Question about Magnetic Ring Mode Switching

[Bladedude]

I've seen a lot of led flashlights out right now that have magnets in the mode selector ring.

My question is if these lights are subjected to magnetic fields or come in contact with magnets will it de-magnitize the flashlight's magnets or cause them to work improperly? :thinking:
If so, what strength magnets are we talking here?

Thanks all

 

[ASheep]

Based on some quick testing I just did with a rare earth magnet after reading your question, yes coming within about 5cm of a strong magnet will cause a Nitecore SR3 to change modes, and possibly cycle onto strobe mode, but after the field is removed, it resumes normal operation. A normal fridge magnet will trigger the switch only if put in direct contact with the body.

 

[Bladedude]

Thanks ASheep, glad to know that no permanent damage was done:twothumbs

 

[csshih]

the magnets in question are indeed neodymium 'rare earth' magnets in the selector rings. they do not demagnetize easily, and probably will never under normal use.

unless you subject your lights to temperatures above 80C.. but that'd be the least of my concerns at that temperature!

 

[ASheep]

Bladedude, No problems, I was willing to take the small risk of it destroying something for scientific purposes! :thumbsup:

the magnets in question are indeed neodymium 'rare earth' magnets in the selector rings. they do not demagnetize easily, and probably will never under normal use.

unless you subject your lights to temperatures above 80C.. but that'd be the least of my concerns at that temperature!

I had a funny feeling they were neodymiums in the SR3 and similar selector ring lights, they're pretty much the only thing that small that can generate enough magnetic flux to actuate a switching system reliably. And yeah, at 80C the reliability of your magnets is the least of your concerns...
On a side note, you can use your SR3 or other selector ring lights to pick up small magnetic objects like glasses screws... very useful!

 

[kramer5150]

FWIW, I was not able to get an Xtar D30 to mode switch with a small neodymium magnet. I think this light uses a magnetic switch, I could be wrong though. I use these small powerful magnets to mount my lights around the house.

 

[AnAppleSnail]

Based on some quick testing I just did with a rare earth magnet after reading your question, yes coming within about 5cm of a strong magnet will cause a Nitecore SR3 to change modes, and possibly cycle onto strobe mode, but after the field is removed, it resumes normal operation. A normal fridge magnet will trigger the switch only if put in direct contact with the body.

You have to defeat a neodymium magnet's field when it's VERY close to the magnetic reed switch. It can be done, but it'd be hard. Generally you won't encounter magnetic fields that'll cause trouble. MAYBE if you're around a BIIIIIIG generator or something you could get weird stuff, but then you'll have trouble holding onto your light - batteries have steel cases.

 

[FrankJ]

"On a side note, you can use your SR3 or other selector ring lights to pick up small magnetic objects like glasses screws... very useful!"

Good point! If I ever get a light with this type of UI, I'll have to make sure to never put down near my bench grinder.

 

[Brasso]

These magnetic selector rings just don't inspire confidence with me.

 

[Bladedude]

Thanks everyone for all the info.
It's cool that you can use these lights to pick up small metal objects! Might have to get me some neodymium magnets to mount my lights like Kramer5150 cuz that's a good idea.:twothumbs Its also nice to know the magnets will hold up before other things fail like batts. I have a Sunwayman M40c on the way!:naughty: Thanks again!