Capacitor in parallel with a resistor between live and full bridge rectifier












1












$begingroup$


I have an LED light bulb and dismantled it to look at the circuit inside.



I made some google search for pcb but couldn't find any relevant info about FST-855 or FST-854:
10 LEDs in seriesPower circuit



After drawing the schematic, I could not figure out what is the purpose of some of the elements. Here is the schematic (sorry for hand drawing):
schematic of led bulb



I was expecting to see the electrolytic cap however did not understand the reason for film cap. Can you tell me why there is this "capacitor in parallel with a resistor" in between Live and full wave rectifier?






led capacitor







share|improve this question









New contributor




user458835 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$








  • 2




    $begingroup$
    A helpful search term: "capacitive dropper"
    $endgroup$
    – Hearth
    3 hours ago
















1












$begingroup$


I have an LED light bulb and dismantled it to look at the circuit inside.



I made some google search for pcb but couldn't find any relevant info about FST-855 or FST-854:
10 LEDs in seriesPower circuit



After drawing the schematic, I could not figure out what is the purpose of some of the elements. Here is the schematic (sorry for hand drawing):
schematic of led bulb



I was expecting to see the electrolytic cap however did not understand the reason for film cap. Can you tell me why there is this "capacitor in parallel with a resistor" in between Live and full wave rectifier?






led capacitor







share|improve this question









New contributor




user458835 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$








  • 2




    $begingroup$
    A helpful search term: "capacitive dropper"
    $endgroup$
    – Hearth
    3 hours ago














1












1








1





$begingroup$


I have an LED light bulb and dismantled it to look at the circuit inside.



I made some google search for pcb but couldn't find any relevant info about FST-855 or FST-854:
10 LEDs in seriesPower circuit



After drawing the schematic, I could not figure out what is the purpose of some of the elements. Here is the schematic (sorry for hand drawing):
schematic of led bulb



I was expecting to see the electrolytic cap however did not understand the reason for film cap. Can you tell me why there is this "capacitor in parallel with a resistor" in between Live and full wave rectifier?






led capacitor







share|improve this question









New contributor




user458835 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$




I have an LED light bulb and dismantled it to look at the circuit inside.



I made some google search for pcb but couldn't find any relevant info about FST-855 or FST-854:
10 LEDs in seriesPower circuit



After drawing the schematic, I could not figure out what is the purpose of some of the elements. Here is the schematic (sorry for hand drawing):
schematic of led bulb



I was expecting to see the electrolytic cap however did not understand the reason for film cap. Can you tell me why there is this "capacitor in parallel with a resistor" in between Live and full wave rectifier?






led capacitor




led capacitor






share|improve this question









New contributor




user458835 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|improve this question









New contributor




user458835 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









share|improve this question




share|improve this question








edited 3 hours ago







user458835













New contributor




user458835 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









asked 3 hours ago









user458835user458835

62




62




New contributor




user458835 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.





New contributor





user458835 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






user458835 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.








  • 2




    $begingroup$
    A helpful search term: "capacitive dropper"
    $endgroup$
    – Hearth
    3 hours ago














  • 2




    $begingroup$
    A helpful search term: "capacitive dropper"
    $endgroup$
    – Hearth
    3 hours ago








2




2




$begingroup$
A helpful search term: "capacitive dropper"
$endgroup$
– Hearth
3 hours ago




$begingroup$
A helpful search term: "capacitive dropper"
$endgroup$
– Hearth
3 hours ago










1 Answer
1






active

oldest

votes


















3












$begingroup$

Welcome to Electrical Engineering!



The point of the capacitor is to limit the current through the full bridge rectifier. According to the “824J400V” indication, it is a 820nF capacitor. Its impedance at 50Hz is 3882Ω. It will limit the current to less than 62mA at 240V.



The point of the resistor in parallel is to discharge the capacitor when the bulb is disconnected.






share|improve this answer









$endgroup$













    Your Answer





    StackExchange.ifUsing("editor", function () {
    return StackExchange.using("mathjaxEditing", function () {
    StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
    StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["\$", "\$"]]);
    });
    });
    }, "mathjax-editing");

    StackExchange.ifUsing("editor", function () {
    return StackExchange.using("schematics", function () {
    StackExchange.schematics.init();
    });
    }, "cicuitlab");

    StackExchange.ready(function() {
    var channelOptions = {
    tags: "".split(" "),
    id: "135"
    };
    initTagRenderer("".split(" "), "".split(" "), channelOptions);

    StackExchange.using("externalEditor", function() {
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled) {
    StackExchange.using("snippets", function() {
    createEditor();
    });
    }
    else {
    createEditor();
    }
    });

    function createEditor() {
    StackExchange.prepareEditor({
    heartbeatType: 'answer',
    autoActivateHeartbeat: false,
    convertImagesToLinks: false,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: null,
    bindNavPrevention: true,
    postfix: "",
    imageUploader: {
    brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
    contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
    allowUrls: true
    },
    onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    });


    }
    });






    user458835 is a new contributor. Be nice, and check out our Code of Conduct.










    draft saved

    draft discarded


















    StackExchange.ready(
    function () {
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2felectronics.stackexchange.com%2fquestions%2f418587%2fcapacitor-in-parallel-with-a-resistor-between-live-and-full-bridge-rectifier%23new-answer', 'question_page');
    }
    );

    Post as a guest















    Required, but never shown

























    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    3












    $begingroup$

    Welcome to Electrical Engineering!



