Neodymium magnets

[Roff]

back to my original question, how do I find out the actual field strength of magnets? can't seem to find it anywhere... perhaps I would have to buy a meter and try it out on various ones

The K&J Magnetics site posted by RadioRon has specs like this:

DY0Y0-N50

Dimensions: 2" dia. x 2" thick
Tolerances: ±0.003" x ±0.003"
Material: NdFeB, Grade N50
Plating/Coating: Ni-Cu-Ni (Nickel)
Magnetization Direction: Axial (Poles on Flat Ends)
Weight: 27.2 oz. (772 g)
Pull Force: 285.0 lbs
Surface Field: 7880 Gauss
Brmax: 14,500 Gauss
BHmax: 50 MGOe

Do you need something different?

 

[solis365]

oh, missed that one, thanks (caught up in debate, lol)

surface field is exactly what i want

 

[audioguru]

Those magnets are so powerful that they say if your skin gets pinched between two of them then they can't be pulled apart.

 

[Cotowar]

A wind generator isnt a bad idea. and you didn't really say how big the project you had in mind was going to be, so I went with something small because its cheaper.

The shake-able flashlights are not really run off batteries. This defeats the purpose of the "Shake". Also, depending on what kind you buy, some are indeed quite bright, and the light output isnt designed to last for hours upon hours. All you have to do is shake it a little though and it will be good to go. They are designed to save you from buying batteries, or having dead batteries when you need the flashlight.

 

[solis365]

yeah i didnt really specify because i wasnt sure, needed to find magnet strengths so i could see what was possible. like i said above, the more i think about it the more i want to design something around 100W

 

[audioguru]

The shake-able flashlights are not really run off batteries. This defeats the purpose of the "Shake".

Here is an Instructable with photos of a fake shake-light:
http://www.instructables.com/id/Salvaging-a-$1-Fake-Shake-Light/

It has two coin batteries that light its LED dimly.

 

[audioguru]

Also, depending on what kind you buy, some are indeed quite bright, and the light output isnt designed to last for hours upon hours. All you have to do is shake it a little though and it will be good to go.

A review of the expensive shake-light made by guess who says it is not good:

 

[gaetan8888]

Hello

Here's a link to a diy double magnets generator, you may find somes more ideas.

DIY 1000 watt wind turbine


Here it's a link to a place to buy parts;

**broken link removed**


For myself I did use neodynium magnets from old big computers hard disks.

Bye

Gaetan

 

[Cotowar]

A review of the expensive shake-light made by guess who says it is not good:

Here is what I'm talking about.
ShakeLight:60 battery-free LED flashlight magnet powered shake light

you use capacitors, not batteries, to store the charge. The capacitors have a slow drain rate because the load is almost nothing, and thus you can light the LED for quite a while before you need to recharge it.

 

[audioguru]

Here is what I'm talking about.
ShakeLight:60 battery-free LED flashlight magnet powered shake light

you use capacitors, not batteries, to store the charge. The capacitors have a slow drain rate because the load is almost nothing, and thus you can light the LED for quite a while before you need to recharge it.

The same review that I posted for the ShakeLight 20 tested the ShakeLight 60.
They are almost the same. The capacitor discharges quickly. After less than 1 minute the light was half. In 5 minutes the light was about 8% and dim. In 30 minutes the light was very dim and in 60 minutes the light was almost zero.
**broken link removed**

 

[Cotowar]

The same review that I posted for the ShakeLight 20 tested the ShakeLight 60.
They are almost the same. The capacitor discharges quickly. After less than 1 minute the light was half. In 5 minutes the light was about 8% and dim. In 30 minutes the light was very dim and in 60 minutes the light was almost zero.
**broken link removed**

I should buy one then. They claim that I can use it for an hour after one minute of shaking, and that it will output enough light for me to work by. If this is not true, I should try it anyways, hurt myself, and sue the hell out of them for false advertisement...LOL.

PS, my bad for believing what was written on the box.

 

[audioguru]

I should buy one then. They claim that I can use it for an hour after one minute of shaking, and that it will output enough light for me to work by. If this is not true, I should try it anyways, hurt myself, and sue the hell out of them for false advertisement...LOL.

PS, my bad for believing what was written on the box.

Where is the head office of ShakeLight? They don't have an address. Their e-mail is xxx.za so where is za? Africa?

Go to Africa and sue them for false advertising. What are your losses from their false advertising? It is not their fault if you hurt yourself in the dark.

 

[Cotowar]

Where is the head office of ShakeLight? They don't have an address. Their e-mail is xxx.za so where is za? Africa?

Go to Africa and sue them for false advertising. What are your losses from their false advertising? It is not their fault if you hurt yourself in the dark.

It is their fault for me hurting myself in the dark while using their light if im under the impression that their light would be adequate to prevent me from hurting myself. This is indeed the case as stated on the box, as well as the website. They say by me shaking vigorously for 60 seconds, I will have enough light to work by for 1 hour. They do claim it is more like moonlight than incandescent light, which does not bother me. After all, doesn't everyone work on their projects by light of the moon?

Regardless, if they claim I can use their product for 1 hour after only 60 seconds of shaking, then I damn well better be able to use it for 1 hour. If I can't someone is getting a law suit.

 

[blueroomelectronics]

Good luck with the law suit. You'd have to prove damages and it would cost a fortune to take through the courts. Actually it would be unlikely to get that far.
Sue the HHO people it's outright fraud.

 

[solis365]

i had an old russian military surplus battery-less flashlight, basically it had a lever that you squeezed, which turned a gear, which turned a smaller gear really fast, which turned some magnets to generate current

although it used an incandescent bulb, and im sure there were no rectifiers and probably no caps; just pumped straight random AC to the filament, because the faster you pumped it the brighter it got, and if you didnt squeeze it the light died after < a second.

and it was noisy... no wonder the russian military.... ahh, i shouldnt. i shouldnt.

however, with some caps and such that thing might get interesting...

 

[audioguru]

We can buy crank powered lights and radios. You crank it for a few minutes and it is supposed to work for a few more minutes from the charge.