Why Optocoupler's are used on Switch Mode Power Supply boards. True Optocoupler testing.
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- เผยแพร่เมื่อ 11 มิ.ย. 2023
- Optocouplers are used on switch-mode power supply boards to send feedback from the cold side to the hot side of the power supply board while keeping both sides isolated from each other. Optocouplers or photocouplers can also be used as a switch to switch something on/off from the hot or cold side of the power supply board to the opposite side without having an electrical connection between the hot and cold side of the power supply.
I will also show you how to test optocouplers in the circuit the REAL way.
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Switch-Mode Power Supply Course: bigdogtvrepaircourse.mykajabi... - แนวปฏิบัติและการใช้ชีวิต
I encourage everyone to subscribe to the repair course. Its not expensive and the lessons are easy to understand and i have enjoyed watching them.
There is a electrical connection from hot to cold. It is called the chassis (frame ground.) It is where many problems can be propagated from the hot to cold side. All decoupling caps on the hot side go to chassis ground, all suppression caps on the hot side go to Chassis. When either fail the current can and does fold back from cold to hot or forward from hot to cold.
Diodemode on a dmm can check an opto quick
Yes, but I was really just showing how it works. Thanks for watching.
Great video and excellent explanation, as always.
The best explanation! Thank you
Thanks as always big dog. APPRECIATE You !.
Always
Another good video. Learned a lot
Thanks for the video and the knowledge.
You bet
Added to my playlist. Very informative. 🤔😏👏😇
Awesome! Thank you!
What is heard only circa 10sec interval clicking sound coming from one relay in the power board.
How can I contact you need some info to sign up for the coarse 😊
Hello Bro...hv got problem with my Samsung smart TV, power indicator light does not ON. I have changed 2 boards, the Main and Power Board but still noughts.. The TV has Power Board, Main Board, T Con Board and the camera board. What's the likely culprit?? Ur expert opinion is very much appreciated. Hassan from Malaysia.
Maybe backlight issue
so to test octocoupler on tv power board can i just put a 20ohm rersistor betwen output to bypass it?
No, please don't. Just check voltage on output to make sure the output side is completing the circuit when you have the 1.1 volts across the input, otherwise you can still use you meter in diode scale too, to check.
@@bigdog8882 ohh ok great to know thank you
I BigDog, i am from Portugal (Europe). At the moment i am crossing some dificulties.
I can´t manage to pay rigth now the course that you offer for a great price.
I took 18 hard months to pay my Oled TV, cause i really enjoy it, but 6 moths before 2 years garantie past... The TV doesn´t turn on, and no IR signal. I have noticed that , power supply is not given any output. Everthing ok until we get DC power at the capacitors before the bridge rectifier, than i saw a open fuse and many components that are short cuted and others open. I can´t manage to get the electrical scheme.
I had study electronics at 30 years ago...i went to study Electromechanics before the first 3 years course of electronics. I can do maintenance at a 250.000$ CNC machine, but I know that i need a lot more knowledge to start repairing TVs, it´s a diferent area to me.
This hard moment will pass, and will come to adress to your course later.
Regards,
Pedro
From my personal experience, people need to be careful with samsung tv power supply, because you still can get a nasty shock from the cold side too . I did receive a nasty shock from a 40 inches samsung led tv power supply on the cold side .
Most likely the LED circuit if it uses a 300+ voltage rated filter capacitor.
Cold does not mean it can’t shock you, ideally it should not kill you but even that may not be 100% true all the time. Remember to always understand what you are doing and if you don’t wait until you learn (like from the ART course)! Glad you are doing well!
@@hernancoronel; I did not start repairing power supplies recently, OK?
I have a onn roku tv and all it does is go to logo screen then off over and over
Hairy stuff & definitely advanced tech compared to the CRT B&W from yester year!