KBK update for Tuesday, 19th July
Another Micro Switch mystery is finally solved. Thanks to discoveries by “fricked” and Deepak Kandepet, we finally know how timed repeat works. Ever since discovering the existence of timed repeat switches (in SD Series, and now in the original SW Series), we have been faced with the question of how a (presumably) simple four-terminal switch could accommodate auto-repeat timing. Such keyboard are fairly unusual, and it has taken until now for someone to trace the circuit. Timed repeat switches are much simpler than expected: they are modified sink pulse switches where one output terminal sits at an intermediate voltage while the key is held, invisible to the encoder but able to be detected by a custom signal generator IC.
Details are given on the SW Series page under timed repeat.
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