In the past I have seen PFC controllers with big thumping relays and massive capacitors. Now all I see is a 8 pin SOIC. Thanks for making these videos. :-)
I studied electronics some 14years ago, and going over your video tutorials I wish you were my teacher back then, or atleast had these youtubes videos available back then. Really inspiring to learn these concepts and practical knowledge from you. Im a software dev but your videos are always on the top of my lists.
Udo Huhn-Rohrbacher Beside your nice presentation I'd like to add a couple of comments 1. Pro's of the PFC: Low Frequency Peak currents (i.e. 50Hz, 60Hz...) are much slower as compared to a Diode Bridge, loaded with a Cap. Also, the current is in shape with the Voltage, i.e. also a sine wave, if the voltage is a sine wave. But it is not only related to sine wave inputs. But, although the voltage and currents look relatively clean, one has to keep in mind, that "clean looking" is related to low frequency only. There are high frequency line and radiated disturbances, which have to be managed to keep such levels within given standards. >>> Input Filters(RFI) + careful Screening (radiated noise) necessary, as for all SMPS. 2. Other Con's of the Boost configuration as shown: - Irush current at turn on. The PFC-Output has an electrolytic capacitor, which is usually also designed to keep the Load (i.e. power supply, DC/DC-Converter part) running for a certain time after a mains voltage Dip or interruption. Since the cap. value is dependend on the load power, and not very low (from a couple of uF to some mF), the inrush current can be very high and it takes some time until the cap. is charged to levels at which the inrush current approach to the nominal load current. Now, what is the problem ? The Fuse can burn, but furthermore, the switching transistor as well. Reason: The Boost inductor (storage choke) is designed to work at switching frequencies. So the period of switching is very short compared to the charge up-time of the electrolytic capacitor. To keep the size of the choke small, it cannot be designed to withstand the inrush current without running into saturation. If this happens, the switching transistor at turn on after saturation has to draw currents only limited by the resistive part of the inductance and input resistance. The Transistor or MOSFET is stressed very much and usually not protected by standard controllers, if not protected otherwise. This is the real reason for the extra Diode from Input to Output. This Diode protects the Tansistor, but does not limit the Inrush current. For that, other parts have to be foreseen. 3. There are other interesting matters, which however would exceed the frame of this comment. Pls refer to www.ti.com for more informations. Best regards Udo
I'm so 100% with ya on the use of that plastic power-up shield! Most of the time I forget to have something similar handy, so I use the dorkier and less elegant "head below bench horizon -click! .. wait a few seconds" technique. A couple reasons why that's a bad method. The first is if any ladies you have a crush on catch ya doing it - *instant* downgrade on street cred. The second, if there IS a *pop* or *ssssssssss* you might miss seeing where it happened and make more troubleshooting work for yourself. Transparent plastic is definitely the way to go!
Great video as usual, I know I have talked about you preparing your subject, but I think this video is more your stile, a "hay let's go down in my lab and see what we can find" sort of stile, and that's one of the things that makes your channel special! :-) You have three times talked about safety, heat detection via IR camera, Caps explosion shield and again today. What about making a video only about that, lethal voltage, exploding components, nasty fumes from burning circuit. And maybe how do you turn on your power supply for the first time, what steps do you take to heighten safety? Taking measurements? What products will add to safety, blast shield, eye protection or ??? :-)
Another supurb posting (as usual) from you Eddie! It's a bit embarrassing, but I somehow 'neglected' to learn more about power-factor correction along my journey as a Tech.....and PLL's too (may the earth below my feet open up and swallow me whole to hide my shame, lol). I'm glad you brought the subject PFC up though.....it might just be the right solution to powering my next tube amp project (which, may I add, is coming along nicely with the support of microcap 12). Be well and thanks for posting! :)
in 1997 i was playing with UC3854,UC3855,UC3818, very complex. Around 2008 there came a new solution "Negative Slope Ramp Carrier Control" IR1150 These 4 have same SO8 pinout: IR1150 = IR1155 = Infineon ICE2PCS02 = TI UCC28180 UCC28180EVM 300W TI Designs: TIDA-00779 3.5KW
In successful real world design a front end PFC with a switcher back end is what I call big boy engineering. Ever component is scrutinized for characteristic which includes parasitic effects. This information will be used to fine tune your simulations to get a good idea of the overall operation, but then you have to design the PCB which also adds parasitic effects, which also have to be understood. What this means is when you select a component like an inductor or a capacitor, for example, using a manufacturers data sheet, you basically get a general feel for the suitability of the device, but you tend not to get too excited because you have to characterize the device on the bench before you understand how it really performs. In the end the data sheet is just marketing guidance, the real proof is always on the bench. With inductors you might even get fed up with not getting the right combination of core and windings and wind your own, which sometimes is faster than waiting for manufacturer samples. Most power supply designers will have an AC isolated (both mains and ground) adjustable power supply for initial testing with some AC supplies being able to switch between 50 and 60 Hertz. The isolation is for safety and DUT isolation from ground. Some have low interwinding capacitance transformer front ends. High AC voltage is dangerous and you should be wearing safety glasses when looking at a high voltage demo board.
Thanks for the great feedback! One thing to note - as you get more experience you learn to read the data sheets better and glean the information that is important. I agree - with magnetics - like inductors - the data sheets do seem like marketing specs. It is often difficult to compare side parts side by side - as the data sheets contain information written slightly different - but just enough that it takes some digging or analysis to understand how to compare two parts. But this also comes with experience and knowing what to look for. Yes, I usually place a plastic box or the lid over the circuit - and wear safety glasses. I set things up so that I don't have to touch it (most often) while it is powered.
