Bedini Schoolgirl

[ren]

Actually I think a finer gauge will make it more efficient, just less powerful, so yes, perhaps less mechanically efficient, but electrically more efficient.

By the way, did you order SWG or AWG 24, because there is a difference?

[FranzOZ]

Thank you very much for your answer; being a "perfectionist" I would order the 23 size (or may be I can lower a bit the number of turns to lower the resistence).
Mr. Bedini's drawing show the coil being 11/2" high and 1" diameter but nothing about the diameter of the core. Any advice on that ? I hope I'm not to much of a pain with my "beginer" questions.
Thanks a lot.
Franz

[FranzOZ]

Thank you Ren.

Wire is AWG.
Why it would be more efficient electricaly with 24 ? (I don't know very much about coils and electromagnetism, just some basics).

Best regards,
Franz

[dambit]

Mr. Bedini's drawing show the coil being 11/2" high and 1" diameter but nothing about the diameter of the core. Any advice on that ? I hope I'm not to much of a pain with my "beginer" questions.
Thanks a lot.
Franz

Hi Franz,

I think you may have the measurments a little off there , but that's ok. From what I can tell most of the coils have a 3.5" flange and are 4" long. The core is usualy 3/4". This is how I build mine anyway, and they work fine. A basic bifilar coil (800 or so turns) however will not fill a spool of that size, but once you start to add more power winds it will. Beginer questions are good, reminds us about the basics again. So ask away.

Cheers,

Steve.

[FranzOZ]

Thank you Steve. The basic design calls for 450 turns, on the other hand you are talking about 800 turns - some other people use 600 or even 1000 windings. So what would be the most efficient number of turns ?; how much is to much ?
I think that on the trigger side a higher number of windings would increase the biasing voltage in the base of the transistor and on the power side would increase the radiant energy in the power coil along with the "kick" applied to the magnet. This if I'm right - considering my very limited knowledge.

[dambit]

Thank you Steve. The basic design calls for 450 turns, on the other hand you are talking about 800 turns - some other people use 600 or even 1000 windings. So what would be the most efficient number of turns ?; how much is to much ?
I think that on the trigger side a higher number of windings would increase the biasing voltage in the base of the transistor and on the power side would increase the radiant energy in the power coil along with the "kick" applied to the magnet. This if I'm right - considering my very limited knowledge.

Hi Franz,

To be honest I don't know what the optimal number of turns is. My first coil only had 360 or so turns. It worked ok but couldn't do much. The coils I have now are made by a transformer winder where I live, and I just give him the spool size (as in the above post) and tell him to fill it. Much easier than wearing away my fingertips winding them myself. I haven't got an official turn count off of him yet, but it would be between 800 and 1000. (that is with multiple windings ie. 5 or 6)

Cheers,

Steve.

[ren]

Hi FranzOZ,

If its electrical efficiency is measured by current draw, then a thinner gauge of the same length will have a lower current draw due to higher resistance. This may not translate to a higher mechanical efficiency however.bThats the basic of it as I see anyway. More turns equal stronger field, but not necessarily a higher voltage spike as some assume. The spike is best influenced by the speed of the switch, faster on and offs equal higher voltage spikes. This is why some people see higher spikes with relays I think.

[FranzOZ]

Hi Franz,

To be honest I don't know what the optimal number of turns is. My first coil only had 360 or so turns. It worked ok but couldn't do much. The coils I have now are made by a transformer winder where I live, and I just give him the spool size (as in the above post) and tell him to fill it. Much easier than wearing away my fingertips winding them myself. I haven't got an official turn count off of him yet, but it would be between 800 and 1000. (that is with multiple windings ie. 5 or 6)

Cheers,

Steve.

Thanks Steve. Lucky you that you have this winder around ; I just hate winding coils , because of that I think to wind 3 ore 4 windings on my first coil, to have room for future expansion.

Take care,
Franz

[FranzOZ]

Hi FranzOZ,

If its electrical efficiency is measured by current draw, then a thinner gauge of the same length will have a lower current draw due to higher resistance. This may not translate to a higher mechanical efficiency however.bThats the basic of it as I see anyway. More turns equal stronger field, but not necessarily a higher voltage spike as some assume. The spike is best influenced by the speed of the switch, faster on and offs equal higher voltage spikes. This is why some people see higher spikes with relays I think.

Thank you Ren, i thought of that, but how long a relay can last at this switching frequency ? If going electromechanicaly may be better using carbon brushes like the people from the Electrodyne Corp. did with the Tesla Switch that they build.

