It does already. I’m 4 classes away from my EE degree and already have a CE degree. Have not learn this much practical material at the university, only on my own and videos like this
@Thewld < Formal learning will teach you the necessary theories which are very important, while these videos provide you practical experience. In my opinion both are equally important to become a knowledgeable engineer. ;)
Very good explanation! Especially about the feedback circuitry. It´s by far the most complex part of these power supplies. When I started learning about switching converters, I originally wanted to build one with all _discrete_ circuitry. Then I learned about the insanity called feedback circuits.
Superior explanation... that is really how it is... It’s worth to mention that half-bridge and full-bridge SMPS are more efficient, more powerful derivatives from push-pull conception - 2 alternately switching transistors, divided windings, 2 diodes which means double the power charging the coil which is collecting energy. Best wishes from Poland.
The startup circuit is especially clever. And they save an optocoupler and still have isolation between primary and secondary. It also makes troubleshooting easier because you connect the oscilloscope to the isolated part.
Anything is possible when you understand the operation of something and what all the components do in the circuit. I would definitely love to see you convert a SMPS into a bench top power supply! Especially if there's two of them to get both positive and negative rails. A retail dual rail power supply is way to expensive but it's a necessary tool for electronic work...
I am new to Circuits but your explanation though complex is very captivating. I will watch again and again it awesome how you put it all together. Thank YOU Thank YOU so much
Fantastic review of the circuit. Best in-depth explanation I have ever heard. I can't believe you remember all the information without reference material. I guess that is why you have so many subscribers.
Well explained. At the first moment, I thought I'll never understand that. But now it's better. I'm an educated electonics specialist, but it was 30 years ago, so my knowledge is a bit rusty now. Thanks for brushing it up!
Yansi (at EEVblog forum) made some observations that may help mods for the conversion to a bench supply): ".. A diode is probably missing in the center tap of the NPN driving transformer. Without it, the current can get partially shunted back to the power supply. Not sure if mistake when the schematic was drawn or intention to shave every cent possible from the BOM (bill of materials - production terminology). I see two more mistakes (either be it schematic drawing, or the Chinese designer guy was on drugs): The base-to-ground resistors of the C1815 driving transistors are connected a bit weird and the auxiliary power winding should in fact be referenced with the center tap AFTER the current sense shunt. The schematic also contains some other interesting circuit nuances I'd consider at least strange and not much reason for them (for example the parallel RC in the pin 16 of the TL494)." As for circuit review: ".. explanation of the current limit feedback loop I find kind of strange ... The current is not sensed by pin 16, that's just GND reference. In fact, it is sensed in the node on the pin 15, where the reference current (5V ref divided by the 100k resistor) should equalize the node voltage to that of GND potential with the current flowing out of the node through the 1k resistor, towards the shunt - yes, the current is sensed as a negative voltage with respect to circuit GND. (That is because this way the burden voltage is compensated for in the voltage feedback loop, as the 5V reference is referenced to control circuit GND, which happens to be the output V- terminal). " ".. very well executed explanation, at least for beginners or those who are looking for more circuit specifics of these power supplies"
The diode in the centre tap is really not there. (I know that this diode is present in AT/ATX power supplies, but they also use the auxiliary transformer for current sensing.) But it works anyway. The current from the auxiliary transformer probably backfeeds into the auxiliary power supply, but it doesn't seem to be a problem. It may actually help to power the chip. ... The base to ground resistors of the C1815s are really connected this way (each of them a different way), no matter how odd it looks. It's not my drawing mistake. I was also surprised by this and I tripple checked it. Maybe this gives the circuit a starting position on power up. ... The current sensing shunt drops only less than 50mV, so it's not that important where the control circuitry ground is connected. But you're right, the ripple of the shunt goes into the auxiliary power. I was also a bit surprised by this. Maybe it's done like this so the transformer has one pin less. The centre taps of the main and auxiliary secondaries are on the same pin. Maybe the auxiliary winding is actually not a winding, but only taps on the main secondary! This may be the explanation. ... The RC on the pin 16 is there for a good reason. Both inputs of an OpAmp should be connected via the same resistance (here it is 1k). This is a common practice with OpAmps. Using the same resistance in both inputs helps to cancel the voltage drop on the resistors caused by the leakage current of the inputs. Ideally the inputs draw or supply no current, but in real life there's always some tiny current. ... Where the current is sensed on the shunt, depends on the perspective :). It depends whether your reference point is before or after the shunt. You're in fact right, but it was easier to explain it saying that the voltage of the shunt is compared with a 50mV reference voltage. This is true if our reference point is before the shunt. Of course, the GND of the chip is connected after the shunt, but this doesn't change the behaviour of the OpAmp.
