Design a 600W LLC Converter for a PC Power Supply
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- Опубліковано 10 лип 2024
- Learn how to design an LLC converter, including the inductor and transformer, using MPS's LLC Design Tool: www.monolithicpower.com/en/de...
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Guys, this is the best explanation I've seen on the internet
Glad you liked it.
excellent video, theory and reality together
Glad you enjoyed it!
yay. a video that covers the inductors. and has an online tool. that seems to work. bonus. helpful. this really does give some clues.
bit harder in my case, i just wanna drive an induction heater. no voltage, high current. sure, its a single turn secondary, thats easy enough. i will have to fudge some numbers here and there... see how they interact. meh.
so...
assume 110V supply, 270nf, get 18.6uH Lr, LN 6, turns ratio 6. so 74.3uH Lm..., around 75khz. (plan on using ir21531?) approx 10k, 1nf on its lil RC timing circuit, easy. now i understand why its timing graph is so... vague. as long as youre high enough it works.
the challenge, the brick wall i face... how to actually implement that inductor as the work coil? make it as the work coil? ie, 6 turns on a diameter/spacing to roughly give 74uH? what happens when a steel slug goes in? what happens when it passes the curie point? coupling? changing coils?
or do i throw the work coil in parallel, it being of so low an inductance it makes very little difference to Lm from the two extremes of no load to full load?
but doesnt it just short it out? throw in another capacitor isolating it?
make Lm as 6 turns on a bunch of ferrites until i hit 74uH then throw one leg of the work coil through, with it either wired as a closed loop, or as a tank circuit of its own?
meh, sure i will figure it out. sort of :)
really, it seems the best way is to...
RELEASE THE SMOKE!!!!!
i have a good baseline to work on now.
If you have any other questions, please go to our forum for technical questions. We have engineers that will respond within 24 hours forum.monolithicpower.com/
When you were calculating the Lr, Cr value through your design sheet, minimum freq. Which came aprox 67000khz and high frequency aprox. 200000khz. So is this a error of your design sheet or anything else???
Hello, as I can see in live demo your converter is working above resonance frequency. Is that lowering the efficiency of the converter, consider there is harder turn off and oscillations.
I am asking cause I face the same problem. Also if your input voltage is at nominal value, shouldn't the the converter working on resonant frequency where the gain is 1 in any loads, according to the graphs in the design steps. Thank you.
In the video, the load is set at 50%, that’s why the switching frequency is lower than the resonant frequency. If this happens at nominal load, the turn ratio should be changed so that the converter works with a resonant gain of 1 at nominal conditions. For any further questions, please go to our forum for technical questions. We have engineers that will respond within 24 hours. forum.monolithicpower.com/
very interesting video and tool. I am designing LLC for battery charging application so how do I proceed where output is varying and I want to operate LLC in constant current mode and constant voltage mode
Thank you. In this case Is recommended to work with high quality factors and low Ln ratio. This will lead to a more narrow frequency span to achieve all the input output configurations. The counter part is that typically you will higher losses. You can refer to www.monolithicpower.com/en/offline-600w-battery-charger-pfc-llc-hr1211
Thanks, very interesting. But there's one question: on 2:26 P=600W, but output power according to sum Vout*Iout is 761W. Is this mistake or it's just my misunderstanding?
Thank you. Good catch ! Yes 600W is the total output power. In this case the 5V and 3.3V output are driven from the 12V output. The power is limited in the 12V power rail, but the rating of the 5 and 3.3 outputs is 15A and 8A.
As you are compromising the gain of LLC converter for stable operation will that effect the overall efficiency considering that efficiency is the key factor for my application.
The impact on the efficiency would be low. But anyway, you could find that when operating in the boundaries of input voltage, the switching losses start to increase. This is because the operating points would be far from resonance so the benefit of Zero Voltage Switching is reduced.
@@monolithicpowersystemsmps534 Thanks for being so generous. it's really helpful and insightful
nice information, sir i want to increases the voltage from 390v to 1000v it is possible by LLC half bridge resonant converter. (isolated dc dc converter) having a power rating of 1200w.
Thank you. The output voltage will have an important role in this decision. Buri in mind that with half bridge the effective input voltage is halved. So, if your target is high voltage output maybe is better to go full bridge. If it is not your case half bridge would be great (Less cost, reduced turn ratio, more compact solution). Just be careful while dimensioning the resonant capacitor, take into account the voltage rating goes down with frequency. Double Metallized Polypropylene Film capacitors works great for this applications.
