LED Flashlight Review
 

Several months ago I reviewed a LED flashlight that used a magnet
sliding through a coil to generat electricity. There were posts that
stated that some Chinese LED flashlights on the market were fakes using
button cells that could not be recharged. The moving slug was just put
in to look good. The one I bought from PRO Hardware was legitimate and
has worked perfectly for three months with very little charging
required. One way to identify a good moving-magnet flashlight is to
put it near some paper clips or such. The magnet is so powerful that
the clips will jump at the flashlight and stick to the side. The
flashlight in question is 7 inches long is made of clear plastic and
has a black ring at the front. It is PRO Hardware number 736N5950. I
imagine that there are lots of them around and they would make good
stocking-stuffers for those of the Kris Kringle persuasion (not that
there's anything wrong with that).

LED Flashlight Review
 

About four months ago,I saw some of those shake em up magnet flashlights
in the sporting goods department at the Wal Mart store.I shook a few of
them up,but none of them showed any light.
cuhulin

LED Flashlight Review
 

ve3... wrote:
Several months ago I reviewed a LED flashlight that used a magnet
sliding through a coil to generat electricity. There were posts that
stated that some Chinese LED flashlights on the market were fakes using
button cells that could not be recharged. The moving slug was just put
in to look good. The one I bought from PRO Hardware was legitimate and
has worked perfectly for three months with very little charging
required. One way to identify a good moving-magnet flashlight is to
put it near some paper clips or such. The magnet is so powerful that
the clips will jump at the flashlight and stick to the side. The
flashlight in question is 7 inches long is made of clear plastic and
has a black ring at the front. It is PRO Hardware number 736N5950. I
imagine that there are lots of them around and they would make good
stocking-stuffers for those of the Kris Kringle persuasion (not that
there's anything wrong with that).

The two that I tried provided a weak light with limited electrical
storage given the size of the flashlight. In an emergancy you want
light shining on the object an hand without having to periodically
shake the light. It's really little more than a gadget for xmas.

LED Flashlight Review
 

) writes:
ve3... wrote:
Several months ago I reviewed a LED flashlight that used a magnet
sliding through a coil to generat electricity. There were posts that
stated that some Chinese LED flashlights on the market were fakes using
button cells that could not be recharged. The moving slug was just put
in to look good. The one I bought from PRO Hardware was legitimate and
has worked perfectly for three months with very little charging
required. One way to identify a good moving-magnet flashlight is to
put it near some paper clips or such. The magnet is so powerful that
the clips will jump at the flashlight and stick to the side. The
flashlight in question is 7 inches long is made of clear plastic and
has a black ring at the front. It is PRO Hardware number 736N5950. I
imagine that there are lots of them around and they would make good
stocking-stuffers for those of the Kris Kringle persuasion (not that
there's anything wrong with that).

The two that I tried provided a weak light with limited electrical
storage given the size of the flashlight. In an emergancy you want
light shining on the object an hand without having to periodically
shake the light. It's really little more than a gadget for xmas.

Well it depends. An ongoing emergency, obviously you want a constant
light since there'll be no other.

But "emergency" can mean a blown fuse, and a need for a light to check
which one. Or checking something in a dark corner merely because the light
isn't good there. The advantage of having a flashlight that doesn't use
batteries is that one can just crank it up when needed to get that bit
of light. Time will tell whether the current crank or shake lights serve
that purpose in the long run.

I can remember with incandescent flashlights, how often when I actually
needed the light the batteries were dead. Maybe bad shelf life, but
I'm beginning to think the switches had too little resistance in the
off position, allowing for a constant current drain without enough for
the bulb to light. So you'd not notice that the batteries were draining,
but the batteries were gone when you needed them.

This is amplified by the bulbs themselves not putting out much light
with the lower battery voltages. When I got an LED adaptor for my
Maglite last year (it just fits in where the bulb used to go), I started
off with batteries that had seen use with the incandescent bulb, so they
were worn out at least partially. The light kept going, until I realized
that "oh, the light has become weak, time to change the batteries". The
incandescent bulb would have changed color and put out less light long
before that.