Just came across your videos recently and I think they are very informative and well produced. This was probably the most complete description of a fairly complex SMPS that I have seen and I have never seen anyone describe the feedback mechanisms in such detail. Really appreciate that.
Thanks, Great description Just two point: 1- I think two 1N4007 diodes (series with 10 ohm resistors) direction, is wrong. 2- Resistor 2.2 ohm in feedback path may protect TL494 from over voltage coming from positive rail, through 3.3nF ). But, for this reason 2.2 ohm is too low, may be it's value was higher, say 1K or 2.2K ohm.
I just found your channel. This is very very informative. I have not as I remember seen any such detailed walk tru a complex diagram. Lucky me I found your channel. Thaks for your effort. Wish I knew just a fraction of what you know of engineering electronics.
Regarding that arrangement error with the NTC thermistor, I think I've now seen the correct implementation of what they've apparently butchered-down: One of the old ATX power supplies I have, a Hipro HP-300SN (probably fairly "high-end" in 1998 when it was designed according to the PCB, though underwhelming by the standards of modern reviewers; now salvaged for parts), used a *pair* of NTC thermistors (each 2R5 nominal; it's common enough in other units to use just one such thermistor which I consider marginal on 230V) in the + and − terminals of the diode bridge; so that the 100~127V input range charges the capacitors through the 2.5Ω on their respective sides, while the 200~250V range charges the pair through the total 5Ω, thereby allowing a more forgiving compromise between maximum inrush and dissipation under load. So perhaps someone later copied such a design, then removed one thermistor without understanding the reason behind the arrangement.
Thanks to a great explanation I understand more than I thought I would, certainly more than basic operation but goodness no's how you guys design these from scratch !
Thanks for this great review and in detail explanation of switching power supplies in half-bridge configuration! This is probably one of the most in-depth explanations i have come across yet! Looking really forward to your modification to a lab bench power supply! There are so many powerfull server PSUs out there very well worth beeing converted to bench PSUs :-) Some of them reach several kW of power and can deliver well over 100 Amps at 50 V e.g. But they are even much more complicated than this example ;-)
Great stuff. The US hasn't used 110 volts since the 80's. 120 volts is the spec these days. (120/120) 240 split phase for most residential homes. Sometimes 208 (120) three phase in some apartment buildings. Commercial buildings is almost always three phase. I see 122-123 volts most of the time at outlets, 245 split phase. Just a center tapped transformer with the neutral as the center tap. Not that any of this matters.
Awesome! Thanks, this helped me to identify the difference between the 12V and 24V model and alter mine into the 24V model. If anyone else want's to do this on the S-250-12 model, change R33 from 10K to 22K, and remove one of the two shunts to prevent over current at the higher voltage. Also if you just want to raise the voltage a bit, replace R33 with 12K and you then get 12V - 16.8V.
What an explanation! a real marathon! congratulations very alive, although, I am convinced, without the help of your cat you would not have done for sure! Lol Replace the aluminum of the main inductor should not make changes if you keep the same section and number of turns: you could only raise the maximum current bearable by the inductor (not the ouput current) Differently, if you change the number of turns you open a world of possibilities .... but in this case, the teacher is you! To the next video!
Hey Electronic Passion! Love your channel, and continue watching DiodeGoneWild, he has a very good electronic knowledge! French: salut Electronic Passion, j'aime beaucoup ta ghaîne, continue de regarder DiodeGoneWild, il a un savoir incroyable en électronique
@@sebastianfischer429 So what type of cat has got people near you? I don't know if it is British Shorthair cat, i thought that it was normal "roof" cat :)
Fantadtic video. Great job at explaining. Only thing i would like is to have pictures of the components on screen as you talk about them in the diagram. Thank you again.
Great video. That's pretty strange with the output filter inductor. You say it may have been from a 12V supply. Maybe it was in a common mode choke configuration on the 12V supply? Then repurposed with the two sides paralleled to work with 5V, but if the inductor were being specified, it's not clear why they wouldn't just use one with a single winding... Anyway, your power supply knowledge is really impressive and it's amazing that you are making these videos rather than doing high-price consulting.
