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Hot!Lr645lg transformerless power supply

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Aville
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2019/05/11 15:33:00 (permalink)
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Lr645lg transformerless power supply

Hello. Did anybody make the lr645 circuit with depletion mode mosfet(like in datasheet)? I tried but either mosfet is burning or lr645lg is burning.
Solved: problem was voltage regulator.
post edited by Aville - 2019/06/07 14:15:19
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    oliverb
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    Re: Lr645lg transformerless power supply 2019/05/24 11:22:31 (permalink)
    5 (1)
    Can you elaborate on what you mean by that? Do you mean it is burning out or just running extremely hot?
     
    It is a linear regulator so running from high voltage the dissipation will be high. For a UK SMPS (>350V bus) the dissipation at 3mA would exceed 1W
     
     
     
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    PStechPaul
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    Re: Lr645lg transformerless power supply 2019/05/24 20:29:01 (permalink)
    4.5 (2)
    The OP has posted the exact same question in several forums and also in an old thread which has a little more information:
    https://www.microchip.com/forums/m927264.aspx
     
    However, we need to see a complete schematic of the OP's circuit, including input voltage and output load, as well as circuit layout and heat sinks for the power dissipating components.

     
    #3
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