Very interesting Eddie! I think your idea on a video about power types; apparent power, active power and real power, would be very informative. Thanks!
Looks like you are one multimeter away from being able to build a time machine. Thanks for showing scope readings. I got a scope but never have time to play with it.
Very well explained a great video, thanks a lot ! :) There is one question on my mind. How did you bring-up the board? Did you first apply the bias supply (12V to 15V), then plug the board to grid? Or, you just first plug the board to grid, then applied the bias supply? Which order did you energize the board?
Great work and good explanation I got all the required information thank you .I have a question, please, why didn't you put a resistance to adjust the load on the output capacitor terminal and should I put it in the circuit or not
Thank you! Are you asking about placing a resistor as a load? I have done a number of other videos on the PFC - have you seen them? Here is the part 2 of this one: th-cam.com/video/95UYDVM_EIs/w-d-xo.htmlsi=EjDHFC-JFXR_F0Pe
I cannot lie, I've definitely had those moments where I'm searching for some kind of blast shield before hitting the ON button. However, I find that the degree to which i squint is inversely proportional to the amount of current limiting that i have in place 😆.
LOL that is an effective surge device;) I had a good friend that taught me that back in college. But, I am also still afraid that things warm up and are not right - then go pop; )
@@KissAnalog so far I've had no problems with that. I often do servicing of different SMPSs, VFDs and BLDC drives (supplied from mains), so it's extremely important to avoid unpleasant surprises (explosions).
Thanks for asking, I'm not sure what part of the video that you are talking about, but PFC does put them in phase. At 27:48 you can see that they are in phase.
Grat video and larned much as usual. Why only two AC lines? Was ground wire missing? Why? I think you used differential probes to tke ground out of the display?
Brad Rich Yes I left the ground out, but in a finished product you would want to use it - unless it was a plastic box maybe. I needed the diff probes as the Neutral is still tied to the ground at the device entrance.
Hi!, thank you so much to take the time for this video, it was pretty useful to me. I wondering if this IC can be used in a three phase AC line. Do you know?
Thanks for your feedback! You could use this in each phase followed by your DC/DC isolated stage and parallel the outputs. So 3 single phase supplies with the isolated outputs working in parallel. This will keep all 3 phases in balance.
The UCC28180, like many of the TI PFC controller ICs, requires a external bias supply input. So, this IC requires a separate DC bias supply to operate, or in other words, it does not operate in front end master mode.
Yes it does require a lower voltage to run the IC, and this is generally done a couple of different ways, so it is meant to be at the front end. Most off-line converters require a low voltage and in general a Kick-start circuit with a Boot-strap circuit are used for this function.
Thanks for asking. Yes you can change the value of R13, but it would be better to put say half the value on R13 and the other half on a variable resistor in series with it. This way there is no way to short it and you can get better resolution.
You mention you shorted the output and blew the input fuse. Since the chip has current sensing why did it not protect itself (hiccup or latch off) rather than causing a catastrophic (blown fuse) event ?
Great question! I used a smaller rated fuse to blow before the circuit was stressed. Once I get some test time and build confidence then I rely on the current limit features;) Make sense?
Sounds good, was just wondering about the current limit capabilities of this boost converter. Also if I was to do a 0-350VDC 200W converter, would this EVM be a good candidate to do it with ? A PFC of >0.9 would not be my primary concern for this converter. Thanks for the great videos as always.
good information thanks a lot. by using ucc28180 IC i want design 1500watt PFC boost converter is it possible sir or any gate driver ic is needed ?. and for EMI what is the actual peak input current i should consider ?. tell me sir
Sorry to respond so late, I'm trying to keep up with subscribers first and then go down the list;) It may not be necessary, but then it might depend on the FET that you are using. Do you have one selected?
Hi, I have a question about the pin that does current sense on the chip. When I use a multimeter on continuity mode, and I probe the current sense pin to ground, I get a continuity ring from the multimeter. Is this normal or is the chip shorted to ground via the current sense pin? Great video by the way.
Thanks Ray for the great question! Try putting your meter in ohm mode not continuity. It could be that the continuity mode places a higher voltage on the pin and turns on the chip in some way. Let us know what you find.
Two mistake a lot of new comers make with drivers the igbt in pfc is connecting the driver voltage supply negative rail to the negative of the mains negative and this issue alway blow the igbt or burn it out fast , the transient high voltage alway shoot to the gate when all negative or connected never do that the driver ic should never series either the high voltage
Lovely video, can you share a picture of the output dc waveform? I understand that the PFC will keep a steady output of 385V irrespective of input voltage (as long as the capacitor is large enough to do that ofcourse) -am I right?
Hi Sir, you are really doing a great work. I wanna ask one thing, how can we find the FFT control across MOSFET or the BOOSTCCMDCM in the UCC28180_avg model? Looking for kind response.
That's a great question Vengu G! If I understand correctly, I think this one would be a good PFC, then it would need an isolated converter to drop the voltage down to a battery charge level.
Love your tutorials ! I would like an ultra low noise tone generator that say had a fixed1kHz 1V (or perhaps variable) output, what would be involved in that ? I thought it may be cheaper than a function gen and be very useful in audio, perhaps a few fixed outputs but particularly quiet ? are there chips that can do this cheaply ? not sure you will see this as its an older vid but what the hey !....cheers.