CM chokes use high-permeability cores, like ferrite. In normal operation the fields cancel each other and all you see is active resistance of the coil. But for CM noise it presents a high impedance, since then you have two inductors in series effectively and 4 times the inductance of the single winding.
Come on! Tell the truth (kápni božskou). Your cat is whispering most of that knowledge to you. LOL But for real nice and simple explanation. Half an hour video from you equals like 10 hours buried in books. Keep it up. Congrats to 100K!
And that is pure knowledge with very much experience in background. I am really suprised with this wonderful and educational video. Great job and thank you !!!! Cheers
You do great videos, you sound like you design switching power supplies for a living. Of course I noticed that all your videos receive a cat scan before they are released. That must be a great help!
Great explanation on this subject! It happens that I'm fixing the 150W version of this very same power supply which is not regulating under load. After seeing your video, I adventured to use the same trick you did in order to see the waveforms on the power and base drive transformers. However, the pulse width at the base is just 7.2us max. I can see that yours is closer to 10us with 2.1A load. One thing that I found strange is that the pulse coming from the TL494's C1 pin gets a width of 15.3us, which goes to the base of its corresponding C1815 transistor driving the pulse transformer, and the pulse width at the collector of this very same transistor is just 7.2us with only 66 ohms. I wonder if this has something to do with this transformer maybe gone bad. Using just 100 ohms as a load kept both readings at same pulse width. Adding 200 ohms in parallel (with this 100 ohm resistor) caused the pulse to go the widest and output voltage fell from 24V to 20V. Could the magnetizing inductance in this pulse transformer have changed? Congrats on this great channel!!
Don't mod this use a ATX power supply using this chip so thousands of discarded power supplies will be saved from the dump by your viewers. Include the extra parts to regulate the current.
Exzellent, exzellent, exzellent! Zhis channel actually DOES, wat all zhe other elektronik channels like EEVblog etc. should do! I have zhis PSU and zhis iz exactly wat I vant to know! Very well done!
I love this videos, you make this hard topics very easy to understand. Please, change the color balance of your camera from 'auto' to a fixed (hopefully calibrated) value. Thanks!
I was just playing around with a free server power supply I got so right now I am all in on this topic. Thanks. I will put up the final "hack" on YT for anyone who happens to come across a similar supply. As it stands now i could not find any info on that particular power supply. Nothing even close actually.
Thank you for give a very valuable knowledge. Sometimes i have problem with understund your english but overall its ok. Subtitles will be very helpfull
I'm watching this while drinking Becherovka and digesting a Medovnik honey cake I ate five weeks ago :-). Wonderful explanation, I wonder if you could also show the noise in the output in some other video...
If tl494 is powered by secondary output Side then how it will turn on at first place to generate voltage on secondary winding to powering ic and for continuing all process ?
It would be great if you explained the step by step when one transistor turns on and how energies the core and the polarity of the voltage in the windings and how randomly both transistor dont turn on at the same time i will be thankful if you explain that in another video you always explain flyback in complete details never done half bridge
thanks for the great info sir, you make understanding everything so easy, i have one question how can we use it for charging lithium battery 54.6, it can just provide cc, we we disable current feed back somehow so that it gives constant current first and as battery voltage increases its current also drops ,regards, thanks in advance
I don't remember a dog.. but I'm sure the cat gives good feedback :) Duly posted to EEVblog original thread! When our knowledgeable host finishes his bench supply conversion I'll link to it in the "Primers, Course Material and Books" thread. Great stuff! www.eevblog.com/forum/beginners/half-bridge-smps-special-diode-gone-wild-(and-cat)-pass-100k-subscribers/
Hi, it would be very cool if you could try to build your own power supply of the various topologies, going simplest to more complex, showing your considerations in the design, and then building it to see how well it works. You could even take parts from other supplies so you built your own 'franken-supplies' :)
Sir your video is very knowledgeable. kindly upload the schematic diagram in pdf format. Thank u. Also I request you to use black gel pen for the better contrast in circuit.
Crazy good explanation, especially for DIY enthusiasts. What about making some custom multi-rail power supplies to power, for example, A316J IGBT driver optocoupler.
You have done many videos on switching power supply, make something on regulated adjustable power supply. Importantly the one in which current can also b adjusted.
