Seems like this would work and be a self runner. Similar to the Ron Cole machine except using a transistor instead of a commutator. You could have your rotor set up NSNSNS or NNSNNS or whatever worked best. Just have your cap dump coil set up so it fires the same time the south pole magnet is over the driver coil and the cap charged coil at the same time. Has anyone tried this before? Do you understand the set up I'M proposing?

Sephiroth
01-11-2009, 03:46 PM
It would depend on how close together the magnets are but if you use the standard two magnet widths apart with a NSNSNS configuration then the coil will energise when the north magnets leave the core and also when the south magnets approach the core.

If the magnets are very close together or touching then the coil will only energise when the north magnet is leaving the core because the time when the north leaves and the south appoaches will over lap in triggering.

theremart
01-11-2009, 07:20 PM
You could vary the strength of the N to be stronger than the South... Perhaps use neos for your North and common ceramic for South so it would have some feed back but the same push as a neo.


I have had some success by putting a neo behind a ceramic magnet ( not in opposing forces ) do note, a strong neo in opposing force can kill a ceramic magnet.


There is a thread on here that talks about Rick's self runner, and if you look on google there is a video of it in operation.

bedini self runner - Google Video (http://video.google.com/videosearch?q=bedini+self+runner&hl=en&emb=0&aq=f#)

bedini self runner - Google Video (http://video.google.com/videosearch?q=bedini+self+runner&hl=en&emb=0&aq=f#)

theremart
01-11-2009, 08:15 PM
Here is another one...

bedini self runner - Google Video (http://video.google.com/videosearch?q=bedini+self+runner&hl=en&emb=0&aq=f#)

BinzerBob
01-01-2010, 04:59 PM
I found an interesting lecture from MIT which shows a small Bedini type motor that uses a top which has a N-S configuration rotor.

YouTube - Lec 18 | MIT 8.02 Electricity and Magnetism, Spring 2002 (http://www.youtube.com/watch?v=FGaSeSP0tCM) Start at 38:20 (38 minutes and 20 seconds).

From this explanation, it is apparent to me that a N-S configuration would make a Push Pull motor. Push as North pole leaves coil, and Pull as South pole approaches coil.

Best regards,