new B&M headlight...

[Steve K]

I've used copper mounts for LEDs before....

For the project shown, it was overkill, but kinda fun to play with.

I haven't opened up a B&M light, so I don't have experience with how good or bad the heatsinking is. I've generally assumed that I'd have to improve it, but if I have a choice, I'd like to get one that requires less hacking up. The newer the light, the better, I'm assuming.

I agree that to avoid damaging the quality of the beam, I'll want to keep the optical characteristics of the LED as unchanged as possible. If improvements to the heatsinking permit that, then that's a good path to take. The worst-case scenario is that I cook the original LED, which means that I change to something bigger, which was always one of the options. I may want to include the option of adding some thermal instrumentation of the LED, just to get an idea of how hot it is running.

 

[Savvas]

...I agree that to avoid damaging the quality of the beam, I'll want to keep the optical characteristics of the LED as unchanged as possible. If improvements to the heatsinking permit that, then that's a good path to take. The worst-case scenario is that I cook the original LED, which means that I change to something bigger, which was always one of the options. I may want to include the option of adding some thermal instrumentation of the LED, just to get an idea of how hot it is running.

OK - maybe the DOSUN U1 is the experimenter's choice. Very solid all-Alu body. See here:

https://intelligentdesigncycles.com/product/dosun-u1-dynamo-headlamp

https://swhs.home.xs4all.nl/fiets/tests/verlichting/koplampen/Dosun_u1/index_en.html

Sam.

 

[Steve K]

I do like the design of the housing! Certainly better thermal properties than the lights with mostly plastic housings.

I saw that SWHS said the cost was 50 Euros and checked to see what Intelligent Design Cycles was charging... and their web site indicates that they don't seem to be selling it.

SWHS says it uses the XP-E, which isn't surprising. With an optimized thermal path, perhaps 2A could be pushed through it??

Well, I may be waiting for someone to sell me their dead Dosun U1, because I'm reluctant to pay 50 Euros for a light that I'm going to hack up. Step one is to get my electronics developed and try it on a simple test bed. If that all works out, then I'll worry about finding a good host. My hope is certainly to find a nice dead light for cheap.

I wonder what the best way is to find one??

 

[Savvas]

Re: New Dynamo Headlights (was 'new B&M headlight')...

In anticipation of inevitable progress, perhaps I should rename this thread 'new dynamo headlights'! Here's a new stVZO unit from Roxim - the D6 - looks good on paper!

From the web page:
"Maximum 70 Lux
180 degree Near Field LightingDynamic Efficiency Control (DEC)
Stand (parking) light
Auto-Sense for Day/Night mode
Daytime Running Light (DRL)
Power inputs:2.4W/6V or 3W/6V
Rear light cable output
Glare-free lens design, complies with German StVZO regulations (K847)*1
Rainproof
Bracket:MB-30F front fork bracket
Optional accessories: MB-10A for handlebars
*1: D6 optical lens has been certified by StVZO regulations"

Anyone seen or used one?

Sam

 

[znomit]

Re: New Dynamo Headlights (was 'new B&M headlight')...

In anticipation of inevitable progress, perhaps I should rename this thread 'new dynamo headlights'! Here's a new stVZO unit from Roxim - the D6 - looks good on paper!

Interesting marketing. Its better than unspecified lights from unspecified competitors. :shakehead

BTW I looked up the 3n20 Dynamo on rosebikes, 15 US$! Definitely getting one for the commuter next winter.
https://www.rosebikes.co.uk/article/shimano-hub-dynamo-dh-3n20/aid:355676
Hotlinked Image Converted to URL

 

[Steve K]

Re: New Dynamo Headlights (was 'new B&M headlight')...

so.... the graph shows the Roxim LED being powered with 0.9A at high speeds, while Brand B's LED is getting 0.5A (a familiar number), and Brand A's poor LED is only getting 0.3A.

Am I just imagining that Brand B just rectifies the dynamo power and feeds it into the LED, and it appears that Roxim is using a buck converter to power theirs?
Of course, if it was a buck, it should be delivering 3W to the LED at much lower speeds than it is.

I've never purchased a modern LED headlight, so I really don't know what's inside them. Seems like a buck converter is pretty basic and shouldn't be uncommon. Thoughts and observations?

 

[angerdan]

Re: New Dynamo Headlights (was 'new B&M headlight')...

Take a look how Busch & Müller constructed the IQ-X:
mtb-news.de/forum/t/der-neue-b-m-lumotec-iq-x-100lux-led-scheinwerfer.787142/

 

[znomit]

Re: New Dynamo Headlights (was 'new B&M headlight')...

so.... the graph shows the Roxim LED being powered with 0.9A at high speeds, while Brand B's LED is getting 0.5A (a familiar number), and Brand A's poor LED is only getting 0.3A.

Brand "B" has two LEDs though.

 

[Flyer]

They seem to make lights with a very good cutoff so oncoming cars are not blinded or annoyed. I like that. In fact, I need such a light since my Lupines are offload lights and the beam goes upwards too. However, B&M light do not seem to be available here in the US and if I run into a problems, it will become a paperweight. Since I am starting to ride at night/evening as the light goes away early, I need a bright (minimum 800-1000 lumens) light that has a road pattern.

 

[samsavvas]

They seem to make lights with a very good cutoff so oncoming cars are not blinded or annoyed. I like that. In fact, I need such a light since my Lupines are offload lights and the beam goes upwards too. However, B&M light do not seem to be available here in the US and if I run into a problems, it will become a paperweight. Since I am starting to ride at night/evening as the light goes away early, I need a bright (minimum 800-1000 lumens) light that has a road pattern.

Peter White sells them doesn't he?

Sam.

 

[znomit]

Run the numbers on what you'll save by buying direct from Europe vs the chance of failure.

You don't need 800-900 lumens on a cutoff beam light because they all hit the road.

ps
Lupine do a cutoff beam light now.
https://www.lupine.de/products/bike-lights/road-use/sl-a

 

[Steve K]

Run the numbers on what you'll save by buying direct from Europe vs the chance of failure.

You don't need 800-900 lumens on a cutoff beam light because they all hit the road.

ps
Lupine do a cutoff beam light now.
https://www.lupine.de/products/bike-lights/road-use/sl-a

that's interesting!

intriguing that they use a linear array of LEDs for the main beam, although they actually form a curve instead of a straight line.