352 Feedback SMPS Switch Mode Power Supply, Optocoupler & Programmable Voltage Reference

Feedback Role in SMPS Switch Mode Power Supply, Optocoupler & Programmable Voltage Reference
i have explained in urdu / hindi language the basic function of switching mode power supply using different types of smps switch mode power supplies. smps concept and troubleshooting repairing or understanding repair switching mode power supply basics and working principle. after watching this video you will be able to understand
1 basic working concept of smps switch mode power supply
2. how PWM pulse width modulator work
3. block diagram of #smps switch mode power supply
4. practical circuit tracing of #smps
5 how to repair mobile charger
6 how to repair power supply of digital satellite receiver
7. how to repair led lcd tv power supplies
8. different faults in stages of smps
9. what is filter and protection circuit in SMPS
10 what is bridge rectifier circuit and how bridge rectifier circuit work
11 what is PWM pulse width modulator circuit and how to check it
12 function of FET, MOSFET, BJT, IGBT or switching modules
13 what is optocoupler or opto-isolator and what is its function in #feedback circuit
14 what is voltage regulation and how it workks in SMPS
15 how to find problem if switch mode power supply have no output
16 what is problem when power supply have fluctuation and output is not regulated
17 current sense in smps
18 short circuit protection
19 how to test troubleshoot and repair smps switch mode power supply and easy test points in fault finding
and much more
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What is TL431 and How to Check it Easily with Multimeter
TL431 circuit explained as a shunt regulator
regulator ic 431 working and how to select biasing resistor
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[@QalbiNuuraChannel]

Wcs bro thanks for sharing as always 🙏

[@notreallyme7465]

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.

[@HaseebElectronics]

You are most welcome please accept my best regards for your valuable words for my efforts

[@mehranmohamad6924]

actually nice .thank you. تبارک الله🙏🙏🙏🙏

[@HaseebElectronics]

thanks a lot

[@abrish1053]

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!!!!!

[@Clip7heApex]

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.

[@HaseebElectronics]

You're very welcome!

[@TYGAMatt]

Fantastic explination. Finally very clear about how the feedback loop works

[@kaupstudio-supportid5956]

MASHA ALLAH beautiful sharing, very technical and informative vlog, a big thumbs up from my side, Imran from KAUP STUDIO

[@HaseebElectronics]

Thank you so much

[@stevemiller5214]

Thanks man! I'm now making money in Electronics Repair because of your tutorials thanks🙏

[@user-kd4ip6dy8c]

You really a good teacher 👏

[@HaseebElectronics]

thanks a lot

[@Elikaee]

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

[@megomiftah]

U are the great knowledgeable teacher rare to meet, thanks alot

[@LimVuthyVlog]

Hello my friend ..! 🙏Very nice .. Thank you for sharing ..! like ❤️❤️👍❤️💓🥰

[@alibabacookingstyle495]

Ma sha allah 🌷🌷 Nice sharing 🌷🌷 Stay connected🌷 Good luck👌🏻❤🌷🇮🇹

[@khaledibrahim8609]

# 1 teacher 👨‍🏫 Thank you جازاك الله خيرًا

[@HaseebElectronics]

thanks a lot. stay blessed

[@mohamedantri9433]

بارك الله فيك أخي الكريم حسييب وجعله في ميزان حسناتكم استاذنا المحترم.

[@HaseebElectronics]

السلام عليكم و رحمة الله و بركاته شكرا جزيلا كل عام و انتم بخير ان شاءالله

[@MrJamez32]

Thank you very much for taking the time to make these videos, i have learned so much from you .

[@HaseebElectronics]

You are very welcome

[@rashidkhan-pd8cf]

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.

[@HaseebElectronics]

wow. i am thankful for your valuable words. please accept my best regards

[@Ahmad-gn1pd]

Jzak Allah khayr ❤️❤️❤️❤️❤️ so much respect and love from Egypt may allah bless you

[@HaseebElectronics]

you are welcome dear brother

[@Ahmad-gn1pd]

@@HaseebElectronics 🙏🏼🙏🏼

[@samalamad774]

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.

[@sagartrueshayar2517]

w salam bhai very useful video

[@ARA-HOUSE]

Lk 9 wonderful upload dear brother ❤

[@DIYwithBatteries]

I like your brief explanation Sir (even better than other countries) as always :D

[@HaseebElectronics]

thanks a lot. stay blessed

[@owenpalma2982]

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..

[@HaseebElectronics]

best regards and special thanks for your valuable comment

[@peymanamiri7560]

Thank you bro. It was wonderful teaching. I wish all of the best for you.i have learn so much about electronic from you.

[@HaseebElectronics]

You are most welcome

[@BajisKitchen]

Mashallah beautiful explanation as always thanks for sharing 👍

[@HaseebElectronics]

thanks a lot. stay blessed

[@carolinediyandvlog]

Good morning awsome video 😁 be safe big like don full 🙈 see

[@hassantj5775]

As usual, very elaborate & informative. Keep it up. Allah bless you. Ameen

[@HaseebElectronics]

best regards and special thanks

[@itechfone135]

Magnifique ce court! Merci

[@user-ut2ii3qi6x]

I thank you for this good video. You explain very well! Looking forward to your new videos!

