Talk:Mechanically powered flashlight

Untitled

Website?

Got one. Check the main page.  :) - Lucky 6.9 20:04, 27 July 2005 (UTC)

ANyone got one of these, are they any good, is the light bright?

They're alright. It more or less works the way it's advertised, so it'd be really useful during a flood or black-out or whatever. The light isn't terribly bright, and it's kind of annoying to shake it all the time, though, so it's not something i'd use for every-day stuff.

I have one myself. They're great for the emergency preparedness kit that the U.S. Dept of Homeland Security states people should have, in case of civil unrest, natural disasters, terrorist attacks. Martial Law 22:31, 8 September 2006 (UTC)

The ones you find at ACE Hardware in the US for around $5 are cheap imitations. I bought one, having never seen a real one up close, and after opening the box, immediately noticed it contained 2 LITHIUM BATTERIES. Those died in a week with VERY limited use. Now to even get the LED to glow I have to shake it for 2 minuets and even then it barely glows. If you are looking for one, do not buy the cheap ones at ACE. 69.208.155.61 05:19, 2 October 2007 (UTC)

new name

Just saw the commercial for these things and it appears they've changed the name of the flashlight to "Faraday's flashlight" or "Faraday flashlight".--Kross^Talk 07:44, 6 January 2006 (UTC)

You can now find them in the local Wal*Mart. Martial Law 22:34, 8 September 2006 (UTC)

Rename

There are other companies that sell similar products. We should rename the article and cover all types in one article, or else merge it with flashlight. — Omegatron 13:26, 13 September 2006 (UTC)

Steel mill explosion hazard ?

The description of this primitive lighting apparatus is unclear, but it seems obvious that a device that throws lots of sparks would be a serious risk in an explosive atmosphere. Small flint and steel sparkers are routinely used to ignite cigarette lighters, for example. I don't have access to either of the references, but could somebody who knows more about these primitive portable lights write a clearer description, and possibly address the explosive risk? Did the "steel mill" have a fine metal screen, or some other method of preventing flame propagation? --Reify-tech (talk) 13:26, 28 March 2012 (UTC)

"it seems obvious that a device that throws lots of sparks would be a serious risk in an explosive atmosphere."

Actually no. It's a fairly simple calculation (although sourcing the input numbers can be difficult) that if the temperature of a burning spark is greater than that needed to ignite a particular gas mixture, then it will ignite. However the corollary of this is that a temperature less than the ignition temperature will be safe. It will also be safe no matter what the density of sparks (and thus the brightness) if you crank the handle faster. Mind you, fitting a magnesium or titanium wheel (which burn at higher temperatures) probably would cause an explosion.

It's a bit harder to demonstrate this for suspensions of flammable powders, as you also need to consider the total energy in each spark particle (i.e. the particle mass for its temperature), not just the temperature. This is an important calculation as it defines whether a dust explosion can become self-sustaining. In the coal mine case, there's no real significance to this as the primary hazard is gaseous firedamp, not coal dust.

With the steel mill, the peak temperature is low enough that it won't ignite firedamp, over the concentrations typically found - as least in Westmorland mines. Andy Dingley (talk) 14:02, 28 March 2012 (UTC)

Thank you for your explanation! If what you say is true (and I have little doubt it is), could you add this explanation and some references to the article, either inline or as a footnote? I'm sure other readers have puzzled over this apparent contradiction. --Reify-tech (talk) 15:34, 28 March 2012 (UTC)

shake flashlight is fake !

It does not work !!! The old dynamo designs works well (I have both of them), but this shake flashlight is an typical example of deliberate fraud - so symptomatic four our present culture, politics and even society :( You probable noticed that in the meantime this crap silently disappeared from the market ... The trick was a simple one - there was an miniature lithium cell hidden inside, capable of delivering the few mA of current necessary for the crappy white LED diode. Of course only for limited time. And with the death of the - NOT rechargeble ! - battery inevitably came also the death of the flashlight, because even frantic shaking produced only a few seconds of weak light. The only effect of this "brilliant" invention was an short one time profit and a long term hill of rubbish ...

Well-made quality designs are available, and work quite well and reliably. There were also the fraudulent designs that you describe, and there was even coverage of them in the article, but somebody deleted their mention from the article a while ago. If you can find WP:RS, you're welcome to add coverage of the fraudulent designs. However, if you claim that all such designs are fraudulent, you haven't yet been fortunate enough to encounter a quality version that actually delivers what it promises, but I assure you that they do exist. Reify-tech (talk) 20:07, 24 July 2015 (UTC)

Yes, I agree. I think fraudulent primary cell designs are just a small part of the market. Perhaps they were more prevalent in the beginning when shake flashlights were sold by mail order. I have one I have used for 9 years. --Chetvorno^TALK 23:20, 24 July 2015 (UTC)