i am about to wind up my first toroid transformer and i have some basic questions i cant seem to find answers to.
is the insulation tape necessary?
i am winding a step up transformer for a ribbon mic and have 6 cores to play with. and an idea on the windings. but i dont understand a couple things.
i see transformers with inner wound primaries and secondaries... how are they not shorting out when they touch? or am i confused?
i know my primary will only be 1-4 turns and the secondary around 130 turns. but do i just put them close without touching? and evenly space the coils around the whole core? or is it necessary to wind over the primary with insulation tape before winding the secondary?
i am playing to help myself understand it by doing it. and i figured these questions answered would help while i wait for my cores to come in the mail
is the insulation tape necessary?
i am winding a step up transformer for a ribbon mic and have 6 cores to play with. and an idea on the windings. but i dont understand a couple things.
i see transformers with inner wound primaries and secondaries... how are they not shorting out when they touch? or am i confused?
i know my primary will only be 1-4 turns and the secondary around 130 turns. but do i just put them close without touching? and evenly space the coils around the whole core? or is it necessary to wind over the primary with insulation tape before winding the secondary?
i am playing to help myself understand it by doing it. and i figured these questions answered would help while i wait for my cores to come in the mail
your transformer will be extremely low power and low voltage, so I see no problem there.
wrap some tape over the naked core , wind on top of that , and you should use enamel wire, that is sufficient insulation between turns unless you have to wind over sharp edges or corners, and, if you have to wind the secondary on top of itself , use some tape between layers .
If you like, soak the wound transformer in hot wax to minimise microphony from the windings and finish with some tape for neatness.
For my curiosity, what are the core size and material? and where do you get them ?
what is your expected inductance of the primary and secondary ?
wrap some tape over the naked core , wind on top of that , and you should use enamel wire, that is sufficient insulation between turns unless you have to wind over sharp edges or corners, and, if you have to wind the secondary on top of itself , use some tape between layers .
If you like, soak the wound transformer in hot wax to minimise microphony from the windings and finish with some tape for neatness.
For my curiosity, what are the core size and material? and where do you get them ?
what is your expected inductance of the primary and secondary ?
From your text it would appear that you have not done sufficient reading about copper wire.
The copper wire that you need to use for transformer winding needs to be enamel coated. This is a thin layer of a laquer based enamel that coats the wire and forms an insulating layer. This is easy to see on copper wire as it will be a brownish (sometimes greenish) layer on the wire that is quite difficult to remove. It can be scraped off or rubbed off with emery paper.
The windings need to be evenly spaced around the core.
Tape will not only add insulation but will help to keep the windings in place. It's not absolutely necessary but does make life easier.
Potting the core will help stop any microphonic effects.
Hope this helps to answer your "newbie" questions before the technocrats try to baffle you with science.
The copper wire that you need to use for transformer winding needs to be enamel coated. This is a thin layer of a laquer based enamel that coats the wire and forms an insulating layer. This is easy to see on copper wire as it will be a brownish (sometimes greenish) layer on the wire that is quite difficult to remove. It can be scraped off or rubbed off with emery paper.
The windings need to be evenly spaced around the core.
Tape will not only add insulation but will help to keep the windings in place. It's not absolutely necessary but does make life easier.
Potting the core will help stop any microphonic effects.
Hope this helps to answer your "newbie" questions before the technocrats try to baffle you with science.
Two very important things too remeber.
1.use the thickest insulation layer next to the core you can get away with and use a material that has a low dielectric constant(i.e thin cardboard works) this will help to keep the transformer capacitance low.
2.spread the windings evenly about the core area as this will help to reduce any leakage inductance.
These methods will help to keep the transformers resonate frequency well above the audio range. jer
1.use the thickest insulation layer next to the core you can get away with and use a material that has a low dielectric constant(i.e thin cardboard works) this will help to keep the transformer capacitance low.
2.spread the windings evenly about the core area as this will help to reduce any leakage inductance.
These methods will help to keep the transformers resonate frequency well above the audio range. jer
Before you start, use one of the coil calculators on the web to determine the length of wire you need for the windings. This will also allow you to calculate the final throat of the torroid. You can then make a "shuttle" with the wire on it to pass through the torroid.
It helps if you turn off the radio so that you can count the turns! Helps further if you have an impedance bridge to measure the inductance when you're done. If you have too few turns you can solder on, but make sure to put a piece of shrink wrap on the wire before soldering.
