Another thread has an interesting discussion of magnets, which
reminded me of an on-topic question [kinda] about magnets.
How do those magnetic bases used for dial indicators work? The lever
to switch the magnet on or off seems to have too little resistance to
be simple mechanical advantage in separating the base from the iron
table it was held to so strongly.
--
Alex
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The base is made of two separate ferrous pieces separated by a non-ferrous
divider (if you look closely you can see the joint between the two pieces).
The magent inside the two pieces can rotate. In the ON position, the north
end of the magnet is enclosed by one of the ferrous pieces and the south end
of the magent is enlosed by the other ferrous piece. In the off position,
the magnetic poles are half inside each ferrous pirce. The ferrous metal
baiscallu short-circuits the magnetic flux lines. Most of the magnetic
field stays inside the ferrous metal and and very little goes out into the
real worl.
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"alexy" <[email protected]> wrote in message
news:[email protected]...
> Dave Hinz <[email protected]> wrote:
>
>>On Fri, 08 Oct 2004 11:40:08 -0400, alexy <[email protected]>
>>wrote:
>>> Another thread has an interesting discussion of magnets, which
>>> reminded me of an on-topic question [kinda] about magnets.
>>
>>OK, I think I know the thread ;)
>>
>>> How do those magnetic bases used for dial indicators work? The lever
>>> to switch the magnet on or off seems to have too little resistance to
>>> be simple mechanical advantage in separating the base from the iron
>>> table it was held to so strongly.
>>
>>It's sliding opposing magnets into place which nullifies the outwards
>>forces. Instead of NNNNNNNN you have NSNSNSNS, so it evens out to
>>nuttin-ish.
>>
>>Dave Hinz
>
> Thanks. Makes sense.
> --
> Alex
> Make the obvious change in the return address to reply by email.
On Fri, 08 Oct 2004 11:40:08 -0400, alexy <[email protected]> wrote:
> Another thread has an interesting discussion of magnets, which
> reminded me of an on-topic question [kinda] about magnets.
OK, I think I know the thread ;)
> How do those magnetic bases used for dial indicators work? The lever
> to switch the magnet on or off seems to have too little resistance to
> be simple mechanical advantage in separating the base from the iron
> table it was held to so strongly.
It's sliding opposing magnets into place which nullifies the outwards
forces. Instead of NNNNNNNN you have NSNSNSNS, so it evens out to
nuttin-ish.
Dave Hinz
"mp" <[email protected]> wrote:
>> How do those magnetic bases used for dial indicators work? The lever
>> to switch the magnet on or off seems to have too little resistance to
>> be simple mechanical advantage in separating the base from the iron
>> table it was held to so strongly.
>
>They work fine.
<g>
In case that was not tongue-in-cheek, I was asking "how", not "how
well".
--
Alex
Make the obvious change in the return address to reply by email.
Dave Hinz <[email protected]> wrote:
>On Fri, 08 Oct 2004 11:40:08 -0400, alexy <[email protected]> wrote:
>> Another thread has an interesting discussion of magnets, which
>> reminded me of an on-topic question [kinda] about magnets.
>
>OK, I think I know the thread ;)
>
>> How do those magnetic bases used for dial indicators work? The lever
>> to switch the magnet on or off seems to have too little resistance to
>> be simple mechanical advantage in separating the base from the iron
>> table it was held to so strongly.
>
>It's sliding opposing magnets into place which nullifies the outwards
>forces. Instead of NNNNNNNN you have NSNSNSNS, so it evens out to
>nuttin-ish.
>
>Dave Hinz
Thanks. Makes sense.
--
Alex
Make the obvious change in the return address to reply by email.