584,837 active members*
5,293 visitors online*
Register for free
Login
Results 1 to 13 of 13
  1. #1
    Join Date
    Aug 2006
    Posts
    14

    Bridge rectifier go poof

    What did I do wrong? I hooked the ac input to the 2 posts not marked with the positive and negative. As soon as I applied power I got the magic smoke.

    I'm using a 28v toroidal transformer and a 35amp 1000v bridge rectifier. I measure the voltage from the transformer and it was 29 volts.

    Thanks,
    Bobby
    Attached Thumbnails Attached Thumbnails bridge.jpg  

  2. #2
    Join Date
    Dec 2003
    Posts
    24216
    You sure they were on opposite corners, not adjacent posts?
    Is the bridge shorted now? was just a capacitor hooked up to the DC side or?
    Al.
    CNC, Mechatronics Integration and Custom Machine Design

    “Logic will get you from A to B. Imagination will take you everywhere.”
    Albert E.

  3. #3
    Join Date
    Oct 2004
    Posts
    727
    Quote Originally Posted by blfinche View Post
    What did I do wrong? I hooked the ac input to the 2 posts not marked with the positive and negative. As soon as I applied power I got the magic smoke.

    I'm using a 28v toroidal transformer and a 35amp 1000v bridge rectifier. I measure the voltage from the transformer and it was 29 volts.

    Thanks,
    Bobby
    Bobby,

    Those markings are not Positive (+) and Negative (-), they are Positive (+) and AC (~). If I remember correctly, the matched connectors are oriented diagonally. See Wikipedia's explanation of the Diode Bridge (with pictures). Note the diagram with the AC Input, DC Output and Load labels in the section devoted to Output Smoothing. Be sure to verify proper connections by tracking down the "Data Sheet" for the bridge rectifier (and other components) you're using. Can't find the right Data Sheet, contact the company you purchased the component(s) from, they should be able to provide it or direct you to the link on the manufacturer's web site.

    I see another bridge rectifier in your future. Be careful with bridge rectifiers, a lesser known name for them is "bridge rectal-fryer". Make sure you take precautions so that you don't find out why... the hard way. :rainfro:
    HayTay

    Don't be the one that stands in the way of your success!

  4. #4
    Join Date
    May 2004
    Posts
    198
    Quote Originally Posted by blfinche View Post
    What did I do wrong? I hooked the ac input to the 2 posts not marked with the positive and negative. As soon as I applied power I got the magic smoke.

    I'm using a 28v toroidal transformer and a 35amp 1000v bridge rectifier. I measure the voltage from the transformer and it was 29 volts.

    Thanks,
    Bobby
    Bobby,
    Look closely at the "minus" sign. I'll bet it is a wavy line signalling AC. I've attached a PDF and a JPEG that shows the rectifier "pinouts". It is a sectional cut from the package wiring diagram included in the package.
    Hope this helps!
    Attached Thumbnails Attached Thumbnails Rectifier.jpg  
    Attached Files Attached Files

  5. #5
    Join Date
    Sep 2006
    Posts
    6463
    Hi blfinche, one of the golden rules before connecting up any electrical 'quiptment is to check the resistance of the connection point.
    This means that if the resistance is low then either a dead short exist or you've got the wrong set of contact points.
    If you don't test the connection then just putting the plug in will result in a heavy current flow and goodbye anything that is in the line, diodes, transformer or worse a fire in the cables.
    I would have thought you would have had a fuse in the output of the bridge rectifier/voltage regulator.
    Moral:- Don't go blindly in where.........
    Ian.

  6. #6
    Join Date
    Aug 2006
    Posts
    14
    I think I have it. I did not connect diagonally. I thought the ~ was a negative sign. So I should connect to the ~ and the corner diagonal to that?

    Thanks,
    Bobby

  7. #7
    Join Date
    Dec 2003
    Posts
    24216
    Quote Originally Posted by handlewanker View Post
    Hi blfinche, one of the golden rules before connecting up any electrical 'quiptment is to check the resistance of the connection point.
    The problem with checking a semiconductor on the normal resistance range on a modern meter is that it will not show conduction due to not enough voltage to forward bias the device, so it shows high resistance, you would need to have a meter with a diode check range.


    Bobby, the AC connections on a bridge are the ~ signs, and generally are on opposing corners, but adjacent posts cause a short.
    Al.
    CNC, Mechatronics Integration and Custom Machine Design

    “Logic will get you from A to B. Imagination will take you everywhere.”
    Albert E.

  8. #8
    Join Date
    May 2006
    Posts
    2420
    Yup you have it now Bobby, connect the AC to the ~ and the diag opposite corner, the DC goes positive on the + side and the negative is on the diagonally opposite corner.

    The way you had it originally meant that there was a dead short across your transformer secondary on one half of the wave, usually the weakest part gives way, in this case sounds like the rectifier, hopefully it didn't damage the transformer, check your voltages once you have it correctly wired, and might not hurt to put a fuse in the circuit.

    Good luck.

    Russell.

  9. #9
    Join Date
    Nov 2020
    Posts
    3

    Re: Bridge rectifier go poof

    Hey so just stumbled across this thread. Very interesting .. I am having a bit of trouble understanding how a bridge rectifier work though. Is it just a bunch of diodes?

  10. #10
    Join Date
    Dec 2020
    Posts
    2

    Re: Bridge rectifier go poof

    Hey Jacob,

    I can certainly help. So a Bridge Rectifier is an assortment of diodes its usually 3 or more and its used to convert AC to DC current.

    Hope that helps..

  11. #11
    Join Date
    Nov 2020
    Posts
    3

    Re: Bridge rectifier go poof

    Ok I understand .. anything else important I should know about them , so that I can understand them more in depth or is that about it ?

  12. #12
    Join Date
    Dec 2020
    Posts
    2

    Re: Bridge rectifier go poof

    Quote Originally Posted by jacobgoona View Post
    Ok I understand .. anything else important I should know about them , so that I can understand them more in depth or is that about it ?
    Yea of course .. there is always more. SO essentially as mentioned before it is an assortment / configuration of a bunch of diodes. it allows current to flow in one direction and not backwards. Also AC current converts to DC. These are generally used in power supplies , battery chargers etc..

    There are a lot of different types of rectifiers , not just a bridge rectifier. There is a Full wave rectifier, Half wave rectifier , three wave rectifier etc.. They all have different configurations and different amounts of diodes but all of them accomplish the same general goal which is to convert AC to DC current. I looked around and found this https://www.derf.com/how-a-bridge-re...step-tutorial/ It is a good overall explanation on how they work and the different types of rectifiers. I would read through that first or maybe search around on google a bit more. This is all readily available information.

    If you still have any other questions about them let me know. Just try to be specific about what your confused on / don't understand.

    Best,

  13. #13
    Join Date
    Nov 2020
    Posts
    3

    Re: Bridge rectifier go poof

    Hey,

    Thanks so much for the thoughtful explanation. Wow just googled it , didn't realize how much information was out there. Appreciate you taking the time still.. I will do my research and see if I am confused about anything still. Will be more specific if I still have questions.

    Best,

Posting Permissions

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