For the feedback sestym, when the current or voltage is high then duty cycle is low then the transistors shorts up the primary side of the driver transformer(which drives the bases of the high voltage BJTs) and thus the voltage drop occurs and also vice versa. So in this sequence can we imagine that the primary windings of driver transformer is just to short up or not necessary to drive bases of the BJTs (Though the switching of the primary side helps to switch hard of the main high voltage BJTs) But I have made this circuit with out this primary windings but yet it is working. (Thogh there is no feedback sestym😅)
Thankyou i understand them a bit better now :-D, (Dog/Cat but no Larma? lol ) That supply is simple in basic operation, but so complex with all the modifications needed for correct operation. The hysteris of the feedback/control does sound like a bloody nightmare. I did wonder how it started as it looks very similar to p'c power supplys, but they have a seperate flyback for the pwm chip and standby supply. Also pc supplys have a split feedback from the many outputs. So the transistors have bias that gives the circuit a kick, once producing power it continues.
Yes, the principle is simple, but it requires a complex control circuitry and a complex circuitry to isolate and drive the bases. This is actually very similar to AT computer power supply (the one with no separate flyback). The newer ATX ones have the flyback to produce +5V in standby mode, and this flyback also produces some voltage for the chip. ATX ones don't have the startup resistors.
Thanks for this great in details explanation. Why is the AC converted to DC then converted back to AC and then converted back to DC? I understand that the chip controls the last Ac to DC to regulate the output voltage but why can't it do this directly on the input?
Your channel has the potential to teach people more than the university.
And also a magically appearing 26Khz above the transformer at 6:11 ;)
It does already. I’m 4 classes away from my EE degree and already have a CE degree. Have not learn this much practical material at the university, only on my own and videos like this
@Thewld < Formal learning will teach you the necessary theories which are very important, while these videos provide you practical experience. In my opinion both are equally important to become a knowledgeable engineer. ;)
This is the best in-depth explanation of a switching power supply that I've seen. Thanks for sharing your knowledge.
It's the best explanation of an SMPS that I ever heard, Congratulations 👏👏👏👏👏. No matter the language I understood everything. Very good 💯💯💯
This is one of the best explenation on the HB converter that i saw, congratulation
Very good explanation! Especially about the feedback circuitry. It´s by far the most complex part of these power supplies.
When I started learning about switching converters, I originally wanted to build one with all _discrete_ circuitry. Then I learned about the insanity called feedback circuits.
Feedback circuits are really unfathomable. Those people who designed them are genius.
Feedback itself is quite easy to understand and quite fun to design also, but compensation is simply insane.
Výborný kanál o "component level" elektronice, díky za tu práci a gratuluju k úspěchu videí.
Calling it excellent is an understatement. Amazing explaination.
You explain everything very easy, so it's very easy to learn from you!👍😀
Superior explanation... that is really how it is... It’s worth to mention that half-bridge and full-bridge SMPS are more efficient, more powerful derivatives from push-pull conception - 2 alternately switching transistors, divided windings, 2 diodes which means double the power charging the coil which is collecting energy. Best wishes from Poland.
The startup circuit is especially clever. And they save an optocoupler and still have isolation between primary and secondary. It also makes troubleshooting easier because you connect the oscilloscope to the isolated part.
These are my favorite youtube video's.
The schematics with an explanation.
They really help to understand the way the circuits work.
THANKYOU!
It's the best explanation of an SMPS that I ever heard, thank you very much 👍
I'm currently learning on how to use the TL494 and I want to try to build my own power supply with it. This is very useful, thank you.
To make it worthwhile I don't think the complicated design of this one is particularly useful for me to try to make in small quantities. YMMV
Don't forget its twin - the KA7500 is pin compatible and runs up to 300kHz
I could understand every bit of information effortlessly. You are the ideal teacher Sir. Please convey my regards to the cat too...
Wow, looking forward to the upgrades... One of the best videos on this topic which I have ever seen...
Anything is possible when you understand the operation of something and what all the components do in the circuit. I would definitely love to see you convert a SMPS into a bench top power supply! Especially if there's two of them to get both positive and negative rails. A retail dual rail power supply is way to expensive but it's a necessary tool for electronic work...
Mega video. So much information. Obsolete scheme or not, it provides so much insight. Thanks a bunch! I will rewatch it several times in coming weeks.
I am new to Circuits but your explanation though complex is very captivating. I will watch again and again it awesome how you put it all together. Thank YOU Thank YOU so much
Fantastic review of the circuit. Best in-depth explanation I have ever heard. I can't believe you remember all the information without reference material. I guess that is why you have so many subscribers.
This scematic-drawing is quite genius! How the hell you know so much about power supplys?
