The Ruthroff Impedance Transformer
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- เผยแพร่เมื่อ 24 พ.ย. 2023
- #209 In this video I look at a Un-un impedance transformer commonly used in various RF circuits. Although it can be built with various impedance ratios and it can work over a wide frequency range, to get the best out of it, it needs to be treated as a transmission line transformers with all of its characteristics.
Balun series:
Ep1 - Communication lines and baluns • Communication lines an...
Ep2 - Voltage and Current baluns • Voltage and Current Ba...
Ep3 - Energy coupling • Energy transfer in Baluns
Ep4 - Transmission line baluns • Transmission-Line Baluns
Ep5 - Transmission line experiments: • Experiments with Trans...
Ep6 - The Ruthroff Transformer: • The Ruthroff Impedance...
Ep7 - The Guanella Transformers: • Analyzing Guanella Imp...
EP8 - LC baluns: • Building INDUCTOR-CAPA...
Further reading:
www.highfrequencyelectronics....
www.highfrequencyelectronics....
www.highfrequencyelectronics....
www.mikrocontroller.net/attac...
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One of the most undertated TH-camrs. Thank you for continuing to make these instructional videos, FesZ!
Don't know if you haven't been posting or if TH-cam keeps flooding my suggestions with bs videos but damn i missed you man
I stick to about 2-3 videos a month; except December (that month I take as holiday) :D
Excellent discussion.
Thanks for another great video! Keep watching 😊
Very well explained, as usual. Many thanks
Great Vdeo; Thanks!
BTW: I have used 26-28ga. teflon wire to make a twisted pair that was very close to 50-Ohms by twisting it about 6-turns per inch.
When I measure it on my VNA, it was good to 30 MHz which is all the further I went since my interest was in the HF spectrum..
73!
Edit: Hey thanks a bunch for the theory references; they are VERY-MUCH-appreciated!
Was it still such after you wrapped it tightly around a form like a toroid? I think the point was that adding small-radius bends in the twisted pair disturbs the impedance.
Very nicely done.
Great short! Measuring Lm: any ideas? ...messing with transformers and T-line magics since 1970, and still haven't gotten anything to work as per the model, so THIS came VERY close! Great job!
In the first documentation link I provided, there are a couple formulas for Lm, (2 and 3); maybe that will help.
Have you done any work on RF power combiners such as the Magic Tee? I'd like to see that. Thanks!
Not yet, but I did start researching the topic :D
love your videos, very high quality content
Excellent content as always .. Thank You for sharing .. Cheers :)
Nice info, thanks :)
hi there i really loved your videos
please make a detailed video regarding proper selection of inductance and capacitance values while building inverters and what is generally recomended while building such inverters like selection of power mosfets, Input DC filteration and how to determine which mosfet or switching device are recomended to acheive desired results
got an old sw radio where one of these exploded, was wondering what it was/what it did.
You made it clear. Congrats!
Concerning the twisted pair line problems: CAT 6/7/8 network cables are good up to GHz frequencies. Any comment on this?
By the way, also USB 3.1 and 4. are GHz compatible.
I stand by my statement :D as long as you can keep the constant inter wire distance and twists, the cable will work just fine. I tried to use a single pair from an old network cable, but without the default plastic around it - that keep everything in place, it came undone - and in the small transformer I built, it didn't really work
One of the main differences between the various CAT nn standards is how well the individual pairs are formed in the cable. The higher CAT standards, like CAT 6, have added material in the cable that hold the pairs more precisely in position along the cable.
Also the amount of allowed "untwist" at the contact ends is much shorter for higher CAT than the more forgiving lower CAT standards.
There are guidelines on how to lay high CAT cables: minimal bend radius etc. And as network cables are up to dozens of meters at least, hardware will probably tolerate a 1m piece smashed. USB cables are for end-user, and good ones are made stiff and thick enough, so that one could not degrade it by bending, coiling etc.
@@FesZElectronics The twisted wire isn't bent sharply like it would in a transformer, so the impedance control is easier.
Also note, the wires are twisted at different rates to reduce pair to pair crosstalk. As mentioned by Orjan, CAT6 adds a plastic "X" the length of the cable to increase pair to pair separation, reducing crosstalk.
I am a connector / cable guy that worked with Intel early in the development of USB 3.1 and USB Type C.
The cable performance was the limiting factor for data rate, using the 2 level signal. I asked Intel's IC guy why USB didn't use multi-level signal like Ethernet (I was on the 10/100, Gigabit, 10GBase-T and a bit of the 40Gb committees as well). I explained how that allowed more gigabits per gigahertz.
As we finished USB3.1, he mentioned they were working on USB4, and it uses a multi-level signal.
The step size in Ethernet was limited by the unshielded cable. Too small, and signal to noise degrades the signal. Too many steps, and the peak was too high, failing EMI. USB uses a shielded, and much shorter, cable. I expect there is at least one more data rate increase in USB.
Is there any possibilities that we can include the type of ferrite core that we are using in the balun construction in ltspice to see its effect . I have done a low power balun for HF band , but now i need it for a high power like 25Kw . Is there any tool where i can put my design and see what all should be changed to withstand this his high power. How much bigger core should i choose to handle this power ?
Thanks a lot .This video helped me a lot to design my balun circuit in ltspice. I just wanted to know can we measure the common mode current and the differntial current thats flowing across the cricuit. I wanted toeasure Like how my rejection my balun circuit does
I think I made an older video on this topic - it was more related to device compliance testing, but the same principles apply - maybe it will help th-cam.com/video/fhPTnoNQG_A/w-d-xo.html
Thank you
How can we calculate and measure the power handling? i think impedance is not linear with current?
Always with this Baluns and ferites and so on one is talking about core saturation... i would appreciate a video ferrite transformer power handeling
sir can you make a mor detaled
video on delay network
6:45 I don't think this explanation is quite complete. If you just double the voltage you will get 2*Z, not 4*Z. You should take into account that the total amount of power doesn't change, thus your new current is 1/2 of the original current, and thus you get 4*Z.
Maybe I did not go into enough details, but if you make the assumption that the transformer is ideal (lossless) then the input an output power will be the same; for any voltage change (input to output), the impedance ration will be the voltage change squared.