greenLED
Flashaholic
YEAH!! :rock:
That looks just as bright as some of the pics I've seen of a Dinotte tail light.
:goodjob:
That looks just as bright as some of the pics I've seen of a Dinotte tail light.
:goodjob:
flashing multiple Luxeon? (red Luxeon rear bike blinker)
- Thread starter greenLED
- Start date
Help Support Candle Power Flashlight Forum
Vermonter73
Enlightened
- Joined
- Jul 25, 2006
- Messages
- 335
N-den, are you going to be selling those? I'm shopping for a BRIGHT taillight for my bike. Hoping to purchase within the next couple weeks.
greenLED
Flashaholic
Knowing how custom projects progress on CPF, I wouldn't hold my breath on this one, Vermonter. I'm really excited that n_den has figured out the electronics, but we still need a solid solution for the casing, etc.
(Welcome to CPF, BTW.)
(Welcome to CPF, BTW.)
n_den
Newly Enlightened
it will be some time before this thing goes up for sale. lots more R&D, even for a small project. but, i'll keep posting as the project moves forward. n_den 
greenLED
Flashaholic
n_den, George posted this tidbit on this thread:
IIRC, his drivers are not expensive, and being specifically designed for biking, I'm guessing it'd be a good match for this project.georges80 said:
I did a serfas tl 300 modification last night
(it was all LBS had in stock; I wanted the
CatEye equiv). Substituted a pair of nylon
6-32 screws for the seat post mount
(scrapped the factory mount entirely) and
bolted it to some scrap 0.125 aluminum.
Worked good.
-=-=-=
What is the design spec?
What kind of controller would your tail light
benefit from? Do you want a custom cadence
for the sequencer? Sleep mode, motion detection,
synchrony to hub RPM?
I recently built a six-digit seven-segment LED
display running at 300 Hz (no flicker at all so
far as the human eye can tell). It drew a lot
less power than the static equivalent brightness.
It (rather dumbly) utilized a Silabs C8051F330,
which is a convenient microcontroller as it is
available in a DIP-20 package (can be inserted
and removed from a socket -- old school). Even
so, I think the overhead for the micro and all
the drive circuitry was somewhere around 6 mA.
I didn't think that was too shabby considering
I didn't program any especially power-reducing
qualities into the firmware (other than picking
a good pulse width and refresh rate for the
seven-segment array itself).
A micro is a heck of a lot more facile than an
NE555, and since some useable ones are available
in DIP packages, no reason not to at least attempt
it on a ratshack breadboard.
The Silabs 'F330 runs off 3.3 volts; I think the
LM2937 is usually specified for an LDO to supply it.
A couple of coin cells would also power it nicely,
I think.
A PC-AT keyboard interface is reasonably possible
here as well, if you had a mind to have a very
large number of buttons to initiate functions
(or if you actually wanted text input for that
matter). An LCD character display is a beginner's
project as well (for status messages in natural
language). These kind of peripherals can be
connected as needed (for an hour while setting
it up for a particular need, then disconnected
and put back on the shelf while you're out on
the road with your programmable lighting system
under the new instructions you typed in on the
keyboard without removing anything from the
bike to do so). PC-AT keyboard is a 2-wire
interface (excluding power and ground). Hitatchi
44780- based LCD displays use 14 pins (can be
completely utilized with a 7x2 IDC cable). A hex
keypad is maybe 9 pins.
One neat thing for a light controller I think
would be a multi-modal potentiometer -- a twist
knob to control, for example, the rate of advance
in a sequencer, or a dimmer control. The 'F330
can support multiple ADC input (several potentiometers
can be read in realtime). I'm also quite keen
on non-modal user interfaces; I think that's the
right direction to go towards (one control, one
function).
This is my second attempt to write this post and
keep it brief; I am categorically unable to do
so (at least this particular morning). The last
one was 670 words, and was perhaps even less on-topic.
