Connect with us

Capacitor getting hot

Discussion in 'General Electronics Discussion' started by JohnWin, Nov 24, 2016.

Scroll to continue with content
  1. JohnWin

    JohnWin

    24
    0
    Nov 24, 2016
    hello, I don't know very much about electronics but am building an LED light panel. I picked up some high frequency pwm dimmers that are suppose to work. When I turn the lights up a capacitor on the dimmer gets very hot and the led's dim down by themselves after about 10-20 seconds.

    The capacitor reads:
    HD98
    China
    %30
    UF 185

    I'm wondering if I can find some more of these and put them in parallel or series to help with the heat/load? Or can I put a bigger capacitor in its place? If so are there any recommendations on what size to use?

    Thanks in advanced for any help!!
     
  2. davenn

    davenn Moderator

    13,653
    1,886
    Sep 5, 2009

    hi
    welcome :)

    show us your circuit
     
  3. JohnWin

    JohnWin

    24
    0
    Nov 24, 2016
    Hi! Thank you!

    I didn't build the circuit myself. Maybe I didn't post in the right area.. I did add a picture of the dimmer. The offending capacitor is the yellowish one in the back.

    I'm just wondering if there is anything I can do to take some of the load off the capacitor like adding another one in parallel or series. Or maybe just replacing it with another high value one.

    Thanks for the reply!
     

    Attached Files:

  4. davenn

    davenn Moderator

    13,653
    1,886
    Sep 5, 2009

    Doesn't look like a capacitor .... and another hint is that it has R1 on the circuit board beside it
    it's either a resistor or a MOV, Metal Oxide Varistor ( used for over voltage protection)

    it probably should get warm when running full power ... but shouldn't be too hot to touch
    it's possible that
    1) it's underrated for the purpose
    2) it may be going faulty

    I prefer option 1
     
  5. Arouse1973

    Arouse1973 Adam

    5,164
    1,081
    Dec 18, 2013
    It's a PTC (Poly Switch).
    Thanks
    Adam
     
  6. JohnWin

    JohnWin

    24
    0
    Nov 24, 2016
    Ok that's interesting. I don't think it's a matter of it going faulty because I have two working for the light panel, one for each of two color led's, and both are doing the same thing (dimming by themself after a little time). If I recall they are rated for up to 35v. And I'm only running 11.6v thru them. It's rather frustrating because the panel is working beautifully until it dims. They do get pretty hot, almost too hot to touch. I'm not sure what to do next. Do you know if there is anyway I can test it or something? Thanks again for the help!
     
  7. JohnWin

    JohnWin

    24
    0
    Nov 24, 2016
    That's for the reply Adam! I'm not sure what a Poly Switch is. Do you know if that's something I can fix?
     
  8. davenn

    davenn Moderator

    13,653
    1,886
    Sep 5, 2009
    IT basically does the same thing as a MOV that I commented on except it works on current rather than voltage

    https://en.wikipedia.org/wiki/Resettable_fuse
     
  9. BobK

    BobK

    7,682
    1,686
    Jan 5, 2010
    What are the specs of the dimmer and of the LEDs you are driving with it. It sounds to me like you are over stressing it.

    Bob
     
    (*steve*) likes this.
  10. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,412
    2,780
    Jan 21, 2010
    I'm with Bob
     
  11. JohnWin

    JohnWin

    24
    0
    Nov 24, 2016
    Yes I believe everybody is right. I'm pretty sure I'm over stressing the dimmers. So I figure I'll add two more dimmers and divide the led's up accordingly. Not stoked about have four knobs instead of two but it's not the end of the world.

    Thank you all for your help!!
     
  12. BobK

    BobK

    7,682
    1,686
    Jan 5, 2010
    You could get one dimmer with more current capability.

    Bob
     
  13. JohnWin

    JohnWin

    24
    0
    Nov 24, 2016
    This is true. I ended up stepping the voltage down to 10v and it stopped the self dimming. I do lose some light output but it's still a nice panel none the less.

    I looked up the specs of the dimmer and it's rated for up to 35v and 5 amps. So I'm still not entirely sure why it's over loading. I'm nowhere near either.

    I plan on building a couple more in the future. So next time I'll get a super beefy dimmer and hopefully won't have a problem.
     
  14. Colin Mitchell

    Colin Mitchell

    1,417
    312
    Aug 31, 2014
    "specs of the dimmer and it's rated for up to 35v and 5 amps."

    provide a link
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-