[@HaseebElectronics]

You're very welcome!

[@mohamedkikia7338]

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.

[@HaseebElectronics]

It's my pleasure please accept my best regards and special thanks

[@ritinarrokomari]

I liked the video very much

[@HaseebElectronics]

thanks a lot. best regards

[@SAMROGER-jp5np]

Waalaikum salam..... thank you master...... Healthy always for you.. Salam from NUSANTARA

[@kuchpanktiyajindagiki]

Thanks for sharing such informative upload

[@HaseebElectronics]

thanks a lot. best regards

[@venugopalkante4111]

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

[@rashidqasmi8173]

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

[@HaseebElectronics]

Best regards dera sir It is my pleasure that my efforts are useful Please accept my best regards

[@nipunlakshandaluwatte9168]

Thanks, brother.. well explained.

[@chandanbarik8782]

Very very thanks sir.....from ur explaination I learn so many think

[@HaseebElectronics]

So nice of you

[@qaiserqureshi100]

Masha Allah Ashraf bhai. God bless

[@HaseebElectronics]

Jazaak Allah khair Qaisar Bhai

[@haseebabdul7157]

Really informative

[@HaseebElectronics]

thanks a lot dear

[@MamtakiRasoi]

Super sharing 👍

[@TheGyimi]

Very informative. Thank you!

[@HaseebElectronics]

best regards

[@BomJimmy]

Superb analysis

[@HaseebElectronics]

best regards and special thanks

[@Flyonwaterslow]

Thank you very much, is the best content i see !!! 👍

[@HaseebElectronics]

best regards

[@desisimplevlogs1]

Masha Allah nice sharing hey brother

[@HaseebElectronics]

Thanks and welcome

[@temyraverdana6421]

Thanks, very clear explanation!

[@HaseebElectronics]

best regards and special thanks

[@user-cq7vr1mo3o]

Maasha’allaah very useful please don’t forget to share and stay connected shukran

[@HaseebElectronics]

Thanks and sure

[@mmohamedfaisal4230]

ماشاء الله congratulations ❤❤

[@MohitGupta-qm6ff]

Best explanation..exactly what i was looking 4

[@HaseebElectronics]

it is my pleasure

[@manafsaidusaidu9950]

thanks haseeb sir for the this informative video..

[@HaseebElectronics]

best regards

[@rajeshnandgave3105]

Excellent explaination Thanks Sir

[@LousyPainter]

You're the best Thanks!

[@HaseebElectronics]

best regards and special thanks

[@user-pq5tz5pn4g]

السلام عليكم بتوفق دائما 👏👏👍

[@HaseebElectronics]

thanks a lot. stay blessed

[@muhammadkamal745]

Very informative information. Thanks

[@HaseebElectronics]

it is my pleasure

[@FancyBangles]

ماشاءاللہ ماشاءاللہ بھائی ❤️❤️❤️

[@HaseebElectronics]

best regards bhai

[@vijayakumarkumar9190]

Very good and useful information sir thanks

[@HaseebElectronics]

best regards

[@manualspellcorrect9073]

Best EE channel on SMPS by far. BTW, I think you meant "role" in the title.

[@HaseebElectronics]

best regards HAHAHAHAHAHAHA ROLE not ROLL loevy thanks for your valuable point

[@BricoolinoSenyor]

اللهم بارك وفقك الله أخي

[@HaseebElectronics]

best regards

[@sushilchoudhary5749]

Thanks for detailed informative video

[@HaseebElectronics]

best regards and special thanks

[@ARA-HOUSE]

Wonderfull LUX Layer ad 😊👍👍👍

[@atulnakrani8502]

Hello sir, I always like your video.

[@HaseebElectronics]

Many many thanks

[@aldotambozzo9578]

Very useful video

[@HaseebElectronics]

thanks a lot

[@tesfayebelay4860]

god blessed you

[@manilapunjabikitchen8154]

Great sharing

[@HaseebElectronics]

Thank you so much 🙂

[@rajugoud1563]

Super sir your smps god.

[@HaseebElectronics]

best regards and special thanks

[@idealsolution4468]

Brilliant sir so so so informative Video Sir

[@HaseebElectronics]

Many many thanks

[@melplishka5978]

Ty. Very well explained.

[@HaseebElectronics]

You're welcome!

[@msbbadsha1456]

awesome video 😱😱

[@HaseebElectronics]

Best regards

[@vuthysuccessmore8551]

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🙏💓👋🤝🤝💓💓🙏👍

[@anlpereira]

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.

[@HaseebElectronics]

best regards normally for 12 volt output 12 volt or 11 volt can be used

[@wesameed824]

Very clear explanation Thanx

[@HaseebElectronics]

best regards

[@kanchankondhare]

🙏💓🌾pranam sirji very nice valuable lesson teach sirji 🌾💓🙏

[@HaseebElectronics]

Thanks and welcome

[@samueldavies646]

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?

