{1205A} Why too high voltage on VCC pin of PWM controller

[@suatkaleli5075]

very informative thanks appreciate your support i think that it is possible to say if the pwm ic is off then the auxilary is off too. if the auxilary is off then the voltage is high up to 54V.

[@HaseebElectronics]

you are right. just watch the ending of the video, at the end there is strong proof for your comment

[@trone32]

You missed your calling you should have been a Teacher, your explanations are excellent, one of the best channels for anything to do with power supplies, so glad I found it.

[@HaseebElectronics]

humble thanks and best regards for your worthy words for my efforts

[@gillywild]

Asalamu alaikum. You are a very patient teacher. Thank you for making these videos

[@HaseebElectronics]

wa alaikum salaam thanks a lot for your valuable words

[@bitdiddle1]

Your explanation of how pin 7 got to 54V was excellent. The fact that an electrolytic operated above it's rated voltage begins to conduct is not one a lot of engineers are familiar with (for example, I wasn't). Then you swapped in a cap with a higher voltage rating just to prove the lower rated cap was conducting. Case closed!

[@HaseebElectronics]

Thanks for your valuable appreciations Around 5% above the rated voltage it's dielectric starts to degrade and cause leakage. This leakage leads to increase in temperature and increments in leakage If source current is enough high and voltage reach around 20% above the rated voltage or more. The capacitor will explode If source current is limited or a low value current, the capacitor remains in circuit as a resistor (due to leakage) kzbin.info/www/bejne/opyppH-meqidiaM

[@xontroi]

Sir this was one of the most informative and educational videos I saw in youtube. Thank you very much!

[@HaseebElectronics]

You are very welcome

[@gamiwv]

I really admire your patience to explain the completely self-explanatory for someone who knows "basic electronics"

[@HaseebElectronics]

it is my pleasure

[@jefftoll604]

Excellent explanation. I enjoy all your videos.

[@rowanallison192]

Thank you Mr Haseeb for explaining.You are appreciated sir and continue what you are doing.Your time is most valuable. 🙏

[@hichamtassi1753]

Very nice way of understanding why sometimes diodes give double reading !

[@HaseebElectronics]

Welcome brother Hicham Sometimes there are some parallel components, which provide second reading

[@williamsullivan9323]

One of your best videos thanks

[@NickNameNemo]

Dear Haseeb thank you a lot! It is best explanation of start up circuit of smps !

[@HaseebElectronics]

best regards

[@rennyc8468]

Thank you for sharing your knowledge. Outstanding explanation!

[@aslamkhan01]

Very good explanation ❤

[@HaseebElectronics]

best regards

[@СмартфонСигма-и5в]

Very informative video. Thank you very much!

[@kumu2024]

Assalamu alaikum. One of the best videos. Thanks. That capacitor is quite dangerous. Normally, capacitors are the No 1 cause of all problems in circuits. And giving it a so critical job, is scary really. The voltage of the capacitor was 35V which is quite low compared to the 330V. Whenever the IC get minimal problem, that capacitor will be damaged also. Thanks for your clarification .. grate to know how the circuit is working.

[@ahmedkhamrich7297]

Vidéo très riche en informations précieuses et très utiles. Mille Merci et à bientôt pour d'autres vidéos.

[@froilansampang6443]

Hi Sir. I've been a happy subscriber on your channel of atleast a year. Very interesting explanation of a lot of circuits I'm hoping you can make video series of led tv too.. thanks

[@rolanddejesus8685]

your the best sir,thank you very much.

[@tvbox8478]

👌👍

[@puruman806]

Well explained. Thank you for your efforts.

[@HaseebElectronics]

You are welcome!

[@Dutch_off_grid_homesteading]

Heya, yes untherstand all of your explanations thank you learned some more

[@HaseebElectronics]

most welcome it is my pleasure

[@kifah_1111]

Thank you

[@HaseebElectronics]

You're welcome

[@md.al-amin6089]

Thanks for this infromative video. Please make a video 'ups no backup problem' Note: Battery new....

[@TheEmbeddedHobbyist]

very nice and well informed video.

[@honeypie-life]

This is very goodjob my friend

[@mihalym.6876]

Thank you your video, explaining the possible errors on VCC line. One more case concerning VCC errors: what if the secondary feedback became open, no regulation at all, like optocoupler is damaged? In this case maximum PWM duty cycle happens - 50% on 3844 - resulting maximum voltage on the VCC supply winding? Is this the case when 20V zener diode protects the 3844 and VCC capacitor - if applied - on the VCC rail of 3844 becaming short and shutting down the IC? Keep posting please!

[@froilansampang6443]

How led tv works? From power supply, mcu, controllers, t con, lcd pannel...etc. Im hoping you can make video series of explanation how everything function. Thank you

[@rowanallison192]

Mr Haseeb.What are you using to discharge the capacitors.Could you please share with your viewers.

[@cong-organic]

I also believe there should be a zener to limit the VCC voltage.

