In the old days, you could touch two wires from a battery to a bulb and
you had a flashlight...sort of. Now with LEDs, if you connect the
emitter directly to a battery, you will have a flashlight, but only for a
few seconds...then you're in the dark again.
LED flashlights require
a driver to operate...a driver is a circuit board with the control
logic chip and power regulators that actually send the power to the
emitter. The MCU or logic chip will give instructions to the power
regulators and the regulators do the real work. Using a Li-Ion battery
is a real advantage because it has very high energy density and is
rechargeable many time, but for safety, it requires a safety shutdown to
prevent over discharging. The driver monitors the charge state of the
battery and will warn you when it's getting low -then will shut down the
light down after some time. All PFlexPRO flashlights have safety
controls to monitor the charge
Lumens are a marketing tool for
flashlights companies -anyone shopping for a flashlight will look at the
lumens to decide which one to buy. The manufactures know this and will
tempt you with high lumen output claims. There are a few categories
for lumen claims:
OUTRAGEOUS: Some manufacturers will
claim whatever they want for light output, These claims aren't based on
anything. When you buy one of these, usually inexpensive
flashlights...how do you know for sure how much light it's putting out?
These manufacturers depend on the consumer not knowing or being able to
test their claims and so they can get away with these outrageous light
EMITTER LUMENS: This output, though based
on something real...
Single Cell Li-ion and LEDs -a Perfect Match!
PFLexPRO products are designed around a single Lithium Ion Cell. We believe this is the best configuration for a small EDC flashlight. The nominal voltage of a single cell Li-ion battery is 3.6-3. volts -the input voltage of a high power LED emitter is in this same voltage range. If a flashlight uses 2 or more Lithium Ion cells, the contral electronics (driver) must reduce the voltage before sending it to the emitter -this reduces efficiency and increases heat generated by the electronics -since heat is 'the enemy', it's best to use a power source (battery) that is close to the required voltage of the led...
There's no better way to increase the durability and reliability of a
flashlight than to pot it! Look at the photo above...the delicate
electrical components are exposed on many flashlights, if they're not
exposed, they are being held in place with solder and solder joints tend
to flex and fail. With the right potting material, these components
are locked into place with no chance of damage. PFlexPRO Flashlights
and Drop Ins are all potted using Stycast 2850FT. This potting
material is popular...
Many of my builds have a choice of Reverse Clicky or Forward Clicky switches.
Which switch to choose? What's the difference?
Forward Clicky (tactical style): With forward clicky, you can depress the switch partially and the light will turn on. If you half press it quickly, the flashlight will change modes. You can use the light by merely half pressing the switch and holding it as long as you want. If you want the flashlight to remain on, just press...
The exciting thing about a custom
flashlight is the ability to choose your emitter...they're a lot of
choices. If you already know what you want/like, you're lucky. If you
don't know, where to start? The best way is to actually see the
different tints (you may know a flashaholic who has several tints
already -and yes, they love to show off their lights. The next best
thing is to read the forums to get an idea of what other people like. I
can describe a few of the most popular tints. If you look at the ANSI
White chart, you will see that starting at the lower left, the tint is
very cool (blueish) and as you move to the upper...
The standard power levels for PFlexPRO products are determined by
thermal tests. The emitter Tj (junction temperature) must remain well
within the safe range with few limitations. At 3.8A, the flashlight
should be handheld and there will be no run time limitations. If the
light is used unattended (laying down or standing on it's tail cap), the
run time on high should be limited to 5 minutes or a lower power
setting should be used. While holding the flashlight, it will feel warm
in your hand, but the heat...