[@ezeoluchukwu5104]

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

[@vijayakarekar]

Thanks sir ji....

[@HaseebElectronics]

best regards

[@aliduadam2761]

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

[@md.kayesuddin5137]

many many tnx......

[@IS-77]

Thank you so much brother

[@HaseebElectronics]

best regards

[@sudheerkumar5966]

Very nice sir

[@HaseebElectronics]

best regards

[@ahmedmadkour]

Hi beautiful brother 😍 give you super 👍 good luck

[@HaseebElectronics]

Thank you so much 😀

[@FoodFunAndEnt]

Very informative video

[@HaseebElectronics]

thanks a lot. stay blessed

[@songzhengchen451]

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?

[@HaseebElectronics]

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.

[@songzhengchen451]

@@HaseebElectronics Thanks for the reply. After googling, I find the parallel RC network I mean is the application of a Type two compensator.

[@ChrisHalden007]

Great video. Thanks. Small question: I have a 19v power supply with the exact circuit your described in your video. R1=80k and R2=12k. I tried to tune it to 12v by changing R1 to 47k (as you described in video 283). It kind of work, but I get a very strange behavior. Roughly 2 times per second it jumps up to 14.7 and slowly (360 ms) goes down to 12v (with no load) ?!?!? When I add a load it varies up and down 2 times per second from 9v to 12.7v. Any clue of what I should do to stabilise the output? Do I need to change Rled, capacity or led bypass resistor?!?!? I am a bit lost and confused. Monitoring the opto led with a oscilloscope i get some kind of square signal so the low side tries to do its job but cannot get rid of the oscillations somehow (( Thanks for your help.

[@TB-jl9fr]

Your voltage reference is also a PI regulator. So, if your systems works most of the time it seems to me that it is "semi stable". The reason could be, that your feedback capacitor at your reference is to high, so your systems swings up some times, or it is to low, so your feedback is so slow to regulate the voltage fast enough.

[@Fazlubd]

brother Haseeb thank you for your tuto i just request you about MPPT solor charger and ups

[@HaseebElectronics]

thanks a lot i will try my best to arrange for mppt

[@meandbabajan76]

Good work

[@HaseebElectronics]

thanks a lot.

[@mumbaiverve2307]

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.

[@eegayeyet]

very informative sir..keep on sharing by the way can i replace the opto coupler by a different model sir because the part number is erase

[@HaseebElectronics]

Yes you can sometime it becomes difficult due to mismatching of CTR (output current vs input current) so it causes to some trouble in output regulation

[@rachidakli3555]

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).

[@HaseebElectronics]

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)

[@Elikaee]

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.

[@jimmycollege3851]

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

[@dreamfly555]

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?

[@HaseebElectronics]

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

[@Bonalafarmer]

Nice explanation sir. Pls clarify one doubt. TNY Switch/PWM switch is the only component failing each time i ON my SMPS. Pls tell how can I rectify it.

[@HaseebElectronics]

please check:- 1. RCD snubber circuit (resistor capacitor & diode connected across the transformer primary winding) 2. check SMPS transformer (might be it is burnt out) 3. check the main dc capacitor 4. check optocoupler (output side connected to control pin of the TNY switch) 5. check rectifier diode (connected with auxillary winding)

[@manhardanmahedu3765]

Wonderful explanation as always,now I want to know what will be the internal resistance of TL431(between pin 3 and 2) when 2.5 volts applied at pin 1 of TL431?( i.e.when it allows 100mA current to flow from pin 3 to pin 2)

[@HaseebElectronics]

as it is working as a zener regulator, so any zener regulator works in reverse biasing. so its resistance behaves as a zener resistance (same as a zener diode because zener works in reverse voltage region)

[@manhardanmahedu3765]

@@HaseebElectronics yes sir understood, thanks for responding.

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[@marinvidovic763]

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[@user-qh5kb7rv7o]

thank you

[@HaseebElectronics]

You're welcome

[@suatkaleli5075]

S.A. My PS is 12 V 20 A output (S-240W-12) it has no optocoupler and TL431 but driver ic is TL494 and there are couple J13009-2 and triple C1815 instead. They the transistors all in good condition but TL494 voltage pins value shows 023 while probes between the legs pin7 (gnd) and pin12 (Vcc) at continuity mode and when 220 applied I hear some noisy voice like parasite at the beginning and at the equipment plug out/turn-off for a while (I think while charging the capacitor and discharging) and low voltage (about 5 volts) at the output. Possible to say some about that-Thanks

[@ajaykumartargotra2768]

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?

[@electroniquepassion]

👍🌹

[@HaseebElectronics]

Best regards

[@hkbtharanga1]

Good thanks

[@HaseebElectronics]

thanks a lot

[@ankur0077nca]

Make video on voltage devider network and pull up push down resistor

[@HaseebElectronics]

sure i will make a detailed video on pull up and pull down resistor

[@AnnaHowa-dz8yv]

Thank u vm sir

[@familydonmiguel2688]

🤗👍🏻

[@HaseebElectronics]

best regards and special thanks

[@med3899]

Love ur tactics.uk 1:00..£