1.When is the flashlight invented?
2. How flashlight works?
3. What material to make the flashlight?
4. How many part the flashlight
has?
5. Battery guide
6. Bulb guide
7, About the reflector.
8. How to use a flashlight?
9. Where the flashlights are mainly made?
10. How to buy a flashlight or purchase mass flashlight?
11. Which manufacturer is suitable to you?
12. Why LED flashlight become popular?
13. LED introduction
14. How to choose batteries for LED flashlight?
15. How to choose flashlight for sepecial purpose?
16.IC circuit used in the flashlight?
and more……
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me

1) When
is the flashlight invented?

In the end of 18 century, the first battery-"voltaic
battery was born, and after about 90 years , the first "dry"
battery was invented. Almost in the meantime of the born of the battery,
in 1809, the first incandescent bulb was made and in about 1880, Edison
make the bulb long time and popular. Then, in1890s, the first flashlight was invented.

2) How flashlight
works?

Like other electric applliance, when the circuit of
the battery and bulb established. The flashlight works. When the electric
cuurent pass the filament of the bulb, the filament is heated and
become a light source. Today, the flashlight often have a reflector.
and modifying the distance of reflector to the filament of bulb will
bring you adjustable beam from spot to flood. Metal made flashlight
often use the flashlight barrel to establish the circuit.

3) What
material to make the flashlight?

In the beginning, the flashlight is often made from
paper, wood and thin steel plate. Now most of flashlight are made
from plastic, thin steel or brass plate, anodized aluminum and rubber.
Aluminum and rubber are good for special purpose such as under the
cold temprature, when diving, for emergency, or in the chemical plant.

4) How
many part the flashlight has?

The metal flashlight are made by tooling so often
have three part, the head to fix the reflector and the barrel to accept
the batteries and the bulb holder, and a tail cap to finish the circuit.
The plastic and ruuber flashlight are made by molding, so no seperated
tail cap being.

5) Battery guide?

Normally, the carbon-zinc battery is suitable and
economical for flashlight. And you can choose alkaline battery if
you use flashlight frequenctly. Button cell is enough for 1 LED light
and can make the flashlight tiny and beautiful. But to a bright flashlight
which need large current to drive it, (Normally above 330mAabove for
AA size) you should choose corresponding battery which can discharge
large current, for example, using Duracell large current batteries
or lithium battery, or rechargeable Ni-Cd and Ni-MH batteries.

6) Bulb guide?

Today, the 2-pin T1 C2R bulb and base type T8 C2R
are the most popular bulb. There are 4 types bulb according to the
gas filled. No gas filled bulb are vacumm bulb, most melt glass sealed
T1 type are vacumm type. And base type T8 is often low presure krypton
or xenon gas filled. Halogen bulb is scarely used in flashlight. Gas
presures in all the melt glass sealed bulb are not high, to get a
high gas presure, a new seal method should be used, such as Carley
bulb. Vacumm type and krypton type will be a bit dim after several
hours used, relatively high presure xenon or halogen will still act
good. The light of krypton bulb is a bit yellow, not as so bright
and white as xenon type and halogen type, for the color temprature
of the xenon bulb is high.

We use the specification Lumen (LM) or MSCP to metre
the total light of a bulb. 1MSCP=12.56*LM.

7) About the reflector.

The reflector is an important part in the flashlight.
The light became "spot to flood" adjustable when the position
of the reflector modified. The reflector should be a paraboloid as
you studied in the school. And it should be well plated.

8) How to use a flashlight?

It is so easy, but should pay attention the followings:
1, Please fetch out the batteries after using. 2, Do not using the
flashlight a long time will increase the life of the bulb. 3, Flashlight
for diving should be "water proof" not "water resistance"
4, Be careful in dangrous place as mentioned below. 5, Do not choose
plastic flashlight in very low temprature. 5, Do not stand the flashlight
on the table with the head downside when the light is "ON".

9) Where
the flashlights are mainly made?

The flashlight manufactuer are mainly located in the
USA, South Korea, Taiwan, and China. About 90% flashlight now are
Made in USA or Made in China. In the USA, Coleman, Mag-lite, Rayovac,
Eveready, Garrity, Duracell are the leading company. In plastic and
rubber flashlight market, Eveready, Garrity, Royovac totally own more
than 50% market share, and Mag-lite and Streamlight are specialized
in Aluminum flashlight for law enforcement. But in the recent years,
when the LED flashlight became more and more popular, the above manufacturer
lose the chance.

However "Made in China" flashlight is the
most active roler in the supermarket. And much American manufactuer
cooperated with Chinese manufactuer to make them flashlight competitive
in the cost. In fact, about 75% plastic flashlight in the world are
made in China. And about 65% are made in a small county called "Ninghai"
in Ningbo, China. On aluminum flashlight, no acurrate data got, but
at least more than 40% are made in China. Mainly in Ningbo too. There
are more than 100 manufacturers making aluminum flashlight in Ningbo.

