This is the first of my series of semi advanced electronics design videos focusing on practical design and application. The video is on inductor design theory. Later videos will go into transformers and practical application.
lol i figured out the shaking camera through your comment - was only listening to the video and throwing a glimpse from time to time! :) Very good video! Keep up the good work
Great explanation. You have an aptitude to teach. One mistake though...you said you can apply a sinusoidal voltage to the tank circuit and adjust the amplitude when you should have said adjust the frequency, and resonance will be indicated by a peak in voltage of the sinusoid. Then the resonance frequency relationship for an LC tank is: fc = 1/[2*pi*sqrt (L*C)] plug in the numbers for C and fc and then solve for L.
I never went to "School" on this subject. But I have to say after all i've self-researched on this, you really helped me understand quite a bit more! Very good video
Lately I've become obsessed wanting to learn how to design my own EL Inverter circuits. It seems like it should require a minimum of parts: an inductor, a capacitor and a transistor to form the oscillator, and a step-up transformer. I'm not sure if suitable transformers are available on the market or if I'd have to design my own. Hantronix sells EL inverters (PCB + transformer) but it would be better to know how to make my own. I am working my way through your great, instructive videos. Thank you!
Hi! Thanks for the video. To make even better videos in future, please consider camera pod. Second you may clip and edit video after just a bit to get it more clear. That was quite astonishing you made it on 1 take! :)
I just looked at it again, and saw that the two 'close' wires from the FWB may NOT actually be attached to each other...can't quite tell at the camera angle. Thanks for these GREAT videos!!!
Very nice. I hope to learn more about audio choke and transformer design. I like the idea of using iron in vacuum tube circuits but often appropriate devices are hard to find and expensive. One of the particular projects of interest is a choke tail pair phase inverter. It seems that it would be fairly straight forward. Adequate frequency range, inductance, and DC current. Typically looking at 15-25kHz with 10-40mA DC and enough inductance to load the tube cathodes. One question, does core material or geometry affect capacitance or is that strictly a matter of winding?
Great video! I have some questions... What are places you recommend for buying ferrite cores from? At 17:05, you say you apply a sinusoidal signal and adjust the VOLTAGE until you get the highest peak value at your oscilloscope. Don't you mean adjust the FREQUENCY until you get the highest peak value at your oscilloscope?
I knew you were off to a good start in this video because you were talking about real things, and did not have any added distractions such as music or other such noise. Also you are putting this at a basic level so most can understand what you are talking about. Even with a MS in electronics, one thing poorly covered was design of transformers, coils, motors etc. Just the basics of how they work and enough to do a simulation on a computer. The only thing that came close is calculating the inductance of an AIR core, and using a Smith chart.
Eric, I want to build your transformer saturation tester thingy. Can you post part numbers for your SCR, shunt resistor, and Capacitor. I have never seen a capacitor that big! I REALLY loved this video. Perhaps if you're interested, I will post pics of my transformer saturation tester......thingy. I have many transformers and inductors that I have taken from old t.v.s and such. This will turn out to be an invaluable tool for me when I build power supplies out of these spare parts. Anyways, thanks in advance, Eric. P.s. Post some more transformer vids if you will........Love them.
beyond the 22 amp point where the L is saturated is it still storing field energy ? or is that point of max energy it has to transfer to the cap ? and does a cap have a limit to how much charge it can hold ? given the label on a cap of its voltage rating my guess is that , at the least, it has a charge/ voltage limit based more on materials/design than physics
Eric, thank you so much for your video.and i have a question,is your capacitor in the "saturation testing"circuit 300mF/600V?but on your paper it is 1000uF/100v.
i'm not sure if i'm doing it right bcs inductance seems to change with frequency in some cores(?) and my L-C meter reads fixed LC tank frequency... but for extracting the inductance-per-turn of a core (that is needed in some calculations) i wind 8 turns, check the inductance with my 10$ L-C meter and then divide the vaule i have by 64, because the inductance increases 4 times every double of the turns number, so instead of 2*2*2=8 turns, it's 4*4*4=64 value not sure... but it seems to work thanks for the saturation measuring method!!
Thanks for your video.İ wonder something. may i ask ? how can i calculate and wind 20 henry and 6 henry iductor.İt shold be as possible as small. with coal core.
