Inova 24/7 magnetically sensitive?

Canuke

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I just picked up one of those Faraday shakelights (currently $9.99 instead of $29.99 at Big 5 sporting goods in Sherman Oaks) and was testing it to see how strong the magnetic field outside of it was. So far, it can just about hold itself onto the bottom of my steel bedframe, affect a 13" TV from just under a goot away, and a compass needle responds from as much as two and a half feet away.

The strange thing I found was that it triggers my Inova 24-7 from its OFF position, either into the #2 (four white dim) or the #8 dial settings, when the magnet is up against it.

Any idea what is happening here? Does the 24/7 use Hall effect switches or something like that? I've read in other posts that the 24/7's electronics can be a bit touchy, so I've been keeping the two apart since.

In a separate question, could shakelights of this design be enshrounded in a ferromagnetic sleeve to shield it? If so, would that compromise its generation capacity?
 

The_LED_Museum

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Well, somewhere around here, I have a Nightstar II shake light I wanted to try this with, but I have no idea whatsoever where I last put it. /ubbthreads/images/graemlins/frown.gif So I guess this little experiment will have to be up to somebody else.
 

TCG

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I noticed this as well. When I fist got the 24/7, I noticed that a magnetic mount was listed as a optional accesory. Sounded like a useful thing, so I grabbed a magnet and thought about making a magnetic holder for it. Couldn't get the magnet close enough to mount without causing the light to activate. Gave up and forgot about it. Don't konw what inside that is getting triggered by the magnet.
 

Canuke

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Well, I just took my compass and held it next to the 24/7, and there is undoubtedly a magnet in there. So, instead of using contact switches, it's using either reed or Hall effect switches to determine the position of the rotor, possibly to minimize wear and intermittents.

So, I'm willing to bet that residual magnetization of something in or around the unit (like the clip on the back) might cause all kinds of strangeness in the 24/7's operation... and if so, then perhaps a tape head demagnetizer might be just the ticket to exorcize gremlins in one (UNLESS that built-in magnet is of some less-than-stable magnetic material, like ordinary alnico, and won't take well to being demagnetized!) You might want to pull the battery before trying that, though. The usual disclaimers apply, I am not responsible for the results of said experiment which I have not tried for myself /ubbthreads/images/graemlins/naughty.gif
 

The_LED_Museum

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[ QUOTE ]
Canuke said:
Well, I just took my compass and held it next to the 24/7, and there is undoubtedly a magnet in there.

[/ QUOTE ]
I took one of my 24/7s and waved it about directly in front of my computer monitor (since I don't have a good compass), looking for color changes or distortions in the picture, and got nothing. Then I tried to deflect the compass needle in my Dostone 5-LED headlamp, and got no response there either. But the Dostone's compass has a bubble in it, so it can't even find magnetic north. /ubbthreads/images/graemlins/mad.gif
So if the 24/7 has magnets in it, they must be of very low magnetic power, to not deflect the compass needle or create color changes/distortions when waved direct against the face of a CRT.
 

JJHitt

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I just rotated a magnet (the one in my Nightstar) 360 degrees around center of the face of the 24/7 (as if the magnet was an hour hand on a clock face) and sure enough: each and every mode came on in turn, just as if I had rotated the head.

I would not try a degaussing coil on the 24/7, it might kill it.
 

Canuke

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I would not try a degaussing coil on the 24/7, it might kill it.

that, and every credit card within four feet /ubbthreads/images/graemlins/ooo.gif, that's why I like my old Realistic tape head unit, much smaller field.

The magnets are very small with a dense field, so I'd expect that they extend very little outside the unit itself. The magnetic actuator design makes sense, as it allows the 24/7 to be completely sealed up inside. From what I can see, there are more than one magnet inside the actuator ring.

The Faraday light that started all this also uses a reed switch for on/off, presumably for the same reason - waterproofing. I found that out when messing with the front lens, and discovered how to remove the entire guts; the reed switch sticks out from the rest of the assembly, up towards the spot on the outer case where the switch is.
 

The_LED_Museum

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Just a FYI: The 24/7 is not entirely watertight. I killed one for three days after throwing it in a bathroom sink for about three minutes.
The web page I put up about the 24/7 is right here if you're interested.
 

lightemup

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I'm interested to hear about the OD 24 / 7 too Craig as I have a yellow 24 / 7 and plan on getting an OD 24 / 7.

Also, I give you a standing ovation for the great service you provide through your accurate and insightful reviews /ubbthreads/images/graemlins/thumbsup.gif I'll be sure to go through your site with a fine comb now that I am just being awakened to the benefits of the LED!

Cam
 

The_LED_Museum

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[ QUOTE ]
Canuke said:
Craig, I checked the review, and in it you said you planned to test the OD green to see if it was watertight... did that one flunk too?

[/ QUOTE ]
O o, congratulations, Iiiiiii'mmmm busteeeeed!!!
I never got around to doing that test...shame on me!!! /ubbthreads/images/graemlins/mad.gif /ubbthreads/images/graemlins/mad.gif /ubbthreads/images/graemlins/mad.gif
Let me try that now and see what happens...BRB...Ok, I dropped it in a bathroom sink full of water at about 80°F for about three minutes, drained the sink, and dried off the outside of the light with some toliet paper. As before, I opened the battery door, dumped out the battery, and examined the inside of the battery compartment - looks dry in there. Checked all the functions, that looks fine too. But I didn't start having problems with the yellow unit for several minutes - it performed as it should and then I started typing web material before it began to malfunction.
About ten more minutes have gone by now (I pulled it out of the sink at 9:56am and it's now 10:12am) and still no malfunctions.

(Edit)
It's now 10:40am and the 24/7 is still functioning correctly.

(Edit)
It's now 12:31pm and there are still no problems to report.
 
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