Advertise on Bikeforums.net



User Tag List

Results 1 to 23 of 23
  1. #1
    la vache fantôme phantomcow2's Avatar
    Join Date
    Aug 2004
    Location
    NH
    Posts
    6,266
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    What will happen if I let this bridge rectifier keep smoking?

    So I just put 39vAC into an old bridge rectifier. I connect bridge rectifier to three 10,000uF capacitors in parallel. As soon as I supply power, I see smoke. I disconnect capacitors, capacitors appear to be fine. But rectifier is spewing out smoke, not sure why. It is rated for 400v and 25amps. It is probably 18 years old though. The transfer was making odd sounds while the rectifier was smoking; almost like a stalling motor. THis is what made me unplug the power. So, what will happen if I leave it plugged in?
    C://dos
    C://dos.run
    run.dos.run

  2. #2
    Hey guyz? Guyz? Wait up!! Siu Blue Wind's Avatar
    Join Date
    Apr 2005
    Posts
    10,540
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    It might get lung cancer.


    ...........or YOU might.......
    Quote Originally Posted by Buddha
    We are what we think. All that we are arises with our thoughts. With our thoughts, we make the world.
    Quote Originally Posted by making View Post
    Please dont outsmart the censor. That is a very expensive censor and every time one of you guys outsmart it it makes someone at the home office feel bad. We dont wanna do that. So dont cleverly disguise bad words.

  3. #3
    la vache fantôme phantomcow2's Avatar
    Join Date
    Aug 2004
    Location
    NH
    Posts
    6,266
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I have an acrylic enclosure for a lathe, perhaps I should place the rectifier inside and find out?
    C://dos
    C://dos.run
    run.dos.run

  4. #4
    Non Tribuo Anus Rodentum and off to the next adventure (RIP) Stacey's Avatar
    Join Date
    Dec 2002
    Posts
    9,163
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Siu Blue Wind
    It might get lung cancer.


    ...........or YOU might.......
    My thoughts exactly!

  5. #5
    The Site Administrator: Currently at home recovering from a couple of strokes,please contact my assistnt admins for forum issues Tom Stormcrowe's Avatar
    Join Date
    Mar 2006
    Location
    South Florida
    My Bikes
    Techna Wheelchair and a Sun EZ 3 Recumbent Trike
    Posts
    16,155
    Mentioned
    11 Post(s)
    Tagged
    4 Thread(s)
    Quote Originally Posted by phantomcow2
    So I just put 39vAC into an old bridge rectifier. I connect bridge rectifier to three 10,000uF capacitors in parallel. As soon as I supply power, I see smoke. I disconnect capacitors, capacitors appear to be fine. But rectifier is spewing out smoke, not sure why. It is rated for 400v and 25amps. It is probably 18 years old though. The transfer was making odd sounds while the rectifier was smoking; almost like a stalling motor. THis is what made me unplug the power. So, what will happen if I leave it plugged in?
    The rectifier is probably fried
    on light duty due to illness; please contact my assistants for forum issues. They are Siu Blue Wind, or CbadRider or the other 3 star folk. I am currently at home recovering from a couple of strokes. I am making good progress, happily.


    . “He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you.”- Fredrick Nietzsche

    "We can judge the heart of a man by his treatment of animals." - Immanuel Kant

  6. #6
    Hey guyz? Guyz? Wait up!! Siu Blue Wind's Avatar
    Join Date
    Apr 2005
    Posts
    10,540
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    You know, I never understand Phantom's threads but I still keep clicking on them.
    Quote Originally Posted by Buddha
    We are what we think. All that we are arises with our thoughts. With our thoughts, we make the world.
    Quote Originally Posted by making View Post
    Please dont outsmart the censor. That is a very expensive censor and every time one of you guys outsmart it it makes someone at the home office feel bad. We dont wanna do that. So dont cleverly disguise bad words.

  7. #7
    Non Tribuo Anus Rodentum and off to the next adventure (RIP) Stacey's Avatar
    Join Date
    Dec 2002
    Posts
    9,163
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Kinda like...



