finished a set of irons for my upcoming 6C33 push-pull power amp build....
power traffo, 1 3/4inch center leg stacked to 3inches....approx. 12kg...thanks to Edrel for the end-bell and legs, powder coated dark brown, ss bolts and nuts with nylon shoulder washers....
power traffo with 2 chokes, one as differential and the other as common mode...
the two output traffos OPT's, 1 1/2 inch center legs stacked to 60mm...
power traffo, 1 3/4inch center leg stacked to 3inches....approx. 12kg...thanks to Edrel for the end-bell and legs, powder coated dark brown, ss bolts and nuts with nylon shoulder washers....
power traffo with 2 chokes, one as differential and the other as common mode...
the two output traffos OPT's, 1 1/2 inch center legs stacked to 60mm...
Hi Sir Tony, I'm new in this thread, This is my first time to post a message here I always reading your thread in how to build/rewind a DIY Transformer I have learned more knowledge and I appreciate to this thread for your sharing of your experience and skills not only this thread also in other thread. You are really expert when it comes to transformer and analyzing amplifier designs.
By the way, I bought a step down transformer made from turkey which is the Primary voltage is 380-220-0 and secondary 0-12-24-48-110 rated at 500va 50hz, I know you can help me because i want to rewind this so that i can use it to my DIY amplifier.
Target primary voltage is 220 and my secondary is 50-0-50
My transformer size,
12cm lenght
10cm height
7cm width
Center Leg = 1 3\4 inches
Stack = 2 3\4 inches
This is my first time to rewind a big transformer, i have a photo of this transformer but i don't know how to upload it here.
Can you please give me the size of the magnet wire i could use in primary and
secondary and also for the no. of turns in primary and secondary.
Best Regards,
By the way, I bought a step down transformer made from turkey which is the Primary voltage is 380-220-0 and secondary 0-12-24-48-110 rated at 500va 50hz, I know you can help me because i want to rewind this so that i can use it to my DIY amplifier.
Target primary voltage is 220 and my secondary is 50-0-50
My transformer size,
12cm lenght
10cm height
7cm width
Center Leg = 1 3\4 inches
Stack = 2 3\4 inches
This is my first time to rewind a big transformer, i have a photo of this transformer but i don't know how to upload it here.
Can you please give me the size of the magnet wire i could use in primary and
secondary and also for the no. of turns in primary and secondary.
Best Regards,
Attachments
why not show me what you have learned and let us proceed from there?
tell me how you plan to proceed and i can help you...
hi tony, i have a toroid transformer taken from an old AVR rated at 1kw and I will use for transformer amp. the primary was broken so i need to wind a new one. i just want to know the number of turns on the primary at 220v and and 45v for secondary (or turns per volt). transformer sizes are 5 inch outer diameter and 3 inch inner diameter 2 inch wide.
thanks
thanks
Last edited:
Tony,
A couple of queries.
I am trying to write a small program [command line type in C] to set out windings for output transformers based largely on Pat Turner's site.
I am a bit confused about the difference between quiescent voltage and the maximum anode voltage on the tube [and quiescent/maximum current].
Pat Turner on his Push-Pull output transformer calculations Page 1 - Class AB1 loadlines -Figure 2 shows a *Q* current at the 500 volt mark. So his quiescent voltage and anode voltage are pretty much the same.
[Also Merlin Blencowe on his website under SE Output Stage also states and highlights the fact that quiescent and anode voltage are the same based on the fact that reactive as opposed to resistive loads are being used ...].
On the other hand Steve Bench on his website under *Loadlines, Power Output and Distortion - Part 5 - Establishing a loadline* is not taking quiescent as maximum anode voltage at all and has a much more sensible way it seems of establishing loadlines .. although he is actually trying to generate composite loadlines which would be next to impossible to program [for me anyway] or at the least very time consuming.
Any thoughts ? My program need to ask this stuff at the beginning for it to work ie calculate the initial Class A, AB, B loadline values.
Next query relates to transformers and Formulas!
Ok Pat Turner works in mms and many text books are US and still use inches and furlongs.
Pat Turner uses a formula as the basis for calculating the area of the transformer centre leg as A = 300*square root(P), which would be in square mms. [Pat Turner OPT calcs Page 2 - Item 14]
RHD4 page 235 gives a formula as A = (square root(P)) / 5.58
A is square inches.
I have another book from 79 called *Practical Transformer Design Handbook* by Lowden which uses the formula as A = 0.16 * square root(P) again in square inches which sort of tallies with the one above, maybe slightly different B values were used.
As I am using Pat Turner's stuff generally I can't see where his formula comes from as there are 645 square mms in a square inch. Do you use pat Turner's site to make your trannies ?
