Gtlab Forum
Тематический => Гитарные усилители и примочки => Тема начата: mensur от Апреля 06, 2011, 08:26:41 am
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Hi Guys,
I want to build EL34/6L6 SE power amp, but I also want to wound OT.
According to Valveheart, full calculation goes like this(for my example):
Power P= 10W(3.6K EL34-6L6SE)
Low freq response fd=60Hz
Primary Impedance Ra=3600 Ohm / 6000 Ohm
Secondary Impedance Rs=4/8 Ohm
Flux density B - 10000Gauss - 1T
According to Valveheart core dimension is determinated by the eq:
Q=sqrt( (Pout*G*10^6) / (fmin*B*Is)) - where:
- Pout is the output power
- G is coefficient of weight between copper and iron /G=1.5 - 1.0/
- f min is the lowest desirable frequency
- Is is the density of current in the wire - Ampere/sq. millimeter (1.5 - 2.5 A/sq. mm).
- B is Magnetic Field Intensity in Gs
I don't get this equation cause every time I calculate it I think it's wrong.
Here's mine example:
Q=sqrt( (10*1.5*10^6) / (82*10000*1.5))=3.5cm^2
I'm confused because of the lower equation, cause for the same input I get:
Q=20*sqrt(Pout/fmin)
Q=20*sqrt(10/82)=6.98cm^2
I wonder how they got 20?Can someone explain this to me
Q=20*sqrt(Pout/fmin) - but this applies for B-5000Gauss, and that's for HiFi, we need guitar OT, so we chose B-10000, other reason is, any power transformer core can be used, cause they are made for 10000Gauss - 1T.
So we get:
Q=10*sqrt(Pout/fmin)
Q=10*sqrt(10W/50Hz)
Q=4.47cm^2 - 6.25cm^2 core we will chosen
Primary turns:
n1=10^8/(4.44*B*fmin*Q)=10^8/(4.44*10000Gauss*50Hz*6.25cm^2)=7.2
U1=sqrt(Ra*Pout)=sqrt(3600*10)=190VAC
Np= n1*U1=1368 turns
Secondary turns:
Ns4=1368/(sqrt(3600/4))=45 turns
Ns8=1368/(sqrt(3600/8))=65 turns
Ns16=1368/(sqrt(3600/4))=91 turn
Primary current:Ip=Ia+Ia'
Ia=SQRT(Pout/Ra))*1000=SQRT(10/3600))*1000 = 52.70mA
Ia'=73mA(this is bias for tube)
Ip= Ia+Ia'=125.70mA
Secondary currents:
Is4=SQRT(Pout/4)=1.58A
Is8=SQRT(Pout/8)=1.12A
Is16=SQRT(Pout/16)=0.79A
Wire diameter:
wp=SQRT(Ip*0,001/3)*1,13=SQRT(125.70*0,001/3)*1,13=0.23mm - 0.3m wire is chosen
ws=SQRT(Is4*0,001/3)*1,13=SQRT(1.58*0,001/3)*1,13 = 0.82mm - 0.7m wire is chosen
Can someone who is experienced in winding OT's can confirm this, before i start wounding the transformer.
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I do not understand English
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Where are you from? Maybe you simply buy a ready-made transformer
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I do not understand English
:o
You can use google.translate.com
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'm doing. ;D
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By the way, he takes bad technical terms and the conversations
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бамбарбия?
киргуду!
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бамбарбия?
киргуду!
Ты хочеш его поставить в тупик?
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пусть знакомится... окультуривается.......
Этож классика уже можно сказать наша
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It does'nt worth effort, in my opinion. It's better to buy such items - too much work for suspicious sound improvements with little money saving.
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By the way, he takes bad technical terms and the conversations
Sorry, I wasn't sarcastic, I just want to find help.
I'm from Serbia, and It's much cheaper to wound transformer, over to get one from internet.
Can somebody explain how can I determine core size form flux density(in my case 5000Gs), power(10W), low frequency(82Hz)?
Here's http://www.valveheart-bg.com/index.html
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Кто нибудь в курс дела может ввести?
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what the transformer core is available to you?
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what the transformer core is available to you?
EI75-25*25mm - 6.25cm^2
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Available wire diameters?
Primary Impedance Ra=3600 Ohm / 6000 Ohm (3600 or 6000) or (3600 and 6000)?
Secondary Impedance 4/8 Ohm (4 or 8) or (4 and 8)?
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I'm confused because of the lower equation, cause for the same input I get:
I wonder how they got 20?Can someone explain this to me
You need to wind the transformer?
OR
Deal with the calculations?
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Available wire diameters?
Primary Impedance Ra=3600 Ohm / 6000 Ohm (3600 or 6000) or (3600 and 6000)?
Secondary Impedance 4/8 Ohm (4 or 8) or (4 and 8)?
That's just for 3.6K(EL34-6L6) / 6K(6V6)
I only want 3.6K/4 and 8R outputs
for primary I will use 0.3mm wire, for secondary I have 0.7mm wire.
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I'm confused because of the lower equation, cause for the same input I get:
I wonder how they got 20?Can someone explain this to me
You need to wind the transformer?
OR
Deal with the calculations?
Both,I want to wind it, cause i have all ready, and need the calculations for it.
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sorry, you need to go ....
later try to articulate their thoughts, to have passed through the translator
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Anatoly Kotelevets' Program results:
Выходная мощность(Вт) = 10.000 W
Сопротивление нагрузки(Ом) = 8.000 R
Сопротивление анодной нагрузки(Ом) = 3600.000 R
Площадь сердечника (кв. см) = 6.250 sm2
Низшая рабочая частота (Гц ) = 60.000 Hz
Ток анода (А) = 0.140 A
Коэффициент трансформации = 0.052
Амплитуда напряжение (В) = 268.328 V
Число витков 1 Обмотки = 2290
Число витков 2 Обмотки = 119
Ток 2 Обмотки (А) = 1.118 A
Диаметр провода 1 обмотки (мм) = 0.299 mm
Диаметр провода 2 обмотки (мм) = 0.740 mm
Максимальная Инукдиция в сердечнике (Гс) = 7031.250 Gs
Толщина прокладки (мм) = 0.267 mm
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Anatoly Kotelevets' Program results:
Выходная мощность(Вт) = 10.000 W
Сопротивление нагрузки(Ом) = 8.000 R
Сопротивление анодной нагрузки(Ом) = 3600.000 R
Площадь сердечника (кв. см) = 6.250 sm2
Низшая рабочая частота (Гц ) = 60.000 Hz
Ток анода (А) = 0.140 A
Коэффициент трансформации = 0.052
Амплитуда напряжение (В) = 268.328 V
Число витков 1 Обмотки = 2290
Число витков 2 Обмотки = 119
Ток 2 Обмотки (А) = 1.118 A
Диаметр провода 1 обмотки (мм) = 0.299 mm
Диаметр провода 2 обмотки (мм) = 0.740 mm
Максимальная Инукдиция в сердечнике (Гс) = 7031.250 Gs
Толщина прокладки (мм) = 0.267 mm
Can you post the program?
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mensur
view private messages
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В этих программах как нибудь площадь куда провод мотать учитывается? А то сечение сечением, а вот количество места под обмотку тоже важно.
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В этих программах как нибудь площадь куда провод мотать учитывается? А то сечение сечением, а вот количество места под обмотку тоже важно.
I'm totaly aware of interleaved windings, I'll take primary in 3 parts and secondary in 2.
So it goes like this:
110 windings - 6 layers of 0.3mm wire - in three parts will be 1980 windings of primary.
68 windings for 4R - 98 windings for 8R - 0.7 wire for secondary.