### Author Topic: WFC Not Over Unity  (Read 12536 times)

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##### Re: multiplier during switch off condition...
« Reply #16 on: December 13, 2012, 14:49:28 pm »
simply you need to find the maximum flux the core can handle

so

Flux = Bmax * Area

than simply primary turns required is = ((volts applied / flux) / frequency)

Hey,

h=0.105 inches = 0.2667 centimeters
w=0.4320 inches = 1.09728 centimeters

A = 1.09728 * 0.2667 = 0.292644576 cm2
A = 0.000029264 m2

Bmax = 500 miliTesla =>0.5 Tesla
flux = A * Bmax => 0.000029264 m2 * 0.5 Tesla => 1.4632 × 10^-5 Wb

turns = [(V / flux) / freq]
turns = [(12 volts / 1.4632 × 10^-5 Wb) / 5kHz] => 164.024057 turns

Ok, so now we have the maximum flux of the core, now what?

Since there is 10 ohms of wire resistance in the primary coil , 164 turns are not enough?

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##### Re: WFC Not Over Unity
« Reply #17 on: December 13, 2012, 15:37:25 pm »
Your calculation is correct, but i'm not sure if Bmax can be 0,5 tesla in ferrite... maybe only at powdered iron cores or up to 1,5 tesla for silicon iron...

I'm not sure but i guess that some compensation for the wire resistance can be done... probably calculating the voltage drop for a given operation.. for say it has 1 ohm primary resistance and should get maybe 5 amps flowing so maybe the target voltage is somewhat the source voltage subtracted by the voltage drop or a percentage of it...

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##### Re: WFC Not Over Unity
« Reply #18 on: December 13, 2012, 16:04:05 pm »
Your calculation is correct, but i'm not sure if Bmax can be 0,5 tesla in ferrite... maybe only at powdered iron cores or up to 1,5 tesla for silicon iron...

I'm not sure but i guess that some compensation for the wire resistance can be done... probably calculating the voltage drop for a given operation.. for say it has 1 ohm primary resistance and should get maybe 5 amps flowing so maybe the target voltage is somewhat the source voltage subtracted by the voltage drop or a percentage of it...

Seb,

Yes it depends on temperature for example: MnZn B for 25 degrees C ; 10kHz; 1200 A/m; 500mT or 100 degrees C ; 10kHz; 1200 A/m; 440mT. 30AWG wire won't take 5 amps!!!

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• let the voltage do the work
##### Re: WFC Not Over Unity
« Reply #19 on: December 13, 2012, 20:38:49 pm »
electron speed is important, if you control electron speed you have OU.

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##### Re: WFC Not Over Unity
« Reply #20 on: December 15, 2012, 09:06:57 am »
ok seb try your math skills on this  http://www.ionizationx.com/index.php/topic,2567.0.html
its an dan danforth homemade inductor, its one of the few parts I hadn't come up with a value for yet
for this early Sri Lankan Meyer  clone

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##### Re: WFC Not Over Unity
« Reply #21 on: December 15, 2012, 10:03:01 am »
There's something I haven't seen being discussed any on these forums and that is the purpose of the 220 Ohms resistor Stan had in parallel with the Primary coil of his VIC Transformer. Anyone want to take a guess what its purpose is? ;-)

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##### Re: WFC Not Over Unity
« Reply #22 on: December 15, 2012, 10:41:13 am »
Used for fine tunning the input freq. to match the ouput freq. is my guess!
« Last Edit: December 15, 2012, 11:39:48 am by GPSSONAR »

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##### why do we burn so many components and go nowhere?
« Reply #23 on: December 15, 2012, 12:23:13 pm »
There's something I haven't seen being discussed any on these forums and that is the purpose of the 220 Ohms resistor Stan had in parallel with the Primary coil of his VIC Transformer. Anyone want to take a guess what its purpose is? ;-)

That would be protection in certain cases, but in this case, it controls the voltage multiplication limiting it to safer levels during switch off conditions... of course other means to protect the switch must be used too...
I pointed this out in many threads-- posts--- here..

When he talks about potential being possibly infinite if electronic components allowed it to happen he meant this.. i can only guess...

I can only add that open circuit do nothing other than burn components and coils... It were the only flaw in my previous theories.. .to those who read them in the past... not wiling to waste time to discuss further... just take a look at older posts if want...

In my primary i clearly see a doubled pulse when theres resonance... thats so because the chokes acts as primary when pulse is off... but there are two resonances when hiting it at 9khz other at 13,5khz strangely... where the second is a perfect sine wave
greatest peak is at 9khz...
could it be boyces longitudinal resonance?

Do you know the method for analysing potential in networks?

well i learned but is hard to explain but a must to understand how things go on. basicaly the sum of the potentials around a circuit must be zero. from that you can understand the stress across the components as function of time if you want...
« Last Edit: December 15, 2012, 14:39:56 pm by sebosfato »