Turn your old hard drive into a flashlight wall mount

We all know that when an old laptop battery no longer manages to keep your computer running for a very long time, there could still be a few individual cells that are worth salvaging. This, however, is not without its risks; but there are other parts of a computer that could continue to serve a purpose in the homes of flashaholics. Salvaging the neodymium magnet form a discarded hard drive should be a risk-free operation as long as you keep your credit cards at a safe distance and avoid getting your skin caught between the magnet and a metal surface.

The onces I have seen all have holes in them which makes it easy to screw them onto the wall. Even when covered with a layer or two of duct tape, they can easily hold a single AA light (with a battery installed).

The photos are proof of concept rather than a permanent solution - I'm sure it could be done in a much more aesthetically appealing fashion.
The donor in this case had a storage capacity of a whopping 850 MB!! I wonder if it is older than the youngest members on this forum...

Nice! Is the general consensus that the magnet won't mess is the flashlight drivers then?

I've got 6 of the suckers but none of them have mounting holes! Will have to get creative... Maybe a row glued to the back of a strip of plastic to hold the clips of my keychain lights...

Got some of these on e-Bay a few weeks back...snapped together and pinched my finger and was treated to some bleeding.

Did it again a few days later.

Powerful toys that don't ask first before biting.

Here's a force calc to help avoid dangerous sizes:

http://www.kjmagnetics.com/calculator.asp

gravelmonkey said:

Nice! Is the general consensus that the magnet won't mess is the flashlight drivers then?

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I don't think there is consensus among laymem (is there ever?) and if there are experts out there who have a definite answer, it seems it takes more than a quick Google search to find them.

There is a rather strong magnet in the tail end of the Xtar WK21 Meteor and although it is not close to the flashlight's electronics, it is rather close to the protection circuit of the Li-Ion cell (if you use a protected recahrgeable one) and I haven't read anything here about damage done by magnets to protected cells.

Magnets do affect some flashlight drivers. I do not know exactly why. In general, the magnet is sticking to the steel cell inside the flashlight, since the body is aluminum.

It would definitely affect lights with magnetic control rings, but could also be fun as rotating the entire light while hung on the magnet should control the intensity.

I wonder if the magnet could pull an inductor off the board? Maybe after repeated use or something.

I have small magnets that were advertised as being the rare earth type. They're pretty strong for how small there.



It looks like the magnets do affect the switching frequency of at least some buck and boost drivers. It tends to increase when the magnets are floating overhead. As soon as they're pulled away, it goes back to normal.

The linear drivers and mode switching/PWM micro-controllers I tested seem to work fine, though.

Mike S said:

I wonder if the magnet could pull an inductor off the board? Maybe after repeated use or something.

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I have been wondering that too, but I painted my concern in broader strokes: "What if the magnet pulls on some small but important component?" I have no idea which components found in the esoteric regions of a flashlights are attracted to magnets, or how securely they are mounted.



According to this site

http://techtips.salon.com/destroying-electronics-electromagnets-26584.html

a powerful electromagnet can cause problems

When you expose a piece of electronic equipment to a powerful electromagnet, it can rip away the collections of electrons that constitute the programs which run the device's circuitry.

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So far, nothing bad has happened to my Zebralight SC52, which spent last night on my improvised wall mount.

I will report back in a month or so if nothing out of the ordinary happens to it, or as soon as I notice signs of adverse effects.

Magnets will cause torches with a magnetic control ring like it did to my Sunwayman V10 Ti + To go haywire but it returns back to normal when moved away from the magnetic field mine was only exposed to the magnetic field very briefly so I don't know what would happen if it was exposed for an extended time and there is no way I am going to risk it by testing to see if the effect is reversible I just make sure it doesn't go any where near powerful magnets

Mike S, Swede74:

I doubt even a neodymium magnet would actually pull an inductor -unless your light has suffered from a few hard drops- but if it happened, it would pull the board traces with the inductor. You can always keep the magnet away from the driver and towards the back end of the light to be on the safer side.

I would worry more about magnetizing the battery and what could stick to the battery -possibly shorting it- when it's not inside the light.

Magnets can cause weird things to happen, even cause your driver to burn due to an excessive current, but I have not seen reports of this so far. Doesn't mean it never happened, but play safe...

Swede74 said:

So far, nothing bad has happened to my Zebralight SC52, which spent last night on my improvised wall mount.

I will report back in a month or so if nothing out of the ordinary happens to it, or as soon as I notice signs of adverse effects.

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It's now a month later, and I'm reporting back as promised. (And bumping my own thread in the process :naughty

I still have seen no signs of harm done to the light or the installed AW 14500 by the magnet. It has spent at least 400 hours attached to the magnet, and has been removed / attached at least 50 times.

The only conclusion one can draw with certainty is that nothing bad has happened to my particular specimen - I can only hope that if others choose to let their lights get intimate with magnets, their sagas will end as happily as mine did.

Nice idea but, the duct tape seems a bit tacky.
How about a nice big piece of heat shrink tubing? :shrug:

Windup said:

Nice idea but, the duct tape seems a bit tacky.
How about a nice big piece of heat shrink tubing? :shrug:

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I could try that, but because of the shape of the magnet I don't think it would look much better. It's probably strong enough to hold a flashlight even if mounted inside a small wooden box, like a matchbox, so for someone with the right tools, skills, time and motivation there are alternatives.