C
I just modified my King Sword KS-303F stock 3 LED flasher into what may
be one of the brightest LED taillights around, and would like to share
how I did it with the group to see if others would be interested in
doing the same/similar stuff. The idea of doing the modification came
about from trying to salvage an old KS light that had a bad switch; it
then dawned on me that the light can be greatly enhanced with the
latest LEDs.
Basically, the King Sword KS-303F is a very simple light. It comes with
3 standard 5 mm deep red LEDs, and is a flash only device. All the LEDs
are connected in parallel, and the switch apparently contains a
built-in flasher. No obvious dropping resistors were noted, and I
believe none are built in (more on this later).
With a soldering gun, I removed the three stock LEDs, and replaced them
with 3 5 mm red THC (High Current, High Candela, High Capability) LEDs
from lsdiodes.com (Note: US postal mail is for some reason extra slow
these days, and the LEDs took 9 days to arrive). For the two additional
positions at the ends of the board, I added 2 3 mm LEDs from
lsdiodes.com as well. One should note that those positions will take 5
mm LEDs; however, 5 mm LEDs will prevent one from replacing the lens
cap. All in all, the upgrade gave me a whopping 51000 mcd of light;
presumably the lens spreads enough light at the edges so that the light
is visible from the side as well. It should be noted that the batteries
used to power the lights need to have a combined voltage of 2.4V, not 3
V. LEDs are very voltage sensitive, and one cannot safely overvolt a
LED and expect much additional output. Rather overvolting an LED by a
little bit causes a HUGE increase in current, and burns the LED out. My
guess is that the light as shipped has the flasher set up in such a way
that the momentary overvoltage doesn't hurt the stock LEDs. Anyhow, 2.4
V total is readily obtained with a set of rechargeable NiMH AA cells
(AA NiCads would work nicely too), and the additional 3 mm LEDs are
rated at 2.4V max for the 5500 mcd variety (the 6000 mcd ones have a
reg rating of 1.7 V, which is far too low).
After closing up the lens and attaching the light to my bike (the screw
and the tab nicely fit the standard rear reflector bracket), I found
that the light is very bright as expected. Somewhat surprisingly, the
light went from a deep red to a orangeish-red. Though initially a bit
annoyed, since the LEDs were sold as "red," I soon found myself liking
the tinge of orange. Aren't red traffic lights tinged orange to enable
color-blind people to see them anyhow? It seems the light is now
comparable in brightness to some car taillights, at a cost of US$8.12
including shipping and handling for the LEDs, and another $8 or so for
the original light. Current draw is presumably greatly increased (if it
weren't, then the new LEDs probably wouldn't of all lit up as they did
with a limited current, though I didn't rigorously measure the
currents), so I estimate the run time is now 12 hrs or so vs the
standard 200, but that's plenty for me.
This makes me wonder how it seems most taillight manufacturers are
reluctant to share specs about their lights besides offering useless
adjectives such as "3 super-bright LEDs" and the like making it
impossible to objectively compare models. Would anybody have comments
on this or similar taillight modifications, and/or know how close I am
to some "ultimate" taillight? What about numerical brightness
specifications for taillights on the road? Thanks.
Later,
Nelson Chen
be one of the brightest LED taillights around, and would like to share
how I did it with the group to see if others would be interested in
doing the same/similar stuff. The idea of doing the modification came
about from trying to salvage an old KS light that had a bad switch; it
then dawned on me that the light can be greatly enhanced with the
latest LEDs.
Basically, the King Sword KS-303F is a very simple light. It comes with
3 standard 5 mm deep red LEDs, and is a flash only device. All the LEDs
are connected in parallel, and the switch apparently contains a
built-in flasher. No obvious dropping resistors were noted, and I
believe none are built in (more on this later).
With a soldering gun, I removed the three stock LEDs, and replaced them
with 3 5 mm red THC (High Current, High Candela, High Capability) LEDs
from lsdiodes.com (Note: US postal mail is for some reason extra slow
these days, and the LEDs took 9 days to arrive). For the two additional
positions at the ends of the board, I added 2 3 mm LEDs from
lsdiodes.com as well. One should note that those positions will take 5
mm LEDs; however, 5 mm LEDs will prevent one from replacing the lens
cap. All in all, the upgrade gave me a whopping 51000 mcd of light;
presumably the lens spreads enough light at the edges so that the light
is visible from the side as well. It should be noted that the batteries
used to power the lights need to have a combined voltage of 2.4V, not 3
V. LEDs are very voltage sensitive, and one cannot safely overvolt a
LED and expect much additional output. Rather overvolting an LED by a
little bit causes a HUGE increase in current, and burns the LED out. My
guess is that the light as shipped has the flasher set up in such a way
that the momentary overvoltage doesn't hurt the stock LEDs. Anyhow, 2.4
V total is readily obtained with a set of rechargeable NiMH AA cells
(AA NiCads would work nicely too), and the additional 3 mm LEDs are
rated at 2.4V max for the 5500 mcd variety (the 6000 mcd ones have a
reg rating of 1.7 V, which is far too low).
After closing up the lens and attaching the light to my bike (the screw
and the tab nicely fit the standard rear reflector bracket), I found
that the light is very bright as expected. Somewhat surprisingly, the
light went from a deep red to a orangeish-red. Though initially a bit
annoyed, since the LEDs were sold as "red," I soon found myself liking
the tinge of orange. Aren't red traffic lights tinged orange to enable
color-blind people to see them anyhow? It seems the light is now
comparable in brightness to some car taillights, at a cost of US$8.12
including shipping and handling for the LEDs, and another $8 or so for
the original light. Current draw is presumably greatly increased (if it
weren't, then the new LEDs probably wouldn't of all lit up as they did
with a limited current, though I didn't rigorously measure the
currents), so I estimate the run time is now 12 hrs or so vs the
standard 200, but that's plenty for me.
This makes me wonder how it seems most taillight manufacturers are
reluctant to share specs about their lights besides offering useless
adjectives such as "3 super-bright LEDs" and the like making it
impossible to objectively compare models. Would anybody have comments
on this or similar taillight modifications, and/or know how close I am
to some "ultimate" taillight? What about numerical brightness
specifications for taillights on the road? Thanks.
Later,
Nelson Chen