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Any PCB designers out there.

  1. Nov 25, 2012 #1
    Any PCB designers, why oh why oh why do you inflict those (insert profanity) awful fuses that are soldered to the board, fuses in fuse holders make life so much easier.
  2. jcsd
  3. Nov 25, 2012 #2

    jim hardy

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    Gold Member

    I've been frustrated by those myself.

    Only reason i can think of is this -
    in some circles the fix for a blowing fuse is to put in a bigger one. Ever heard the phrase "Put a penny behind the fuse" ? That has burned down a lot of homes.
    The soldered in fuse assures that it will be replaced only by somebody who has at least an inkling of what he is doing.

    I like designed-in safety. Henry Ford was a genius at such things - headlight circuits in early Fords were protected by thermal overloads that cycled as they heated and cooled, so a faulted wire to a headlight would cause them to cycle on and off allowing you to limp home. A fuse would have left you with no lights at all. My '53 Ford was so wired and i think it dates back to 1929 Model A.

    Some 1980's Fords have a headlight fuse inside the dimmer switch, which assures that should the headlight circuit develop a short it'll get fixed by somebody with at least the competence to find it, instead of putting in a bigger fuse and setting the car afire.

    I don't know how it's done today.

    So the answer to your question might be the proverbial 'ounce of prevention'
    or it might be simply saving a step in assembly.

    When studying designs it is often fruitful to ask yourself "Why would a rational man have done this?"

    old jim
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