Werner Almesberger
2017-02-12 02:22:14 UTC
A long time ago, we discussed battery contacts:
http://lists.en.qi-hardware.com/pipermail/discussion/2016-March/011018.html
http://lists.en.qi-hardware.com/pipermail/discussion/2016-March/011019.html
I eventually settled for the Keystone 5225 / 5203 pair.
Let's see how this turned out.
First, we need a place to put the contacts, a sort of pockets at
the ends of the battery compartment where the case holds the
contacts in place.
After an embarrassing start that 1) was prone to cracking, and
2) would have required teleportation for proper assembly ...
Loading Image...
... I eventually came up with a more solid solution, one that
doesn't require applied Sci-Fi:
Loading Image...
Loading Image...
In the latter image, we see from left to right:
- the side wall,
- a step in the side wall, leaving room for the bottom shell,
- the rear wall of the contact pocket, supporting the contact and
leaving room for the cable,
- the space where the base plate of the contact goes,
- the front wall of the contact pocket, with an opening for the
spring (minus) or nipple (plus)
With the battery inserted, it looks like this:
Loading Image...
Prying the battery from the compartment can be a bit difficult, but
one can eject it by simply slapping Anelok into one's palm. I still
have to test if the spring tension is sufficient for preventing
disconnection when the device falls to the floor or such. In any
case, it's easy to adjust the length of the battery compartment.
This all may look pretty, but does it actually work ? Let's find
out ...
Loading Image...
It does indeed !
Now, what started the whole discussion was the idea that one could
design the contacts such that a reversed battery would not make
contact, and thus couldn't cause trouble:
http://lists.en.qi-hardware.com/pipermail/discussion/2016-March/011017.html
Let's see what happens ...
Loading Image...
This is what the plus side contact looks like when the battery is
reversed:
Loading Image...
And here is it with the correct orientation:
Loading Image...
It looks a little tight, perhaps 100 um. The wall has a thickness of
1.2 mm, so I may still be able to make it slightly thinner before it
starts to crumble.
- Werner
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http://lists.en.qi-hardware.com/pipermail/discussion/2016-March/011018.html
http://lists.en.qi-hardware.com/pipermail/discussion/2016-March/011019.html
I eventually settled for the Keystone 5225 / 5203 pair.
Let's see how this turned out.
First, we need a place to put the contacts, a sort of pockets at
the ends of the battery compartment where the case holds the
contacts in place.
After an embarrassing start that 1) was prone to cracking, and
2) would have required teleportation for proper assembly ...
Loading Image...
... I eventually came up with a more solid solution, one that
doesn't require applied Sci-Fi:
Loading Image...
Loading Image...
In the latter image, we see from left to right:
- the side wall,
- a step in the side wall, leaving room for the bottom shell,
- the rear wall of the contact pocket, supporting the contact and
leaving room for the cable,
- the space where the base plate of the contact goes,
- the front wall of the contact pocket, with an opening for the
spring (minus) or nipple (plus)
With the battery inserted, it looks like this:
Loading Image...
Prying the battery from the compartment can be a bit difficult, but
one can eject it by simply slapping Anelok into one's palm. I still
have to test if the spring tension is sufficient for preventing
disconnection when the device falls to the floor or such. In any
case, it's easy to adjust the length of the battery compartment.
This all may look pretty, but does it actually work ? Let's find
out ...
Loading Image...
It does indeed !
Now, what started the whole discussion was the idea that one could
design the contacts such that a reversed battery would not make
contact, and thus couldn't cause trouble:
http://lists.en.qi-hardware.com/pipermail/discussion/2016-March/011017.html
Let's see what happens ...
Loading Image...
This is what the plus side contact looks like when the battery is
reversed:
Loading Image...
And here is it with the correct orientation:
Loading Image...
It looks a little tight, perhaps 100 um. The wall has a thickness of
1.2 mm, so I may still be able to make it slightly thinner before it
starts to crumble.
- Werner
_______________________________________________
Qi Hardware Discussion List
Mail to list (members only): ***@lists.en.qi-hardware.com
Subscribe or Unsubscribe: http://lists.en.q