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-   -   More About Lights (http://www.cyclebanter.com/showthread.php?t=252150)

[email protected] March 5th 17 07:56 PM

More About Lights
 
Since you people have been talking about lights I've been looking. Like sms I really don't like the idea of having normal batteries that wear out quickly or the idea of always keeping your battery on charge.

This means you need a bulb generator or a hub generator. The hub generator seems a good answer but they don't appear to make half of the power of a bulb generator.

But that's a little hard to tell since they seem to have a great deal of trouble listing the output of the various dynamos.

You can get a 6 watt bulb generator but the hubs appear to all deliver 3 watts.

Now there are extremely efficient hubs that even Frank wouldn't have any trouble peddling in his old broken down and crippled state.

But when you look up the lights you find the same problem - you have a very difficult time finding power in and lumens out.

There are a few things that I really like the idea of in a commuter bike:

A front wheel hub generator - the German Schmidt which is extremely reliable and apparently is 78% efficient so Jorge could not complain that he is having trouble pedalling against the tide.

The Shimano Alfine is an 11-speed rear hub which has the decided advantage of being able to put a total cover chain guard around the entire chain and SINGLE SPEED front ring and still be able to leap tall buildings in a single bound.

Now building this set of wheel would cost the better part of a thousand dollars and we're all a bunch of cheapskates.

But with bikes costing $5K+ I'm sure you could build the perfect commuter for half that amount.


Sir Ridesalot March 5th 17 08:12 PM

More About Lights
 
On Sunday, March 5, 2017 at 1:56:13 PM UTC-5, wrote:
Since you people have been talking about lights I've been looking. Like sms I really don't like the idea of having normal batteries that wear out quickly or the idea of always keeping your battery on charge.

This means you need a bulb generator or a hub generator. The hub generator seems a good answer but they don't appear to make half of the power of a bulb generator.

But that's a little hard to tell since they seem to have a great deal of trouble listing the output of the various dynamos.

You can get a 6 watt bulb generator but the hubs appear to all deliver 3 watts.

Now there are extremely efficient hubs that even Frank wouldn't have any trouble peddling in his old broken down and crippled state.

But when you look up the lights you find the same problem - you have a very difficult time finding power in and lumens out.

There are a few things that I really like the idea of in a commuter bike:

A front wheel hub generator - the German Schmidt which is extremely reliable and apparently is 78% efficient so Jorge could not complain that he is having trouble pedalling against the tide.

The Shimano Alfine is an 11-speed rear hub which has the decided advantage of being able to put a total cover chain guard around the entire chain and SINGLE SPEED front ring and still be able to leap tall buildings in a single bound.

Now building this set of wheel would cost the better part of a thousand dollars and we're all a bunch of cheapskates.

But with bikes costing $5K+ I'm sure you could build the perfect commuter for half that amount.


Once again; *SOME PEOPLE PREFER THE CONVENIENCE OF BATTERY LIGHTS FOR THEIR OWN USES!*

If I had to spend $2,500.00 for a commuter bicycle I'd seriously look at a used car just for commuting.

Cheers

[email protected] March 5th 17 08:26 PM

More About Lights
 
On Sunday, March 5, 2017 at 11:12:01 AM UTC-8, Sir Ridesalot wrote:
On Sunday, March 5, 2017 at 1:56:13 PM UTC-5, wrote:
Since you people have been talking about lights I've been looking. Like sms I really don't like the idea of having normal batteries that wear out quickly or the idea of always keeping your battery on charge.

This means you need a bulb generator or a hub generator. The hub generator seems a good answer but they don't appear to make half of the power of a bulb generator.

But that's a little hard to tell since they seem to have a great deal of trouble listing the output of the various dynamos.

You can get a 6 watt bulb generator but the hubs appear to all deliver 3 watts.

Now there are extremely efficient hubs that even Frank wouldn't have any trouble peddling in his old broken down and crippled state.

But when you look up the lights you find the same problem - you have a very difficult time finding power in and lumens out.

There are a few things that I really like the idea of in a commuter bike:

A front wheel hub generator - the German Schmidt which is extremely reliable and apparently is 78% efficient so Jorge could not complain that he is having trouble pedalling against the tide.

The Shimano Alfine is an 11-speed rear hub which has the decided advantage of being able to put a total cover chain guard around the entire chain and SINGLE SPEED front ring and still be able to leap tall buildings in a single bound.

Now building this set of wheel would cost the better part of a thousand dollars and we're all a bunch of cheapskates.

But with bikes costing $5K+ I'm sure you could build the perfect commuter for half that amount.


Once again; *SOME PEOPLE PREFER THE CONVENIENCE OF BATTERY LIGHTS FOR THEIR OWN USES!*

If I had to spend $2,500.00 for a commuter bicycle I'd seriously look at a used car just for commuting.

Cheers


I don't recall forcing anything on you. Or do you simply object to opinions?

Jeff Liebermann March 5th 17 08:32 PM

More About Lights
 
On Sun, 5 Mar 2017 10:56:09 -0800 (PST), wrote:

But when you look up the lights you find the same problem - you
have a very difficult time finding power in and lumens out.


Hint: Measuring lumens is messy and expensive. Here's what it took
to verify lumens in 2014:
http://www.roadbikereview.com/reviews/2014-bike-lights-shootout-lumen-measurements
(I like the lumens/dollar bar graph).

For numbers and beam pattern photos, try:
https://www.bikelightdatabase.com
http://reviews.mtbr.com/2016-bike-lights-shootout-lumen-measurements
http://reviews.mtbr.com/2016-bike-lights-shootout-beam-patterns
http://road.cc/content/buyers-guide/212914-updated-your-guide-best-front-lights-cycling-beam-comparison-engine
http://www.roadbikereview.com/reviews/2014-bike-lights-shootout-tunnel-beam-patterns
There are others, but that's what I found in my bookmark collection.
There are also comparisons and tests on YouTube.