Dr. House
Dr House !!! Super Docteur en France !!
Probobly he is an electronic entusiast and lovingly dedicated to electronics
cristony solomon
I think yes
Jeżeli jest geniuszem to ty jesteś debilem
Can one draw a schematic just by looking at a circuit. If yes how do I learn.
Well explained. At the first moment, I thought I'll never understand that. But now it's better. I'm an educated electonics specialist, but it was 30 years ago, so my knowledge is a bit rusty now. Thanks for brushing it up!
im 5 mins in and never have a learned so much off one video and hes only just warming up
Yansi (at EEVblog forum) made some observations that may help mods for the conversion to a bench supply):
".. A diode is probably missing in the center tap of the NPN driving transformer. Without it, the current can get partially shunted back to the power supply. Not sure if mistake when the schematic was drawn or intention to shave every cent possible from the BOM (bill of materials - production terminology). I see two more mistakes (either be it schematic drawing, or the Chinese designer guy was on drugs): The base-to-ground resistors of the C1815 driving transistors are connected a bit weird and the auxiliary power winding should in fact be referenced with the center tap AFTER the current sense shunt. The schematic also contains some other interesting circuit nuances I'd consider at least strange and not much reason for them (for example the parallel RC in the pin 16 of the TL494)."
As for circuit review:
".. explanation of the current limit feedback loop I find kind of strange ... The current is not sensed by pin 16, that's just GND reference. In fact, it is sensed in the node on the pin 15, where the reference current (5V ref divided by the 100k resistor) should equalize the node voltage to that of GND potential with the current flowing out of the node through the 1k resistor, towards the shunt - yes, the current is sensed as a negative voltage with respect to circuit GND. (That is because this way the burden voltage is compensated for in the voltage feedback loop, as the 5V reference is referenced to control circuit GND, which happens to be the output V- terminal).
"
".. very well executed explanation, at least for beginners or those who are looking for more circuit specifics of these power supplies"
The diode in the centre tap is really not there. (I know that this diode is present in AT/ATX power supplies, but they also use the auxiliary transformer for current sensing.) But it works anyway. The current from the auxiliary transformer probably backfeeds into the auxiliary power supply, but it doesn't seem to be a problem. It may actually help to power the chip. ... The base to ground resistors of the C1815s are really connected this way (each of them a different way), no matter how odd it looks. It's not my drawing mistake. I was also surprised by this and I tripple checked it. Maybe this gives the circuit a starting position on power up. ... The current sensing shunt drops only less than 50mV, so it's not that important where the control circuitry ground is connected. But you're right, the ripple of the shunt goes into the auxiliary power. I was also a bit surprised by this. Maybe it's done like this so the transformer has one pin less. The centre taps of the main and auxiliary secondaries are on the same pin. Maybe the auxiliary winding is actually not a winding, but only taps on the main secondary! This may be the explanation. ... The RC on the pin 16 is there for a good reason. Both inputs of an OpAmp should be connected via the same resistance (here it is 1k). This is a common practice with OpAmps. Using the same resistance in both inputs helps to cancel the voltage drop on the resistors caused by the leakage current of the inputs. Ideally the inputs draw or supply no current, but in real life there's always some tiny current. ... Where the current is sensed on the shunt, depends on the perspective :). It depends whether your reference point is before or after the shunt. You're in fact right, but it was easier to explain it saying that the voltage of the shunt is compared with a 50mV reference voltage. This is true if our reference point is before the shunt. Of course, the GND of the chip is connected after the shunt, but this doesn't change the behaviour of the OpAmp.
Just came across your videos recently and I think they are very informative and well produced. This was probably the most complete description of a fairly complex SMPS that I have seen and I have never seen anyone describe the feedback mechanisms in such detail. Really appreciate that.
Fantastic. I fixed one of these yesterday. I thought it was complicated but not this complicated!
I arrived to your channel by accident and I'm enjoying it a lot. Your videos are the best!
Your explanation is superior... I can not get out of admiration.
Thanks, Great description
Just two point:
1- I think two 1N4007 diodes (series with 10 ohm resistors) direction, is wrong.
2- Resistor 2.2 ohm in feedback path may protect TL494 from over voltage coming from positive rail, through 3.3nF ).
But, for this reason 2.2 ohm is too low, may be it's value was higher, say 1K or 2.2K ohm.
Please do a QNA on 100k subscribers.
103k now..
@@FaysalKhalashi 104k now...
