DIY lights - LED project

[mountain_lion]

 

 

 

Nice setup mountain lion!  Any closeups of the dimming setup?  I like that idea.

 

I use the Buckpuck's control and ref pins to control the light.

 

Open circuit (infinite resistance) between ref and control is 100% load current.

Short circuit between ref en control is 0% load current (LEDs off).

By varying the resistance between ref and control any % output current and thus dim level can be achieved.

 

I have a fixed resistor (which results in approx 300mA load current).

The 3 position toggle switches this resistor in or out for dim and high. 3rd position on the toggle shorts ref and control to turn off the light (there is still a few mA load on the battery in the off state, so I disconnect the battery before storing the light).

 

I will still experiment a bit to see what is the best dim level.

I want the difference between dim & bright to be sufficient so that on coming car drivers who do not dim their lights will notice that I am "flashing" them.

 

 

mountain_lion2008-04-30 09:43:44

[Willehond]

I found this heat sink in an old PC' date='




[/quote']

 

That is one cool mofo heatsink ML!  I am jealous... Wow, it looks like it was made for the light!

[Willehond]

OK, for those of you still interested after 11 pages of ideas, here is my shoppping list building a great LED lightset:

 

from Rabtron (mostly):

 

1 x	BuckPuck 1000mA DC LED Driver (PCB Mount)	R 227.43
3 x	Luxeon Star Hex Cool White 1Watt LED's	R 171.55
1 x	Collimator Clear Lens - for 3 Luxeon LED's	R 76.68
1 x	Heat Sink Compound 10g	R 28.59
	Speed Services - Counter Delivery (From Dispatch to your nominated post office counter within 1 to 2 Days):	R 51.30
1 x	PVC 50mm pipe connector	R 5.99
1 x	50mm round heatsink - EXPENSIVE IMPORT!!!	R 160.00
1 x	Plastic press button	R 6.99
1 x	8 piece plastic AA battery holder	R 8.50
1 x	1 metre length 50mm dia plumbing pipe (only need a about 2cm!)	R 10.00
	Miscellaneous wires, heatshrink, solder etc.	R 20.00
	TOTAL	R 767.02

 

Heat sink and housing (PVC pipe connector):

 

 

Battery holder, buckpuck current contrller and back of the heatsink with collimator holes marked out:

 

 

LED's in series with heat silicone backing on heat sink:

 

The guts of the light connected:

 

 

The battery pack with light switch and the 50mm PVC pipe bits I had to cut off to seal the unit in the pipe connector.  It press fits, so no need to glue!

 

 

The back of the unit:

 

 

The completed setup excluding handlbar conecto, the vinyl case for the battery holder and with velcro strap:

 

 

Ready to mount:

 

On the bike:

 

The end result at 20 metres!

[sampie]

Hi Willehond

Can you maybe send a photo where using the light outside' date=' will be interesting to see a 10 and 20m view.

[/quote']

Sampie, here it is, the shrub at the back is 20metres away from the light.

 

Taken wit the light I FINALLY finished assembling today.  Very happy!

[sampie]

Thank You

VERY Impressive !!!!!!!!

[1hill@aTime]

sorry to but in here, how long will the set of batterys last approx?

[Willehond]

sorry to but in here' date=' how long will the set of batterys last approx?[/quote']

 

Not sure, but I am hoping for at least four hours.  I have not run them down yet as I keep on recharging between rides.  Should do a test, but it is not my main priority just yet.  Maybe ML or one of the other guys know.

 

With 8 batteries rated at 2700mAh each and consumption rated at 1000mA, it should theoretically last days, but I fear not...

[Flea]

So when can we hope to see them advertised in the Classified's section - you have all that extra pipe that needs to be used?

[Willehond]

So when can we hope to see them advertised in the Classified's section - you have all that extra pipe that needs to be used?

 

Indeed !  I have enough pipe for another 50 lights, but it's the cheap bit unfortunately

 

Nah, no good building this for other people.  The fun is in building it yourself and riding with your own nuclear light source.  Come on, order your bits and build your own.  it's a fun way to spend a cold, wet winters day.  Loads of those around soon.

 

[1hill@aTime]

I'm sure sourcing the items from local electronics shops wont be a problem, that will save on courier costs, maybe just the heat sink is the only problem i see.

[Willehond]

1hiil, the heat sink was a bit of an extravagant indulgence, but the rest was all sourced locally and cheap as they come.  Try Rabtron.co.za as they have all the bits you need.  You can also do their cheap snail mail delivery option if you are REALLY skint...

[mountain_lion]

 

So when can we hope to see them advertised in the Classified's section - you have all that extra pipe that needs to be used?

 

Indeed !  I have enough pipe for another 50 lights' date=' but it's the cheap bit unfortunately

 

Nah, no good building this for other people.  The fun is in building it yourself and riding with your own nuclear light source.  Come on, order your bits and build your own.  it's a fun way to spend a cold, wet winters day.  Loads of those around soon.

 

[/quote']

 

I agree, the fun is in building your own light. The time invested does not make worthwhile to build lights for others.

If you want to buy a light, get one of the commercial products.

 

WH, perhaps you can put your surplus pipe in the classified section. Flea seems to be interested in some!

 

At least I did not have to buy pipe; still had some off-cuts left over from last years bathroom renovations.

 

 

[mountain_lion]

 

sorry to but in here' date=' how long will the set of batterys last approx?[/quote']

 

Not sure, but I am hoping for at least four hours.  I have not run them down yet as I keep on recharging between rides.  Should do a test, but it is not my main priority just yet.  Maybe ML or one of the other guys know.

 

With 8 batteries rated at 2700mAh each and consumption rated at 1000mA, it should theoretically last days, but I fear not...

 

I have not done a runtime test yet either.

 

We are only driving the LEDs at 600mA, so in theory the runtime from 2700mAh batteries = 2700 / 600 = 4.5h.

 

However the battery manufactures tend to be optimistic about capacity and also base their values on low load currents, which give longer battery life cycles.

 

Still, excluding 24h races, run time of more than 3h will not often be required.  600mA x 3h = 1800 mAh.

I am sure you should be able to get at least that out of a cell rated as 2700mAh.

 

My dim setting reduces the load current to 300mA, which doubles the run time.

 

 

[markStockton]

 

sorry to but in here' date=' how long will the set of batterys last approx?[/quote']

 

Not sure, but I am hoping for at least four hours.  I have not run them down yet as I keep on recharging between rides.  Should do a test, but it is not my main priority just yet.  Maybe ML or one of the other guys know.

 

With 8 batteries rated at 2700mAh each and consumption rated at 1000mA, it should theoretically last days, but I fear not...

 

My set-up is the same as Willies, and on a 2 hour ride I use less than half of the available capacity in the cells. Therefore I estimate you should be able to get 4 to 5 hours light.

 

[mountain_lion]

 

My set-up is the same as Willies' date=' and on a 2 hour ride I use less than half of the available capacity in the cells. Therefore I estimate you should be able to get 4 to 5 hours light.

[/quote']

 

Mark, how did you determine the remaining capacity in your cells?

 

 

[mountain_lion]

OK, finally some pics of the light mounted on Mrs mountain_lion's bike.

 

Front view:

 

Side view showing mount and battery pouch:

 

Pilot's view:

Under stem mount keeps the light out of harms way with an uncluttered handle bar. Note the dimming switch on the right of the bar:

 

Because of the short stem that she is using, I had to improvise a bit to get the old flasher mount fitted. A piece of wood with some holes drilled and attached with a cable tie (which has since been trimmed) did the trick.

 

Mrs mountain_lion used the light for the Dirtopia night ride and it performed well.