It is amazing how many documents and videos exist that completely skip over how this thing actually works. Problem statement: A simple rectifier into capacitor power supply draws current only when the incoming sine wave happens to have a higher voltage (plus 2 diode drops) than the capacitor. At that moment, the capacitor starts charging and its effective resistance nearly zero thus current demand is very high, but only for a few milliseconds. Solution statement: Find a way to spread out that spike that happens 120 times per second; find some way to extract energy from the entire sine wave not just the peaks. The magic smoke is a FLYBACK regulator; known here as a boost regulator but it depends on the flyback effect of the inductor. This is the same phenomenon that generates the spark in your gasoline powered internal combustion engine. For a few microseconds, the inductor is *shorted to ground* which seems like a bad thing but while shorted to ground it is building a magnetic field. Then you suddenly open that path to ground. The magnetic field starts to collapse. It wants to push electric current in the same direction that it has been flowing. What is special is that it does not care about voltage; it will push X number of electrons up a very steep hill if necessary. So, even though the capacitor already has 300 volts on it, and you charged the inductor at a moment where the incoming sine wave had only 20 volts, when you interrupt the ground path, the inductor will push 20 volts no matter what; making a spark if it needs to. It pushes that 20 volts right onto the 300 volts already on the capacitor and THAT is how you glean energy from the 20 volt (or any volt) portion of the incoming sine wave and scoop it up on top of your storage capacitor. Detailed nuance: We don't actually fully charge the inductor, that would be bad, and we don't completely dump the charge either. So we "top off" the capacitor with these little impulses that RIDE the incoming wave. It is by its very nature current limited since the thing that charges the main storage capacitor is the FLYBACK impulses from the inductor. The crossover distortion will happen because at some low voltage part of the sine wave there just is not enough TIME to charge the inductor. (RL time constant) and consequently even with nearly 100 percent duty cycle you cannot effectively boost to the 300 volt capacitor. Conversely, when the incoming wave is at its peak, we allow the inductor to conduct for only a few microseconds; it doesn't need much high-voltage pulse to charge its magnetic field.
Thanks - but this video 'does' explain this. It is similar to what you describe - but there are some very important misconceptions and/or errors in your discourse. 1) You start off with an incorrect 'Problem Statement'. The 'Problem Statement' is that this results in a bad power factor, thus; an Active Power Factor Correction circuit is used. Sometimes a Passive Power Factor Correction circuit is used. 2) The 'Bulk' capacitor does have some impedance, and this is actually important. It is low - but not nearly zero. 3) I think you meant that a circuit switching at 120,000 times a second - not 120 times. 4) This is a boost - not a flyback - even though they are similar. A flyback uses a transformer as an inductor which also provides isolation. A boost only uses an inductor and does not provide isolation, so this is not a flyback. It is appropriately termed a 'Boost Converter'. 5) When the waveform is at 20 V level - it isn't this voltage that gets pushed to the top - it is the energy stored in the inductance that gets pushed to the capacitor. The level of voltage that this results in is dependent on the volt-second principal that I discuss in another video. 6) Your detailed nuance is what I described in this video as 'Continuous - mode' operation, but there are other modes of operation that do fully drain the energy from the inductor. The 'discontinuous mode' might be more commonly used than the 'continuous mode'. I actually explain these different modes of operation. 7) It actually is not by 'nature' current limited. This in fact is actually an unfortunate parameter of the 'Boost' converter. It does not have a controlled device from input to output to limit the current - and the inductor will pass whatever current that wants to go thru it - if the load demands it. If you short your output (with safety gear on) it will become obvious very quickly that the inductor will not limit the current to a safe level. If the output is shorted - the current will pass thru the inductor and diode - fully charging the inductor past its ability to contain this charge. So it saturates, and the current rises until the diode, inductor, or another device in the path fails open. So, there is no natural current limit or short circuit protection. The control chip is set up to offer an over current protection - that will work to some level. A current sense resistor and the control chip will protect the switching FET and Inductor to keep them from overloading themselves - but this will not limit the current in case of short circuit or severe overload. 8) The crossover distortion is not caused by lack of Time as you say - it is caused by the lack of available energy when the incoming voltage is near zero or at zero. Also, at the top of the waveform it is still about energy and not the 'high voltage'. All along the waveform the duty cycle is controlled to result in the current waveform resulting in an amplitude that looks sinusoidal at the input. Thus resulting in a power factor near unity. I have a number of videos on these PFC converters. You have a fair understanding - so if you would be more open to learning - you could improve your understanding by watching this video as well as the others that I have on this topic. I also have videos on Flyback converters. This might help in understanding the differences in Boost vs Flyback converters.
@@KissAnalog I appreciate the additional information and corrections. "3) I think you meant that a circuit switching at 120,000 times a second - not 120 times." No, I meant a 60 Hz main power line, so 120 times a second a voltage peak. A traditional power supply lightly loaded draws power only in the case that the instant voltage on the mains exceeds the voltage of the capacitor (and diode forward drops typically 0.6 volts). I'm not sure how this affects power factor since it isn't exactly a phase shift but is certainly going to be a bit ugly on the current waveform as compared to the nice clean voltage waveform. I concur that shorting out the output would not be inherently current limited. I suppose I should have been more clear; a boost regulator can only maintain boost up to a certain design limit, the storage capacity of the inductor and capacitor. Exceed that current limit on the output, and the boost can no longer maintain voltage boost. "The crossover distortion is not caused by lack of Time as you say - it is caused by the lack of available energy when the incoming voltage is near zero or at zero." I suppose that's a better way of looking at it. I was thinking of the time constant and you've only got a few milliseconds or microseconds depending on the switching rate.
