building my own bike light budget $50

[ev tocak]

and this to fine tune* it http://www.ebay.com/itm/DC-DC-100W-...566?pt=LH_DefaultDomain_0&hash=item2a26501b86

 

[heathyoung]

Indeed.

You can modify the 150W buck converters available cheaply (someone else did this here) with a little effort.

100W is rather a lot of light for a bike - I was running 3 cree XM-L lights for night-time singletrack (some of the most fun you can have) and rarely was short of light.

What are you planning to be doing that you need that much light? Riding with sunglasses at night?

I just bought a 5 cree xm-l its still in the mail somewhere can't wait to get it. I'm just building this 100w light for fun. Why..... because i can, I mean.... I think I can lol. Ill let you know.

By the way, what is night-time single track?

5 X XM-L is pretty decent.

Singletrack - http://en.wikipedia.org/wiki/Single_track_(mountain_biking) <--- This, done in pitch darkness with very bright headlights. You hit a few trees on the way usually. Body armour is optional, but recommended, especially on a powered bike

 

[its_me_jason]

Hi Jason , if this buck converter u pasted is based on lm317 ...it wont work dont bother with it .U need a led driver with that + step down .
Best of luck

Not sure what you mean by based on lm317?

I know the 100W led I bought needs Forward Voltage between 30-35Vdc and a current 3000 - 32000mA

Here are the specs on the buck converter

-input: 4.5-63V ( I'm going to have 36V ping, 41V charged )
-output: 3-60V ( I would tune this down to 30V )
-D-value of voltage: at least 3V between input and output voltage ( In the morning with a fully charged battery this should not be an issue )
-current: Max current=3/(input voltage-output voltage)
-load regulation: ±1%
-voltage regulation:±0.5%
-Dynamic response speed:5% 200uS
-temperature: industry class （-40℃ to +85℃）

from what I saw on one site (ill see if i can find it again) it said all i would need is a buck converter with low ripple as the led driver.

Lm 317 linear volt.reg ..from the photo it sure looks like it ,u are going to power 100w led with it correct '?
If so it wont work ,Also from the specs it doesnt say max wattage ...i suggest u to ask seller bout it.
here is what could work for u ,check da specs
http://www.ebay.com/itm/DC-DC-48V-t...0838854788?pt=US_Adapters&hash=item43b758bc84

Ok I found out that the Max current is = 3 /(input voltage-output voltage) for this DC to DC step down buck power converter below

the 100w led says it needs a DC Forward Voltage of 30-35V, but Skedgy Sky has informed me that forward voltage can be less than 30V so more like 1-35V
the led description also reads a DC Forward Currect (IF) : 3000 - 3200mA


Thanks for the link to the DC/DC 48V to 12V 10A. I was looking at that one for a while. a few things confused me about it though.


1. If the output is 12V and the 100w led needs 30-35V doesn't that mean the led would be running at half the potential brightness?

2. if Output Current is 10A and the Output Power is 120W. The 100w led would definitely melt into a puddle. unless the output voltage is controllable? i dont think it is

 

[ev tocak]

Ok I found out that the Max current is = 3 /(input voltage-output voltage) for this DC to DC step down buck power converter below
View attachment 2
the 100w led says it needs a DC Forward Voltage of 30-35V, but Skedgy Sky has informed me that forward voltage can be less than 30V so more like 1-35V
the led description also reads a DC Forward Currect (IF) : 3000 - 3200mA
View attachment 1

Thanks for the link to the DC/DC 48V to 12V 10A. I was looking at that one for a while. a few things confused me about it though.


1. If the output is 12V and the 100w led needs 30-35V doesn't that mean the led would be running at half the potential brightness?

2. if Output Current is 10A and the Output Power is 120W. The 100w led would definitely melt into a puddle. unless the output voltage is controllable? i dont think it is

...thats why i suggested this ,u somehow missed it : http://www.ebay.com/itm/DC-DC-100W...t=LH_DefaultDomain_0&hash=item2a26501b86[url]

 

[its_me_jason]

oh...... page two, missed it! thanks for the info.
I'll order these parts and post how well it goes, maybe some video too!

thanks agian ev tocak

 

[ev tocak]

oh...... page two, missed it! thanks for the info.
I'll order these parts and post how well it goes, maybe some video too!

thanks agian ev tocak

yw ,one more thing those massive heatsinks you want to use will be heavy ,and not a best looking solution either :|
Why not an old comp. cooler with a fan if u have one around ? it would look nicer ,also it would run cooler even if u arent moving at all .

 

[its_me_jason]

Already bought the heat sink but ya that would be a good idea too!

I found this cheaper converter, it looks solid!
http://www.ebay.ca/itm/171016854096?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649

 

[its_me_jason]

Finally got the 100W led in the mail today! still waiting on the drivers , so.... I powered it up for the first time with a few 9volts lying around.

ENJOY!

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