Sir I wish to thank you for all you do. I have watched many of your videos. I have learned a lot from you about switching power supplies. I never knew your trick of back feeding to test the feedback circuit. Very smart cookie you are. Thank you for all you have shared with us.
Sir i have great respect for you because your explanation is different from others by many and you use your full of energy doing so Thanks so much may almighty Allah be with you!!!!!
You have explained this better than anywhere else online. Subscribed. Just a side note: at 7:24 I believe it is best to connect the RLED to the stable post filtered Vout rather than pre filter. This will aid the stability of the LED voltage and gain the benefit of filtering. Great video.
You have a wonderful way of explaining and making things that are often quite complicated appear easy to understand. Thank you for taking the time to make these videos using your gift for teaching as they are very gratefully received.
Greetings, Mr. Haseeb hereby I would like to express my gratitude for your sincere efforts to enhace our knowledge of electronics. I watched this video many times and it was incredibly helpful for me. Thank you for making these educational videos. You teach so nicely. Hats off to you
its like a very capable surgeon with scalpel in his hand teaching you anatomy of body.jazakAllah brother and thumbs down seems from people who's brains are pull down to ground rail 'caz of shot capacitor.
As salaamu alaikum Bhai! This is an excellent explanation of the closed loop feedback circuit using the TL431. Keep up the good work. Your videos are very educational and informative.
resistor connected across pin 1 & 2 is called bias resistor, it works as protection resistor to the LED, capacitor is used as bypass capacitor for protection from false switching as it is isolating device so there is must not be any connection between pin 1 & 3. if you experienced in some un-isolated circuit, i don't know about it. as i never observed it.
Hello, hello friend, I am a new friend, thank you for sharing a good video, I like our friend, we are always good friends, I wish you good health🙏💓👋🤝🤝💓💓🙏👍
Hi and asalam bro .. Thank you it is great but i could not understand the direction of current . ia it from 12v rial supply through Resistor and opto coupler or from zenor upwards . Regards jamal
Thanks so much for the explanations. My question is : how would behave the feedback circuit when the output voltage is higher than 12 volts (réf voltage > 2.5 volts).
yes it is controlled by voltage divider network. in voltage divider network we have two resistors. when 2.5 volt will arrive at pin 1 of TL431 (reference pin) at that time the TL431 will conduct only. so the voltage divider network is connected between the output pins, it will sense the 12v out. if less it will decrease the reference pin. if the voltage will go above than 12 volts, it will provide more conduction to provide more light in input LED and optocoupler output tranasistor will saturate and it will inform PWM controller if output voltage are un-controlled , in the that case the auxiliary winding will provide OLP over load protection (please check video number 525 for aux winding role)
Greetings, a few days ago I exactly faced this question and surfed everywhere on the Internet to find the answer; thank God, through this reply I could get the picture of feedback's reaction to the exceeding output voltage. So thank you both.
So looks like the opto-coupler will output (to the controller) an Over voltage or Under voltage signal, instead of a linear signal. Is it true then the output voltage will oscillate between very slightly over and very slightly under the desired output voltage? This is because at one moment, the voltage is over the desired voltage so the controller will reduce the On time of the switching transistor until the voltage is under in which time the controller will increase the On time of the switching until it's over, i.e. oscillate between over and under. So if we were to measure the output of the opto-coupler in an oscilloscope, we would see a square wave?
welcome dear. i really appreciate your pinpoint understanding. when we connect load it causes to create sawtooth ramps on capacitor in case of heavy ramps and close to triangular wave at light load or no load. i will explain in upcoming video using oscilloscope and multimeter
Salam alaikum ,i now know clearly how this feedback works,I have bee searching for this explanation for long but I have it now mashallah,I want to know the purpose of R BIAS resistor how it work.some smp design u see a resistor at the cathode of the regulator to the 12v main voltage is it the same as R BIAS resistor or it for a different purpose.thank
Hi. Does the voltage at the reference pin HAVE to be 2.5V?When the 10k resistor is in place, the voltage would only be 2V, like you said...so not enough?
R1 and R2 values to b calculated by checking the IRef from the TL431 datasheet (normally 4-10 microampere is teh best range) for best compensation feedback) when it will receive 2.5 volt at reference pin (it is fed from voltage divider network R1 & R2), TL431 will allow to flow cathode current, which will allow to drive the optocoupler 10K resistor was just as an example purpse, please check video number 229 & 275
@@HaseebElectronics Thank you so much. I just want to say how useful and brilliantly explained your videos are. Especially the SMPS videos and how you break the circuit into sections. Many thanks once more.