--
Jeff Liebermann

150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Sir Ridesalot March 5th 17 10:34 PM

More About Lights
 
On Sunday, March 5, 2017 at 2:26:07 PM UTC-5, wrote:
On Sunday, March 5, 2017 at 11:12:01 AM UTC-8, Sir Ridesalot wrote:
On Sunday, March 5, 2017 at 1:56:13 PM UTC-5, wrote:
Since you people have been talking about lights I've been looking. Like sms I really don't like the idea of having normal batteries that wear out quickly or the idea of always keeping your battery on charge.

This means you need a bulb generator or a hub generator. The hub generator seems a good answer but they don't appear to make half of the power of a bulb generator.

But that's a little hard to tell since they seem to have a great deal of trouble listing the output of the various dynamos.

You can get a 6 watt bulb generator but the hubs appear to all deliver 3 watts.

Now there are extremely efficient hubs that even Frank wouldn't have any trouble peddling in his old broken down and crippled state.

But when you look up the lights you find the same problem - you have a very difficult time finding power in and lumens out.

There are a few things that I really like the idea of in a commuter bike:

A front wheel hub generator - the German Schmidt which is extremely reliable and apparently is 78% efficient so Jorge could not complain that he is having trouble pedalling against the tide.

The Shimano Alfine is an 11-speed rear hub which has the decided advantage of being able to put a total cover chain guard around the entire chain and SINGLE SPEED front ring and still be able to leap tall buildings in a single bound.

Now building this set of wheel would cost the better part of a thousand dollars and we're all a bunch of cheapskates.

But with bikes costing $5K+ I'm sure you could build the perfect commuter for half that amount.


Once again; *SOME PEOPLE PREFER THE CONVENIENCE OF BATTERY LIGHTS FOR THEIR OWN USES!*

If I had to spend $2,500.00 for a commuter bicycle I'd seriously look at a used car just for commuting.

Cheers


I don't recall forcing anything on you. Or do you simply object to opinions?


BUT you did NOT express an opinion. You said: On Sunday, March 5, 2017 at 1:56:13 PM UTC-5, wrote:
Since you people have been talking about lights I've been looking. Like sms I really don't like the idea of having normal batteries that wear out quickly or the idea of always keeping your battery on charge.

This means you need a bulb generator or a hub generator. The hub generator seems a good answer but they don't appear to make half of the power of a bulb generator."


You intaht case is not myself nor is it a lot of other people who prefer battery powered lights for whatever reasons thosepeople have.

Cheers

Barry Beams March 6th 17 12:22 AM

More About Lights
 
On Sunday, March 5, 2017 at 10:56:13 AM UTC-8, wrote:
Since you people have been talking about lights I've been looking. Like sms I really don't like the idea of having normal batteries that wear out quickly or the idea of always keeping your battery on charge.

This means you need a bulb generator or a hub generator. The hub generator seems a good answer but they don't appear to make half of the power of a bulb generator.

But that's a little hard to tell since they seem to have a great deal of trouble listing the output of the various dynamos.

You can get a 6 watt bulb generator but the hubs appear to all deliver 3 watts.

Now there are extremely efficient hubs that even Frank wouldn't have any trouble peddling in his old broken down and crippled state.

But when you look up the lights you find the same problem - you have a very difficult time finding power in and lumens out.

There are a few things that I really like the idea of in a commuter bike:

A front wheel hub generator - the German Schmidt which is extremely reliable and apparently is 78% efficient so Jorge could not complain that he is having trouble pedalling against the tide.

The Shimano Alfine is an 11-speed rear hub which has the decided advantage of being able to put a total cover chain guard around the entire chain and SINGLE SPEED front ring and still be able to leap tall buildings in a single bound.

Now building this set of wheel would cost the better part of a thousand dollars and we're all a bunch of cheapskates.

But with bikes costing $5K+ I'm sure you could build the perfect commuter for half that amount.


Several items:
Scale heat by 1:1, because a light along with the driver circuit is not a theoretically perfect system. My package's heatsink can cool 20 watts of heat to stay under 65C on the hottest outside point for seven minutes, at 72F/ 21C. It stays under ~50C with only a 6mph/10kph airflow.
Patent number:8662697.

Burn time:
What if you had five or ten hours battery time at your generator's brightness? My Oculus gives at least that much brightness, and a quickly field replaceable battery so you can put in a fresh battery. Other rechargeables leave you out of light and out of luck when the battery drains.
Oculus also comes with a spare battery included.

Lumens per dollar: 1800/150 = 12.
Lumens per gram: 1800/205 (with 18650, bracket and strap included) = 8.8

Diffusers and arrays generate huge amounts of glare vs the usable visibility that they create in the primary field of view that the eyes pay attention to.

Btw MTBR is pay for play. Discreetly, obscurely, but pay for play for sure.. They also take deliberately altered pictures.
See:
https://drive.google.com/drive/folde...2c?usp=sharing
These are pics that Francis posted on his personal Facebook with a defaming title and captions. Note the overexposure/underexposure of the far horizon blue tine, and white light dots in the distance. Also the biased center weighted versus full field light metering.
He pulled the pics and posting, but refuses to test my lights or make any mention of them on his websites. I'll put my Oculus 1800 against ANYTHING he thinks is the best of anything.
Side by side with the L&M Taz, along with the head of L&M, we see my light and the his light as neither absolute superiority in terms of the raw beam the lights put out. Roadies mostly prefer my beam over the Taz right away, some MTB riders like the Taz' beam.
Honest side by side beam pictures on trails and roads will show that, not the skewed crap in favor of a big MTBR support that Francis posted.

[email protected] March 6th 17 01:03 AM

More About Lights
 
On Sunday, March 5, 2017 at 11:32:51 AM UTC-8, Jeff Liebermann wrote:
On Sun, 5 Mar 2017 10:56:09 -0800 (PST), wrote:

But when you look up the lights you find the same problem - you
have a very difficult time finding power in and lumens out.