3:33 ----------- How/what can you use that transformer(or inductor) for? I see that there are only 2 terminals instead up 4 or more? Do you just power it and that's it? What are some practical applications for that?
I heard somewhere that the laminated iron core is very lossy and pretty much useless above 400Hz. How is the performance, say at 10 or 20kHz? Is it usable or too lossy
There are laminated iron cores with different laminate thickness. The thinner the laminations, the higher the frequency you can use. But even the thinnest lamination cores are not great in the multi-kiloherz frequencies because they do have more losses than other cores you could use. I don´t know exactly how bad they generally are. But at least using your average core from a 50/60Hz Transformer for a switching power supply is not very efficient.
At about 11:45 you state that the voltage (of the capacitor) is constant. How can it be, as it us RAPIDLY discharging through the inductor under test (LUT) when fired by the SCR?. THANKS FOR THE GREAT VIDEOS!
Nice observation. I agree with you. But I think it's an assumption that it'll be fairly constant because the time dt is very short. before saturation occurs. And that capacitor is pretty big.
In your measuring device: timestamp 9:46 I noticed a rather unusual bridge configuration, is this making the four diodes of the bridge into one diode for doubling the voltage AND current rating, thus converting it into a larger single rectifier? That should give a GREAT match on the four diodes.
You state that the capacitor in your 'tester' is 300uF. Isn't that actually a 3,300uF label? I plan to build it. That big wire is just always blocking the view! Thanks for the great video series!
Thanks for sharing this good video going into deeper explanations of inductances. At the end of your video you said you could figure the inductance of the inductor of your tank circuit by increasing the voltage of the sinusoidal signal to the highest point on your scope reading. Wouldn't it be that you could adjust the Frequency of your sinusoidal signal unit you reach the peak resonance? Or am I mistaken? Thank you.
can you do a video to explain how an average layman trying to self learn electronics can test an inductor for its strength. How much stronger my homemade inductor is compared to my 10 mH inductor I bought, for example. I would like to know what magnetic strength my inductor or solenoids have ... but, I do not know how to figure it out - or how to test it.
i guess Im asking randomly but does any of you know of a trick to log back into an Instagram account?? I stupidly lost my password. I would appreciate any assistance you can offer me!
@Avi Iker thanks so much for your reply. I found the site thru google and Im trying it out atm. Takes quite some time so I will reply here later when my account password hopefully is recovered.
Hi, I m building a dc-dc converter. 12v input, 380 volt output.. I am using e19/10/5 n27 grade ferrite core. The switching frequency is 100 khz. 50khz on one mosfet, i.e pushpull topology. Primary turns are 17 using25 swg and secondary are 550 36swg. But the output is on for sometime and then goes off. I m using sg3525 for pwm and p55ng06 mosfets. There is no air gap. Plz reply.
can yon give me a calculation of high frequency of Ferric core i have tl494 using IRF mosfet. my input voltage is 12v but i want it 12-0-12 input and the output is 35-0-35v want sizes and number of turns ? i have 5x6 cm ferric core transformer
Mr. Goodchild, can you share some insight into why/ how the laminates of some power trans are welded across laminates where the E and I laminates meet?
That makes perfect sense. I have this idea in my head that the laminates are insulated against each other to avoid eddy currents. Thanks for you time....
ຮຸ່ງ ພຸ່ງແຣງ I can not get 1 volt from 4 truns i get 1 volt from 3 turns ... I want to know calculation method before winding i shuld know how many turns required.
Please!!!!-- He is no where near The Great Nikola Tesla!!! I am not saying this young man does not have knowledge but to put him on the same level as Tesla is a BIG stretch!!
Note a parallel LC circuit should be fed from a current generator for it to resonate or else if fed from a low impedance voltage signal generator there should be a high resistance put in series to match the high impedance of the parallel LC circuit at resonance.
Very electrically conductive? You really think so? 17% the conductivity of copper is good? I was under the impression that it was resistance that turned into heat because iron SUCKS as a conductor, as evidenced by welders and all of the metal melting videos. The copper wires just let the current breeze right through, but when it hits the nail or whatever between the 2 ends of the wires, it melts immediately. Iron is used due to being magnetic, and separated into laminations, and often used with shunts or air pockets to control the magnetic field generated by the windings when powered
