Building a tail light, Need help!

[zhd]

I wanted to build a very bright strobing tail light for bicycle(and cheap), so i bought these parts. But i need help to assemble them. I have only one led and i dont want to damage it by doing a mistake. If i ruin a part, i will have to wait for another three weeks :shakehead

Driver: https://www.fasttech.com/p/1127407
Led: https://www.fasttech.com/p/1574704
Lens 1: https://www.fasttech.com/p/1108211
Lens 2: https://www.fasttech.com/p/1404701
Switch: https://www.fasttech.com/p/1135000

The led is red, it has lower operating voltage than white ones which is 2.0-2.5V. The driver can handle this? This is what i worry about most.
The driver has 5 modes. How do i switch between modes? The switch i bought is on/off. Is this correct or do i need one click ones(i have that kind too)
I will experiment with lenses once i get the led running. 60 degree lens will be visible from a far distance but i might use other lens to get some side visibility. Or i may use them both. Or i may dont use them at all. What you guys think, which would work best?
The driver feeds the led with 500ma at 1.5V and 800ma at 3.6V. I will use a single AAA or AA. Don't want to blind other drivers.
I will improvise to make the case, have some ideas which includes a lot of hot glue. Wont be really pretty, but thats not a problem for me.




Thank you all!

 

[nein166]

Welcome to CPF your going to have fun on this project

Your parts will work after a bit of improvized mounting

The planoconvex lense should create a moon shaped beam kinda focused but it depends on distance between LED and lense,
farther apart = more focused
closer = more flood
between 1 to 1/4 inch of adjustment
I think with a proper case set up the 60 degree would work best on a bike tail light because it will be partly visible from the side
you might consider diffusing it by scratching up the outside with a scotchbrite pad to get more visibility from side angles

The optic with holder looks like it should be floody and not adjustable, however the white housing will light up red

The driver will provide the power the LED needs, 1xAA is best since the forward voltage of the led is below 3v dont use 2xAA
2 NiMH should work okay though

wire up the led to the provided wires on the driver (+red)
the switch between the battery and either contact on the back of the driver
center pad is battery positive, outer ring is battery negative
LED=>black_&_red_wires=>Driver=>Battery=>switch=>wire_back_to_driver<=

the switch will change the modes.
Click to turn on
then half-press and release to change to the next level.
click again to turn off

For the case remember the Heat made by the LED will need to go away from it
screw or glue the LED star to something metal with a heat conductor compound between the two
Its only 1 watt so you don't need much but alot of hotglue is not a good plan to mount a LED
a small 1-2" cpu heatsink should be plenty

 

[find_bruce]

You pretty much have it covered & Nein has picked up the other issues.

The heat dissipation for 1w is easy to deal with, so here are a few ideas for cheap ways to mount the leds

• copper plumbing cap
• computer heat sink
• a P60 drop in module, like this crazy bright vent light
• gut something like this and fit your parts in it
• an easy2led housing - currently US$9 + shipping

I have used each of the last 3 and they are both neat and cheap

I have a slightly different take on lenses for rear lights. Mt thinking is that it helps if it is (1) a large point source of light - easier to see & much less dazzling & (2) needs to be visible from a wide range of angles. To do this I have used 2 diffusers

• a deodorant ball - a ping pong ball is just as effective &
• a silicone diffuser which I have used on p60 drop in modules.

I don't have any pics of the diffuser, but here are a couple of the deodorant ball

And this is the light at ~0.5A

 

[BrianMc]

Another lens for a tailight: The clear cap from silicone caulk:


The afterburner effect:


Good 270 degree coverage:




Hotshot hot spot and wash of red from DIY taillights:



Short video- the non flashing lights have the caulk cap lenses:

 

[find_bruce]

Thanks Brian for the reminder that your lights were one of the things that convinced me about side visibility and increasing the apparent size of the light