Hint: Measuring lumens is messy and expensive. Here's what it took
to verify lumens in 2014:
http://www.roadbikereview.com/reviews/2014-bike-lights-shootout-lumen-measurements
(I like the lumens/dollar bar graph).

For numbers and beam pattern photos, try:
https://www.bikelightdatabase.com
http://reviews.mtbr.com/2016-bike-lights-shootout-lumen-measurements
http://reviews.mtbr.com/2016-bike-lights-shootout-beam-patterns
http://road.cc/content/buyers-guide/212914-updated-your-guide-best-front-lights-cycling-beam-comparison-engine
http://www.roadbikereview.com/reviews/2014-bike-lights-shootout-tunnel-beam-patterns
There are others, but that's what I found in my bookmark collection.
There are also comparisons and tests on YouTube.

--
Jeff Liebermann

150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558


Thanks Jeff. These however all appear to be battery powered lights. We were sort of looking for lights that operated on the hub dynamo of 6V 3W or the Globe dynamo of 12V 6W or four times the power.

This is why the hub generator has so little drag.


[email protected] March 6th 17 01:08 AM

More About Lights
 
On Sunday, March 5, 2017 at 1:34:33 PM UTC-8, Sir Ridesalot wrote:
On Sunday, March 5, 2017 at 2:26:07 PM UTC-5, wrote:
On Sunday, March 5, 2017 at 11:12:01 AM UTC-8, Sir Ridesalot wrote:
On Sunday, March 5, 2017 at 1:56:13 PM UTC-5, wrote:
Since you people have been talking about lights I've been looking. Like sms I really don't like the idea of having normal batteries that wear out quickly or the idea of always keeping your battery on charge.

This means you need a bulb generator or a hub generator. The hub generator seems a good answer but they don't appear to make half of the power of a bulb generator.

But that's a little hard to tell since they seem to have a great deal of trouble listing the output of the various dynamos.

You can get a 6 watt bulb generator but the hubs appear to all deliver 3 watts.

Now there are extremely efficient hubs that even Frank wouldn't have any trouble peddling in his old broken down and crippled state.

But when you look up the lights you find the same problem - you have a very difficult time finding power in and lumens out.

There are a few things that I really like the idea of in a commuter bike:

A front wheel hub generator - the German Schmidt which is extremely reliable and apparently is 78% efficient so Jorge could not complain that he is having trouble pedalling against the tide.

The Shimano Alfine is an 11-speed rear hub which has the decided advantage of being able to put a total cover chain guard around the entire chain and SINGLE SPEED front ring and still be able to leap tall buildings in a single bound.

Now building this set of wheel would cost the better part of a thousand dollars and we're all a bunch of cheapskates.

But with bikes costing $5K+ I'm sure you could build the perfect commuter for half that amount.

Once again; *SOME PEOPLE PREFER THE CONVENIENCE OF BATTERY LIGHTS FOR THEIR OWN USES!*

If I had to spend $2,500.00 for a commuter bicycle I'd seriously look at a used car just for commuting.

Cheers


I don't recall forcing anything on you. Or do you simply object to opinions?


BUT you did NOT express an opinion. You said: On Sunday, March 5, 2017 at 1:56:13 PM UTC-5, wrote:
Since you people have been talking about lights I've been looking. Like sms I really don't like the idea of having normal batteries that wear out quickly or the idea of always keeping your battery on charge.

This means you need a bulb generator or a hub generator. The hub generator seems a good answer but they don't appear to make half of the power of a bulb generator."


You intaht case is not myself nor is it a lot of other people who prefer battery powered lights for whatever reasons thosepeople have.

Cheers


Well, I didn't realize that English isn't your first language. So rather than me changing my comments I suggest that you learn English.

Jeff Liebermann March 6th 17 02:26 AM

More About Lights
 
On Sun, 5 Mar 2017 16:03:30 -0800 (PST), wrote:

Thanks Jeff. These however all appear to be battery powered
lights. We were sort of looking for lights that operated on
the hub dynamo of 6V 3W or the Globe dynamo of 12V 6W or
four times the power.


Sorry, I thought you were still open to looking at battery powered
lights. Here's what I fished out of my bookmark dumpster. No reviews
and few tests, but some interesting dynamo graphs and numbers:
http://www.myra-simon.com/bike/dynotest.html
http://pilom.com/BicycleElectronics/DynamoCircuits.htm
http://www.eeweb.com/blog/extreme_circuits/power-mosfet-bridge-rectifier

This one is well worth reading (or skimming) and has quite a few test
results:
http://swhs.home.xs4all.nl/fiets/tests/verlichting/index_en.html

This is why the hub generator has so little drag.


Well, let's do some arithmetic. If your dynamo is rated at 3 watts,
and your lighting is rated at 70 lumens/watt, then the most you can
perhaps deliver is 210 lumens. 6 watts will get perhaps 420 lumens.
Usually, it's less as the losses accumulate. Rectification losses,
optical losses, heat degradation, and connector losses all conspire to
produce lower output.

You might find it useful to know how bright you want your light. For
that, you'll need a Lux meter. I have a Lutron LX-102 which works
nicely, and two junk meters I bought on eBay for sanity checks:
http://www.ebay.com/sch/i.html?_nkw=lux+meter
Get one that has a wide range. Lowest on mine is 1000 lux, and
highest range is 50,000 lux.

Find a dark night and an accomplice to operate the meter and send them
down the road to the farthest distance that you might want to
illuminate with your headlight. Use a headlight or flashlight to
light up that area. Have your accompli's take a reading. It will
probably be zero. Now, cut the distance in half and take a
measurement. It will be 2x as bright (lux) at half the distance or 4x
as bright at 1/4th the distance. Adjust the brightness for what it
would have been if the light meter was sufficiently sensitive.

Converting the brightness (lux) to luminous flux (lumens) requires
that you know the distance to the accomplice, and the illumination
angle. (1 lux = 1 lumen/square-meter)

The form below makes a mess of bad assumptions but is good enough for
a rough approximation:
https://www.ledrise.com/shop_content.php?coID=19
Once you know how many lumens you think you need, and have adjusted
for overly ambitious expectations, you can determine which lighting
technology is suitable.

