Out of curiosity....
How do I measure the advantage of bifilar windings? Difference in R between the two secondaries?
I already got one set of transformers from toroidman (Canterbury Windings) and he argued that it gives better matching using one spool of wire than two spools of wire with bifilar winding.
It is likely that I have misunderstood the purpose of bifilar windings so take it easy with me
Cheers,
Nic
How do I measure the advantage of bifilar windings? Difference in R between the two secondaries?
I already got one set of transformers from toroidman (Canterbury Windings) and he argued that it gives better matching using one spool of wire than two spools of wire with bifilar winding.
It is likely that I have misunderstood the purpose of bifilar windings so take it easy with me
Cheers,
Nic
I am not an Tx expert, but if you have 2 secondaries wound next to each other, other than one after the other, it is more than likely that each turn of each secondary will see the same flux, have the same length, and hence the same behaviour. The interwinding capacitance would be higher, but one can also argue whether it is a disadvantage in symmetrical split rails for a balanced Class A amp. For my circlotrons, I had a different type of winding done. Not bifilar.
For the winder bifilar is more work, so some might want to argue it away.
Does it sound better ? I have no proof one way or another.
An honest answer,
Patrick
For the winder bifilar is more work, so some might want to argue it away.
Does it sound better ? I have no proof one way or another.
An honest answer,
Patrick
That depends how you define the term bifilar.
In my understanding dual bifilar secondaries mean, to me, that two wires of full cross section are wound next to each other at the same time, so that they have not only the same turns, but same lengths and see essential the same magnetic field. Each of these two wires will become one secondary.
There is another way to define bifilar. e.g. If one orders a 1500VA transformer at say 2x16Vrms, the rated current is so high that a large cross section is required. This cross section can sometimes not come from a single wire, as such a thick wire is difficult to bend round the core and hence the danger of the insulation being damaged at the corners. Or the winding machine cannot cope with such high forces required. In such cases, the winder may choose to make up the cross section of each secondary with multiple wires. e.g. each secondary has 3 wires in parallel. But he can choose to finish wind the first secondary first, and then the second on top of the first.
And then you can have a combination of both -- two windings each of 3 wires. The 6 wires would then have to be wound side by side.
This is my understanding.
And the first variant is the one I intended to specify.
Patrick
In my understanding dual bifilar secondaries mean, to me, that two wires of full cross section are wound next to each other at the same time, so that they have not only the same turns, but same lengths and see essential the same magnetic field. Each of these two wires will become one secondary.
There is another way to define bifilar. e.g. If one orders a 1500VA transformer at say 2x16Vrms, the rated current is so high that a large cross section is required. This cross section can sometimes not come from a single wire, as such a thick wire is difficult to bend round the core and hence the danger of the insulation being damaged at the corners. Or the winding machine cannot cope with such high forces required. In such cases, the winder may choose to make up the cross section of each secondary with multiple wires. e.g. each secondary has 3 wires in parallel. But he can choose to finish wind the first secondary first, and then the second on top of the first.
And then you can have a combination of both -- two windings each of 3 wires. The 6 wires would then have to be wound side by side.
This is my understanding.
And the first variant is the one I intended to specify.
Patrick
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