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Mini fuse holder — Parallax Forums

Mini fuse holder

ArchiverArchiver Posts: 46,084
edited 2003-01-03 02:39 in General Discussion
Hi all,

In looking at the Christmas lights, the light strings have mini fuses
in them. very small.

does anyone know if there is a fuse holder for a circuit board for
these little guys ?

I seems that the second largest item on the board is the fuse. This
seems a natural for mini boards.

Dave

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-01-02 04:42
    They make fuses the size of 1/4 watt resistors that can be soldered in or
    pushed into a couple of machine tool sockets. There are also the 5 x 20 mm
    fuses they use in consumer electronics -- you can even get some fuse clips
    and lay the board out to accept them.

    For a low-tech solution, a single strand out of a 18 ga lamp cord is good
    for about 1 amp.

    Original Message

    > In looking at the Christmas lights, the light strings have mini fuses
    > in them. very small.
    >
    > does anyone know if there is a fuse holder for a circuit board for
    > these little guys ?
    >
    > I seems that the second largest item on the board is the fuse. This
    > seems a natural for mini boards.
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-02 04:44
    In a message dated 1/1/2003 8:42:33 PM Pacific Standard Time,
    daweasel@s... writes:

    > They make fuses the size of 1/4 watt resistors that can be soldered in or
    > pushed into a couple of machine tool sockets. There are also the 5 x 20 mm
    > fuses they use in consumer electronics -- you can even get some fuse clips
    > and lay the board out to accept them.
    >
    > For a low-tech solution, a single strand out of a 18 ga lamp cord is good
    > for about 1 amp.
    >

    A strand from 18 gauge lamp cord? That is geneous!!!!! I am going to try it.
    I have some applications that can use that kind of fuse.


    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-02 05:07
    Thank Heathkit -- they used it on several of their kits. This is the cheapy
    brown fine-strand zip-cord you see on most lamps and not the speaker wire
    with the larger strands.

    Go to www.mouser.com and search for 504-MCR -- this will list the
    subminiature axial resistors.

    Original Message

    > > They make fuses the size of 1/4 watt resistors that can be soldered in
    or
    > > pushed into a couple of machine tool sockets. There are also the 5 x 20
    mm
    > > fuses they use in consumer electronics -- you can even get some fuse
    clips
    > > and lay the board out to accept them.
    > >
    > > For a low-tech solution, a single strand out of a 18 ga lamp cord is
    good
    > > for about 1 amp.
    > >
    >
    > A strand from 18 gauge lamp cord? That is geneous!!!!! I am going to try
    it.
    > I have some applications that can use that kind of fuse.
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-02 05:09
    DOH! Axial fuses.

    > Go to www.mouser.com and search for 504-MCR -- this will list the
    > subminiature axial resistors.
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-02 11:45
    I use 10 Ohm 1/8 or 1/4 watt resistors.
    They make great slow blow fuses. They heat up and give off lots of smoke
    before they pop.
    Of course it depends on the short and how much current and voltage you run
    through it.
    We used this technique in Radio Control Systems we used to build a long time
    ago.
    Nicad battery packs can provide lots of current if you short them and the 10
    ohm resistor would
    protect everything including the wires. The resistor was cheaper than the
    fuse.
    If you need higher current then use a 5 ohm or lower value resistor.
    The advantage the fuse had is that you can get a good fuse to pop or blow
    faster, helping to
    protect highly sensitive components from damage. If you aren't using those
    types of parts a resistor works great.


    Original Message
    From: Rodent [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=Z7LVWT4YU6rOYmnSMCxeFbB_oa5F89Jh5nHdUPNQaxKaoPxxIeNEEnU3CJIYL-CVWaoaivMeZEA5su5kFw]daweasel@s...[/url
    Sent: Wednesday, January 01, 2003 10:42 PM
    To: basicstamps@yahoogroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] Mini fuse holder


    They make fuses the size of 1/4 watt resistors that can be soldered in or
    pushed into a couple of machine tool sockets. There are also the 5 x 20 mm
    fuses they use in consumer electronics -- you can even get some fuse clips
    and lay the board out to accept them.

    For a low-tech solution, a single strand out of a 18 ga lamp cord is good
    for about 1 amp.

    Original Message

    > In looking at the Christmas lights, the light strings have mini fuses
    > in them. very small.
    >
    > does anyone know if there is a fuse holder for a circuit board for
    > these little guys ?
    >
    > I seems that the second largest item on the board is the fuse. This
    > seems a natural for mini boards.




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  • ArchiverArchiver Posts: 46,084
    edited 2003-01-02 12:20
    Ahhh... the problem with non-standards.

    twisted wire comes in different hardnesses, and in a strand the wires
    are different diameters. a very flexible cord, like a coffee pot
    will have many more strands than say a TV cord.

    Thinner strands make a more flexible bundle and cost more.

    This is a great idea. probably good idea to get a lenght, test it
    and keep it aside for your stock.

    even better is that from the solder, the base is thicker forcing the
    failure to be in an area of greater visibility.