Thanks for your time! I appreciate it.
tetonca (ars wa1tnr)
NW Connecticut
fenix L1D-CE as of later this morning
(it was all LBS had in stock; I wanted the
CatEye equiv). Substituted a pair of nylon
6-32 screws for the seat post mount
(scrapped the factory mount entirely) and
bolted it to some scrap 0.125 aluminum.
Worked good.
-=-=-=
What is the design spec?
What kind of controller would your tail light
benefit from? Do you want a custom cadence
for the sequencer? Sleep mode, motion detection,
synchrony to hub RPM?
I recently built a six-digit seven-segment LED
display running at 300 Hz (no flicker at all so
far as the human eye can tell). It drew a lot
less power than the static equivalent brightness.
It (rather dumbly) utilized a Silabs C8051F330,
which is a convenient microcontroller as it is
available in a DIP-20 package (can be inserted
and removed from a socket -- old school). Even
so, I think the overhead for the micro and all
the drive circuitry was somewhere around 6 mA.
I didn't think that was too shabby considering
I didn't program any especially power-reducing
qualities into the firmware (other than picking
a good pulse width and refresh rate for the
seven-segment array itself).
A micro is a heck of a lot more facile than an
NE555, and since some useable ones are available
in DIP packages, no reason not to at least attempt
it on a ratshack breadboard.
The Silabs 'F330 runs off 3.3 volts; I think the
LM2937 is usually specified for an LDO to supply it.
A couple of coin cells would also power it nicely,
I think.
A PC-AT keyboard interface is reasonably possible
here as well, if you had a mind to have a very
large number of buttons to initiate functions
(or if you actually wanted text input for that
matter). An LCD character display is a beginner's
project as well (for status messages in natural
language). These kind of peripherals can be
connected as needed (for an hour while setting
it up for a particular need, then disconnected
and put back on the shelf while you're out on
the road with your programmable lighting system
under the new instructions you typed in on the
keyboard without removing anything from the
bike to do so). PC-AT keyboard is a 2-wire
interface (excluding power and ground). Hitatchi
44780- based LCD displays use 14 pins (can be
completely utilized with a 7x2 IDC cable). A hex
keypad is maybe 9 pins.
One neat thing for a light controller I think
would be a multi-modal potentiometer -- a twist
knob to control, for example, the rate of advance
in a sequencer, or a dimmer control. The 'F330
can support multiple ADC input (several potentiometers
can be read in realtime). I'm also quite keen
on non-modal user interfaces; I think that's the
right direction to go towards (one control, one
function).
This is my second attempt to write this post and
keep it brief; I am categorically unable to do
so (at least this particular morning). The last
one was 670 words, and was perhaps even less on-topic.
Thanks for your time! I appreciate it.
tetonca (ars wa1tnr)
NW Connecticut
fenix L1D-CE as of later this morning
Last edited:
I hope it's not too late for an outsider to join this discussion - I've just finished a rear light build and was going to do a separate mailing when I found this one.
My design specs:
Bright but not blinding
Fast strobe
Good side visibility (very important)
Indestructable and water proof
Long battery life (100hr +)
Low cost
The solution was 2 x 10mm red leds (from Best Hong Kong) epoxied into a piece of 25mm solid acrylic rod.
The rod gives a great lens effect and since the leds are totally enclosed good protection. The ends of the rod are lightly "sand blasted" to make them opaque.
As you can see oblique / side visibility is very high due to internal reflections without the use of extra leds (and current draw).
It's powered by 2 x 123's and a simple 555 astable circuit with a 30% duty cycle. It draws 15ma (average). The bats etc are in a small box on the cycle frame which also contains a power supply for my twin Q5 dyno driven headlamp.
Total cost for the tail lamp (excluding the 123's) = <$10.
In daylight it looks like a piece of clear glass.
What do you think?
My design specs:
Bright but not blinding
Fast strobe
Good side visibility (very important)
Indestructable and water proof
Long battery life (100hr +)
Low cost
The solution was 2 x 10mm red leds (from Best Hong Kong) epoxied into a piece of 25mm solid acrylic rod.
