Back EMF Test

[patmac]

Yeah, but no at all, that math is some complicated, I've some notions about it, you need too know technical data if you're designing some for example look this:

If you want design a wall transformer 1:10 then you take the start to make the coils, primary and secondary:

primary 10 turns and secondary 100 turns: but that take carefull because if that wall transformer is to get low the potential 120 AC to 12 AC for example, you need to knwo what AWG wire can support that current, and you need to know how much current you need on secondary, then you choose the core, for high current you need a wire with more diammeter, but more diammeter will need a core bigger to make 100 turns. if you put only 10 turns to wall 120AC copper will melt, if you put wire very gross and put on wall 120AC you can make a short circuit: understand me?. I=V/R, then you can calculate how current you will get with length wire. In the presents you can find many software for some calculations.

[EgmQC]

Yeah, but no at all, that math is some complicated, I've some notions about it, you need too know technical data if you're designing some for example look this:

If you want design a wall transformer 1:10 then you take the start to make the coils, primary and secondary:

primary 10 turns and secondary 100 turns: but that take carefull because if that wall transformer is to get low the potential 120 AC to 12 AC for example, you need to knwo what AWG wire can support that current, and you need to know how much current you need on secondary, then you choose the core, for high current you need a wire with more diammeter, but more diammeter will need a core bigger to make 100 turns. if you put only 10 turns to wall 120AC copper will melt, if you put wire very gross and put on wall 120AC you can make a short circuit: understand me?. I=V/R, then you can calculate how current you will get with length wire. In the presents you can find many software for some calculations.

I understand what you say, its realy logical for a step down transformer but what is the ratio for 1:1 coil ? its late here so maybe i need some sleep so sorry if im a little bit confuse. i just want to know how calculate the BEMF from a 1:1 coil VS Voltage appliyed.

Best Regards,
Eric

[EgmQC]

That I said it, to demonstrated that if you put more turns on your Bedini without another change will give it more HV as Back EMF, really Back EMF is relationated with impendance on coil, not with turns directally, but technically speaking when you make your coil, more turns is more impendance obviouslly if you use the same AWG wire. I was referring me that if I put more turns on my same Bedini SG, I will get higher Back EMF, then logically amp draws get low but can charge a battery much better.

Look the CitizenDC's post:
... "This ratio is 1:100 on standard ign-coils. So 12 volts become 1200 volts."....

Technically speaking that ratio is in OHM, because if you have a coil with primary one turn and secondary one hundred turns both with same AWG, then OHM ratio is 1:100. Size core or material core is proportional to inductance because you can give the same turns but need more wire (Henry) is the time that spend to saturate the core, after the core is saturated circuit is like close circuit and amp drawing is proportional to cal wire and length wire. You can search the web to get that technical data and know the impendance of your coil. Like coil spend some time to get saturated, more core is more time, (seamless to capacitors, but please no confuse them) Back EMF time is higher too.

Forget it, you already answed my question here. Sorry to waste some of your time Patmac. Time to go to bed i think. Thx alot for your help Patmac.

Best Regards,
Eric