10) How to
buy a flashlight or purchase mass flashlight?

If you want to buy a flashlight for personnel use,
you must be clear about your purpose first. Then you can buy it for
supermarket or search a suitable flashlight on Ebay. Similar to those
trading company or purchasing department, if the flashlight are used
for law enforcement or for chemical plant, Streamlight is good. Of
course, Maglite is a alternative too. If the flashlights is for promotion
or for other general purpose, find a chinese manufactuer will bring
more margin for you. Just search "plastic flashlight manufacturer"
or "aluminum flashlight manufacturer" will bring you hundreds
flashlight manufacturer for your choice. It is better to find a maufacturer
have more than 5 years history in making flashlight so that there
will be no problem on quality and delivery. Also a manufacturer specialized
in flashlight or other related line is better. Manufacturer in Ningbo
is the most competitive in China, such as Han’s
Lite, many flashlight manufacturer will match your demand.

11) Which manufacturer is suitable to you?

First of all, I think, a manufacturer who can well
communicate with you on flashlight knowlege, technics, and know-how
of making will be appreciated. and secondly, the manufactuer should
quickly response to your inquiry. Thirdly, the good should be in high
quality and the delivery time is short, not exceed a month. And finally,
very important, the mnufactuer should be responsibile to their quality
problem and other defectives.

12) Why
LED flashlight become popular?

In 1992, GaN was used to make bright blue light LED.
A new light source revolution came. Base on blue LED, bright white
light LED was made. The LED have high light effiency up to 40LM/W.
The LED have great advantage compared with the traditional filament
bulb. It is solid so that will not be broken in use. The LED life
time is up to 100,000 hours, and the bulb life is about 20 hours only.
The high light effiency and low current drive make the LED light source
more popular. In about 1998, LED pointer and LED flashlight became
popular, and now it seems that LED type flashlight have the same market
share as the bulb type flashlight. It can be sure that the LED flashlight
will exceed bulb type flashlight in 2005 as more and more great LED
are developed now.

13) LED introduction?

After the first GaN LED is made by Nichia, a Japan
company. Now LED are mainly made in Japan, USA and Taiwan, China.
Today, 5mm two pins LED and Luxeon LED from Lumileds are the most
known used in the flashlight. 5mm LED is often specified inthe light
angel and light denisty (mcd) , please chose a high "mcd"
one when the light angel is same. Since 2004, more 1W, 2W, 3W high
flux LED are found in the market. These high flux LED are often specified
in Lumen (LM). Luxeon is still the leading brand in the market. The
high flux LED from Nichia, Osram are very good too.

14) How to choose
batteries for LED flashlight?

For 1 5mm LED, now most manufacturer ofen use button
cell batteries to drive it. And some manufactuer use 1 AAA or AA battery
to drive with a step-up IC or a charge pump IC. 3-15 LEDs flashlight
can be drive by 3AAA (or AA) batteries or 2AA batteries with IC circuit.
16-30 LEDs flashlight should use C size or D size flashlight. To high
flux LED flashlight, Luxeon for example, 1W LED can be drive by 3AAA
(AA) batteries or 2AA batteries with IC circuit, but it is better
use Ni-MH or Ni-Cd battery, or using large current batteries such
as lithium battery or special large current alkaline battery. To drive
a 3W or 5W LED, it is better using large current battery mentioned
above and with a step-down or LDO IC circuit.

15) How to choose flashlight for
sepecial purpose?

Just be carefull. For example, if you want a flashlight
for law enforcement, the flashlight should have a silent switch, tight
battery house and strong spring etc. For dangrous chemical place,
you should choose a flashlight will not bring spark when using the
switch and installing the batteries. For travel and explore, please
choose a LED flashlight which can use a long time or a solar flashlight
or a dymo flashlight.

16) IC circuit used in the flashlight?

There are three type IC circuit in the flashlight,
The first is the circuit to control the light as singal lamp, or a
warning system, or to keep battery to be long life. The second is
charge pump circuit or step up circuit. The voltage to drive LED flashlight
is normally 3.6V, so a step up circuit needed to step the battery
voltage <1.5V or <3.0V up to 3.6V. Step up IC circuit is better
than charge pump in the efficiency but need more elements and and
space. The third is LDO or step down IC circuit for high flux LED
flashlight. The circuit make the LED get large and stable electric
current. Same as above the step down IC circuit is better and more
expensive and complex.

Flashlight become more diversiform after the LED to be the light source. You can disscuss the design, solution and features of LED flashlight and other flashlight light here. The review of other outdoor equipment and safty product is welcome too.