Need Help with Triac and Phase Control Unit Not Working

Discussion in 'General Electronics Chat' started by bwilliams60, Nov 19, 2014.

  1. bwilliams60

    Thread Starter Active Member

    Nov 18, 2012
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    Need a little help from the forum. I have a router (woodworking) that has blown a tantalum smd capacitor on the board and need to identify it if possible. Here is what I have for markings
    EPCOS
    C155
    R9 06
    I believe it is 1,500,000 pF. Is that correct? Is that the same as 1.5 uF?
    If good so far, what voltage am I looking for. I'm guessing in the range of 16 V?

    Let me know if you can. Thank you
     
  2. bwilliams60

    Thread Starter Active Member

    Nov 18, 2012
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    Nothing???
     
  3. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    A picture is worth a thousand words.
     
  4. b1u3sf4n09

    Member

    May 23, 2014
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    Do you have a picture of the cap or the board? Epcos no longer makes tantalum capacitors; that group was bought by Kemet:

    http://kemet.mediaroom.com/2005-12-12-KEMET-Agrees-to-Acquire-EPCOS-Tantalum-Capacitor-Business

    I only mention this because finding old Epcos datasheets is proving a little difficult. You are correct in your assessment of the capacitance. The value I have memorized is 104, which corresponds to the most common capacitance: 0.1μF (10pf * 10^4)

    My current guess to the rest: R9 - 9V rated voltage, 06 - year code 2006
     
    Last edited: Nov 20, 2014
  5. b1u3sf4n09

    Member

    May 23, 2014
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    If you want a replacement and don't want to worry about overvoltage, get the highest rated cap in that same footprint. This would be the simplest and fastest solution.

    If you have a schematic, we can take a crack at finding the appropriate rating for the capacitor.
     
  6. jeremynguyen

    New Member

    Nov 21, 2014
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    In my opinion, you'd better get the highest rated cap in that same footprint. It is the best way I think.
     
  7. bwilliams60

    Thread Starter Active Member

    Nov 18, 2012
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    Here is a picture of a similar EPCOS smd capacitor. They seem to be very hard to find.
    Was I correct in saying that 155 is equal to 1.5 uF?
     
  8. b1u3sf4n09

    Member

    May 23, 2014
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    Read post #4. Your assessment of the capacitance is correct, and Epcos hasn't made tantalum capacitors since 2005.
     
  9. bwilliams60

    Thread Starter Active Member

    Nov 18, 2012
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    I am not going to be able to find a 1.5uF tantalum SMD capacitor in my area quickly. Is there something I can substitute for this cap? I have room for a regular mount cap. Any suggestions. Ceramic or polyester film?
     
  10. b1u3sf4n09

    Member

    May 23, 2014
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    That would depend on the function of the capacitor. Where is it located in the circuit?
     
  11. bwilliams60

    Thread Starter Active Member

    Nov 18, 2012
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    Can someone tell me if I can use another type of capacitor here? The burnt one is right of the hole in the upper section. it is a 1.5uF tantalum cap that is hard to find
     
  12. bwilliams60

    Thread Starter Active Member

    Nov 18, 2012
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    I've changed the title of this thread. Need help on replacement parts
     
    Last edited: Nov 25, 2014
  13. b1u3sf4n09

    Member

    May 23, 2014
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    What is the part number of the IC and the 3 pin parts? I can't quite read them.
     
  14. bwilliams60

    Thread Starter Active Member

    Nov 18, 2012
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    The IC is a U211B. Other numbers on it are T 327 and 46304-12. The TRIAC is a BTA24 600BW. Are these the parts you are referring to? The potentiometers are 47K ohms.
     
  15. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    Aren't tantalum caps polarized? A ceramic or film cap probably wouldn't work. Don't you have any "junk" electronics in the shop? Maybe scrounge a cap from a junk item?
     
  16. BobTPH

    Active Member

    Jun 5, 2013
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    There may be other reasons why a ceramic or film capacitor would not work, but not because it is non-polarized. A polarized capacitor can be replaced with a non-polarized capacitor (but not the other way around.)

    Bob
     
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  17. bwilliams60

    Thread Starter Active Member

    Nov 18, 2012
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    Good point shortbus. Didn't think about polarity when I should have. Regardless, I have looked through my junk and can't find any 1.5 uF caps anywhere. Will have to keep digging. Thanks for your help
     
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  18. ian field

    Distinguished Member

    Oct 27, 2012
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    Why wouldn't a non polarised cap work in place of an electrolytic?!

    There have been very many occasions that I've replaced dried out small electrolytics with either multilayer ceramic chip of mylar film.

    The only issue I've encountered is finding non-electrolytic types compact enough to fit the available space.
     
  19. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    I guess now that tant caps have lowered in price it doesn't make a difference. Just can't see a manufacturer using a tant where a ceramic would do the job.
     
  20. ian field

    Distinguished Member

    Oct 27, 2012
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    One caution - tantalum caps are probably the least tolerant of reverse polarity.

    When I used to repair PC monitors, I frequently encountered one popular model that sometimes had a tant bead fitted the wrong way round. The circuit only handled small signal levels, but every single reversed tant had gone leaky.

    It was only a few uF, so I always replaced it with a foil type.
     
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