Toroid Primary 2 Yellow Wire Wich one is + , -

[hironimo]

Hi


I have two toroids wich i would like to use as step up transformers.
The 7V windings are on the amp side and should be wired in parallel and the 230v output windings should be in series and center tapped to the bias power supply.

so the 230v output windings have both the same color and i don't know wich one i have to connect

thanks







50 VA
primary 230 VAC, 48...60 Hz
secondary 7 VAC (2x)
Prüfspannung
4 kV

[nigelwright7557]

It doesnt matter as its AC.

[bolserst]

Originally Posted by hironimo

Hi
The 7V windings are on the amp side and should be wired in parallel and the 230v output windings should be in series and center tapped to the bias power supply.

If both wires for the 230 volt winding are the same color and don't exit the transformer in physically different locations, there really isn't any way to know other than try both possibilities and measure the results.

1) Apply 1Vrms to all 4 of the primaries. You should measure about 30Vrms on each of the secondaries.
2) Now connect together one yellow wire from transformer #1 with one yellow wire from transformer #2.
3) Measure the voltage between the two remaining free yellow wires. If you get 60Vrms, you guessed correctly and the wires you connected together should be used as the center tap.
Don't forget to mark them so you don't have to repeat this test again later
4) If you get close to 0Vrms, you guessed wrong. Switch the wire from transformer #2 that you have hooked up with transformer #1. You should now measure 60Vrms between the remaining free yellow wires.

Good luck!

[hironimo]

Thank you I will try it out
and yes thats right under normal use in ac it would not matter

[CharlieM]

Originally Posted by hironimo

Hi


I have two toroids wich i would like to use as step up transformers.

50 VA
primary 230 VAC, 48...60 Hz
secondary 7 VAC (2x)
Prüfspannung
4 kV

Hi hironimo,
Could you please post where you purchased these trannys? The reason I ask is that 230v toroids are generally not available in the US and it's so hard to find an overseas source that 1) accepts online payment via US credit card and 2) will ship to the USA.

BTW: I'm using tandem 230v/2x6v toroids in my hybrid esl's and they sound wonderful and I'll bet yours will too.

[URL="http://jazzman-esl-page.blogspot.com/"]

regards,
Charlie

[hironimo]

Hi Charlie

I bought the Toroidal Core Transformer online:

https://www.distrelec.com:443/ishopW...&vendorPhrase=

but I don't know if they ship to to the USA


regards

Hironimo

[hironimo]

Hi

Thank you bolserst
I found out which two yellow wires are connected to the center tab.

the bias power supply I want to use has negative output.

I have now two remaining free yellow wires which go to the stators does it matter which one is connected to the front and back stator ( like + /- with normal magnet speaker) ?

thank you

[bolserst]

Originally Posted by hironimo

I have now two remaining free yellow wires which go to the stators does it matter which one is connected to the front and back stator ( like + /- with normal magnet speaker) ?

hi hironimo,

Yes, switching which wires go to which stator changes the phase just like swapping +/- with a magnetic speaker. You can also switch the phase by swapping the connections to the transformer primaries.

Is your ESL full range? or a hybrid where you will be crossing over to a magnetic woofer.

If full range, then it doesn't really matter which way you hook up. Most people like to retain positive pressure output for a positive signal input from the amplifier, but I haven't personally found it to make any difference to my ears.. However, you will need to make the same connections on both left and right channels for both the stators and for the transformer primaries so they have the same phase.

If hybrid, you will need to use the connection that provides the best summation at the crossover point with the woofer. For example, if you are crossing over at 400Hz, play a 400Hz sine wave and listen on the FRONT side of the ESL with your ear midway between the ESL and the woofer. Listen to the loudness. Then switch the connections of either the woofer or the ESL, but NOT both. Then listen to the 400Hz sine wave again. The connection producing the loudest response is the connection providing matched phasing between the ESL and the woofer.

If you have some measurement or RTA software on your computer, you can play pink noise and choose the connection that gives the smoothest response at the crossover point.

[hironimo]

Hi Bolserst


thank you.

I want to build a hybrid , the esl -panels are 20 x 40 inch made of perforated steel 1mm thick with 2 mm holes 40% and 65mil D/s spacing with two vertical spacers.two torroids 230v/7v x 2 50 VA per panel and a regulated bias power supply.
the plan is to use two Behringer Reference A500 amplifier and a crossover SUPER-X PRO CX3400 ( SUPER-X PRO CX2310 ).
for the + /- thing i will try that but it needs some time till i get there.
now i'm at that point where i have to decide what kind of woofer I should use.A TL with a peerless sls-10 (cheap trick 220) (Strassacker: Lautsprecher - Boxen - Selbstbau) according to the ESl cookbook it is a good idea to use a TL.
or a dipole like Dipol W8Q ( Dipol W8Q - Lautsprecher Selbstbau by blue planet acoustic)
but i haven't heard any of them so i can't really tell.


so long

hironimo

[CharlieM]

Originally Posted by hironimo

Hi Bolserst


thank you.

I want to build a hybrid , the esl -panels are 20 x 40 inch made of perforated steel 1mm thick with 2 mm holes 40% and 65mil D/s spacing with two vertical spacers.two torroids 230v/7v x 2 50 VA per panel and a regulated bias power supply.
the plan is to use two Behringer Reference A500 amplifier and a crossover SUPER-X PRO CX3400 ( SUPER-X PRO CX2310 ).
for the + /- thing i will try that but it needs some time till i get there.
now i'm at that point where i have to decide what kind of woofer I should use.A TL with a peerless sls-10 (cheap trick 220) (Strassacker: Lautsprecher - Boxen - Selbstbau) according to the ESl cookbook it is a good idea to use a TL.
or a dipole like Dipol W8Q ( Dipol W8Q - Lautsprecher Selbstbau by blue planet acoustic)
but i haven't heard any of them so i can't really tell.


so long

hironimo

I think the perf size /open area and d/s spacing you described will give very good efficiency.

My 12x40 panels are similarly configured and they can play very loud so I'm sure that your 20x40 panels will be more than big enough for a hybrid. There is some tradeoffs with larger panel size, though, as the larger capacitance can reduce the treble response, depending the interaction of the capacitance with the trannys. With the toroids and step-up ratio you will have, I think you're probably OK with 20x40-- but if you're like me and don't have a firm understanding of how to calculate the capacitance and its effects on treble response, you might want to ask some of the more knowledgeable guys here on the forum to verify that your panels size will still give good treble response or if a slightly smaller panel would be better.

With 40" height panels and TL bass, I think your panels would be a good match for a horizontally baffled TL box placed under the stat panels like Sheldon Stokes used on his ESL 1.0's shown here: [URL="http://www.quadesl.com/diy_esl1.shtml"]

good luck with your project and keep us posted :-)
Charlie