Hi Eddie, Thanks for very good explanation. I couldn't find any explanation why on many toroidal transformers is written: "Only for lightening". In other words, why would I not be able to use such a transformer for, for example, a car battery charger? Excuse me in my poor English, it's not my native language. Thanks and best regards!
Hi Kiss Analog You are very professional ! We are 15 years factory in producing transformer,locating in Guangzhou China. Thanks for very good explanation.
Thank you! I appreciate you! Do you make transformers for Audio? Maybe 25 V - 0 - 25 V outputs at 300 VA or maybe 500 VA? If so, where could we purchase them?
@@KissAnalog Yes,we can,our engineer is more than 25 years experience.My email is johntan@poweradapter.com.cn,more details,we can communicate by email,Kiss Analog
Power toroids are not made of powdered iron. They are 'tape' wound with thin strips of magnetic steel that are slit to the required width and length for the core requirements.
This is a very good explanation on how windings work. I actually learned something. However, I am going to disagree with you on saying that toroids are better. And believe me, this is the first time in any of your videos I've disagreed with something haha:) but the reason being is that toroids are in fact only superior if the situation has limited space (often times this is the case nowadays). Where EI core transformers completely wipe the floor with toroids is when you consider that EI does a much better job filtering the mains noise and any DC leakage into the mains etc. The capacitance is also another factor to consider. For example, my power amplifier I've had both transformer types before. Guess which one sounds superior in every way- the EI Core! Haha much more dynamic and clean with all things considered. However, the entire front of the chassis is dedicated to the huge EI core on both sides other than the power switch and rectifier, so there's quite a bit of empty space but it's totally worth it to me😁 I would agree though that most of today's smaller chassis basically require a toroid
Thanks for your great feedback! You make some great points - and I should have specified that Toroids are better at containing the magnetic field. So, yes if an EI core has the space around it and/or has shielding (caps and shadow band) then that can help contain the field as well. A toroid can also be fitted with a shield winding to greatly minimize the noise from input to output (or visa versa).
I am an electrical engineer trying to answer the question of what happens when the transformer is driven into saturation. What does the primary and secondary voltage and current look like. It has been difficult to find a video on what happens to the flux lines as the core saturated. Maybe you could cover the saturation end.
Core saturation means that the core cant support any more lines of flux. Refer to a B-H curve where B is flux and H is the energy required to create the flux (excitation current). Most common core materials the curves look like an out of shape s. Most core materials have a linear portion where the B and H rise proportionately up to a point 'the knee'. Here H rises dramatically while B rises slowly. This is where saturation begins. The higher H goes, the more current is drawn by the primary coil. .
At 19:00, you say that the toroid core is usually made out of iron powder. Other references say that at 50/60 Hz the core is usually a strip of silicon steel that is wrapped into a torus shape and then fastened, while powdered iron is used above line frequency. The one line-frequency toroid I've seen taken apart was sheet steel wrapped into a coil.
Thanks Dave! Great catch. I'm so used to building SMPS that I must have said that by mistake. Low freq like 60 or even 400 Hz transformers are made with different types of steel I believe. There's a new material that's made a big splash and I need to look into that.
Was the "one turn = 1V" just rhetorical or is it always true, no matter the type of core (the matter it is made of as well as its shape and size) or the wire gauge?
Hi Eddie, I thought I had watched all your video's ! Just spotted this one. Does it matter which winding is wound first, I.E. primary first then secondary on top ? Adam
Hi Adam. Yes it can. It really depends on the Turns ratio, or number of turns. A toroidal has better coupling, so it may matter less, but place the winding with the fewer turns closer to the core. It may help to place the secondaries between two halves of the primary. So half the primary then secondaries then second half of the primary.
I want to more about the shielding you were talking about. I saw a video where he wrapped a amall wire between each turn of the primary before he wound the secondary over it.
@@KissAnalog In another video he split the toroid in half then glued it back together with paper insulation in between before winding. Why is this necessary when the transformer will be used to feed a single ended rectifier/amp?
@@KissAnalog What kind of metal can I use to make my own toroid? Where do I get it? Why do choke toroids use sintered iron oxide and transformer toroids are wrapped from sheet metal? What kind of sheet metal? The thickness of the metal vs frequency would be another useful point but I already know about that. Why does a choke stabilize the arc of a welder? Just food for thought. Take it or leave it. Your channel is awesome!
That is not advisable unless you need more power and the transformer is going to saturate. A proper sized transformer is better. That kind of defeats the purpose and advantage of a Toroids (self shielding).
On a toroid core Is there any positives or negatives for doing the primary winding FIRST ? If making a transformer for a low frequency inverter, doing the secondary first gives you the opportunity to rewind the primary if you have under shot the "gain".
Jack Patteeuw It is often better to sandwich the secondaries between the primary. So, wind half the primary then the secondaries, and then the other half of the primary. If you want to add more turns later to adjust the ratio - it is easy to do. Great question!!
When it comes to efficiency between the two, which is greater and what is the efficiency of each ??? What about for a welding machine which is better Kiss Analog ??? Thanks a bunch Sir.
I want to build a tube amp with toroidal power and output transformers... is it okay to the V+ voltage from the power supply through the output transformer primary center tap to the anodes of the tubes as is normally done with EI transformers? Will it saturate too quickly?
The tube amp is Class A so it will most likely need a large transformer. I think the size gets pretty big, so that’s why EI are used more commonly. Make sure your transformer can handle the power. Let us know how it goes for you;)
