Making sense of this Circuit

Discussion in 'General Electronics Chat' started by SimplyElectronics, Aug 28, 2016.

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  1. SimplyElectronics

    Thread Starter New Member

    Jul 14, 2016
    Hi Guys,

    I am currently practicing my reverse engineering skills starting at creating a schematic from an existing circuit board.
    I have been able to draw the schematic based on a simple led circuit powered from AC. (This is simplified, fuses and discharge resistor gone)

    I know the 330nF cap is taking current down to 25mA before rectification.

    After this, I am struggling to figure out what the electrolytic cap is doing (smoothing?) and why R1 is there.

    I know what a zener diode does and how they work, but not sure what it is needed for here?

    If someone could help me understand this I would be ever so grateful. I'm sure something will click with sudden realisation as soon as someone explains.
    Thank You in advance :)

    Circuit Help-01.png
  2. bertus


    Apr 5, 2008

    Did you read the User Agreement ?
    We do not allow leds to mains.

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