Best regards,
Franz

[krispy]

HI Guys, Just getting started with my first attempt - A couple dumb questions to make sure I get it right the first time....

Can someone recommend the best Iron core diameter? the drawings show seem to imply a 1" OD spool flange x 1.5" tall? this seems small, but so is magnet wire! if these dimensions are the ones to use, then I would think the core could be no more than 3/8" diameter...could it be 1/2?

Also, I'm thinkning I'll use a piece of rebar for my core...any comments on this? If I cant find any welding rod this may be my best option.

Oh, and one more thing...can I wrap it directly to the core, or should there be a space? i.e, if I wrapped a typical plastic spool, and slid the core in afterwards? this could allow me to test with different core materials...

Thanks in advance for any advice guys, wish me luck!

[sinergicus]

consumption going up

Hi ;I hope this tread has not died...
Because I have a question .
With my 1000 windings on coil 0.3 mm wire diameter consumption at 9 v is
100 ma.When I put a battery at the end to charge it,the sped going down and the consumption going up very much.(200 ma !!).My question is why?

Normally in my opinion) this should not occur.The energy that charging the second battery , coming from around,from the outside.Why ,my consumption going high?

[Ted Ewert]

Hi ;I hope this tread has not died...
Because I have a question .
With my 1000 windings on coil 0.3 mm wire diameter consumption at 9 v is
100 ma.When I put a battery at the end to charge it,the sped going down and the consumption going up very much.(200 ma !!).My question is why?

Normally in my opinion) this should not occur.The energy that charging the second battery , coming from around,from the outside.Why ,my consumption going high?

Can you draw us a schematic of how you have it hooked up?

[juju]

ola sinergico!! =)

Hi ;I hope this tread has not died...
Because I have a question .
With my 1000 windings on coil 0.3 mm wire diameter consumption at 9 v is
100 ma.When I put a battery at the end to charge it,the sped going down and the consumption going up very much.(200 ma !!).My question is why?

Normally in my opinion) this should not occur.The energy that charging the second battery , coming from around,from the outside.Why ,my consumption going high?

probably your are puting the back EMF on the negative, or maybe the connection of your trigger coil is in the colector?

Are you using NPN or PNP?

NPN (in phase): trigger coil goes from the base to the emiter, and the emiter to battery negative. drive coil goes from the battery positive to the colector.

PNP (out of phase): colector goes to battery negative, trigger coil goes from the base to the emiter, and drive coil goes from the battery positive to the emiter.

the path for your charging battery is a diode coming from the end of the drive coil, and going to the battery positive, if you connect it to the battery negative your consumption will be higher,

does this answer your question?

hugs

[sinergicus]

problem solved but apear another strange things ...

I unsoldered all wires and soldered back carefully.

Now the charging battery not affect the consumption ,everything is fine ,but after a while -few minutes, ,without any reason ,the speed decreasing progressively until the rotor stooped and must give him another hit to start it and go up to speed .This thing happening again and again.Why?
I didn't touch anything when the rotor stooped....

Another interesting thing I observed is the voltage across the charging battery
that goes up instantly when I put a condenser (350 microfarad 400 v)in parallel with this.From 12 v goes up to 15-16 volts....

My coil is trifilar ,0,3 mm thick with 680 ohm in the base of 2n3055 transistor and 1n4007 at the charging batteryes.
Power source is 9v dc from an transformer, alimented from wall (220ac stepped down at 9v Dc)


I put the third battery to charge it at the third wire using 1n4007 (like in trifilar bedini systems ).

When I doing this ,the second charging battery from the collector and power source+ ,go down with 1-2 volts.

For example ;if the second battery in charging mode, show without third battery coupled at third wire ,13 volt + ,with third battery will go down to approximately 12 volts (;still charging both batteries but seems the radiant energy ,from power coil,halves between that 2 batteries.The same effect is obtained if I coupled both batteries at the same output (2n3055 collector and + from power source ,normally. )

Seems ,the third wire will not add supplementary power to batteries ?
Another thing I observed,if I try to charge an HV capacitor at the third wire,
the voltage going fast at 50 v and after that, charging very slow...

Instead ,the same cap at the collector and + of power source ,the voltage goes very fast at 124 volts.... So again;the third wire,in my opinion, is not very useful...

Any opinion , thoughts?

[juju]

hmm

i dont know why your motor is going down but i suspect that maybe can be the third wiring you mention? or something else...

if you load a third windiring, the power you get in that coil, will be the same power you will loose from the colector to positive charge. And i think that will affect the drive coil to, and consumption!

so i dont recommend it, use it just as a generator coil outside of the drive/trigger coil.

hugs