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  1. #1
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    LED Driver Circuit with flyback transformer

    Hello to everyone,

    Currently I'm designing LED drvr cct. The specs for my design are as follow:

    *********************************
    Vin = 100 - 240 V
    Vo = 20
    Po = 100
    efficiency = 80%
    duty cycle = 0.45
    flyback transformer, isolated and DCM
    using TL5001 and optocoupler
    *********************************

    Attached is my circuit for the design. I need guidance from the expert or anyone on how to implement the PWM using TL5001 with opto-coupler. Is this design okay? Is the value of capacitors and resistors correct? I designing the TL5001 based on the example application using TL5001 but the example only for step down converter and low voltage. I also need someone to check my feedback design.

    Sorry for my bad English.

    Thank you for all your help.

    •   Alt6th December 2009, 16:29

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  2. #2
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    Re: LED Flyback Circuit

    anyone? please guide me.... Just need someone to check my schematic, the value of the feedback and PWM design.



    •   Alt7th December 2009, 17:29

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  3. #3
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    LED Flyback Circuit

    Anybody, need help at least could anybody tell me whether the connection of my optocoupler is correct or not? should I connect it to the Feedback of TL5001 or VCC. I've searched the forum but still confused.



    •   Alt10th December 2009, 15:07

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  4. #4
    FvM
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    LED Flyback Circuit

    You should analyze the circuit rather than searching the forum. No current will flow through the optocoupler in the presented circuit.



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    LED Flyback Circuit

    I'll try to analyze the circuit by referring to AN4137. I really confused on this thing and need some guide. I still learning about power electronic. Could you please help me?

    In the AN4137 example, it connected the opto-coupler at two point. I want to let the variable resistor to control the current and that's why I connect it at the cathode of the led. May I know where is the correct location to connect the opto-coupler.

    One more thing, in the example of TL5001 the feedback pin connects to two parallel resistor. Do I need these resistors?


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