And of course, the bulbs would break or burn out, and then you'd be
stuck with no light. At least LED flashlights aren't going to have the
breaking problem, and it will be some time before they burn out.

So on some level, the cranks and the shakers may be less necessary with
LED flashlights, since they work better with lower voltage. But then,
that's why the cranks and the shakers have come along at this time, because
the LEDs work better than the incandescent with lower voltage and current.

Michael

LED Flashlight Review
 

There is always candles for emergency light.And they can be stored
forever too.
cuhulin

LED Flashlight Review
 

Stumbling around on the internet,I saw this website,
www.flashlightreviews.com

I guess some of those magnetic shake and bake flashlights are better
than some other magnetic shake and bake flashlights.
cuhulin

LED Flashlight Review
 

Cuhulin,

Hence that that old time reminder
Pre-Flash-Light} aka : hand-torch
Shake It -but- Don't Break It ! :o)

by the light of the silvery led ~ RHF

LED Flashlight Review
 

Brenda Ann wrote:


I find those sizes very hard to believe. Even a one farad capacitor
is pretty large and in some cases, larger than an average flashlight.


Depends upon the working voltage. I had seen 1 farad caps 20 years ago
that were not much larger than a couple of small mercury cells. I'm
sure they've gotten them even smaller by now.


True. I forgot about the voltage aspect, as I was thinking about the
sizes used by the auto sound nuts in their vehicles. A one Farad size in
those applications is about the size of a one litre (about a US Quart)
container. I can't imagine a hand shaken flashlight would make enough of
a voltage to allow a size reduction of any great magnitude..

I'm probably wrong, so please post any more information you may have
access to.

As for those car stereo lunatics, I think they will all be deaf after a
few years. I can hear their bloody bass five cars away. How can the use
of headphones by a car driver be illegal when that megawatt idiocy is
allowed to continue?



mike

LED Flashlight Review
 

On Nov 26, 12:06 am, "Brenda Ann" wrote:
--
Say no to institutionalized interference.
Just say NO to HD/IBOC!

"m II" wrote in messagenews:bIbah.9746$Hp3.7156@clgrps13...
ve3... wrote:

'''''''''''''''''''''''''''''''''''''''''''''''''' '''''''''''''''''''''''''*'''''''''''''''''''''''' ''''''''''''''''''''''
On Sept 10, 2006 wrote, "The button cells are
actually "supercaps". They are in the range of 1 to 10 farads."
Apparently the "supercaps" hold their charge over a long period of
time.

I find those sizes very hard to believe. Even a one farad capacitor is
pretty large and in some cases, larger than an average flashlight.Depends upon the working voltage. I had seen 1 farad caps 20 years ago that
were not much larger than a couple of small mercury cells. I'm sure they've
gotten them even smaller by now.

BAD,

"The existence of a One-Farad Capacitor {Super-Cap}
is due to modern materials development and is now
useful for general experiments."
Size : This Capacitor is only 2.9cm in diameter and 2.5cm high.
http://en.wikipedia.org/wiki/Farad
http://electronics.howstuffworks.com/capacitor2.htm
http://www.sargentwelch.com/product....,+One-Farad_E_

Supercapacitors "Super Caps" {It's In There}
http://www.findarticles.com/p/articl...09/ai_n9278003
http://www.uoguelph.ca/~antoon/gadgets/caps/caps.html

LED Flashlight Review
 

m II wrote:

As for those car stereo lunatics, I think they will all be deaf after a
few years. I can hear their bloody bass five cars away. How can the use
of headphones by a car driver be illegal when that megawatt idiocy is
allowed to continue?



mike


Well, since you've asked...