    Because you like pancakes.

  8. #8
    Senior Member pedex's Avatar
    Join Date
    Mar 2004
    Posts
    5,361
    Mentioned
    4 Post(s)
    Tagged
    1 Thread(s)
    it will let all the smoke out and quit working

  9. #9
    Tom (ex)Builder twahl's Avatar
    Join Date
    Jul 2004
    Location
    Manassas, VA
    My Bikes
    Specialized Allez
    Posts
    2,814
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Yeah once you let the magic smoke out, things quit working.

    And sometimes those big guys with the big noisy trucks come and visit.
    Tom

    "It hurts so good..."

  10. #10
    old codger icithecat's Avatar
    Join Date
    Sep 2004
    Location
    Victoria B.C.
    Posts
    1,124
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I love the smell of PCBs in the morning................

  11. #11
    Senior Member
    Join Date
    Dec 2004
    My Bikes
    Electra Townie 7D
    Posts
    3,398
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Give it the patch

  12. #12
    Senior Member pmseattle's Avatar
    Join Date
    Jun 2004
    Location
    Seattle, WA
    Posts
    451
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by phantomcow2
    So I just put 39vAC into an old bridge rectifier. I connect bridge rectifier to three 10,000uF capacitors in parallel. As soon as I supply power, I see smoke. I disconnect capacitors, capacitors appear to be fine. But rectifier is spewing out smoke, not sure why. It is rated for 400v and 25amps. It is probably 18 years old though. The transfer was making odd sounds while the rectifier was smoking; almost like a stalling motor. THis is what made me unplug the power. So, what will happen if I leave it plugged in?
    Hmmm, assuming all the diodes in the bridge are OK, the caps should have charged up to the peak value of the AC signal since you have no DC load to discharge them. Maybe one of the caps is bad ( internal short ), or maybe one of the rectifier diodes is shorted. Anyway, the fire is due to something drawing excess current, so it will continue to burn until whatever component is drawing excess current burns up and becomes an open circuit. And along the way, it will stink real bad.

  13. #13
    Senior Member
    Join Date
    Aug 2006
    Posts
    998
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Is it a plasticy smell, or ozone? I'm wondering myself if its a cap's dielectric that is burning (and that stuff is bad to inhale.)

    Nothing lasts forever; I'd consider replacing the FWBR and/or looking at the step-down transformer.

  14. #14
    Trans-Urban Velocommando ax0n's Avatar
    Join Date
    Nov 2006
    Location
    Lenexa, KS
    My Bikes
    06 Trek 1200 - 98 DB Outlook - 99 DB Sorrento
    Posts
    2,400
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Was there a load on the circuit? Are you sure you weren't overamping it?
    ax0n: Geeky and bikey
    My latest tip: Carrying your laptop
    My latest geeky project: Ethernet-testing cuff links

  15. #15
    Senior Member DannoXYZ's Avatar
    Join Date
    Jul 2005
    Location
    Saratoga, CA
    Posts
    11,507
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I betcha the caps are on backwards.... give us a schematic of your circuit, eh?
    Last edited by DannoXYZ; 01-16-07 at 03:22 AM.

  16. #16
    Senior Member gapowermike's Avatar
    Join Date
    Jun 2005
    Location
    McDonough, Georgia
    My Bikes
    Trek 1000 & 4100 & 5500
    Posts
    860
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by icithecat
    I love the smell of PCBs in the morning................
    +1. We removed some PCB filled 12kV capacitors a few years ago after one ruptured in a substation. I think it was the combination of the PCB's and the burning oil. We all should get to experience said stench.
    RIP Stacey. =3.