Thanks for your response! I appreciate you and your knowledge. I worked at a large defense contractor that was doing a project for Boeing (who I once worked for), and they were reporting something about power factor that just wasn't correct. The engineers (who are top notch) at both companies had it wrong. I'll have to do a video on this. It is not as simple as people think. Yes the diodes in a bridge rectifier do throw off the power factor. The current is no longer in phase - even though it looks like it is being pulsed at the top of the waveform. That does not put or keep it in phase with the voltage. This is the mistake that most people (great engineers) make. This is my life, so I happen to understand it enough to know how to measure it and simulated it. Once I explain you will slap your knee and say - damn - that's cool;)
@@KissAnalog As I think further on it, I realize that it matters what the mains hits first. If it is a transformer, then when unloaded the power supply is going to exhibit a 90 degree phase shift between current and voltage on the primary of the transformer, hence a power factor of zero. Looking at the secondary, the diodes become conducting at peak voltage but minimum current. As the voltage changes direction of growth (not yet direction but heading back to zero) the current crosses zero and starts up to its maximum BUT for a moment the magnetic field ceases to oppose primary current flow and you start to get current and voltage in phase. Then when the diodes stop conducting the transformer primary current can resume increasing. So it is still out of phase but not by 90 degrees hence a power factor greater than 0 but not by a lot. I remember a mnemonic for this sort of thing: "ELI the ICE man" E (voltage) leads I (current) when inductive "L".
@@KissAnalog It is interesting that inverters are sensitive to power factor. Even though my computer uses less than 80 watts it has a capacitive input power supply and the surge and pulsed current demand vastly exceeds that of a resistive 80 watt load. The bigger Goal Zero (Yeti 1000 and Yeti 1000x) have "slow start" capability that helps in some situations. Ramps up in about 1/2 second or so and works well.
Great Question! It actually has good response. The PFC converters typically have lower freq gain bandwidth because of the low power freq coming in. I'll be doing another video on this very soon. Hopefully this week;)
I sure can and I do plan to do that. I hope soon I will do that. Thanks for asking! This is just the thing that I hope to provide as a recipe for people to follow and be confident in doing. I'll put together a video very soon;)
an a.c. p.f.c, simply saves power, thus saves fuel. thus save money. overtime. sounds complex and indirect. ask a specialist. if you want. you dont need too. just. you can.
it synchronize, the alternate current. from the input too the output. sometimes. the atached device or apliances. drags power from the socket. on the ... clumbsey way.
You mean the eval card? They don't make a lot of these and they are made for engineers like myself to evaluate and see how the circuit performs. They put them on sale just for those small companies or individuals that want to try them. The chip itself is very inexpensive, and the circuit in quantity is low cost as well.
@@KissAnalog Right That was exactly what I suspected. Because a Buck boost PFC can be made really cheap. So that really doesn't make sense to use the board commercially. But thanks for the clarification.
Your videos are great and you do exactly what I'm interested in. This is one of my favorite channels on TH-cam.
Jack Stanek Thanks Jack - I appreciate you!! Let me know if there’s something you want to see;)
Yes Sir , we need more discrete analog electronic topologies rather than commercial end products reviews...
In the past I have seen PFC controllers with big thumping relays and massive capacitors. Now all I see is a 8 pin SOIC. Thanks for making these videos. :-)
You bet - and thank you for your feedback Adithya!
I studied electronics some 14years ago, and going over your video tutorials I wish you were my teacher back then, or atleast had these youtubes videos available back then. Really inspiring to learn these concepts and practical knowledge from you. Im a software dev but your videos are always on the top of my lists.
Thank you Gohar - I appreciate that great feedback! Glad to have you here.
Man... wish industry had more people like you in it.
You are my kinda' guy! Great vids.
Thanks so much! it is people like you that make me want to keep this channel going;) I appreciate you!
Udo Huhn-Rohrbacher
Beside your nice presentation I'd like to add a couple of comments
1. Pro's of the PFC: Low Frequency Peak currents (i.e. 50Hz, 60Hz...) are much slower as compared to a Diode Bridge, loaded with a Cap. Also, the current is in shape with the Voltage, i.e. also a sine wave, if the voltage is a sine wave. But it is not only related to sine wave inputs.
But, although the voltage and currents look relatively clean, one has to keep in mind, that "clean looking" is related to low frequency only. There are high frequency line and radiated disturbances, which have to be managed to keep such levels within given standards. >>> Input Filters(RFI) + careful Screening (radiated noise) necessary, as for all SMPS.
2. Other Con's of the Boost configuration as shown:
- Irush current at turn on. The PFC-Output has an electrolytic capacitor, which is usually also designed to keep the Load (i.e. power supply, DC/DC-Converter part) running for a certain time after a mains voltage Dip or interruption. Since the cap. value is dependend on the load power, and not very low (from a couple of uF to some mF), the inrush current can be very high and it takes some time until the cap. is charged to levels at which the inrush current approach to the nominal load current. Now, what is the problem ? The Fuse can burn, but furthermore, the switching transistor as well.
Reason: The Boost inductor (storage choke) is designed to work at switching frequencies. So the period of switching is very short compared to the charge up-time of the electrolytic capacitor.