Haseeb can i ask you a question! How to measure output in continuous through ADC of microcontroller and isolated also. I think this circuit track only reference output through comparator. Please guide me with answer. Thanks alot
this circuit is isolated but it measures the voltage in secondary side and transfers information to the primary using optocouler link. to to take isolated you can use Current transformer and then process through any ADC
@@HaseebElectronics if my output is 12v can i track output voltage from 0 to 12v analog with optocoupler? Or it give 0 and 1 output according to reference (digital output)?
Hi there, I am repairing PFC power supply Bn44-00636b, 5.3v stb ok, 12v not presented, supply keep clicking on off...also this reference ic I am getting 2.488v...I think if I follow your instructions, I need 2.5v?
Wcs bro thanks for sharing as always 🙏
Sir I wish to thank you for all you do. I have watched many of your videos. I have learned a lot from you about switching power supplies. I never knew your trick of back feeding to test the feedback circuit. Very smart cookie you are. Thank you for all you have shared with us.
You are most welcome
please accept my best regards for your valuable words for my efforts
Super sharing 👍
u are very clarifying every point nice to understant everything, thanku for this video
Thanks man! I'm now making money in Electronics Repair because of your tutorials thanks🙏
Thankyou for that excellent explanation of the TL431 and optocoupler combination.
Sir i have great respect for you because your explanation is different from others by many and you use your full of energy doing so Thanks so much may almighty Allah be with you!!!!!
Fantastic explination. Finally very clear about how the feedback loop works
MASHA ALLAH beautiful sharing, very technical and informative vlog, a big thumbs up from my side, Imran from KAUP STUDIO
Thank you so much
Vermiş olduğunuz bilgilerden dolayı teşekkür ederim. ALLAH razı olsun.
You have explained this better than anywhere else online. Subscribed.
Just a side note: at 7:24 I believe it is best to connect the RLED to the stable post filtered Vout rather than pre filter. This will aid the stability of the LED voltage and gain the benefit of filtering.
Great video.
You have a wonderful way of explaining and making things that are often quite complicated appear easy to understand. Thank you for taking the time to make these videos using your gift for teaching as they are very gratefully received.
You're very welcome!
U are the great knowledgeable teacher rare to meet, thanks alot
Lk 9 wonderful upload dear brother ❤
Greetings, Mr. Haseeb hereby I would like to express my gratitude for your sincere efforts to enhace our knowledge of electronics. I watched this video many times and it was incredibly helpful for me. Thank you for making these educational videos. You teach so nicely. Hats off to you
its like a very capable surgeon with scalpel in his hand teaching you anatomy of body.jazakAllah brother and thumbs down seems from people who's brains are pull down to ground rail 'caz of shot capacitor.
wow. i am thankful for your valuable words.
please accept my best regards
Ma sha allah 🌷🌷
Nice sharing 🌷🌷
Stay connected🌷
Good luck👌🏻❤🌷🇮🇹
Masha Allah nice sharing hey brother
Thanks and welcome
Excellent explanation
# 1 teacher 👨🏫
Thank you
جازاك الله خيرًا
thanks a lot. stay blessed
Thank you very much for taking the time to make these videos, i have learned so much from you .
You are very welcome
Teacher thanks , i am going to enter. In power electronics. And i am likely bigner of age 58 year old i think i have learnt a lot from you
Best regards dera sir
It is my pleasure that my efforts are useful
Please accept my best regards
w salam bhai
very useful video
Thank you bro. It was wonderful teaching. I wish all of the best for you.i have learn so much about electronic from you.
You are most welcome
Hello my friend ..! 🙏Very nice .. Thank you for sharing ..! like ❤️❤️👍❤️💓🥰
Hello sir, I always like your video.
Many many thanks
Thank you very much, is the best content i see !!! 👍
best regards
Waalaikum salam.....
thank you master......
Healthy always for you..
Salam from NUSANTARA
Thanks sir 🙏 sab samagh main agya
بارك الله فيك أخي الكريم حسييب وجعله في ميزان حسناتكم استاذنا المحترم.