Lets say you want to see 8 meters ahead and 20 degrees to each side
(or 40 degree conical beamwidth) at 20 lux, which is rather dim.
Plugging into the web page above, I get 485 lumens needed. You won't
be able to do that with a 3w dynamo, but might squeeze by with a 6w
and an oval shaped beam.


--
Jeff Liebermann

150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann March 6th 17 06:50 AM

More About Lights
 
On Sun, 05 Mar 2017 17:26:21 -0800, Jeff Liebermann
wrote:

Find a dark night and an accomplice to operate the meter and send them
down the road to the farthest distance that you might want to
illuminate with your headlight. Use a headlight or flashlight to
light up that area. Have your accompli's take a reading. It will
probably be zero. Now, cut the distance in half and take a
measurement. It will be 2x as bright (lux) at half the distance or 4x
as bright at 1/4th the distance. Adjust the brightness for what it
would have been if the light meter was sufficiently sensitive.


No brain today. That should be half the distance equals 4 times as
bright and 1/4th the distance equals 16 times as bright.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

James[_8_] March 6th 17 06:57 AM

More About Lights
 
On 06/03/17 10:22, Barry Beams wrote:


Burn time: What if you had five or ten hours battery time at your
generator's brightness? My Oculus gives at least that much
brightness, and a quickly field replaceable battery so you can put in
a fresh battery. Other rechargeables leave you out of light and out
of luck when the battery drains. Oculus also comes with a spare
battery included.


What if I don't want to play with batteries?


--
JS

James[_8_] March 6th 17 07:04 AM

More About Lights
 
On 06/03/17 12:26, Jeff Liebermann wrote:

Well, let's do some arithmetic. If your dynamo is rated at 3 watts,
and your lighting is rated at 70 lumens/watt, then the most you can
perhaps deliver is 210 lumens. 6 watts will get perhaps 420 lumens.
Usually, it's less as the losses accumulate. Rectification losses,
optical losses, heat degradation, and connector losses all conspire to
produce lower output.


We know that a 3W dynamo is quite capable of delivering more power than
3W, once the bicycle speed increases. 6W from a 3W dynamo is quite
achievable, and the retardation torque drops off as speed increases too.

--
JS

DATAKOLL MARINE RESEARCH March 6th 17 08:12 AM

More About Lights
 
Assumptions or measured ?

Jeff Liebermann March 6th 17 06:22 PM

More About Lights
 
On Mon, 6 Mar 2017 17:04:13 +1100, James
wrote:

On 06/03/17 12:26, Jeff Liebermann wrote:

Well, let's do some arithmetic. If your dynamo is rated at 3 watts,
and your lighting is rated at 70 lumens/watt, then the most you can
perhaps deliver is 210 lumens. 6 watts will get perhaps 420 lumens.
Usually, it's less as the losses accumulate. Rectification losses,
optical losses, heat degradation, and connector losses all conspire to
produce lower output.


We know that a 3W dynamo is quite capable of delivering more power than
3W, once the bicycle speed increases. 6W from a 3W dynamo is quite
achievable, and the retardation torque drops off as speed increases too.


Maybe:
http://www.myra-simon.com/bike/dynotest.html
See "Electrical Output" graph.

Kinda looks like all of them will sorta deliver 2.5 watts before the
core saturates (to provide some level of voltage regulation). Further
down the page is a "Low Speed Power" graph, which shows that most can
produce 2.0-2.5 watts at 10km/hr. One could assume that the dynamo
will deliver 4.0 watts, but that would require buying one of the few
better (hub) dynamos listed, and riding at 25-30km/hr (15-19mph).

If I were designing or sizing a lighting system suitable for my slow
style of "cruising", I would use the worst case 10km/hr (6mph) and 2.0
watt figures.


--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

AMuzi March 6th 17 07:37 PM

More About Lights
 
On 3/6/2017 11:22 AM, Jeff Liebermann wrote:
On Mon, 6 Mar 2017 17:04:13 +1100, James
wrote:

On 06/03/17 12:26, Jeff Liebermann wrote:

Well, let's do some arithmetic. If your dynamo is rated at 3 watts,
and your lighting is rated at 70 lumens/watt, then the most you can
perhaps deliver is 210 lumens. 6 watts will get perhaps 420 lumens.
Usually, it's less as the losses accumulate. Rectification losses,
optical losses, heat degradation, and connector losses all conspire to
produce lower output.


We know that a 3W dynamo is quite capable of delivering more power than
3W, once the bicycle speed increases. 6W from a 3W dynamo is quite
achievable, and the retardation torque drops off as speed increases too.


Maybe:
http://www.myra-simon.com/bike/dynotest.html
See "Electrical Output" graph.

Kinda looks like all of them will sorta deliver 2.5 watts before the
core saturates (to provide some level of voltage regulation). Further
down the page is a "Low Speed Power" graph, which shows that most can
produce 2.0-2.5 watts at 10km/hr. One could assume that the dynamo
will deliver 4.0 watts, but that would require buying one of the few
better (hub) dynamos listed, and riding at 25-30km/hr (15-19mph).

If I were designing or sizing a lighting system suitable for my slow
style of "cruising", I would use the worst case 10km/hr (6mph) and 2.0
watt figures.



I don't know about currents but 6V 4W bulbs for standard
dynamo systems have been around for twenty years and some
customers like them. I don't know if the dynamo drag is
noticeably greater.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971



[email protected] March 6th 17 07:47 PM

More About Lights
 
On Sunday, March 5, 2017 at 5:26:18 PM UTC-8, Jeff Liebermann wrote:
On Sun, 5 Mar 2017 16:03:30 -0800 (PST), wrote:

Thanks Jeff. These however all appear to be battery powered
lights. We were sort of looking for lights that operated on
the hub dynamo of 6V 3W or the Globe dynamo of 12V 6W or
four times the power.