The rod gives a great lens effect and since the leds are totally enclosed good protection. The ends of the rod are lightly "sand blasted" to make them opaque.
As you can see oblique / side visibility is very high due to internal reflections without the use of extra leds (and current draw).
It's powered by 2 x 123's and a simple 555 astable circuit with a 30% duty cycle. It draws 15ma (average). The bats etc are in a small box on the cycle frame which also contains a power supply for my twin Q5 dyno driven headlamp.
Total cost for the tail lamp (excluding the 123's) = <$10.
In daylight it looks like a piece of clear glass.
What do you think?
greenLED
Flashaholic
I think it's *brilliant*! That rod of acrylic is great to tackle the 360º issue. Do you have pics of the wiring and the batt box, circuit, etc.?
Thanks for sharing.
Thanks Green Led. Very kind. I'm kinda new around here and am slowly finding my way around.
The circuit is a basic 555 astable.
See:
http://www.doctronics.co.uk/555.htm
I used this only because I had one I'd built for another project and had it lying around in my junk box. It was designed for 5 Hz with a 30% duty cycle but 5 Hz looked too slow so I tweaked the timer R until it looked right to me. I haven't measured the frequency but I'd guess it's 7 or 8 Hz. It flashes at about the same frequency as the highway patrol cars here (in Australia).
The leds are:
http://www.besthongkong.com/product_info.php?cPath=3&products_id=40
Clear body, 10mm diameter and claiming 40,000 mcd at 20ma If. (Ho ho ho). In any event they make enough light driven at 30ma on the 30% duty cycle and can easily be seen in full daylight.
The control box is mounted on the frame of the bike.
Inside the box.
As you can see this was not made to look cute and I'm guilty of keeping it simple. I plan to use the spare space in the box for another toy in the future.
I'll do a separate posting on the headlight in the next week or so.
The circuit is a basic 555 astable.
See:
http://www.doctronics.co.uk/555.htm
I used this only because I had one I'd built for another project and had it lying around in my junk box. It was designed for 5 Hz with a 30% duty cycle but 5 Hz looked too slow so I tweaked the timer R until it looked right to me. I haven't measured the frequency but I'd guess it's 7 or 8 Hz. It flashes at about the same frequency as the highway patrol cars here (in Australia).
The leds are:
http://www.besthongkong.com/product_info.php?cPath=3&products_id=40
Clear body, 10mm diameter and claiming 40,000 mcd at 20ma If. (Ho ho ho). In any event they make enough light driven at 30ma on the 30% duty cycle and can easily be seen in full daylight.
The control box is mounted on the frame of the bike.
Inside the box.
As you can see this was not made to look cute and I'm guilty of keeping it simple. I plan to use the spare space in the box for another toy in the future.
I'll do a separate posting on the headlight in the next week or so.
chesterqw
Flashlight Enthusiast
either a 555 or 556 timer should work pretty well...
not sure how to get the current pumped up so much...
not sure how to get the current pumped up so much...
greenLED
Flashaholic
That's impressive 1 what - very nice. So you're powering the rear blinker off the 123's and the headlight of the dyno? Very clever.
Illum
Flashaholic
if your going to be using luxeon Is the heatsink need not be too big...plus the fact the bike is in motion makes the forced air cooling concept seem ideal
if I understand your concept correctly, your looking for a total of 5 luxeons for a tailight?!
thats um.... :wow:
if I understand your concept correctly, your looking for a total of 5 luxeons for a tailight?!
thats um.... :wow:
greenLED
Flashaholic
That was me brainstorming almost a year ago. There are actually lights like that, but they're powered off 12V batts.
I think 1, coupled with an optical system like 1 what showed would be plenty. Alternatively, 2 Luxes (and Lux I would be enough), coupled with wide-angle optics, and pointing slightly outwards would be plenty bright and bring the V requirements down considerably.