It helps if you turn off the radio so that you can count the turns! Helps further if you have an impedance bridge to measure the inductance when you're done. If you have too few turns you can solder on, but make sure to put a piece of shrink wrap on the wire before soldering.
I have magnet wire from radio shack and a 23mm toroid core from allelectronics.com. I used a link someone else had posted in another forum for the core.
I guess what I'm asking is,
Should the primary and secondary be wound half and half like a pizza, or wound on top of each other but insulated by the tape. And could plumbers Teflon-like tape work for insulation?
I guess what I'm asking is,
Should the primary and secondary be wound half and half like a pizza, or wound on top of each other but insulated by the tape. And could plumbers Teflon-like tape work for insulation?
also i have no clue about the inductance, i dont even know how to calculate it, i have been slowly reading before bed like its my homework, but its not easy to soak in all at once. i figured i would wind one and take measurements and calculate if in have the right step up in the end for my ghetto first ribbon microphone, and as i progress i will learn more theory and get an idea on what works best for sound and specific uses for a transformer. i also plan on making a mic input toroid and a direct box toroid eventually
ANY suggestions would help
ANY suggestions would help
ok i got my toroid cores in today, they are 23mm amorphous cores. i dont
can have all the parts for the microphone yet and i was thinking about winding one for a diy direct box in the mean time for fun.
looking for a 200k:1.5k transformer, probably a 12:1 ratio (like a jensen kinda). Where do i start to figure out my winds? wire size for primary and secondary?
can have all the parts for the microphone yet and i was thinking about winding one for a diy direct box in the mean time for fun.
looking for a 200k:1.5k transformer, probably a 12:1 ratio (like a jensen kinda). Where do i start to figure out my winds? wire size for primary and secondary?
2.spread the windings evenly about the core area as this will help to reduce any leakage inductance.
This goes for all of the windings.
Teflon tape is okay ,but it is very thin.
It will take quite a few layers to get a good thickness.
Do you have a datasheet on the core you have?
Also do you have or acsess to a signal generator and scope?
Take a look at the thread " transformer deisign for esl" or do search on the subject or just check my other post from this time last year.
Some of my data may seem confusing but the theory is correct and that should get you started.
If you don't have the data on your core the methods I show will help you to determine them and how many turns to start with.
Don't despair it is alot of information to chew.
It took me awhile to figure out what was happening,But now I know. jer
This goes for all of the windings.
Teflon tape is okay ,but it is very thin.
It will take quite a few layers to get a good thickness.
Do you have a datasheet on the core you have?
Also do you have or acsess to a signal generator and scope?
Take a look at the thread " transformer deisign for esl" or do search on the subject or just check my other post from this time last year.
Some of my data may seem confusing but the theory is correct and that should get you started.
If you don't have the data on your core the methods I show will help you to determine them and how many turns to start with.
Don't despair it is alot of information to chew.
It took me awhile to figure out what was happening,But now I know. jer
Here are a few links in this thread that discuss transformer design as well. jer
http://www.diyaudio.com/forums/planars-exotics/161485-step-up-transformer-design.html#post2093314
Even though H.V. setups are discussed it is the same theory.
http://www.diyaudio.com/forums/plan...er-foil-caps-ribbon-membrane.html#post2510983
http://www.diyaudio.com/forums/planars-exotics/161485-step-up-transformer-design.html#post2093314
Even though H.V. setups are discussed it is the same theory.
http://www.diyaudio.com/forums/plan...er-foil-caps-ribbon-membrane.html#post2510983
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I'm curious as to why enamel coated wire is preferred over plastic coated wire?
Becuase of the thickness of the insulation.
The thinner it is ,then more windings can fit in a given space or a thicker gauge wire can be used.
The better you can fill the space on an E-I core lowers the leakage inductance.
On a toriod core one must fill the complete circumfrence of the core.
I hope that helps . jer
The thinner it is ,then more windings can fit in a given space or a thicker gauge wire can be used.
The better you can fill the space on an E-I core lowers the leakage inductance.
On a toriod core one must fill the complete circumfrence of the core.
I hope that helps . jer
Yep, it did help...thanks for the education. I wind my own crossover inductors, and I'll be sure to stick to enameled wire for future projects.
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