Sorry, I thought you were still open to looking at battery powered
lights. Here's what I fished out of my bookmark dumpster. No reviews
and few tests, but some interesting dynamo graphs and numbers:
http://www.myra-simon.com/bike/dynotest.html
http://pilom.com/BicycleElectronics/DynamoCircuits.htm
http://www.eeweb.com/blog/extreme_circuits/power-mosfet-bridge-rectifier

This one is well worth reading (or skimming) and has quite a few test
results:
http://swhs.home.xs4all.nl/fiets/tests/verlichting/index_en.html

This is why the hub generator has so little drag.


Well, let's do some arithmetic. If your dynamo is rated at 3 watts,
and your lighting is rated at 70 lumens/watt, then the most you can
perhaps deliver is 210 lumens. 6 watts will get perhaps 420 lumens.
Usually, it's less as the losses accumulate. Rectification losses,
optical losses, heat degradation, and connector losses all conspire to
produce lower output.

You might find it useful to know how bright you want your light. For
that, you'll need a Lux meter. I have a Lutron LX-102 which works
nicely, and two junk meters I bought on eBay for sanity checks:
http://www.ebay.com/sch/i.html?_nkw=lux+meter
Get one that has a wide range. Lowest on mine is 1000 lux, and
highest range is 50,000 lux.

Find a dark night and an accomplice to operate the meter and send them
down the road to the farthest distance that you might want to
illuminate with your headlight. Use a headlight or flashlight to
light up that area. Have your accompli's take a reading. It will
probably be zero. Now, cut the distance in half and take a
measurement. It will be 2x as bright (lux) at half the distance or 4x
as bright at 1/4th the distance. Adjust the brightness for what it
would have been if the light meter was sufficiently sensitive.

Converting the brightness (lux) to luminous flux (lumens) requires
that you know the distance to the accomplice, and the illumination
angle. (1 lux = 1 lumen/square-meter)

The form below makes a mess of bad assumptions but is good enough for
a rough approximation:
https://www.ledrise.com/shop_content.php?coID=19
Once you know how many lumens you think you need, and have adjusted
for overly ambitious expectations, you can determine which lighting
technology is suitable.

Lets say you want to see 8 meters ahead and 20 degrees to each side
(or 40 degree conical beamwidth) at 20 lux, which is rather dim.
Plugging into the web page above, I get 485 lumens needed. You won't
be able to do that with a 3w dynamo, but might squeeze by with a 6w
and an oval shaped beam.


--
Jeff Liebermann

150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558


As a very occasional night rider I am interested in battery powered lights but I think that I was attempting to give a thought to a commuter that would use his light a great deal.

I notice that a large number of the people in our group have flashing red rear lights and it isn't long before these batteries run down enough that the taillight even blinking is almost entirely unnoticeable. So I don't have much respect for battery power for a great deal of use.

Sir Ridesalot March 6th 17 08:00 PM

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On Monday, March 6, 2017 at 1:47:41 PM UTC-5, wrote:
On Sunday, March 5, 2017 at 5:26:18 PM UTC-8, Jeff Liebermann wrote:

Snipped
I notice that a large number of the people in our group have flashing red rear lights and it isn't long before these batteries run down enough that the taillight even blinking is almost entirely unnoticeable. So I don't have much respect for battery power for a great deal of use.


I have a rear red light I bought from MEC (Mountain Equipment Co-op)along with a front light that came with the five AAA batteries (2= rear, 3 = front)that were less than $15.00 for the pair and that rear light on flashing mode lasts for months and I do a LOT of night time riding.

Cheers

JBeattie March 6th 17 08:15 PM

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On Sunday, March 5, 2017 at 9:57:44 PM UTC-8, James wrote:
On 06/03/17 10:22, Barry Beams wrote:


Burn time: What if you had five or ten hours battery time at your
generator's brightness? My Oculus gives at least that much
brightness, and a quickly field replaceable battery so you can put in
a fresh battery. Other rechargeables leave you out of light and out
of luck when the battery drains. Oculus also comes with a spare
battery included.


What if I don't want to play with batteries?


Then you're done with the battery light discussion and may move on to helmets.

-- Jay Beattie.

Sir Ridesalot March 6th 17 08:45 PM

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On Monday, March 6, 2017 at 2:15:56 PM UTC-5, jbeattie wrote:
On Sunday, March 5, 2017 at 9:57:44 PM UTC-8, James wrote:
On 06/03/17 10:22, Barry Beams wrote:


Burn time: What if you had five or ten hours battery time at your
generator's brightness? My Oculus gives at least that much
brightness, and a quickly field replaceable battery so you can put in
a fresh battery. Other rechargeables leave you out of light and out
of luck when the battery drains. Oculus also comes with a spare
battery included.


What if I don't want to play with batteries?


Then you're done with the battery light discussion and may move on to helmets.

-- Jay Beattie.


or carbon frames versus steel frames.

Cheers

Frank Krygowski[_2_] March 6th 17 09:05 PM

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On Monday, March 6, 2017 at 1:37:23 PM UTC-5, AMuzi wrote:
On 3/6/2017 11:22 AM, Jeff Liebermann wrote:
On Mon, 6 Mar 2017 17:04:13 +1100, James
wrote:

On 06/03/17 12:26, Jeff Liebermann wrote:

Well, let's do some arithmetic. If your dynamo is rated at 3 watts,
and your lighting is rated at 70 lumens/watt, then the most you can
perhaps deliver is 210 lumens. 6 watts will get perhaps 420 lumens.
Usually, it's less as the losses accumulate. Rectification losses,
optical losses, heat degradation, and connector losses all conspire to
produce lower output.


We know that a 3W dynamo is quite capable of delivering more power than
3W, once the bicycle speed increases. 6W from a 3W dynamo is quite
achievable, and the retardation torque drops off as speed increases too.


Maybe:
http://www.myra-simon.com/bike/dynotest.html
See "Electrical Output" graph.