@@aakasoto 154k now
That's a good idea
165k
I just found your channel. This is very very informative. I have not as I remember seen any such detailed walk tru a complex diagram. Lucky me I found your channel. Thaks for your effort. Wish I knew just a fraction of what you know of engineering electronics.
Regarding that arrangement error with the NTC thermistor, I think I've now seen the correct implementation of what they've apparently butchered-down:
One of the old ATX power supplies I have, a Hipro HP-300SN (probably fairly "high-end" in 1998 when it was designed according to the PCB, though underwhelming by the standards of modern reviewers; now salvaged for parts), used a *pair* of NTC thermistors (each 2R5 nominal; it's common enough in other units to use just one such thermistor which I consider marginal on 230V) in the + and − terminals of the diode bridge; so that the 100~127V input range charges the capacitors through the 2.5Ω on their respective sides, while the 200~250V range charges the pair through the total 5Ω, thereby allowing a more forgiving compromise between maximum inrush and dissipation under load. So perhaps someone later copied such a design, then removed one thermistor without understanding the reason behind the arrangement.
Thanks to a great explanation I understand more than I thought I would, certainly more than basic operation but goodness no's how you guys design these from scratch !
Thanks for this great review and in detail explanation of switching power supplies in half-bridge configuration! This is probably one of the most in-depth explanations i have come across yet! Looking really forward to your modification to a lab bench power supply! There are so many powerfull server PSUs out there very well worth beeing converted to bench PSUs :-) Some of them reach several kW of power and can deliver well over 100 Amps at 50 V e.g. But they are even much more complicated than this example ;-)
This was very interesting. I hadn't seen this topology before, was impressed with the start up arrangement. Your cat is very cool!
Great stuff. The US hasn't used 110 volts since the 80's. 120 volts is the spec these days. (120/120) 240 split phase for most residential homes. Sometimes 208 (120) three phase in some apartment buildings. Commercial buildings is almost always three phase. I see 122-123 volts most of the time at outlets, 245 split phase. Just a center tapped transformer with the neutral as the center tap. Not that any of this matters.
This is one of your best videos man, if not the best
Oh your english is such a great inspiration to others learning it!
Very good video and explaining. The idea to convert it to a bench power supply is very good too !
Awesome! Thanks, this helped me to identify the difference between the 12V and 24V model and alter mine into the 24V model. If anyone else want's to do this on the S-250-12 model, change R33 from 10K to 22K, and remove one of the two shunts to prevent over current at the higher voltage. Also if you just want to raise the voltage a bit, replace R33 with 12K and you then get 12V - 16.8V.
This video and explanations is very professional. Top ranked.
As an engineer, i learned a lot from you. Thanks a lot.
What an explanation! a real marathon! congratulations very alive, although, I am convinced, without the help of your cat you would not have done for sure! Lol
Replace the aluminum of the main inductor should not make changes if you keep the same section and number of turns: you could only raise the maximum current bearable by the inductor (not the ouput current)
Differently, if you change the number of turns you open a world of possibilities .... but in this case, the teacher is you!
To the next video!
very good explanation! i love the black magic that power supply is made of..
this was very very informative, I guess half-bridge is not black magic anymore
thanks
Your english is becaming better and better 👍👍👍
Fantastic video. Please keep making videos about SMPSs. Thank you very much!
you have a very beautiful cat !!!
Hey Electronic Passion! Love your channel, and continue watching DiodeGoneWild, he has a very good electronic knowledge!
French: salut Electronic Passion, j'aime beaucoup ta ghaîne, continue de regarder DiodeGoneWild, il a un savoir incroyable en électronique
exceptional intellectual or creative power or other natural ability- genius, now its 100k subs,good job bro
You also have a British Shorthair cat like me. They look very nice
Standart type of cat in central and eastern europe :D
@@JanKowalski_777 Haha, everyone that I know that has cats, doesnt have British Short Hair Cats. (Germany, Saxony)
I'm puzzled, the cat is like you?
@@sebastianfischer429 So what type of cat has got people near you? I don't know if it is British Shorthair cat, i thought that it was normal "roof" cat :)
@@JanKowalski_777 They have tabby cats, Eurpoean Shorthair and German Longhair.
Fantadtic video. Great job at explaining.
Only thing i would like is to have pictures of the components on screen as you talk about them in the diagram.
Thank you again.