The reason is that I want the rear to be working even if the bike is not in motion (obvious safety reason). The headlight only needs to be on when the bike is moving. As much as I like Luxeons I chose not to use them because of the current requirements and I'm not convinced that I need that much light output if I can utilize more efficent optics. My ultra cheap 10mm leds make more than enough light with very little current drawn - therefore long battery life. I'd rather use the dyno output for the front since it is my very strong impression that cars RESPECT light, especially high color temp light such as the Q5 WC. The dyno means I dont have to mess about with either replacing primary cells on a regular basis or charging issues.
greenLED
Flashaholic
Very clever. Yes, those newer 10mm LED's are really nice, and the acrylic enclosure is ideal. Nice job!
alexlockhart
Newly Enlightened
- Joined
- Jun 27, 2007
- Messages
- 60
I've only just now had the time to read through this thread and digest it. I'm interested in all the ideas here, especially since there is such a dearth of good commercial taillights. Until I found the Planet Bike Superflash a few months ago, I was using a Cateye TL-LD1000, which worked, but was not very bright, and wasted light pointing straight off to the sides. The Superflash is the brightest commercial rear light (except for the extremely expensive NiteRider and DiNotte, which both require separate battery packs), and I'm fairly satisfied with it for now.
I don't have a car, and my regular commute to work is 20 miles round trip, plus riding wherever else I go for shopping, errands, and activities with friends, etc. I do a lot of my riding at night, probably half or more, in Austin, where the motorists are careless and inconsiderate.
I've been designing a complete DIY bike electrics system, including a headlight and taillight, so I've been giving a lot of thought to what kind of lights are best. I've been thinking about where the cars are in relation to my bike in every circumstance on the road, and thinking about the light distribution pattern of headlights and taillights on cars.
I'm surprised at how many people seem to think it's a good idea to have light blasting all over in every direction. In relation to your bike, cars on the road are always going to be inside about a 10° angle vertically, and although cars are in a 360° angle horizontally, the ones that need to see you are either behind or in front of you. In fact, when you're riding on a straight road with no intersections or side roads, the only place where cars are that need to see you is inside about a 10° angle horizontally from the rear. But at intersections and side-roads, the oncoming traffic and the cross-traffic has to see you, so you need some light pointing forward in about a 40° angle horizontally. And the traffic behind you is a little more spread out at intersections, so you need light pointing backwards at maybe a 30° angle. These are estimates, but the general idea is that you only need to point light to the places where cars are actually going to be, and any light pointed outside that is wasted. Most commercial, and even most DIY lights, have round beams, either narrow for long throw, or wide for good flood. The narrow ones are too narrow - cars that are not straight in front or behind can't see you, and the wide ones waste half their light pointing up in the sky or down at the ground, where no cars are.
Looking at headlights and taillights on cars (at least the new ones - old ones were a lot sloppier in their beam patterns), they are designed with the type of elliptical beam that points light in about the angles I just described - about 10° vertically, and about 50-60° horizontally forward and about 20-30° horizontally rearward. Since they're based on bright halogens with reflectors, there's often some spill light much wider than that, but the focused light is in that elliptical beam pattern, which is exactly where it should be for visibility to other traffic.
So, the elliptical optics for LEDs are a perfect choice for bicycle lighting. They distribute the light in a pattern that puts the brightest light in the places where cars will be, and very little gets wasted pointing at the sky, at the ground, and to the sides. My lights are designed with 4 white Crees in the front with Carclo optics - two 10° optics for me to see the road, and two 10x41° optics for traffic to see me. In the rear I'll use 1 red Cree (about 80lm at 600mA) with the same optic, which produces a 14x37° pattern with the red LED. The light on my ceiling (guessing at lux with my eye) from the red Cree is about twice as bright as the light from the Superflash, but spread out extremely wide - like having 10 Superflashes all pointed in a fan-type array.