To keep the size of the choke small, it cannot be designed to withstand the inrush current without running into saturation. If this happens, the switching transistor at turn on after saturation has to draw currents only limited by the resistive part of the inductance and input resistance. The Transistor or MOSFET is stressed very much and usually not protected by standard controllers, if not protected otherwise. This is the real reason for the extra Diode from Input to Output. This Diode protects the Tansistor, but does not limit the Inrush current. For that, other parts have to be foreseen.
3. There are other interesting matters, which however would exceed the frame of this comment. Pls refer to www.ti.com for more informations.
Best regards Udo
Thank you Udo for the very informed feedback! Fantastic points!!! I’ll be sure to share these points in my follow up to this video! I appreciate you.
Really clear demonstration of active PFC, thank you.
Thanks so much Genghisnico13! I appreciate you!
thanks, that's exactly what I'm looking for... I pay so much for reactive power, even though only the cameras and LEDs work.
Thank you!
I'm so 100% with ya on the use of that plastic power-up shield! Most of the time I forget to have something similar handy, so I use the dorkier and less elegant "head below bench horizon -click! .. wait a few seconds" technique. A couple reasons why that's a bad method. The first is if any ladies you have a crush on catch ya doing it - *instant* downgrade on street cred. The second, if there IS a *pop* or *ssssssssss* you might miss seeing where it happened and make more troubleshooting work for yourself. Transparent plastic is definitely the way to go!
LOL - thank you! ya gotta keep your street cred;)
You have nice toys in the background! I suspect you have fun doing things. Congratulations on finding things you enjoy!
Thanks so much!
Best of the best👍
TDM Lab Thank you - I appreciate you!
Thanks, Eddie.
You bet Robert! Hope you are well!
Great video as usual, I know I have talked about you preparing your subject, but I think this video is more your stile, a "hay let's go down in my lab and see what we can find" sort of stile, and that's one of the things that makes your channel special! :-)
You have three times talked about safety, heat detection via IR camera, Caps explosion shield and again today.
What about making a video only about that, lethal voltage, exploding components, nasty fumes from burning circuit. And maybe how do you turn on your power supply for the first time, what steps do you take to heighten safety? Taking measurements?
What products will add to safety, blast shield, eye protection or ??? :-)
Thank you Fried Mule - I really appreciate your feedback and help! I like that idea about how to test safely - thank you!
I've got 2 Klien meters one clamp and one non clamp. And a wish.com oscilloscope. Learning a lot about the different meters available from your videos
That’s great Zane! Thanks for the feedback. Let us know how it goes.
Oh, I meant to include, with a handle "Kiss Analog" you ought to have a Simpson 260 front and center on the bench.
LOL - I have one - so you just might see it soon;)
Thank you man 🥺 you made the best explanation
Thank you! I appreciate you!
Another supurb posting (as usual) from you Eddie! It's a bit embarrassing, but I somehow 'neglected' to learn more about power-factor correction along my journey as a Tech.....and PLL's too (may the earth below my feet open up and swallow me whole to hide my shame, lol).
I'm glad you brought the subject PFC up though.....it might just be the right solution to powering my next tube amp project (which, may I add, is coming along nicely with the support of microcap 12).
Be well and thanks for posting! :)
Ted van Matje Thank you Ted! I’m glad it helped. Let me know if you have something that you would like me to demonstrate.
@@KissAnalog will do eddiie....thanks man :)
Another informative video.. Thank you.. 🙏
Debi Hansen Thank you Debi! I appreciate you!
in 1997 i was playing with UC3854,UC3855,UC3818, very complex.
Around 2008 there came a new solution "Negative Slope Ramp Carrier Control" IR1150
These 4 have same SO8 pinout:
IR1150 = IR1155 = Infineon ICE2PCS02 = TI UCC28180
UCC28180EVM 300W
TI Designs: TIDA-00779 3.5KW
Thanks Erik for the great feedback! Yes, the new controllers that do PFC specific are really great and make the job much easier;)
Thanks!
Thank you for your generosity!
In successful real world design a front end PFC with a switcher back end is what I call big boy engineering. Ever component is scrutinized for characteristic which includes parasitic effects. This information will be used to fine tune your simulations to get a good idea of the overall operation, but then you have to design the PCB which also adds parasitic effects, which also have to be understood.
What this means is when you select a component like an inductor or a capacitor, for example, using a manufacturers data sheet, you basically get a general feel for the suitability of the device, but you tend not to get too excited because you have to characterize the device on the bench before you understand how it really performs. In the end the data sheet is just marketing guidance, the real proof is always on the bench. With inductors you might even get fed up with not getting the right combination of core and windings and wind your own, which sometimes is faster than waiting for manufacturer samples.
Most power supply designers will have an AC isolated (both mains and ground) adjustable power supply for initial testing with some AC supplies being able to switch between 50 and 60 Hertz. The isolation is for safety and DUT isolation from ground. Some have low interwinding capacitance transformer front ends. High AC voltage is dangerous and you should be wearing safety glasses when looking at a high voltage demo board.
Thanks for the great feedback!
One thing to note - as you get more experience you learn to read the data sheets better and glean the information that is important. I agree - with magnetics - like inductors - the data sheets do seem like marketing specs. It is often difficult to compare side parts side by side - as the data sheets contain information written slightly different - but just enough that it takes some digging or analysis to understand how to compare two parts. But this also comes with experience and knowing what to look for.
Yes, I usually place a plastic box or the lid over the circuit - and wear safety glasses. I set things up so that I don't have to touch it (most often) while it is powered.
Hi Eddie, another great video. Thanks so much.
Thank you - I appreciate you!