السلام عليكم و رحمة الله و بركاته
شكرا جزيلا
كل عام و انتم بخير ان شاءالله
Good morning awsome video 😁 be safe big like don full 🙈 see
I liked the video very much
thanks a lot. best regards
Jzak Allah khayr ❤️❤️❤️❤️❤️ so much respect and love from Egypt may allah bless you
you are welcome dear brother
@@HaseebElectronics 🙏🏼🙏🏼
actually nice .thank you. تبارک الله🙏🙏🙏🙏
thanks a lot
Very informative information. Thanks
it is my pleasure
Maasha’allaah very useful please don’t forget to share and stay connected shukran
Thanks and sure
Very clear explanation Thanx
best regards
Brilliant sir so so so informative Video Sir
Many many thanks
Masha Allah Ashraf bhai.
God bless
Jazaak Allah khair Qaisar Bhai
Hi beautiful brother 😍 give you super 👍 good luck
Thank you so much 😀
السلام عليكم بتوفق دائما 👏👏👍
thanks a lot. stay blessed
You really a good teacher 👏
thanks a lot
اللهم بارك
وفقك الله أخي
best regards
I highly appreciate the you teach haseeb keep it up... it helps me a lot in my research about SMPS circuitry .... more power god bless you..
best regards and special thanks for your valuable comment
Mashallah beautiful explanation as always thanks for sharing 👍
thanks a lot. stay blessed
ماشاء الله congratulations ❤❤
Really informative
thanks a lot dear
Magnifique ce court! Merci
Thanks for sharing such informative upload
thanks a lot. best regards
Great sharing
Thank you so much 🙂
Superb analysis
best regards and special thanks
Very informative video
thanks a lot. stay blessed
Wonderfull LUX Layer ad 😊👍👍👍
Very good and useful information sir thanks
best regards
Thanks for detailed informative video
best regards and special thanks
As usual, very elaborate & informative. Keep it up. Allah bless you. Ameen
best regards and special thanks
Very very thanks sir.....from ur explaination I learn so many think
So nice of you
ماشاءاللہ ماشاءاللہ بھائی
❤️❤️❤️
best regards bhai
Good work
thanks a lot.
I like your brief explanation Sir (even better than other countries) as always :D
thanks a lot. stay blessed
Very informative. Thank you!
best regards
Excellent explaination Thanks Sir
thanks haseeb sir for the this informative video..
best regards
You're the best Thanks!
best regards and special thanks
🙏💓🌾pranam sirji very nice valuable lesson teach sirji 🌾💓🙏
Thanks and welcome
Best explanation..exactly what i was looking 4
it is my pleasure
Thanks, brother.. well explained.
god blessed you
Super sir your smps god.
best regards and special thanks
I thank you for this good video. You explain very well! Looking forward to your new videos!
You're very welcome!
Thank you so much brother
best regards
Good experience and expertise explanation, sir I request you to make video on how to use short circuit killer for fault idenfication in smps PCB
I liked the fixed option that you showed in the end of the video. For a 12V output, what Zener voltage should I use? Thank you very much.
best regards
normally for 12 volt output
12 volt or 11 volt can be used
awesome video 😱😱
Best regards
Thanks, very clear explanation!
best regards and special thanks
This a nice tutorial and educative. Please can u make tutorial on how to wind smps transformer or if the tutorial is here please the link
As salaamu alaikum Bhai! This is an excellent explanation of the closed loop feedback circuit using the TL431. Keep up the good work. Your videos are very educational and informative.
It's my pleasure
please accept my best regards and special thanks
Ty. Very well explained.
You're welcome!
Best EE channel on SMPS by far.
BTW, I think you meant "role" in the title.
best regards
HAHAHAHAHAHAHA ROLE not ROLL
loevy thanks for your valuable point
Very nice sir
best regards
Thanks for sharing. It is quite clear. And sometimes I see there is an RC parallel to the 1 and 3 legs, what is this used for?
resistor connected across pin 1 & 2 is called bias resistor, it works as protection resistor to the LED, capacitor is used as bypass capacitor for protection from false switching
as it is isolating device so there is must not be any connection between pin 1 & 3. if you experienced in some un-isolated circuit, i don't know about it. as i never observed it.
@@HaseebElectronics Thanks for the reply. After googling, I find the parallel RC network I mean is the application of a Type two compensator.
Very useful video
thanks a lot
amazing tutorials thank you! how do I determine the value of the components like Rled, and the capacitor across pin 3 and 1 of tl431?