Kinda looks like all of them will sorta deliver 2.5 watts before the
core saturates (to provide some level of voltage regulation). Further
down the page is a "Low Speed Power" graph, which shows that most can
produce 2.0-2.5 watts at 10km/hr. One could assume that the dynamo
will deliver 4.0 watts, but that would require buying one of the few
better (hub) dynamos listed, and riding at 25-30km/hr (15-19mph).

If I were designing or sizing a lighting system suitable for my slow
style of "cruising", I would use the worst case 10km/hr (6mph) and 2.0
watt figures.



I don't know about currents but 6V 4W bulbs for standard
dynamo systems have been around for twenty years and some
customers like them. I don't know if the dynamo drag is
noticeably greater.


6V 4W? I'm aware of 6V 3W bulbs, which are (or were) used mostly with bottle
dyno systems when driving a headlamp but no taillamp. They were an alternative
to 2.4 W in front and 0.6W in back.

I'm not aware of any common use of 6V 4W bulbs.

- Frank Krygowski

David Scheidt March 6th 17 09:10 PM

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Frank Krygowski wrote:
:On Monday, March 6, 2017 at 1:37:23 PM UTC-5, AMuzi wrote:
: On 3/6/2017 11:22 AM, Jeff Liebermann wrote:
: On Mon, 6 Mar 2017 17:04:13 +1100, James
: wrote:
:
: On 06/03/17 12:26, Jeff Liebermann wrote:
:
: Well, let's do some arithmetic. If your dynamo is rated at 3 watts,
: and your lighting is rated at 70 lumens/watt, then the most you can
: perhaps deliver is 210 lumens. 6 watts will get perhaps 420 lumens.
: Usually, it's less as the losses accumulate. Rectification losses,
: optical losses, heat degradation, and connector losses all conspire to
: produce lower output.
:
: We know that a 3W dynamo is quite capable of delivering more power than
: 3W, once the bicycle speed increases. 6W from a 3W dynamo is quite
: achievable, and the retardation torque drops off as speed increases too.
:
: Maybe:
: http://www.myra-simon.com/bike/dynotest.html
: See "Electrical Output" graph.
:
: Kinda looks like all of them will sorta deliver 2.5 watts before the
: core saturates (to provide some level of voltage regulation). Further
: down the page is a "Low Speed Power" graph, which shows that most can
: produce 2.0-2.5 watts at 10km/hr. One could assume that the dynamo
: will deliver 4.0 watts, but that would require buying one of the few
: better (hub) dynamos listed, and riding at 25-30km/hr (15-19mph).
:
: If I were designing or sizing a lighting system suitable for my slow
: style of "cruising", I would use the worst case 10km/hr (6mph) and 2.0
: watt figures.
:
:
:
: I don't know about currents but 6V 4W bulbs for standard
: dynamo systems have been around for twenty years and some
: customers like them. I don't know if the dynamo drag is
: noticeably greater.

:6V 4W? I'm aware of 6V 3W bulbs, which are (or were) used mostly with bottle
:dyno systems when driving a headlamp but no taillamp. They were an alternative
:to 2.4 W in front and 0.6W in back.

:I'm not aware of any common use of 6V 4W bulbs.

It's a standard lantern size.

--
But all of a sudden Igor Stravinsky shows up with bag of psilocybin
mushrooms and a chainsaw.... -- Jens

Duane[_3_] March 6th 17 09:43 PM

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On 06/03/2017 2:45 PM, Sir Ridesalot wrote:
On Monday, March 6, 2017 at 2:15:56 PM UTC-5, jbeattie wrote:
On Sunday, March 5, 2017 at 9:57:44 PM UTC-8, James wrote:
On 06/03/17 10:22, Barry Beams wrote:


Burn time: What if you had five or ten hours battery time at your
generator's brightness? My Oculus gives at least that much
brightness, and a quickly field replaceable battery so you can put in
a fresh battery. Other rechargeables leave you out of light and out
of luck when the battery drains. Oculus also comes with a spare
battery included.


What if I don't want to play with batteries?


Then you're done with the battery light discussion and may move on to helmets.

-- Jay Beattie.


or carbon frames versus steel frames.

Cheers


I was hoping for bike lanes...

Doug Landau March 6th 17 10:03 PM

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What if I don't want to play with batteries?


Then you're done with the battery light discussion and may move on to helmets.


or carbon frames versus steel frames.



Stainless!!!
http://gearpatrol.com/2017/01/26/bes...l-bike-makers/


Joerg[_2_] March 6th 17 10:33 PM

More About Lights
 
On 2017-03-06 10:47, wrote:
On Sunday, March 5, 2017 at 5:26:18 PM UTC-8, Jeff Liebermann wrote:
On Sun, 5 Mar 2017 16:03:30 -0800 (PST),

wrote:

Thanks Jeff. These however all appear to be battery powered
lights. We were sort of looking for lights that operated on the
hub dynamo of 6V 3W or the Globe dynamo of 12V 6W or four times
the power.


Sorry, I thought you were still open to looking at battery powered
lights. Here's what I fished out of my bookmark dumpster. No
reviews and few tests, but some interesting dynamo graphs and
numbers: http://www.myra-simon.com/bike/dynotest.html
http://pilom.com/BicycleElectronics/DynamoCircuits.htm
http://www.eeweb.com/blog/extreme_circuits/power-mosfet-bridge-rectifier



This one is well worth reading (or skimming) and has quite a few test
results:
http://swhs.home.xs4all.nl/fiets/tests/verlichting/index_en.html

This is why the hub generator has so little drag.


Well, let's do some arithmetic. If your dynamo is rated at 3
watts, and your lighting is rated at 70 lumens/watt, then the most
you can perhaps deliver is 210 lumens. 6 watts will get perhaps
420 lumens. Usually, it's less as the losses accumulate.
Rectification losses, optical losses, heat degradation, and
connector losses all conspire to produce lower output.