  17. #17
    la vache fantôme phantomcow2's Avatar
    Join Date
    Aug 2004
    Location
    NH
    Posts
    6,266
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Basically, here is how it all went:

    Have one transformer, with a 39vAC output. 116 input. -39volt output goes to the bridge rectifier, approx 36 volt output from the rectifier. The negative and positive will be connected appropriately to three 10,000uF capacitors in parallel. Then, there will be a 2kohm 1W bleed resistor connecting - and + at the end. I will probably stick a few fuses in there too.
    I am not too disappointed though. THese rectifiers are close to 20 years old, they have lived a prosperous life. Radioshack sells one that is 400v @ 6A. My load is not even 2A. The capacitors and transformer are professionally mounted on an original case, I know they are okay.
    C://dos
    C://dos.run
    run.dos.run

  18. #18
    la vache fantôme phantomcow2's Avatar
    Join Date
    Aug 2004
    Location
    NH
    Posts
    6,266
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Also,
    I saw the images my friend got when he tested the output of his identical rectifier with is 'scope. The best way I would describe it, is 15/16 wave rectification.
    C://dos
    C://dos.run
    run.dos.run

  19. #19
    Tiocfáidh ár Lá jfmckenna's Avatar
    Join Date
    Dec 2003
    Location
    The edge of b#
    My Bikes
    A whole bunch-a bikes.
    Posts
    5,414
    Mentioned
    0 Post(s)
    Tagged
    1 Thread(s)
    I think you need tosubmerge the apparatus in water to cool it down.

  20. #20
    You Know!? For Kids! jsharr's Avatar
    Join Date
    Apr 2005
    Location
    Just NW of Richardson Bike Mart
    My Bikes
    '05 Trek 1200 / '90 Trek 8000 / '? Falcon Europa
    Posts
    6,113
    Mentioned
    12 Post(s)
    Tagged
    3 Thread(s)
    Quote Originally Posted by jfmckenna
    I think you need tosubmerge the apparatus in water to cool it down.
    +1 Bath water is good for this. You will have more control of the process if you are in the tub with the electronics. The other nice thing about the water bath cooling method is watching the smoke filled bubbles pop as they rise to the surface. Have Fun!
    Are you a registered member? Why not? Click here to register. It's free and only takes 27 seconds! Help out the forums, abide by our community guidelines.
    Quote Originally Posted by colorider View Post
    Phobias are for irrational fears. Fear of junk ripping badgers is perfectly rational. Those things are nasty.

  21. #21
    You know you want to. Eatadonut's Avatar
    Join Date
    Jun 2005
    Location
    Norman, Oklahoma
    My Bikes
    Pinarello Prince, 1980's 531 steel fixie commuter, FrankenMTB
    Posts
    1,896
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by phantomcow2
    15/16 wave rectification.


    That might be useful in some VERY niche projects...
    Weather today: Hot. Humid. Potholes.

  22. #22
    Warrior Cyclist cycle17's Avatar
    Join Date
    Jul 2005
    Location
    Davis, CA
    My Bikes
    07 Madone SL, 06 Madone 5.5 & 04 5500
    Posts
    1,548
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    If the recitfier has diodes in it...I bet that you popped one or two of them. Leaving it connected might frey the rest of them. A schematic of your setup and the rectifier would be more insightful.
    Just Do It..

  23. #23
    The Guadfather Lecterman's Avatar
    Join Date
    Sep 2005
    Location
    Fart Worth
    My Bikes
    Trek, Centurion, Kuwahara coming soon
    Posts
    1,090
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Basically this:

    The Seven Plagues
    1. Ugly and painful sores will break out on the people who have the mark of the beast and worship his image.
    2. The sea will turn into blood like that of a dead man, and every living thing in the sea will die.
    3. Rivers & springs will become blood.
    4. The sun will scorch people with fire.
    5. The kingdom of the beast will plunge into darkness. Men will gnaw their tongues in agony and curse the God of heaven because of their pains and their sores, but they will refuse to repent of what they have done.
    6. The great river Euphrates will dry up to prepare the way for the kings from the East.
    7. Cities and countries will collapse and huge hailstones of about a hundred pounds each will fall from the sky upon men, and they will curse God on account of the plague of hail, because the plague will be so terrible.

    OR

    It will just break and be rendered useless.
    Are you a registered member? Why not? click here to register. Its free, and only takes 27 seconds!
    Help out the forums, abide by our community guidelines.
    "Minor bun engine, made Benny Lava!!!"

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •