Bi-toroid Transformer of Thane C. Heins

[Web000x]

Hey sprocket

You must be kidding because what I am stumbling onto is by accident and you are validating my finds but I am unsure of the best way to proceed.

Use an audio amplifier. Tune your primary to the impedance of the output of the audio amp, ohm's per feet of primary wire. Use a simple tone generator that you can find on a phone app or computer program. Run that into your audio amp. You'll more than likely not be really interested in the frequencies outside of the capabilities of an audio transformer with these size builds. You can use any audio amp in your house, just make sure your primary matches the output impedance of the amp.

Dave

[sprocket]

One thing I do know is that the H-Bridge you posted is the way to go and the PDF of the DIY sine wave inverter is the best there is. The narrow duty cycle pulses of DC and then the increasing width as the sine wave reaches it's peak is a great expose.

I am not going to build every circuit that I need. With all of the microprocessor based stuff around all pre-made, I should be able to buy board sections and nail them together like carpenter builds a house.

Do you know if that 0-300khz board will connect up to an H-bridge? Does it have the 4 outputs?

I will look and be back.

Mike

@BroMikey - I think we may be thinking along different lines here. I'm thinking along the lines of verifying that there really is something special going on with a Bit-toroid transformer, whereas you seem to be gearing up to build power-applications from the get-go. For instance, the only reason I can see to use a H-bridge would be in serious power applications (eg. an inverter) whereas I'm thinking along the lines of being able to drive the bit-toroid primary with 5-10 watts, as in the videos you linked to. I keep coming back to the ferrites, there is no way you are going to be able to feed serious power into a primary of toroids the size that are used in the video - and I can't even get my hands on toriods that big!

So I'd be thinking along the lines of verification - if there really is something special about this setup, then I could always look to beef things up power-wise later on.

So precisely what kind of output are you looking for from of the variable AC power supply you're planning to build?

[Matthew Jones]

...and I can't even get my hands on toriods that big!

They aren't hard to build. Most of the toroids for power application are sheet metal. You can get coil of 12 inch at the hardware store for 10 buck. Some spray paint primer to isolate it. Build any size you want.

Then its weight based for capacity, 100 va = 2lbs.

You can also cast one with soft steel buckshot and epoxy. Same formula and they can go up to about 2 khz.

You'll have to read on winding them.

They don't cost a bunch, you can buy 1 kva versions for $150 but you'll have a hard time finding the right winding pattern and you can't reverse them. So if you buy for 120vac to 12 vac it will not work in reverse only step down. Even if it appears to work you'll be around 25 - 30% efficient. They have to be wound correctly for the application.

Matt

[kEhYo77]

I think, that Auroratek core topology is basically a BiTT. It can easily be assembled using off the shelf C cores.

[BroMikey]

@BroMikey - I think we may be thinking along different lines here.
So precisely what kind of output are you looking for from of the variable AC power supply you're planning to build?

Hi Sprocket

Here is what I have well similar to it I got this off of EBAY here is a welder transformer I have winding for a 220vac



I want to input 1000 watts so I can get three.

@Sprocket and @Web000x

Yes to both I have some 8" and 7" toroidals and want to pour some magnetite bars to construct the double square TOROID.

Yes to everything. Yes I will use the simple audio amp with signal genny.

I think I don't really know what I am talking about on windings though. If I use these 220vac winding slipping them off the old core, maybe a random winding would need to be adjusted on the primary?

I really don't know so I figure get my feet wet first!!


Yes the signal generator should be connected to an H-Bridge to get a smoother more pure sine wave. Great document sprocket. That is the best.

Bubba can sure build a circuit dudes.


I have some materials to throw together a test but really I did want to start with anything less than a well considered double square toroid. Carefully selecting core materials that will have flux density pathways that are easiest between the two secondaries and the core on the primary should be many times greater.

Permalloy or ferrite have varying grades of conductivity. Look in the picture you will see bands of parmalloy my question it where can I get some?




I want to try this frame work so maybe a 15" X 10" is a good start.

Mike

[Web000x]

Yes to both I have some 8" and 7" toroidals and want to pour some magnetite bars to construct the double square TOROID.

Mike

I tried casting a core with magnetite and epoxy once. It performed horribly. I could get no transformer action out of two separate windings. However, I didn't use big enough neo magnets during the curing process. Make sure you don't skip any of Peter L's advice when making them or you will undoubtedly fail at producing anything useful..

Dave

[BroMikey]

Transformer Core


Hello Web000x

I sure will follow Peters instructions.

Here is a fun video for making an average size transformer.


(Transformer 5) - Core construction of power transformers - YouTube



transformer core testing - YouTube

[Hrothgar]

Yes I sound crazy, but!

I tried casting a core with magnetite and epoxy once. It performed horribly. I could get no transformer action out of two separate windings. However, I didn't use big enough neo magnets during the curing process. Make sure you don't skip any of Peter L's advice when making them or you will undoubtedly fail at producing anything useful..

Dave

I've poured some Magnetite cores using candle wax as the binding agent. I poured into paper forms (paper nickel tubes with a nickel plugging the bottom are easy, the kind that are already round in the bag.) When hot the oil base of the wax has little if any surface tension on the fe3o4, meaning if you keep the form hot and don't move it the fe3o4 will settle and compact itself, separating from the excess wax up top and it is a readily visible separation. The paper can be peeled off easily and the wax itself is an insulator also if you want to make them stronger just take a roll of brown paper and some white school glue from the hardware store. Dilute the glue with water and tape the end of the paper to the core. then roll the paper around the core brushing it with the diluted glue burping the air as you roll it up. Use about a foot of paper and let it dry it will shrink to fit the core.
The end product will be strong paintable, oil resistant and recyclable.

note I've tried using epoxy to mix magnetite, never again.

[BroMikey]

Study Guide of Magnets

Whenever we start a new thought it is best to not take for granted that it is a snap like falling off a log so to speak or like we know everything and can learn nothing.

Embarrassing as it may seem we know very little about magnetism and how it reacts.


Chech out the children's SCIENCE GUY show here


Magnetism How Does It Work? - YouTube


When I first discovered that I knew nothing about the dynamics of operation of the way that natures runs things was when I worked with gases when they are burned and flowing down tube.

I learned to study the simplest ideas ahead of time.

If we are going to mimic the complex process with it's potential variables of magnetic alignments, a crash course for the kiddies is in order.

Starting with me, I must confess I don't think about this everyday so I need some of the iron filings knocked off the rough edges of my understanding.

Some of the most basics are the building blocks to making magnetic flux bars or ferrites of any kind.

Like Iron, nickel and cobalt being the three major metals that are magnetic.

When we explore casting iron filings into a placid medium we must understand a few things about the way castings are best formed first regardless of the casted items.

I have casted many things into a wide range of epoxies and filers. I will share when I get back more.

Here are a few more to stimulate our beginning. This is where we start. Simplicity is the answer.

Weather casting with microsheres, ground glass or the dust of your choosing cast is a science without adding magnetism.

We know very little.

I dug up a dozen Patents that will blow your mind on the process of commonly casted ferrites.

Drr Magneto
ELECTROMAGNETISM (FULL SHOW) - YouTube

[sprocket]

@Matthew Jones - I've never had the courage (or the workshop!) to try building transformers. That figure of 30% efficiency you mentioned surprised me though - all that work and only 30% efficient! Are commercially-made transformers really that superior - Google gives figures of 95-98%?

@BroMikey - Haha, you certainly are serious about this! About the H-bridge, yes, when you are talking about 100 of watts to KW's, it is the only way to go if you are looking for a fairly good 'constructed' sine-wave output. But with the situation I had in mind of 5-10W, you could drive a pair of transistors in class-B with your sine-gen and get an almost perfect sine output. The downside is the much lower power capability than is possible with the H-bridge setup - the H-bridge mosfets are either full-on or full-off and therefore don't generate much heat relative to the current they're shunting, whereas a class-B transistors are in a half-on/half-off state during their on-time, so will dissipate much more heat. The up-side is that there is a lot less components involved so is much easier to build.

@kEhYo77 - Would that not mean that AuroraTek has gotten a license from Thane to manufacture? Those metglass cores are petty expensive - wonder what kind of profit per-unit Bill will be making? The charger is priced at $595.

[sprocket]

@BroMikey - Speaking of learning, there's a book I read recently called "The Story Of Chemistry" by Bernard Jaffe which I thought was excellent. I'm not really into chemistry, but the author does an excellent job in knitting together the major discoveries made over more than 100+ years. Even more now - the book was written in 1957! So, a book recommendation of sorts!

It's available on-line 'somewhere'...

[BroMikey]

Non DC Pulsing ALTERNATING CURRENT SINE WAVE

@BroMikey - Speaking of learning, there's a book I read recently called "The Story Of Chemistry" by Bernard Jaffe which I thought was excellent. I'm not really into chemistry, but the author does an excellent job in knitting together the major discoveries made over more than 100+ years. Even more now - the book was written in 1957! So, a book recommendation of sorts!

It's available on-line 'somewhere'...

Hey Sprocket me too

I have always been into the electrochem stuff since 1968 and on ward.

My chem teacher stopped me from making HHO said it was to dangerous in 8th grade, I flunked him and he gave me a "D"
while giving Kirk Gibson an "A" for skipping over half the classroom work because he was an ICON JOCK.

I loved to do chemistry early on, never gave up even though one of those teachers was always trying to get me over to his house for all the wrong reasons. The gym teach was on my paper route and had 2-3 girls over every other night for extracurricular fun, if you know what I mean. This is Detroit 1970's.

I learned right away that the teachers didn't give a rats rear end about learning. So I had to learn it all on my own. Detroit like any public school is a sewer.

Here is a board ads9850 making lfe easy

http://www.eimodule.com/download/EIM...Module_V01.pdf


I will be giving you all what I can on resin casting and if I get the camera out show you the failed casting as well as the good ones.

Boron microspheres go well with epoxy bound ferrites.

Find me that book sprocket I don't see it. I like Chemistry. I eat a book fast now because I used to live in the library all summer till I reached college and drove to bigger ones.

Mike

[BroMikey]

H Bridge to sinewave jenny

Some H bridge circuits



http://www.irf.com/product-info/data...a/irs2453d.pdf

[sprocket]

.....
Find me that book sprocket I don't see it. I like Chemistry. I eat a book fast now because I used to live in the library all summer till I reached college and drove to bigger ones.

Mike

Available here.

[BroMikey]

Thanks Sprocket

I busted out my acrobat reader 6 and this old book is my kind. I just love the old history of how so much of chemistry got started in the last few centuries.

Great read for freshening up.

Mike

PS here is the Bitt. Notice the large core material is 50 percent larger on the two secondaries and the smaller amount of material one on each side so the primary can feed the secondaries.