Very interesting Eddie! I think your idea on a video about power types; apparent power, active power and real power, would be very informative. Thanks!
Ok thanks for the feedback! I’ll put that together:)
Looks like you are one multimeter away from being able to build a time machine. Thanks for showing scope readings. I got a scope but never have time to play with it.
LOL thanks David!
Very well explained a great video, thanks a lot ! :) There is one question on my mind. How did you bring-up the board? Did you first apply the bias supply (12V to 15V), then plug the board to grid? Or, you just first plug the board to grid, then applied the bias supply? Which order did you energize the board?
Thanks so much! Yes I did apply the 12V first.
Great work and good explanation I got all the required information thank you .I have a question, please, why didn't you put a resistance to adjust the load on the output capacitor terminal and should I put it in the circuit or not
Thank you! Are you asking about placing a resistor as a load? I have done a number of other videos on the PFC - have you seen them? Here is the part 2 of this one: th-cam.com/video/95UYDVM_EIs/w-d-xo.htmlsi=EjDHFC-JFXR_F0Pe
I cannot lie, I've definitely had those moments where I'm searching for some kind of blast shield before hitting the ON button. However, I find that the degree to which i squint is inversely proportional to the amount of current limiting that i have in place 😆.
LOL - that’s perfect! Thank you!
I'd spare you that plastic shield by adding tungsten bulb in series with AC line input, with bypass switch, when it's safely started.
LOL that is an effective surge device;) I had a good friend that taught me that back in college. But, I am also still afraid that things warm up and are not right - then go pop; )
@@KissAnalog so far I've had no problems with that. I often do servicing of different SMPSs, VFDs and BLDC drives (supplied from mains), so it's extremely important to avoid unpleasant surprises (explosions).
Thanks - I'll do a video on this - so everyone understands the Pros and Cons of the various methods:)
Good one!!
Thank you! Cheers!
Is there any way to do CC-CV charging of batteries using this converter? Is there any way to change output current with the same voltage
Great question! There should be a second stage dropping the voltage down - and in this second stage you could use it for CC and CV charging.
The input current and voltage are having a phase difference right as seen in the oscillscope. Then how is the power factor correction working sir ?
Thanks for asking, I'm not sure what part of the video that you are talking about, but PFC does put them in phase. At 27:48 you can see that they are in phase.
With my respect to your valuable & informative video, the UCC28180 is the worst chip for PFC
Thank you for this feedback!! I am working on a design now - can you tell me the issues? I really appreciate it;) Aldo what chip do you recommend?
@@KissAnalog You may read the story here (e2e.ti.com/support/power-management/f/196/t/704476)
I use IR*** chips for PFC, they are just perfect
Thanks I like IR too. I might have one to demo;)
Can you explain,bcz i face trouble
Grat video and larned much as usual. Why only two AC lines? Was ground wire missing? Why? I think you used differential probes to tke ground out of the display?
Brad Rich Yes I left the ground out, but in a finished product you would want to use it - unless it was a plastic box maybe. I needed the diff probes as the Neutral is still tied to the ground at the device entrance.
Hi!, thank you so much to take the time for this video, it was pretty useful to me. I wondering if this IC can be used in a three phase AC line. Do you know?
Thanks for your feedback! You could use this in each phase followed by your DC/DC isolated stage and parallel the outputs. So 3 single phase supplies with the isolated outputs working in parallel. This will keep all 3 phases in balance.
Great video, is that metal bracelet you're wearing conductive?
Thank you! It sure is;) Don't worry - I don't put my hands near the live circuit. I set things up then apply the power;)
Hi, can I apply some changes to make the output voltage variable?
Thanks for this question. You can place a potentiometer in the voltage divider feedback to adjust the output voltage.
The UCC28180, like many of the TI PFC controller ICs, requires a external bias supply input. So, this IC requires a separate DC bias supply to operate, or in other words, it does not operate in front end master mode.
Yes it does require a lower voltage to run the IC, and this is generally done a couple of different ways, so it is meant to be at the front end. Most off-line converters require a low voltage and in general a Kick-start circuit with a Boot-strap circuit are used for this function.
If I make the R13 as a variable resistor, can I change the output voltage based on my requirement?
Thanks for asking. Yes you can change the value of R13, but it would be better to put say half the value on R13 and the other half on a variable resistor in series with it. This way there is no way to short it and you can get better resolution.
@@KissAnalog Thank you sir for your suggestion. Great interesting work !!
How wood you use that in an audio amplifier at 360 volts
John sweda You would need to add an isolated DC/DC converter. I plan to do a part two where I do this;) Thanks for asking.
You mention you shorted the output and blew the input fuse. Since the chip has current sensing why did it not protect itself (hiccup or latch off) rather than causing a catastrophic (blown fuse) event ?
Great question! I used a smaller rated fuse to blow before the circuit was stressed. Once I get some test time and build confidence then I rely on the current limit features;) Make sense?
Sounds good, was just wondering about the current limit capabilities of this boost converter. Also if I was to do a 0-350VDC 200W converter, would this EVM be a good candidate to do it with ? A PFC of >0.9 would not be my primary concern for this converter.
Thanks for the great videos as always.
Yes - I think so. But then you would follow this up with an isolated converter for the voltage that you want.
good information thanks a lot.
by using ucc28180 IC i want design 1500watt PFC boost converter is it possible sir or any gate driver ic is needed ?.
and for EMI what is the actual peak input current i should consider ?. tell me sir
Sorry to respond so late, I'm trying to keep up with subscribers first and then go down the list;) It may not be necessary, but then it might depend on the FET that you are using. Do you have one selected?