Does the opto coupler control the duty cycle of the PWM or only enable/disable the PWM IC. Optocouplers are quite non linear devices, i think. TIA.
brother Haseeb thank you for your tuto i just request you about MPPT solor charger and ups
thanks a lot
i will try my best to arrange for mppt
Hello, hello friend, I am a new friend, thank you for sharing a good video, I like our friend, we are always good friends, I wish you good health🙏💓👋🤝🤝💓💓🙏👍
Hi and asalam bro .. Thank you it is great but i could not understand the direction of current . ia it from 12v rial supply through Resistor and opto coupler or from zenor upwards . Regards jamal
thank you
You're welcome
many many tnx......
Thanks so much for the explanations. My question is : how would behave the feedback circuit when the output voltage is higher than 12 volts (réf voltage > 2.5 volts).
yes it is controlled by voltage divider network. in voltage divider network we have two resistors. when 2.5 volt will arrive at pin 1 of TL431 (reference pin) at that time the TL431 will conduct only. so the voltage divider network is connected between the output pins, it will sense the 12v out. if less it will decrease the reference pin.
if the voltage will go above than 12 volts, it will provide more conduction to provide more light in input LED and optocoupler output tranasistor will saturate and it will inform PWM controller
if output voltage are un-controlled , in the that case the auxiliary winding will provide OLP over load protection (please check video number 525 for aux winding role)
Greetings, a few days ago I exactly faced this question and surfed everywhere on the Internet to find the answer; thank God, through this reply I could get the picture of feedback's reaction to the exceeding output voltage. So thank you both.
Make video on voltage devider network and pull up push down resistor
sure i will make a detailed video on pull up and pull down resistor
is there written blog for this explanation by you?
Very good.
Thank you for your kind words. 😊
Good thanks
thanks a lot
So looks like the opto-coupler will output (to the controller) an Over voltage or Under voltage signal, instead of a linear signal. Is it true then the output voltage will oscillate between very slightly over and very slightly under the desired output voltage? This is because at one moment, the voltage is over the desired voltage so the controller will reduce the On time of the switching transistor until the voltage is under in which time the controller will increase the On time of the switching until it's over, i.e. oscillate between over and under. So if we were to measure the output of the opto-coupler in an oscilloscope, we would see a square wave?
welcome dear.
i really appreciate your pinpoint understanding. when we connect load it causes to create sawtooth ramps on capacitor in case of heavy ramps and close to triangular wave at light load or no load.
i will explain in upcoming video using oscilloscope and multimeter
Salam alaikum ,i now know clearly how this feedback works,I have bee searching for this explanation for long but I have it now mashallah,I want to know the purpose of R BIAS resistor how it work.some smp design u see a resistor at the cathode of the regulator to the 12v main voltage is it the same as R BIAS resistor or it for a different purpose.thank
👍👍👍
it is my pleasure
Hi. Does the voltage at the reference pin HAVE to be 2.5V?When the 10k resistor is in place, the voltage would only be 2V, like you said...so not enough?
R1 and R2 values to b calculated by checking the IRef from the TL431 datasheet (normally 4-10 microampere is teh best range) for best compensation feedback)
when it will receive 2.5 volt at reference pin (it is fed from voltage divider network R1 & R2), TL431 will allow to flow cathode current, which will allow to drive the optocoupler
10K resistor was just as an example purpse,
please check video number 229 & 275
@@HaseebElectronics Thank you so much. I just want to say how useful and brilliantly explained your videos are. Especially the SMPS videos and how you break the circuit into sections. Many thanks once more.
@@REVERSE_BIAS please accept my best regards and special thanks
Haseeb can i ask you a question!
How to measure output in continuous through ADC of microcontroller and isolated also. I think this circuit track only reference output through comparator. Please guide me with answer. Thanks alot
this circuit is isolated but it measures the voltage in secondary side and transfers information to the primary using optocouler link.
to to take isolated you can use Current transformer and then process through any ADC
@@HaseebElectronics if my output is 12v can i track output voltage from 0 to 12v analog with optocoupler? Or it give 0 and 1 output according to reference (digital output)?
@@Ahmad-gn1pd @Ahmad please wait. i will try my best to explain it in detail
@@HaseebElectronics ok thanks alot. Jzak allah khayr ❤️❤️
Hi there, I am repairing PFC power supply Bn44-00636b, 5.3v stb ok, 12v not presented, supply keep clicking on off...also this reference ic I am getting 2.488v...I think if I follow your instructions, I need 2.5v?