I would prefer to use the original formulas rather than rough formulas for calculating areas etc. such as :
P = 0.707 * J * f * W * A * B
-> but again there is more confusion here as some formulas lump in a figure of 10^-8 such as the Lowden book on Page 58:
P = 0.707 * J * f * W * A * B * 10^-8 !!!!!! [this time in square cms]
What is that ten to the power of minus eight figure as it does not account for different dimensions between mms, cms, inches, it is way too large.
I cannot find an explanation for it ANYWHERE.
Any ideas, I would like to try to reconcile a proper formula to a rough one and go from there ? Thanks
A couple of queries.
I am trying to write a small program [command line type in C] to set out windings for output transformers based largely on Pat Turner's site.
I am a bit confused about the difference between quiescent voltage and the maximum anode voltage on the tube [and quiescent/maximum current].
Pat Turner on his Push-Pull output transformer calculations Page 1 - Class AB1 loadlines -Figure 2 shows a *Q* current at the 500 volt mark. So his quiescent voltage and anode voltage are pretty much the same.
[Also Merlin Blencowe on his website under SE Output Stage also states and highlights the fact that quiescent and anode voltage are the same based on the fact that reactive as opposed to resistive loads are being used ...].
On the other hand Steve Bench on his website under *Loadlines, Power Output and Distortion - Part 5 - Establishing a loadline* is not taking quiescent as maximum anode voltage at all and has a much more sensible way it seems of establishing loadlines .. although he is actually trying to generate composite loadlines which would be next to impossible to program [for me anyway] or at the least very time consuming.
Any thoughts ? My program need to ask this stuff at the beginning for it to work ie calculate the initial Class A, AB, B loadline values.
Next query relates to transformers and Formulas!
Ok Pat Turner works in mms and many text books are US and still use inches and furlongs.
Pat Turner uses a formula as the basis for calculating the area of the transformer centre leg as A = 300*square root(P), which would be in square mms. [Pat Turner OPT calcs Page 2 - Item 14]
RHD4 page 235 gives a formula as A = (square root(P)) / 5.58
A is square inches.
I have another book from 79 called *Practical Transformer Design Handbook* by Lowden which uses the formula as A = 0.16 * square root(P) again in square inches which sort of tallies with the one above, maybe slightly different B values were used.
As I am using Pat Turner's stuff generally I can't see where his formula comes from as there are 645 square mms in a square inch. Do you use pat Turner's site to make your trannies ?
I would prefer to use the original formulas rather than rough formulas for calculating areas etc. such as :
P = 0.707 * J * f * W * A * B
-> but again there is more confusion here as some formulas lump in a figure of 10^-8 such as the Lowden book on Page 58:
P = 0.707 * J * f * W * A * B * 10^-8 !!!!!! [this time in square cms]
What is that ten to the power of minus eight figure as it does not account for different dimensions between mms, cms, inches, it is way too large.
I cannot find an explanation for it ANYWHERE.
Any ideas, I would like to try to reconcile a proper formula to a rough one and go from there ? Thanks
donnyab,
RDH4 uses imperial units, Patrick uses cgs....
this is for a power traffo running 50/60 hz, for audio opt i simply scale to 20hz....but i think Patrick's computation is better...one thing i noticed is that if you follow his computations to the letter, you will end up with bigger traffos than commercial offerings....
this is because dc resistance was assumed to be zero and it can be done...computations for tubes need not be too accurate...."in the ballpark" is acceptable....
have you seen the book by Wolpert? it is available for download at YvesM's website...
you will soon find out that formulas are fine, but actually building one and testing is even more rewarding...
i just use a wire table, a pencil and paper and then i'm go......
RDH4 uses imperial units, Patrick uses cgs....
this is for a power traffo running 50/60 hz, for audio opt i simply scale to 20hz....but i think Patrick's computation is better...one thing i noticed is that if you follow his computations to the letter, you will end up with bigger traffos than commercial offerings....
this is because dc resistance was assumed to be zero and it can be done...computations for tubes need not be too accurate...."in the ballpark" is acceptable....
have you seen the book by Wolpert? it is available for download at YvesM's website...
you will soon find out that formulas are fine, but actually building one and testing is even more rewarding...
i just use a wire table, a pencil and paper and then i'm go......
as you have the traffo with you, why not unwind the wires and count them as you go....
you are asking too much from that torroid....you need to give me the size of the core without the wires, once you have taken out the wires, measure it again and we'll see...
building one and testing one ... if I ever get that far ha ha
still trying to get my head around all the formulas .. Pat Turner I think uses a very low B figure and that would mean his transformers are much bigger, almost like he is designing them for mild steel ?
so the 300 figure in his formula is probably too big by a factor of up to three
thanks
still trying to get my head around all the formulas .. Pat Turner I think uses a very low B figure and that would mean his transformers are much bigger, almost like he is designing them for mild steel ?
so the 300 figure in his formula is probably too big by a factor of up to three
thanks