[@erbaelektronix25]

Hy i got a SMD component that I could not find on internet it bears marking 22J37(SOT-23 size), could you help identifies him?

[@HaseebElectronics]

good morning can you please its picture to my whatsapp [phone] or gmail id ashraf4ta4 with component id on PCB (D, Q U etc)

[@HV_SMPS]

hello thanks a lot my smps feedback is on the auxiliary winding in start the uc3843a vcc voltage is good but suddenly voltage rise up about 70 volt. why????

[@EmmanuelKalinde]

Many thanks for your detailed explanation Sir. Please Sir do you have electronic book which recommend so that I may broaden my electronics knowledge. If you have please share

[@philipscharles1333]

Sir very informative video thank you somuch sir I have doubt why they are not using zener diode to regulate startup votage for the ic so that it cannot go beyond required startup voltage.

[@tvbox8478]

yumuşak başlatmayı öğren! learn soft starter!

[@Subhan-Allah111]

PLEASEE IWANT schematic for stable 12 volt 15 amp smps.Thank you brother may Allah bless you.

[@nankinanko5790]

Please sir, what type of topology is used in that type of SMPS? I'm about to design 320W power supply, and according to my research, flyback topology isn't adviced for such high power aoplications. Should I go with the half-bridge, full-bridge, or can the flyback handle this power requirment? Please help me sir. Thanks.

[@MbaduMalonda-sc5dg]

Sir can you explain the difference between smps transformer and pulse transformer because i see on video #592 they used two bjt transistor to drive the pulse transformer and what confuse me the most is whta signal is switching the transistor base is ac or dc and what current is passing between collector and emitter has there is capacitor which we know its blocked dc and ac current, please sir try to review that video on 300w half bridge smps

[@NhyirabaNanaCee]

Please How will I contact you Sir

[@HaseebElectronics]

Gmail id ashraf4ta4 Whatsapp [phone]

[@cemkurt6102]

Thankyou

[@HaseebElectronics]

Most welcome

[@BlackLion-u6k]

still watching your teaching videos from Ethiopia 🇪🇹 .Thank u sir 🙏

[@bahagursoy8138]

Dear Sir I am looking for MT1008 battery charger circuit. Because it was iquonic circiut. Please help me . Best regards Baha

[@yamansaadO]

وعليكم السلام ورحمه الله وبركاته ❤

[@tvbox8478]

👌👌 👍 ✋

[@salehneyestani7627]

In this case, we have to change that capacitor or not? Because of that 54 volt on it

[@salehneyestani7627]

I mean, that over voltage, damaged the cap?

[@tvbox8478]

önce kondansatörü söküp kontrollerini yapacaksın (Lcr metre !) eğer henüz bozulmamış ise aynı kondansatörü kullanabilirsin 😊

[@vivekbalakrishnan5520]

Good

[@enpaperlightsboxvietnam4101]

I want the author to make a video on the construction of an electronic induction cooker and an IGBT electronic welding machine

[@johanbotha9889]

Sir, is it safe to say that the 50V electrolitic capacitor acts like a proctector in case the IC goes open circuit too. If I understand it right the 50V capacitor dropped the 333V coming through the 100k and 43k resistors? For how long will that 50V capacitor be able to be powered by the 333V before it blows up? Thanks for this info!🙏👏

[@hishamspi508]

If the ic was removed from the board we see a voltage between 60 to 70 voltage in the vcc cabacitor why it not expolded while it Working voltage is 50

[@HaseebElectronics]

Most of time capacitor doesn't explode Because there is very low current coming from start-up resistor If start-up resistor is slightly low value then the capacitor will explode Sometimes capacitor's dielectric become weak and when auxiliary winding is energized then it causes to explode the capacitor

[@hishamspi508]

@@HaseebElectronics Well, if the current is very low, this means that the capacitor will not explode even if we apply a voltage higher than the value written on it.

[@hishamspi508]

@@HaseebElectronics I have a lot of questions that need someone with a lot of knowledge in electronics to explain them. Is there a way to contact you?

[@HaseebElectronics]

@hishamspi508 you can send questions here Or Gmail ashraf4ta4 Or Whatsapp [phone]

[@hishamspi508]

@@HaseebElectronics Thank you😘😘😘

[@cong-organic]

So it seems to be a bad design, just relying on the IC to keep the cap under safe voltage.

[@kumu2024]

Too scary to depend on a capacitor to hold the voltage to a level. Often capacitors are not so reliable.

[@tvbox8478]

kapasitörsüz olmaz; çünkü aynı zamanda bulunduğu yere gerekli enerjiyi sağlayan depo görevi de görür !! bir baraj gibi...

[@cong-organic]

@@tvbox8478 there are other designs that do not sorely rely on capacitors

[@technical5880]

[@OzaKu-gk1ex]

Allahumma barik lak. Salam Alaikum warahmathullahi wabarakathuh My Brother Please give your WhatsApp no or email that i wanted to post an image of a burnt power supply. Has some questions