My lights are on the "test bench" now (my floor) and I'll be building them in the next week or 2. I'll be posting here with my progress, with beamshots so you can see what it looks like. I'll be using copper end caps as housing, and a Li-Ion battery pack in a water bottle for both front and rear lights, so the housing and battery aspects are not at all like what you're looking for. But the beam pattern issues are the same for any light, and I think a single red LED with a good elliptical optic will look as bright to a motorist as a car brake light at the same distance.
I don't plan to have my rear light blink - I'll have a high and low steady mode only. I'll put my Superflash on my helmet and will probably leave that flashing. I don't think flashing rear lights are really that great - I think that became the norm because when faced with the dimness of old 5mm LEDs, it was the only way to make them noticeable enough. Cars have never used flashing rear lights; they just use lights that are bright enough in the first place. As Martin said, if a whole country (Germany, and actually a lot of Europe) has decided you don't need flashing rear lights, maybe you don't.
Sorry for such a long post. Hope all my rambling thoughts are helpful in your search. Maybe if you got 3 or 4 Superflashes and arrayed them so they make a nice elliptical beam, you'd be set. But that would blow your budget, and you'd have to keep track of 6-8 AAA batteries, and it's still only about half as bright as a red Cree with an elliptical beam. If you can figure out some acceptable way to house a Cree and optic and batteries, then you could wire a cheap blinky controller to a Bucktoot or something, and you'd be set. Some company really needs to make this commercially.
Alex
I don't have a car, and my regular commute to work is 20 miles round trip, plus riding wherever else I go for shopping, errands, and activities with friends, etc. I do a lot of my riding at night, probably half or more, in Austin, where the motorists are careless and inconsiderate.
I've been designing a complete DIY bike electrics system, including a headlight and taillight, so I've been giving a lot of thought to what kind of lights are best. I've been thinking about where the cars are in relation to my bike in every circumstance on the road, and thinking about the light distribution pattern of headlights and taillights on cars.
I'm surprised at how many people seem to think it's a good idea to have light blasting all over in every direction. In relation to your bike, cars on the road are always going to be inside about a 10° angle vertically, and although cars are in a 360° angle horizontally, the ones that need to see you are either behind or in front of you. In fact, when you're riding on a straight road with no intersections or side roads, the only place where cars are that need to see you is inside about a 10° angle horizontally from the rear. But at intersections and side-roads, the oncoming traffic and the cross-traffic has to see you, so you need some light pointing forward in about a 40° angle horizontally. And the traffic behind you is a little more spread out at intersections, so you need light pointing backwards at maybe a 30° angle. These are estimates, but the general idea is that you only need to point light to the places where cars are actually going to be, and any light pointed outside that is wasted. Most commercial, and even most DIY lights, have round beams, either narrow for long throw, or wide for good flood. The narrow ones are too narrow - cars that are not straight in front or behind can't see you, and the wide ones waste half their light pointing up in the sky or down at the ground, where no cars are.
Looking at headlights and taillights on cars (at least the new ones - old ones were a lot sloppier in their beam patterns), they are designed with the type of elliptical beam that points light in about the angles I just described - about 10° vertically, and about 50-60° horizontally forward and about 20-30° horizontally rearward. Since they're based on bright halogens with reflectors, there's often some spill light much wider than that, but the focused light is in that elliptical beam pattern, which is exactly where it should be for visibility to other traffic.
So, the elliptical optics for LEDs are a perfect choice for bicycle lighting. They distribute the light in a pattern that puts the brightest light in the places where cars will be, and very little gets wasted pointing at the sky, at the ground, and to the sides. My lights are designed with 4 white Crees in the front with Carclo optics - two 10° optics for me to see the road, and two 10x41° optics for traffic to see me. In the rear I'll use 1 red Cree (about 80lm at 600mA) with the same optic, which produces a 14x37° pattern with the red LED. The light on my ceiling (guessing at lux with my eye) from the red Cree is about twice as bright as the light from the Superflash, but spread out extremely wide - like having 10 Superflashes all pointed in a fan-type array.
