Wikipedia:Reference desk/Archives/Science/2018 February 21

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February 21

what is the U-shaped piece of wire in the front for?

example: https://en.wikipedia.org/wiki/File:Makita_DJV181.jpg All (newer) power jigsaws seem to have it. My old tool (90's) doesn't. What is this thing for? Thank you in advance 78.50.150.23 (talk) 12:40, 21 February 2018 (UTC)

As a general rule of thumb, modifications along the lines of "all the old ones don't have this, and all the new ones do, and I can't quite see what it does" are often safety-related, and result from either a regulatory change or an expensive lawsuit. (Rarely, changes to improve the safety of equipment result from manufacturer initiative—but that's not usually how capitalism works.)

In this particular instance, the bit of wire is a safety wire or guard wire (see the parts diagram and list, item 10). It's to help keep stuff – stray junk, power cords, the user – clear of the moving parts of the jigsaw. I expect a wire is used rather than a solid window because it's light, it's cheap, it's durable, and it won't get clogged up with sawdust. TenOfAllTrades(talk) 12:56, 21 February 2018 (UTC)

Thank you! I had downloaded like 3 manuals from different companies (Bosch, Einhell and Ryobi) but none had such a nice diagram. The purpose of the wire is not immediately obvious so I was wondering. Thanks again! 78.50.150.23 (talk) 13:28, 21 February 2018 (UTC)

It just kills me the old saw has become unusable because of a tiny part (blade pick-up clip) they for some reason chose to make from some brittle zinc or aluminium type stuff... and that I could probably machine myself -- if I had the tools 78.50.150.23 (talk) 13:40, 21 February 2018 (UTC)

What is a direct-view portable TV?

I don't have a lot of time when I'm at libraries to search for these things. But Wikipedia doesn't seem to have the information. Here is where I saw the term. At home, I try to stay away from unfamiliar sites.— Vchimpanzee • talk • contributions • 21:37, 21 February 2018 (UTC)

Philco Safari

• Literally, it's quite simple: it means it was a portable TV where you looked directly at the screen. Seems obvious now, but this wasn't how the previous ones had worked.

In particular, Sony's was the second portable TV (counting the well-known ones) and the first had been the Philco Safari [1]. This used a tiny tube, and to make it appear larger it was set inside the case, projecting onto a screen. To make the case more compact, that in turn had needed the tube to be pointed vertically and the image turned with a mirror. Sony achieved a couple of things: the screen was big enough width-wise to be visible when viewed directly, it was still short enough (the deflection angle needed to be big enough, despite the limits of tube technology) to not be a huge case and then it was still efficient enough to work as a portable set. Andy Dingley (talk) 21:59, 21 February 2018 (UTC)

Thanks for the intelligible reply Andy Dingley, could something be added to our History of television article about non-direct-view TV sets like these for example as there doesn't seem to be any mention at present? Alansplodge (talk) 13:02, 22 February 2018 (UTC)

That was my objective as well. Thank you. My first memory of Sony was of a very small TV in a restaurant.— Vchimpanzee • talk • contributions • 19:29, 22 February 2018 (UTC)