    Simplicity. and cheap !




    --- In basicstamps@yahoogroups.com, smartdim@a... wrote:
    > In a message dated 1/1/2003 8:42:33 PM Pacific Standard Time,
    > daweasel@s... writes:
    >
    > > They make fuses the size of 1/4 watt resistors that can be
    soldered in or
    > > pushed into a couple of machine tool sockets. There are also the
    5 x 20 mm
    > > fuses they use in consumer electronics -- you can even get some
    fuse clips
    > > and lay the board out to accept them.
    > >
    > > For a low-tech solution, a single strand out of a 18 ga lamp cord
    is good
    > > for about 1 amp.
    > >
    >
    > A strand from 18 gauge lamp cord? That is geneous!!!!! I am going
    to try it.
    > I have some applications that can use that kind of fuse.
    >
    >
    > [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-02 12:46
    I found that the 2AG is the smallest standard fuse, but that there
    are no fuse holders available.

    The PICO fuses are ones I have used before, about the size of a small
    cap, nice by expensive.

    Thermal resettable fuses may be an option.

    The one failure I have had so far was that while installing, an ac
    line went to ground letting the AC rip across the board and burn up
    the ground traces.

    I hope more people contribute to this with options. I like the
    single strand, a simple pair of binding posts and presto, replaceable.

    Seems that someone should do that in a standard jumper block.


    Dave




    Dave





    --- In basicstamps@yahoogroups.com, Rodent <daweasel@s...> wrote:
    > Thank Heathkit -- they used it on several of their kits. This is
    the cheapy
    > brown fine-strand zip-cord you see on most lamps and not the
    speaker wire
    > with the larger strands.
    >
    > Go to www.mouser.com and search for 504-MCR -- this will list the
    > subminiature axial resistors.
    >
    >
    Original Message
    >
    > > > They make fuses the size of 1/4 watt resistors that can be
    soldered in
    > or
    > > > pushed into a couple of machine tool sockets. There are also
    the 5 x 20
    > mm
    > > > fuses they use in consumer electronics -- you can even get some
    fuse
    > clips
    > > > and lay the board out to accept them.
    > > >
    > > > For a low-tech solution, a single strand out of a 18 ga lamp
    cord is
    > good
    > > > for about 1 amp.
    > > >
    > >
    > > A strand from 18 gauge lamp cord? That is geneous!!!!! I am
    going to try
    > it.
    > > I have some applications that can use that kind of fuse.
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-02 15:10
    In a message dated 1/1/2003 9:10:03 PM Pacific Standard Time,
    daweasel@s... writes:

    > DOH! Axial fuses.
    >
    > >Go to www.mouser.com and search for 504-MCR -- this will list the
    > >subminiature axial resistors.
    >

    I figured "fuses".....


    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-02 20:56
    How long is the exposed strand? Doesnt the length make a difference in how
    fast it would blow? I would think that a longer strand (like 1 inch) would
    have more heat buildup and quicker burn-out than a real small one(1/4 inch)?
    Is that not correct?


    Original Message
    From: smartdim@a... <smartdim@a...>
    To: basicstamps@yahoogroups.com <basicstamps@yahoogroups.com>
    Date: Wednesday, January 01, 2003 10:44 PM
    Subject: Re: [noparse][[/noparse]basicstamps] Mini fuse holder


    >In a message dated 1/1/2003 8:42:33 PM Pacific Standard Time,
    >daweasel@s... writes:
    >
    >> They make fuses the size of 1/4 watt resistors that can be soldered in or
    >> pushed into a couple of machine tool sockets. There are also the 5 x 20
    mm
    >> fuses they use in consumer electronics -- you can even get some fuse
    clips
    >> and lay the board out to accept them.
    >>
    >> For a low-tech solution, a single strand out of a 18 ga lamp cord is good
    >> for about 1 amp.
    >>
    >
    >A strand from 18 gauge lamp cord? That is geneous!!!!! I am going to try
    it.
    >I have some applications that can use that kind of fuse.
    >
    >
    >[noparse][[/noparse]Non-text portions of this message have been removed]
    >
    >
    >To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    >from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    >
    >
    >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-02 21:16
    At 02:56 PM 1/2/03 -0600, William wrote:
    >How long is the exposed strand? Doesnt the length make a difference in how
    >fast it would blow? I would think that a longer strand (like 1 inch) would
    >have more heat buildup and quicker burn-out than a real small one(1/4 inch)?
    >Is that not correct?
    >
    >Not correct. You're "burning through" the diameter, not the length.
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-02 23:11
    If I remember right (Heathkit has been gone over 10 years) it was about 1/2"
    long. I really don't think it would make much difference though, as the
    critical dimension is the diameter of the strand.

    Original Message

    > How long is the exposed strand? Doesnt the length make a difference in
    how
    > fast it would blow? I would think that a longer strand (like 1 inch)
    would
    > have more heat buildup and quicker burn-out than a real small one(1/4
    inch)?
    > Is that not correct?