I need to charge 330uF up to 900v in 50 continuous milliseconds, I was trying with pwm switching, but I can't have speed and the transistors burn out, have you achieved it?? I tried a ramp generator to control the pwm and have constant current in the capacitor but no
can i use LLC to supply controlled current to an inductive load with very low inductance L? thank you
Yes, but you’ll need current control in the secondary. If you have any other questions, please visit our Technical Forum: forum.monolithicpower.com/
Sir i have a 12v 2amp adaptor
Sir that adaptor doesn't have any drive ic just 2 transistors (S8550, BC548) and a mosfet (pfb2n60)
sir how is switching pulse given to mosfet gate (please reply)
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Hi MPS - what chip is recommended for boost operation at 800/1000 Watts?
Thank you for your inquiry. Please go to our forum for technical questions. We have engineers that will respond within 24 hours. forum.monolithicpower.com/
@@monolithicpowersystemsmps534 many thanks and great work on this video!
I am going to use a transformer with Lr in the transformer using the leakage inductance. To measure the inductance Lr I plan to short-circuit the secondary to cancel Lm. But how can I measure Lm, I can't think of. Could you give me an idea? Thank you
Thank you for your inquiry. Please go to our forum for technical questions. We have engineers that will respond within 24 hours. forum.monolithicpower.com/
Awesome do you have or retail a demo board to learn from
Thank you for your inquiry. For direct project assistance, please contact our MPS Now team. www.monolithicpower.com/en/support/mps-now.html
We are planning to design a llc/cllc circuit as a part of an ev hackathone . In the design tool provided output voltage can be add upto 90 voltages. But we want >90v. Then how to plot the graph manually? or can we plot it in matlab..Please reply
Thank you for your inquiry. Please go to our forum for technical questions. We have engineers that will respond within 24 hours. forum.monolithicpower.com/
Could you plz provide the presentation? Thank you
Unfortunately, we do not have a presentation file for this video.
Thanks for reply. That’s ok too. I’ll rewatch it and take notes
How to select Ln and Q
For Technical questions, please reach out to our MPS NOW Team at www.monolithicpower.com/contact/mps-now-technical-support.html
The site does not work,is there any alternative site ?
Please use the following link for the LLC Design Tool. www.monolithicpower.com/en/design-tools/design-tools/llc-design-tool.html
Where are the most loses for a gaming PSU say 850w ?
At the output. 850W at 12V means over 70A, with this current even few tens of milli ohms can represent huge loses. In this case center taped (MP692x) output is great since you have the half of semiconductors. The counter part is that you will end up with more copper in the transformer. I would definitely recommend using foil in this case.
Nice video,s to learn.
Mine question is not completely about LLC bet LCC or LCL, both are better for mine use. I am diy'er so no company, I have a question about the transformer for a LCC converter, what induction do I need? because I do only read on papers and video,s on you tube how to do the resonance tank, who I do now about but not the transformer. I now the LLC has the transformer included into the resonance tank, and it is a constant voltage action,'I can design using a tool, But for LCC there is no usable tool and need to calculate myself, I have to buy a good calculator who can do graphic so I see the formula,s as on papers. Oke, back to LCC because it is a constant current output to transformer I presume this transformer needs a high reactance and as such a high inductance? The transformer is current source driven so it has to keep load on tank as low as possible?. So question is what to do, just experiment with inductance value,s until the primary has as high as possible efficiency, so lowest primary current on full load.
The supply is for a hybrid amp, the tubes voltages. there are more then one on the transformer, 1 x 350 v 0.1 amp 2 x 120 v 0.25 amps 12.6 volts 6 amps, and 6.3 volts 5 a 10 amps. so total power is not that high, because the danger a tube get faulty supply can go to very low load so a LLC do not well here, I read that a LCL is even better then a LCC for this, but first looks a constant current supply. Nice stuf to play with. Yes I am used to very high voltages and now the dangers as a old tv restaurateur.
I do sim with Lt-spice and get a lot of different outcomes.
regards
Thank you for your inquiry. Please go to our forum for technical questions. We have engineers that will respond within 24 hours. forum.monolithicpower.com/