Many communities have passed ordinances, mostly for noise control,
making the use of such car stereo's illegal. The criteria are centered
on the distance from the vehicle that the sound is still audible. In
Aurora, if a car stereo is audible 50 feet from the vehicle (which would
be a little less than 5 cars away), the driver can be cited, and the
vehicle impounded.

Similar ordinances have been passed in a number of communities in and
around Chicago.

But that's only the tip of the Fletcher-Munson curve.

There has been legislative debate downstate, as well as in
communities around the state, about the long term safety concerns, not
unlike concerns surrounding headphones, of such high pressure sound
levels in cars while driving. Competition grade stereos have resulted in
permanent hearing loss from the extreme overpressure produced by huge
subwoofers firing into the cab. With the windows closed, the
overpressure produced by tight bass notes or kick drums can (and
frequently have) rupture ear drums. Where such debate stalls, is that
the safety aspects of driving with music playing are centered on the
ability to hear emergency vehicles, horns, tire screeches, and oncoming
traffic...all sounds with huge midrange components. Such sounds are
still audible though high bass content. One "expert" explaining to
legislators actually made the argument that a factory radio at high
levels is more isolating to ambient sounds than a customized vehicle's
twin aftermarket subwoofers. Not unlike (mandatory radio content,
here....) trying to hear the Liberty Net through the noise on Saturday
nights. If the stereo is on in the other room, and the bass is thumping,
you have less trouble hearing your RX-320's output, than you do if the
atmospheric noise is high. Why? Because the atmospherics and the LibNet
voices are competing for the same spectra, where the ear is most
sensitive...the bass is not. Take out the upper end on the atmospheric
noise, and intelligibility of voices is increased. Subwoofers in cars
are not competing for intelligibility with sirens, horns and the guy in
the car behind you accompanying his gesticulations with spontaneously
assembled language.

And there is another phenomenon at play. The truth is, that inside
the car, those subwoofers simply don't seem as loud to the driver, as
they do to YOU, sitting outside the car. Bear in mind that the guy in
the car 5 vehicles away with his windows open has actually created a
kind of two stage bandpass box for his subs...the enclosure in which
they're mounted is one, but the vehicle cab space into which they fire,
is actually another. And with a window open, when that over pressure
spews out, it does so through a crude bass port and becomes a wave
front. By the time it reaches you 5 cars away, that wave front is
defined, and has subtle directional components. Inside the cab, however,
it's merely overpressure that's uniformly impinging on the ears of the
driver without directional components.

These directional components, though very subtle, and often
consciously indistinct are at the very heart of how the mind processes
audio for the auditory sense. Humans here in stereo. The mind processes
in stereo. Without stereo field information, even highly defined audio
becomes indistinct, and can be lost in ambience. This is how you can
carry on a conversation in a crowded room. The mind allows focus on a
single voice among hundreds through recognition parameters...timbre,
tone, resonance as well as patterns of rhythm, and anomaly...and spatial
orientation. Using the stereo soundfield, the mind processes the subtle
phase differences from a single source, and locates it in space. So, in
a crowded room of hundreds of voices, one can identify and follow a
single voice by it's sound AND location.

Put your finger in one ear, take away that stereo spatiality
reference, and see how difficult it can become.

This phenomenon, btw, is what's behind the use of stereo detectors
in communication receivers. Military and commercial receivers have been
doing this for some time, because it makes it much easier for code
receivers to copy on crowded bands. Similar success has been realized in
SSB and AM modes.

Back to the issue, though...in the car, without the spatial
references, the mind finds the overpressures of bass to be less
objectionable, even less audible, than you do outside the car, with a
defined, and spatially locatable wavefront.

Literally, it's more irritating for you, because it's more difficult
for the mind to ignore.

And armed with expert testimony in this, the industry has stalled
legislation that would ban high powered stereos in cars, as was done
with headphones.

If you ever have the opportunity to drive a vehicle equipped with a
high watt stereo and big subs, you'll be surprised, at the end of the
drive, at how comfortable you are with the level, and how loud it is for
the rest of us outside the car.