4 Feb
2014
4 Feb
'14
5:10 p.m.
On 03/02/14 21:20, Tony Duell wrote:
Are those the ones with a core that's sturated by
a permanent magnet, and
which is desaturated when the key is pressed so that there is increased
coupling between 2 'widnigns' on said core?
Yep, that seems to be the design principle. There are two U-shaped leads
(four terminals) -- drive and sense -- and a core-memory-sized ferrite
ring in the hoops, like this:
___ ___
/ \ / \
| | | |
| XXXXXX |
| | | |
The "X" is the ferrite ring.
I might be able to fix the switch if I can remove the wire hoops and
find a suitable replacement ferrite, though that seems at least as
difficult (possibly moreso) as finding replacement keyswitches.
I'm actually tempted to get a Nd magnet and a few small ferrites and try
this on a breadboard. Seems like it might be a fun experiment to do in
an evening and then write up (or demonstrate in a video).
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/