Hi, I have a question about the pin that does current sense on the chip. When I use a multimeter on continuity mode, and I probe the current sense pin to ground, I get a continuity ring from the multimeter. Is this normal or is the chip shorted to ground via the current sense pin? Great video by the way.
Thanks Ray for the great question! Try putting your meter in ohm mode not continuity. It could be that the continuity mode places a higher voltage on the pin and turns on the chip in some way. Let us know what you find.
How much power wasted on boosting the inductor?
Great Question! The inductor has a little low, but not much.
Two mistake a lot of new comers make with drivers the igbt in pfc is connecting the driver voltage supply negative rail to the negative of the mains negative and this issue alway blow the igbt or burn it out fast , the transient high voltage alway shoot to the gate when all negative or connected never do that the driver ic should never series either the high voltage
Thank you for your feedback!
Lovely video, can you share a picture of the output dc waveform? I understand that the PFC will keep a steady output of 385V irrespective of input voltage (as long as the capacitor is large enough to do that ofcourse) -am I right?
Thank you and I do have some videos on this that will come out soon;) and yes - you are right;)
Hi Sir, you are really doing a great work. I wanna ask one thing, how can we find the FFT control across MOSFET or the BOOSTCCMDCM in the UCC28180_avg model? Looking for kind response.
Thanks so much Fab bop! I appreciate you! I’ll do a video on this very soon;)
Hello sir which type pfc good for SMPS based battery charger please
That's a great question Vengu G! If I understand correctly, I think this one would be a good PFC, then it would need an isolated converter to drop the voltage down to a battery charge level.
Love your tutorials ! I would like an ultra low noise tone generator that say had a fixed1kHz 1V (or perhaps variable) output, what would be involved in that ? I thought it may be cheaper than a function gen and be very useful in audio, perhaps a few fixed outputs but particularly quiet ? are there chips that can do this cheaply ? not sure you will see this as its an older vid but what the hey !....cheers.
Thanks so much! I appreciate you! I like this idea - let me look into this and see what I can come up with;)
It is amazing how many documents and videos exist that completely skip over how this thing actually works.
Problem statement: A simple rectifier into capacitor power supply draws current only when the incoming sine wave happens to have a higher voltage (plus 2 diode drops) than the capacitor. At that moment, the capacitor starts charging and its effective resistance nearly zero thus current demand is very high, but only for a few milliseconds.
Solution statement: Find a way to spread out that spike that happens 120 times per second; find some way to extract energy from the entire sine wave not just the peaks.
The magic smoke is a FLYBACK regulator; known here as a boost regulator but it depends on the flyback effect of the inductor. This is the same phenomenon that generates the spark in your gasoline powered internal combustion engine.
For a few microseconds, the inductor is *shorted to ground* which seems like a bad thing but while shorted to ground it is building a magnetic field. Then you suddenly open that path to ground.
The magnetic field starts to collapse. It wants to push electric current in the same direction that it has been flowing. What is special is that it does not care about voltage; it will push X number of electrons up a very steep hill if necessary. So, even though the capacitor already has 300 volts on it, and you charged the inductor at a moment where the incoming sine wave had only 20 volts, when you interrupt the ground path, the inductor will push 20 volts no matter what; making a spark if it needs to. It pushes that 20 volts right onto the 300 volts already on the capacitor and THAT is how you glean energy from the 20 volt (or any volt) portion of the incoming sine wave and scoop it up on top of your storage capacitor.
Detailed nuance: We don't actually fully charge the inductor, that would be bad, and we don't completely dump the charge either. So we "top off" the capacitor with these little impulses that RIDE the incoming wave.
It is by its very nature current limited since the thing that charges the main storage capacitor is the FLYBACK impulses from the inductor.
The crossover distortion will happen because at some low voltage part of the sine wave there just is not enough TIME to charge the inductor. (RL time constant) and consequently even with nearly 100 percent duty cycle you cannot effectively boost to the 300 volt capacitor.
Conversely, when the incoming wave is at its peak, we allow the inductor to conduct for only a few microseconds; it doesn't need much high-voltage pulse to charge its magnetic field.
Thanks - but this video 'does' explain this. It is similar to what you describe - but there are some very important misconceptions and/or errors in your discourse.
1) You start off with an incorrect 'Problem Statement'. The 'Problem Statement' is that this results in a bad power factor, thus; an Active Power Factor Correction circuit is used. Sometimes a Passive Power Factor Correction circuit is used.
2) The 'Bulk' capacitor does have some impedance, and this is actually important. It is low - but not nearly zero.
3) I think you meant that a circuit switching at 120,000 times a second - not 120 times.
4) This is a boost - not a flyback - even though they are similar. A flyback uses a transformer as an inductor which also provides isolation. A boost only uses an inductor and does not provide isolation, so this is not a flyback. It is appropriately termed a 'Boost Converter'.
5) When the waveform is at 20 V level - it isn't this voltage that gets pushed to the top - it is the energy stored in the inductance that gets pushed to the capacitor. The level of voltage that this results in is dependent on the volt-second principal that I discuss in another video.
6) Your detailed nuance is what I described in this video as 'Continuous - mode' operation, but there are other modes of operation that do fully drain the energy from the inductor. The 'discontinuous mode' might be more commonly used than the 'continuous mode'. I actually explain these different modes of operation.