Great video. That's pretty strange with the output filter inductor. You say it may have been from a 12V supply. Maybe it was in a common mode choke configuration on the 12V supply? Then repurposed with the two sides paralleled to work with 5V, but if the inductor were being specified, it's not clear why they wouldn't just use one with a single winding...
Anyway, your power supply knowledge is really impressive and it's amazing that you are making these videos rather than doing high-price consulting.
CM chokes use high-permeability cores, like ferrite. In normal operation the fields cancel each other and all you see is active resistance of the coil. But for CM noise it presents a high impedance, since then you have two inductors in series effectively and 4 times the inductance of the single winding.
Come on! Tell the truth (kápni božskou). Your cat is whispering most of that knowledge to you. LOL But for real nice and simple explanation. Half an hour video from you equals like 10 hours buried in books. Keep it up. Congrats to 100K!
Thank you so much for this explanation! It's help me to understand how it's work, especially the PID of the feedback system
Top notch video.
Examples are crucual for effective and complete learning. I think.
Super video, perfect explanation of the controll loop stability.
And that is pure knowledge with very much experience in background. I am really suprised with this wonderful and educational video. Great job and thank you !!!! Cheers
You do great videos, you sound like you design switching power supplies for a living. Of course I noticed that all your videos receive a cat scan before they are released. That must be a great help!
I like seeing your pets in your videos. They are a good addition :)
I want that schematic
Great explanation
We want Q+A!!! 100k subscribers have been achieved!
Outstanding explanations and schematic, very nice, try to explain in another video, boost pfc circuit.
Very keen to see your conversion into a power supply 😁
I love the reverse engineering aspect you cover in your channel.
amazing
keep going
we need the push pull topology too
Great explanation on this subject!
It happens that I'm fixing the 150W version of this very same power supply which is not regulating under load. After seeing your video, I adventured to use the same trick you did in order to see the waveforms on the power and base drive transformers.
However, the pulse width at the base is just 7.2us max. I can see that yours is closer to 10us with 2.1A load.
One thing that I found strange is that the pulse coming from the TL494's C1 pin gets a width of 15.3us, which goes to the base of its corresponding C1815 transistor driving the pulse transformer, and the pulse width at the collector of this very same transistor is just 7.2us with only 66 ohms. I wonder if this has something to do with this transformer maybe gone bad. Using just 100 ohms as a load kept both readings at same pulse width.
Adding 200 ohms in parallel (with this 100 ohm resistor) caused the pulse to go the widest and output voltage fell from 24V to 20V.
Could the magnetizing inductance in this pulse transformer have changed?
Congrats on this great channel!!
Excellent video! Extremely informative and educational. Thank you and keep making more videos like this!
Great Scott and you both e plain everything perfectly.
Can you mod it to a bench power supply and take us through how To do it? Great video man.
Thanks :) I definitely plan to do so :)
Good idea!
@@DiodeGoneWild Show us your 80's PSU with tracking. I found it really Interesting and efficient method of regulation.
if this can be modded sucessfully, i will buy the same PSU and do the mod as well. A 0-30V, 0-10A bench PSU would be very useful.
Don't mod this use a ATX power supply using this chip so thousands of discarded power supplies will be saved from the dump by your viewers. Include the extra parts to regulate the current.
Exzellent, exzellent, exzellent!
Zhis channel actually DOES, wat all zhe other elektronik channels like EEVblog etc. should do!
I have zhis PSU and zhis iz exactly wat I vant to know!
Very well done!
I love this videos, you make this hard topics very easy to understand. Please, change the color balance of your camera from 'auto' to a fixed (hopefully calibrated) value. Thanks!
I was just playing around with a free server power supply I got so right now I am all in on this topic. Thanks.
I will put up the final "hack" on YT for anyone who happens to come across a similar supply. As it stands now i could not find any info on that particular power supply. Nothing even close actually.
a phenomenal job by you and your cat! you guys never disappoint!
Your Reverse Engineering is Outstanding...
Thank you for give a very valuable knowledge. Sometimes i have problem with understund your english but overall its ok. Subtitles will be very helpfull
I'm watching this while drinking Becherovka and digesting a Medovnik honey cake I ate five weeks ago :-). Wonderful explanation, I wonder if you could also show the noise in the output in some other video...
So cool. Just the way i like it!!!! Brings back memories!!! Now show us how to design the tl494 down to pn material. Please.
Qq where do i put current limit pot on pin 16? Vref vdiv low?
