I am reading about the various so-called Grama and other Shabbat switches developed in Israel for use in hospitals and security situations.

It seems that there was one solution created by Rabbi Halperin of the Institute for Science and Halakha, and a separate mechanism made by Tzomet.

I get the impression that they differ as to their methods, but I didn't find a detailed explanation of the different mechanisms and what the underlying difference of opinion was between the two.

Can anyone recommend a good source material for this? (I can get to the Otzar Hahokhma if necessary.)

  • Great question, I once attempted to understand the difference and it really seemed like the difference between Gatorade and Vitamin Water - different packaging and taste but same essential ingredients. The Kosher Switch though seemed to me to use a different mechanism. See the 7th question at their FAQ here, under ‘Halacha’ category, and links. – Oliver Oct 28 '18 at 18:02
  • R' Halperin passed away last week....may this be a merit to his neshama. – chacham Nisan Oct 29 '18 at 18:55
  • It's a good question. I don't remember the answer, but as far as I remember, they're using very different solutions (from Halaha perspective). A Posek might even say that one is OK, while the other isn't, and vice-versa. I assume you can read about Tzomet's mechanism in their website, or in one of the Tkhumin books. – Zvika Nov 6 '18 at 21:48

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