7) It actually is not by 'nature' current limited. This in fact is actually an unfortunate parameter of the 'Boost' converter. It does not have a controlled device from input to output to limit the current - and the inductor will pass whatever current that wants to go thru it - if the load demands it. If you short your output (with safety gear on) it will become obvious very quickly that the inductor will not limit the current to a safe level. If the output is shorted - the current will pass thru the inductor and diode - fully charging the inductor past its ability to contain this charge. So it saturates, and the current rises until the diode, inductor, or another device in the path fails open. So, there is no natural current limit or short circuit protection. The control chip is set up to offer an over current protection - that will work to some level. A current sense resistor and the control chip will protect the switching FET and Inductor to keep them from overloading themselves - but this will not limit the current in case of short circuit or severe overload.
8) The crossover distortion is not caused by lack of Time as you say - it is caused by the lack of available energy when the incoming voltage is near zero or at zero. Also, at the top of the waveform it is still about energy and not the 'high voltage'. All along the waveform the duty cycle is controlled to result in the current waveform resulting in an amplitude that looks sinusoidal at the input. Thus resulting in a power factor near unity.
I have a number of videos on these PFC converters. You have a fair understanding - so if you would be more open to learning - you could improve your understanding by watching this video as well as the others that I have on this topic. I also have videos on Flyback converters. This might help in understanding the differences in Boost vs Flyback converters.
@@KissAnalog I appreciate the additional information and corrections.
"3) I think you meant that a circuit switching at 120,000 times a second - not 120 times."
No, I meant a 60 Hz main power line, so 120 times a second a voltage peak. A traditional power supply lightly loaded draws power only in the case that the instant voltage on the mains exceeds the voltage of the capacitor (and diode forward drops typically 0.6 volts). I'm not sure how this affects power factor since it isn't exactly a phase shift but is certainly going to be a bit ugly on the current waveform as compared to the nice clean voltage waveform.
I concur that shorting out the output would not be inherently current limited. I suppose I should have been more clear; a boost regulator can only maintain boost up to a certain design limit, the storage capacity of the inductor and capacitor. Exceed that current limit on the output, and the boost can no longer maintain voltage boost.
"The crossover distortion is not caused by lack of Time as you say - it is caused by the lack of available energy when the incoming voltage is near zero or at zero."
I suppose that's a better way of looking at it. I was thinking of the time constant and you've only got a few milliseconds or microseconds depending on the switching rate.
Thanks for your response! I appreciate you and your knowledge. I worked at a large defense contractor that was doing a project for Boeing (who I once worked for), and they were reporting something about power factor that just wasn't correct. The engineers (who are top notch) at both companies had it wrong. I'll have to do a video on this. It is not as simple as people think. Yes the diodes in a bridge rectifier do throw off the power factor. The current is no longer in phase - even though it looks like it is being pulsed at the top of the waveform. That does not put or keep it in phase with the voltage. This is the mistake that most people (great engineers) make. This is my life, so I happen to understand it enough to know how to measure it and simulated it. Once I explain you will slap your knee and say - damn - that's cool;)
@@KissAnalog As I think further on it, I realize that it matters what the mains hits first. If it is a transformer, then when unloaded the power supply is going to exhibit a 90 degree phase shift between current and voltage on the primary of the transformer, hence a power factor of zero. Looking at the secondary, the diodes become conducting at peak voltage but minimum current. As the voltage changes direction of growth (not yet direction but heading back to zero) the current crosses zero and starts up to its maximum BUT for a moment the magnetic field ceases to oppose primary current flow and you start to get current and voltage in phase. Then when the diodes stop conducting the transformer primary current can resume increasing. So it is still out of phase but not by 90 degrees hence a power factor greater than 0 but not by a lot.
I remember a mnemonic for this sort of thing: "ELI the ICE man" E (voltage) leads I (current) when inductive "L".
@@KissAnalog It is interesting that inverters are sensitive to power factor. Even though my computer uses less than 80 watts it has a capacitive input power supply and the surge and pulsed current demand vastly exceeds that of a resistive 80 watt load. The bigger Goal Zero (Yeti 1000 and Yeti 1000x) have "slow start" capability that helps in some situations. Ramps up in about 1/2 second or so and works well.
How fast response it has?
Great Question! It actually has good response. The PFC converters typically have lower freq gain bandwidth because of the low power freq coming in. I'll be doing another video on this very soon. Hopefully this week;)
how can we use ucc28810 in for the buck mode?
Can you show how to design one from start to finish? Maybe something simple like a 1-2kw supply?
I sure can and I do plan to do that. I hope soon I will do that. Thanks for asking! This is just the thing that I hope to provide as a recipe for people to follow and be confident in doing. I'll put together a video very soon;)
@@KissAnalog that would be great! ❤️
an a.c. p.f.c, simply saves power, thus saves fuel. thus save money. overtime. sounds complex and indirect. ask a specialist. if you want. you dont need too. just. you can.
it synchronize, the alternate current. from the input too the output. sometimes. the atached device or apliances. drags power from the socket. on the ... clumbsey way.
Yes PFC is the way to go and provides cleaner power. Thanks for the feedback!
My god. It's expensive 😐😮
You mean the eval card? They don't make a lot of these and they are made for engineers like myself to evaluate and see how the circuit performs. They put them on sale just for those small companies or individuals that want to try them. The chip itself is very inexpensive, and the circuit in quantity is low cost as well.
@@KissAnalog Right
That was exactly what I suspected. Because a Buck boost PFC can be made really cheap. So that really doesn't make sense to use the board commercially. But thanks for the clarification.
Thank you!!