Awesome video. Am I the only one who thinks if a great video is already "half-hour" long, it should be extended by another "half-hour" ? :)
You are a very good teacher. Thanks.
still eager to see the SMPS to Lab PS conversion ;-)
Your videos are very informative, thanxforyourteaching
If tl494 is powered by secondary output Side then how it will turn on at first place to generate voltage on secondary winding to powering ic and for continuing all process ?
Just after posting my question i came to continue watching video 18:00 and surprisingly here's same question ..... M curious to kno....
It would be great if you explained the step by step when one transistor turns on and how energies the core and the polarity of the voltage in the windings and how randomly both transistor dont turn on at the same time i will be thankful if you explain that in another video you always explain flyback in complete details never done half bridge
thanks for the great info sir, you make understanding everything so easy, i have one question how can we use it for charging lithium battery 54.6, it can just provide cc, we we disable current feed back somehow so that it gives constant current first and as battery voltage increases its current also drops ,regards, thanks in advance
I don't remember a dog.. but I'm sure the cat gives good feedback :) Duly posted to EEVblog original thread! When our knowledgeable host finishes his bench supply conversion I'll link to it in the "Primers, Course Material and Books" thread. Great stuff!
www.eevblog.com/forum/beginners/half-bridge-smps-special-diode-gone-wild-(and-cat)-pass-100k-subscribers/
Your videos are extremely Knowledgeable and informative thanks :)
As I remember a ferrites have an internal distributed air gap, we do not see it but they have one.
Hi, it would be very cool if you could try to build your own power supply of the various topologies, going simplest to more complex, showing your considerations in the design, and then building it to see how well it works. You could even take parts from other supplies so you built your own 'franken-supplies' :)
Sir your video is very knowledgeable. kindly upload the schematic diagram in pdf format. Thank u. Also I request you to use black gel pen for the better contrast in circuit.
Crazy good explanation, especially for DIY enthusiasts. What about making some custom multi-rail power supplies to power, for example, A316J IGBT driver optocoupler.
When will we get to see the SMPS to Lab PS conversion? :)
Great video, love the cat transitions.
This schematic looks bloody complex but this is basically as simple a half bridge switching power supply can get.
You have done many videos on switching power supply, make something on regulated adjustable power supply. Importantly the one in which current can also b adjusted.
Check out his website danyk.cz, there's one in there.
Thank's for your upload this video.
Very interesting, on GDT dead time can be passed.
For the feedback sestym, when the current or voltage is high then duty cycle is low then the transistors shorts up the primary side of the driver transformer(which drives the bases of the high voltage BJTs) and thus the voltage drop occurs and also vice versa.
So in this sequence can we imagine that the primary windings of driver transformer is just to short up or not necessary to drive bases of the BJTs
(Though the switching of the primary side helps to switch hard of the main high voltage BJTs)
But I have made this circuit with out this primary windings but yet it is working.
(Thogh there is no feedback sestym😅)
Another brilliant walkthrough, thanks!
Thankyou i understand them a bit better now :-D, (Dog/Cat but no Larma? lol )
That supply is simple in basic operation, but so complex with all the modifications needed for correct operation.
The hysteris of the feedback/control does sound like a bloody nightmare.
I did wonder how it started as it looks very similar to p'c power supplys, but they have a seperate flyback for the pwm chip and standby supply.
Also pc supplys have a split feedback from the many outputs.
So the transistors have bias that gives the circuit a kick, once producing power it continues.
Oh that bloody feedback gives more than a kick, the darn thing will runaway into ashes if you don't short out the control transformer during deadtime.
MrJohhhnnnyyy
Ow err a self destructing switchmode, do you make psus for china :) lol.
Yes, the principle is simple, but it requires a complex control circuitry and a complex circuitry to isolate and drive the bases. This is actually very similar to AT computer power supply (the one with no separate flyback). The newer ATX ones have the flyback to produce +5V in standby mode, and this flyback also produces some voltage for the chip. ATX ones don't have the startup resistors.
sir can you tell me the value of the zener diode that in the right position of the schematic that named on the board ZD1 ??
???
Thanks for this great in details explanation. Why is the AC converted to DC then converted back to AC and then converted back to DC? I understand that the chip controls the last Ac to DC to regulate the output voltage but why can't it do this directly on the input?
@glyn hodges Thanks a lot for taking the time to explain this!
Even your cat is gone totally wild.,.really nice video,explanation n cat too,...lucky to be ur channel subscriber,,,,
love n regards from india