You might find it useful to know how bright you want your light.
For that, you'll need a Lux meter. I have a Lutron LX-102 which
works nicely, and two junk meters I bought on eBay for sanity
checks: http://www.ebay.com/sch/i.html?_nkw=lux+meter Get one
that has a wide range. Lowest on mine is 1000 lux, and highest
range is 50,000 lux.

Find a dark night and an accomplice to operate the meter and send
them down the road to the farthest distance that you might want to
illuminate with your headlight. Use a headlight or flashlight to
light up that area. Have your accompli's take a reading. It will
probably be zero. Now, cut the distance in half and take a
measurement. It will be 2x as bright (lux) at half the distance or
4x as bright at 1/4th the distance. Adjust the brightness for what
it would have been if the light meter was sufficiently sensitive.

Converting the brightness (lux) to luminous flux (lumens) requires
that you know the distance to the accomplice, and the illumination
angle. (1 lux = 1 lumen/square-meter)

The form below makes a mess of bad assumptions but is good enough
for a rough approximation:
https://www.ledrise.com/shop_content.php?coID=19 Once you know
how many lumens you think you need, and have adjusted for overly
ambitious expectations, you can determine which lighting technology
is suitable.

Lets say you want to see 8 meters ahead and 20 degrees to each
side (or 40 degree conical beamwidth) at 20 lux, which is rather
dim. Plugging into the web page above, I get 485 lumens needed.
You won't be able to do that with a 3w dynamo, but might squeeze by
with a 6w and an oval shaped beam.


-- Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com Santa Cruz CA 95060
http://802.11junk.com Skype: JeffLiebermann AE6KS
831-336-2558


As a very occasional night rider I am interested in battery powered
lights but I think that I was attempting to give a thought to a
commuter that would use his light a great deal.


I use my lights a great deal because they are on during the day as well
except on segregated bike paths.

Recharging is 2nd nature to me. Bike gets parked back in the garage,
li'l round connector gets plugged in, done. Sometimes I deliberately do
not charge past 8V until shortly before a ride. That improves battery
lifetime.

The real McCoy would be a worryfree system like in a car where it
recharges while riding. If I ever switch the road bike front wheel to
one with a hub dynamo I will do that. Right now it only has a bottle
dynamo, too much drag and it eats the left side wall of "modern" tires.
Power output of those is well above 3W at higher speeds if you provide
the proper electronics. I could go into that but it's nerdy tech stuff.
Essentially you need what is called a SEPIC or at least a buck converter
plus some sort of maximum power point tracking (MPPT) control for that
converter. Sounds more complicated than it really is but do not expect
the bicycle industry to deliver anything even remotely close anytime soon.

Realistically you could eke out 4-6W depending on you speed. That's not
enough to feed a MagicShine clone which wants 8W on high plus a watt or
so for the rear lights. And maybe another 1-2W for the MP3 player. Plus
the smart phone. And the electric razor :-)

In my case this would work nicely because I need the full 10W total only
on county roads and in city areas where car drivers tend to misbehave.
Else it drops to a net load of 4-5W or even much lower. So the dynamo
would recharge the watt-hours you used up on the county road. Once the
battery gets full it throttles back. Just like in car.


I notice that a large number of the people in our group have flashing
red rear lights and it isn't long before these batteries run down
enough that the taillight even blinking is almost entirely
unnoticeable. So I don't have much respect for battery power for a
great deal of use.


Yep, that's a major nuisance. However ... one can power these lights off
a regular 8.4V Li-Ion battery or even a dynamo (after rectification) by
providing a 3V regulator. Small enough to fit where the two AAA cells
used to be.

If battery rear lights at least had a low-battery warning. Technically
that would be a piece of cake. But no ... nothing :-(

--
Regards, Joerg

http://www.analogconsultants.com/

Joerg[_2_] March 6th 17 10:39 PM

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On 2017-03-06 13:03, Doug Landau wrote:

What if I don't want to play with batteries?

Then you're done with the battery light discussion and may move on to helmets.


or carbon frames versus steel frames.



Stainless!!!
http://gearpatrol.com/2017/01/26/bes...l-bike-makers/


Nah, wood!

https://connorcycles.com/

--
Regards, Joerg

http://www.analogconsultants.com/

Jeff Liebermann March 7th 17 01:50 AM

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On Mon, 6 Mar 2017 20:10:38 +0000 (UTC), David Scheidt
wrote:

Frank Krygowski wrote:
:On Monday, March 6, 2017 at 1:37:23 PM UTC-5, AMuzi wrote:
: I don't know about currents but 6V 4W bulbs for standard
: dynamo systems have been around for twenty years and some
: customers like them. I don't know if the dynamo drag is
: noticeably greater.


:6V 4W? I'm aware of 6V 3W bulbs, which are (or were) used mostly with bottle
:dyno systems when driving a headlamp but no taillamp. They were an alternative
:to 2.4 W in front and 0.6W in back.


:I'm not aware of any common use of 6V 4W bulbs.


It's a standard lantern size.


http://www.rayovacindustrial.com/Products/Lights/Bulbs/K13-2TB-Krypton-Bulb-for-4D-Flashlights.aspx
Ray-0-Vac K13-2TB. Made for 4D cell lanterns. 6v 3.6 watts.
I couldn't find a 4 watt version. Most of what I found were 2.4 and
3.0 watt bulbs for bicycles.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann March 7th 17 03:27 AM

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On Mon, 6 Mar 2017 10:47:34 -0800 (PST), wrote:

As a very occasional night rider I am interested in battery
powered lights but I think that I was attempting to give
a thought to a commuter that would use his light a great deal.


Do "occasional night riders" buy $150 headlights?

I notice that a large number of the people in our group
have flashing red rear lights and it isn't long before
these batteries run down enough that the taillight even
blinking is almost entirely unnoticeable. So I don't have
much respect for battery power for a great deal of use.


Well, that's one of the advantages of a dynamo. You never have to
worry about a dead or discharged battery or remember to carry a spare
dead or discharged battery. (Yes, I've done that).