    > >> For a low-tech solution, a single strand out of a 18 ga lamp cord is
    good
    > >> for about 1 amp.
    > >>
    > >
    > >A strand from 18 gauge lamp cord? That is geneous!!!!! I am going to try
    > it.
    > >I have some applications that can use that kind of fuse.
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-03 01:11
    --- In basicstamps@yahoogroups.com, Bruce Bates <bvbates@u...> wrote:
    > At 02:56 PM 1/2/03 -0600, William wrote:
    > >How long is the exposed strand? Doesnt the length make a
    difference in how
    > >fast it would blow? I would think that a longer strand (like 1
    inch) would
    > >have more heat buildup and quicker burn-out than a real small one
    (1/4 inch)?
    > >Is that not correct?
    > >
    > >Not correct. You're "burning through" the diameter, not the length.

    Would this mean that the long wire, although it would not benefit
    from any heat sinks, would burn out at the same current as a short
    wire that benefitted by the solder joints as heat sinks ?

    I would imagine there are some thermaldynamics to add to the
    calculations. even if it were just a time factor until it would burn
    thru.

    The concept sound interesting. it would appear that one could use a
    simple 2 pin jumper, jamb a section of wire in the shorting block
    instead of the full shorting block and the wire would be the home
    brew fuse.

    Dave
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-03 01:24
    "Dave Mucha " wrote:
    >
    > --- In basicstamps@yahoogroups.com, Bruce Bates <bvbates@u...> wrote:
    > > At 02:56 PM 1/2/03 -0600, William wrote:
    > > >How long is the exposed strand? Doesnt the length make a
    > difference in how
    > > >fast it would blow? I would think that a longer strand (like 1
    > inch) would
    > > >have more heat buildup and quicker burn-out than a real small one
    > (1/4 inch)?
    > > >Is that not correct?
    > > >
    > > >Not correct. You're "burning through" the diameter, not the length.
    >
    > Would this mean that the long wire, although it would not benefit
    > from any heat sinks, would burn out at the same current as a short
    > wire that benefitted by the solder joints as heat sinks ?
    >
    > I would imagine there are some thermaldynamics to add to the
    > calculations. even if it were just a time factor until it would burn
    > thru.
    >
    > The concept sound interesting. it would appear that one could use a
    > simple 2 pin jumper, jamb a section of wire in the shorting block
    > instead of the full shorting block and the wire would be the home
    > brew fuse.

    In fact in the dim, dark, ancient past domestic AC current fuse holders
    were built as small ceramic blocks with two brass blades and
    accompanying screw terminals. You attached a piece of fuse wire between
    the two blades and pushed the block into the mating receptical. If the
    lights blew, you started pulling blocked looking for melted wire. And If
    your home used this sort of fuse holder, you also kept a roll of fuse
    wire handy for when the thing blew. Normally the fuse wire was an alloy,
    but in a pinch you could use suitably sized copper wire. The trick was
    not to install wire *too* think and create a fire hazard.

    I don't know if these were common here in the U.S. but in Australia,
    where I grew up, they were the standard issue until circuit breakers
    came along in the past twenty or thirty years. This isn't a new idea, by
    any means.

    I've also serviced equipment that uses this idea for a cheap main fuse
    between two posts. Obviously, it's more of a pain to replace than a
    simple fuse, but it has the benefit of low cost.


    - peterd



    Peter Deutsch pdeutsch@g...
    Gydig Software

    ""It doesn't hurt to be optimistic. You can always cry later."
    -- Lucimar Santos De Lima
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-03 02:39
    In the U.S., probably starting back in the 40's or so, they either had large
    cartridge type fuses for mains, or screw-in glass fuses for individual
    circuits. The only thing I have ever seen with a bare fuse element was the
    main fuse of some of the 70's models of Honda motorcycles.

    Original Message

    > > The concept sound interesting. it would appear that one could use a
    > > simple 2 pin jumper, jamb a section of wire in the shorting block
    > > instead of the full shorting block and the wire would be the home
    > > brew fuse.
    >
    > In fact in the dim, dark, ancient past domestic AC current fuse holders
    > were built as small ceramic blocks with two brass blades and
    > accompanying screw terminals. You attached a piece of fuse wire between
    > the two blades and pushed the block into the mating receptical. If the
    > lights blew, you started pulling blocked looking for melted wire. And If
    > your home used this sort of fuse holder, you also kept a roll of fuse
    > wire handy for when the thing blew. Normally the fuse wire was an alloy,
    > but in a pinch you could use suitably sized copper wire. The trick was
    > not to install wire *too* think and create a fire hazard.
    >
    > I don't know if these were common here in the U.S. but in Australia,
    > where I grew up, they were the standard issue until circuit breakers
    > came along in the past twenty or thirty years. This isn't a new idea, by
    > any means.
    >
    > I've also serviced equipment that uses this idea for a cheap main fuse
    > between two posts. Obviously, it's more of a pain to replace than a
    > simple fuse, but it has the benefit of low cost.
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