    The point of the capacitor is to limit the current through the full bridge rectifier. According to the “824J400V” indication, it is a 820nF capacitor. Its impedance at 50Hz is 3882Ω. It will limit the current to less than 62mA at 240V.



    The point of the resistor in parallel is to discharge the capacitor when the bulb is disconnected.






    share|improve this answer









    $endgroup$


















      3












      $begingroup$

      Welcome to Electrical Engineering!



      The point of the capacitor is to limit the current through the full bridge rectifier. According to the “824J400V” indication, it is a 820nF capacitor. Its impedance at 50Hz is 3882Ω. It will limit the current to less than 62mA at 240V.



      The point of the resistor in parallel is to discharge the capacitor when the bulb is disconnected.






      share|improve this answer









      $endgroup$
















        3












        3








        3





        $begingroup$

        Welcome to Electrical Engineering!



        The point of the capacitor is to limit the current through the full bridge rectifier. According to the “824J400V” indication, it is a 820nF capacitor. Its impedance at 50Hz is 3882Ω. It will limit the current to less than 62mA at 240V.



        The point of the resistor in parallel is to discharge the capacitor when the bulb is disconnected.






        share|improve this answer









        $endgroup$



        Welcome to Electrical Engineering!



        The point of the capacitor is to limit the current through the full bridge rectifier. According to the “824J400V” indication, it is a 820nF capacitor. Its impedance at 50Hz is 3882Ω. It will limit the current to less than 62mA at 240V.



        The point of the resistor in parallel is to discharge the capacitor when the bulb is disconnected.







        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered 3 hours ago









        user2233709user2233709

        858210




        858210






















            user458835 is a new contributor. Be nice, and check out our Code of Conduct.










            draft saved

            draft discarded


















            user458835 is a new contributor. Be nice, and check out our Code of Conduct.













            user458835 is a new contributor. Be nice, and check out our Code of Conduct.












            user458835 is a new contributor. Be nice, and check out our Code of Conduct.
















            Thanks for contributing an answer to Electrical Engineering Stack Exchange!


            • Please be sure to answer the question. Provide details and share your research!

            But avoid …



            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.


            Use MathJax to format equations. MathJax reference.


            To learn more, see our tips on writing great answers.




            draft saved


            draft discarded














            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2felectronics.stackexchange.com%2fquestions%2f418587%2fcapacitor-in-parallel-with-a-resistor-between-live-and-full-bridge-rectifier%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown





















































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown

































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown







            -

            Popular posts from this blog

            A CLEAN and SIMPLE way to add appendices to Table of Contents and bookmarks

            Image
            0 I found a lot of questions abount appendices and ToC. Many users want appendices to be grouped in an Appendix part, however some problems arise with ToC, hyperref, PDF viewer bookmarks, and so on. There are different solutions which require extra packages, command patching and other extra code, however none of them satisfies me. I almost found an easy way to accomplish a good result, where appendices are added to bookmarks in the right way and hyperref links point to the right page. However, the number of the "Appendix" part page is wrong (it's the number of appendix A). Is there any EASY way to fix that? This is a MWE: documentclass{book} usepackage[nottoc,notlot,notlof]{tocbibind} usepackage{hyperref} begin{document} frontmatter tableofcontents mainmatter part{First} chapter{...
            Read more

            Calculate evaluation metrics using cross_val_predict sklearn

            Image
            1 In the sklearn.model_selection.cross_val_predict page it is stated: Generate cross-validated estimates for each input data point. It is not appropriate to pass these predictions into an evaluation metric. Can someone explain what does it mean? If this gives estimate of Y (y prediction) for every Y (true Y), why can't I calculate metrics such as RMSE or coefficient of determination using these results? python scikit-learn cross-validation share | improve this question edited Nov 28 '18 at 17:52 desertnaut 20.3k 7 43 79 ...
            Read more

            Insert data from modal to MySQL (multiple modal on website)

            Image
            0 I have problem with inserting data to MySQL from modal. My modal: <a href="#" class="badge badge-pill badge-success">6 komentarzy</a> <a href="#" class="badge badge-pill badge-danger">brak komentarzy</a> <a data-toggle="modal" href="#add_desk_comm_{$desk_['desk_id']}" data-target="#add_desk_comm_{$desk_['desk_id']}" class="ediiit">(dodaj)</a> <div class="modal fade" id="add_desk_comm_{$desk_['desk_id']}" tabindex="-1" role="dialog" aria-labelledby="edit_printer" aria-hidden="true"> <div class="modal-dialog" role="document"> ...
            Read more