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?

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

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

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.

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.

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.

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

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

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!