Mounting a Bridge Rectifier

Discussion in 'The Projects Forum' started by Blatboy, Sep 18, 2014.

  1. Blatboy

    Thread Starter Member

    Jun 11, 2012
    46
    0
    Greetings. I'm building a power supply, using the book "TAB Electronics Guide to Understanding Electricity and Electronics" by G. Randy Slone. (I've talked about it earlier on this, this, and this thread.)

    I've gotten a new enclosure, and finally started actually putting this thing together.

    I'm having a hard time figuring out how to mount the bridge rectifier. In the book, Mr. Slone only says:

    Assuming there were no problems with the bridge rectifier module, mount it, close to the T1 and T2 secondaries, with the appropriate hardware.
    Is it ok to mount that sucker to the chassis? Looking at it, if I bend the leads up I'll still have about 2mm clearance to the chassis. Is that ok, assuming my wiring is careful? (I'm considering using heat shrink on the connections.) It gets my spidey senses tingling having the top of the leads so close to the chassis, so before I did that, I wanted to be sure that's cool. I've attached a picture of how I would potentially mount it...

    Thanks!

    IMG_0820.JPG
     
  2. #12

    Expert

    Nov 30, 2010
    16,248
    6,745
    Put some heat sink cream under the rectifier and heat shrink the connections, or blob them with silicon caulk after the wires are attached. That spacing is good for 150 (peak) volts, easy.

    Edit: If that sheet metal is pretty thin, you can add 2 or 3 square inches of 1/4 inch thick aluminum as a heat spreader between the rectifier and the sheet metal. I had to do that with a 5 amp Triac in a Radio Shack sheet metal box.
     
    Last edited: Sep 18, 2014
    Blatboy likes this.
  3. Blatboy

    Thread Starter Member

    Jun 11, 2012
    46
    0
    Thanks. The metal isn't that thin, so I think it'll be fine. I have some heat sink cream.... so great! Thanks!!!!
     
  4. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
    2,039
    287
    Yep...heat sink glop has pretty high breakdown voltage. Those bridges are designed to be bolted right to a chassis, which is why they have a hole in the middle.
     
  5. wayneh

    Expert

    Sep 9, 2010
    12,087
    3,027
    I think we understand your plan, but just to be sure, the 2mm you mention is from the chassis surface that the rectifier itself is mounted to? That would be fine. A clearance of only 2mm against some OTHER surface that might flex towards the pins and close the gap, is obviously not acceptable.
     
    Blatboy likes this.
  6. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,500
    2,365
    My choice would be to add a square piece of aluminum, especially if mounted next to heat producers such as a transformer.
    Max.
     
    Blatboy likes this.
Loading...