My lights are on the "test bench" now (my floor) and I'll be building them in the next week or 2. I'll be posting here with my progress, with beamshots so you can see what it looks like. I'll be using copper end caps as housing, and a Li-Ion battery pack in a water bottle for both front and rear lights, so the housing and battery aspects are not at all like what you're looking for. But the beam pattern issues are the same for any light, and I think a single red LED with a good elliptical optic will look as bright to a motorist as a car brake light at the same distance.
I don't plan to have my rear light blink - I'll have a high and low steady mode only. I'll put my Superflash on my helmet and will probably leave that flashing. I don't think flashing rear lights are really that great - I think that became the norm because when faced with the dimness of old 5mm LEDs, it was the only way to make them noticeable enough. Cars have never used flashing rear lights; they just use lights that are bright enough in the first place. As Martin said, if a whole country (Germany, and actually a lot of Europe) has decided you don't need flashing rear lights, maybe you don't.
Sorry for such a long post. Hope all my rambling thoughts are helpful in your search. Maybe if you got 3 or 4 Superflashes and arrayed them so they make a nice elliptical beam, you'd be set. But that would blow your budget, and you'd have to keep track of 6-8 AAA batteries, and it's still only about half as bright as a red Cree with an elliptical beam. If you can figure out some acceptable way to house a Cree and optic and batteries, then you could wire a cheap blinky controller to a Bucktoot or something, and you'd be set. Some company really needs to make this commercially.
Alex
Last edited:
I've just seen this thread and may be able to contribute a little mechanically.
On my site, I've shown how to make a very robust taillight from basic parts. I'm using a U-shaped brass profile, a bunch of SMD LEDs, a clear hose to cover it all.
For more power, the mechanics can be upscaled: Larger brass profile that accommodates power LEDs, larger diameter hose.
To include electronics, one would use an H-shaped brass profile: LEDs on one side, batteries and electronics on the opposite side. If dynamo-powered then no switch is required, if battery-powered a reed switch can be used to turn the light on / off, this prevents playing children from turning it on (I always have a magnet on my keys).
The ends of the light are closed by either folding the hose backwards or by plugging something into the hose.
The light is best bolted to the rear luggage rack.
All mechanical parts of this can be rather easily found in the third world and the mechanics are pretty much indestructible. What I experienced is that mould can grow inside the hose if it gets moist inside. This will eventually blacken the hose, but it takes a while to happen and it costs nothing to clean.
But before upscaling this, try the original SMD LED design. It's already pretty bright.
On my site, I've shown how to make a very robust taillight from basic parts. I'm using a U-shaped brass profile, a bunch of SMD LEDs, a clear hose to cover it all.
For more power, the mechanics can be upscaled: Larger brass profile that accommodates power LEDs, larger diameter hose.
To include electronics, one would use an H-shaped brass profile: LEDs on one side, batteries and electronics on the opposite side. If dynamo-powered then no switch is required, if battery-powered a reed switch can be used to turn the light on / off, this prevents playing children from turning it on (I always have a magnet on my keys).
The ends of the light are closed by either folding the hose backwards or by plugging something into the hose.
The light is best bolted to the rear luggage rack.
All mechanical parts of this can be rather easily found in the third world and the mechanics are pretty much indestructible. What I experienced is that mould can grow inside the hose if it gets moist inside. This will eventually blacken the hose, but it takes a while to happen and it costs nothing to clean.
But before upscaling this, try the original SMD LED design. It's already pretty bright.
greenLED
Flashaholic
Very interesting comments, guys - thanks.
Alex, I've mentioned using wide-angle optics a couple of times in the past, but I've never actually tried one in my bike setup. You are right about the beam dispersion and viewing angle they provide vs. the "stock" optics with round beams.
Alex, I've mentioned using wide-angle optics a couple of times in the past, but I've never actually tried one in my bike setup. You are right about the beam dispersion and viewing angle they provide vs. the "stock" optics with round beams.
Not got the flashing yet, but posted my proto-build at https://www.candlepowerforums.com/threads/177708 , using carclo elliptical optics.