I think you'll find a fair number of riders in your group using low
cost rear flashers like this:
http://www.ebay.com/itm/142066277090
$0.97 gets you a two AAA batteries packaged inside a flasher (postage
included). That's about the same price as the batteries, assuming
that they're alkaline and not carbon-zinc. One of my friends says
that he picks them out of the trash at the end of club rides because
people just toss them instead of trying to figure out how to pry open
the case and change the battery. It wouldn't do them much good even
if it was easy to open, because the COB (chip on board) electronics,
buried under a blob of epoxy, will self destruct if you touch, bend,
or push on it. As for not noticing a failure, most club riders will
inform your if they see a problem.

I don't think it's fair to compare a $150 headlight, with a $0.97 tail
light. Others have mentioned various schemes to get more out of a
tail light. There are tail lights available or under design that have
motion sensors, LiIon battery, low battery indicator, solar charging,
USB charging, dynamo charging, wireless charging, side lighting,
programmable flashing, high brightness daylight mode, motion alarm,
automobile tailgating detection (via a bright headlight detector),
Bluegoof telemetry, and whatever else I forgot. Of course, they don't
cost $0.97.



--
Jeff Liebermann

150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

SMS March 7th 17 03:37 AM

More About Lights
 
On 3/5/2017 5:26 PM, Jeff Liebermann wrote:
On Sun, 5 Mar 2017 16:03:30 -0800 (PST), wrote:

Thanks Jeff. These however all appear to be battery powered
lights. We were sort of looking for lights that operated on
the hub dynamo of 6V 3W or the Globe dynamo of 12V 6W or
four times the power.


Sorry, I thought you were still open to looking at battery powered
lights. Here's what I fished out of my bookmark dumpster. No reviews
and few tests, but some interesting dynamo graphs and numbers:
http://www.myra-simon.com/bike/dynotest.html
http://pilom.com/BicycleElectronics/DynamoCircuits.htm
http://www.eeweb.com/blog/extreme_circuits/power-mosfet-bridge-rectifier

This one is well worth reading (or skimming) and has quite a few test
results:
http://swhs.home.xs4all.nl/fiets/tests/verlichting/index_en.html

This is why the hub generator has so little drag.


Well, let's do some arithmetic. If your dynamo is rated at 3 watts,
and your lighting is rated at 70 lumens/watt, then the most you can
perhaps deliver is 210 lumens. 6 watts will get perhaps 420 lumens.
Usually, it's less as the losses accumulate. Rectification losses,
optical losses, heat degradation, and connector losses all conspire to
produce lower output.


WE passed 70 lumens per watt a long time
ago.http://www.cree.com/LED-Components-and-Modules/Products/XLamp/Arrays-Directional/XLamp-MKR.
And bicycle light manufacturers are early adopters of the latest LEDs.

A dynamo can produce more than 3 watts at high speeds. In the olden days
of incandescent dynamo lights there was protection circuitry to limit
the power to the bulb by cutting off the voltage over 6V. But these high
power LEDs can handle 15W so there's no need to limit the power.

This light http://supernova-lights.com/en/supernova-e3-triple-2 claims
640 lumens at 4.5W. 4.5W is definitely possible from a nominal 3W
dynamo. It claims 800 lumens peak.

Note that his light, while sold in Germany, is not "road legal."
because, according to reviews, it doesn't suffer the problems of StVZO
lights, "It has a very broad light output that is closer to a floodlight
than a focused beam, and so doesn’t give the ‘tunnel’ effect of some of
the powerful battery-powered lights. This means it’s great for
illuminating branches and hazards above you and off to the side." As we
all know, the problem with StVZO legal lights are related to the
extremely focused spot beam. The best option, to avoid annoying others,
is to not use the highest settings when riding on narrow roads or paths.
You don't want endanger yourself by using sub-par StVZO lights unless
it's mandated by law.

Jeff Liebermann March 7th 17 04:41 AM

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On Mon, 6 Mar 2017 18:37:14 -0800, sms
wrote:

WE passed 70 lumens per watt a long time
ago.http://www.cree.com/LED-Components-and-Modules/Products/XLamp/Arrays-Directional/XLamp-MKR.
And bicycle light manufacturers are early adopters of the latest LEDs.


I got burned badly when I specified an LED that was rated at 100
lumens/watt, and got something that was about 70 lumens/watt. If you
look at the Xlamp MK-R data sheet at:
http://www.cree.com/~/media/Files/Cree/LED-Components-and-Modules/XLamp/Data-and-Binning/XLampMKR.pdf
the footknots always says:
"Flux values @25*°C are calculated and for reference only."
I'm not sure exactly what that means, but from my limited experience,
it means that if you pulse the power to the LED with a very short duty
cycle, you might get something near the rated efficacy. If you run it
on DC, it won't even come close. Calculated also means that they
didn't bother to verify their own calculations with an integrating
sphere measurement.

Assuming 200 lumens/watt and 1000 lumens output, that would require 5
watts of input power. Looking at the same data sheet (Pg 15) the 6v
chart shows that 5w is 5.8v @ 0.85A. So far, so good. However, if we
look at the Relative Flux Vs. Current (tJ = 85*°C) graph on Pg 16, the
output is derated to 65% of 1000 lumens. Producing only 650 lumens.
Using those numbers, the efficacy is now:
650 lumens / 5 watts = 130 lumens/watt
Note that the 85C is the junction temp, not the case or heat sink
temp.

Then, there is matching LED chips. See Pg 20
"Performance Groups - Luminous Flux (Tj = 85*°C)"
where one can pick the chip output anywhere from about 515 to 1290
lumens. What is not obvious is that the efficiency also drops at the
lower output levels, resulting in even lower lumens/watt.

Then there's the loss in output due to reflectors and lenses and the
increase of input current from current regulator losses. I would
guess(tm) 15% loss of lumens to the optics, and 10% for the regulator
efficiency. So, we start with
650 lumens / 5 watts = 130 lumens/watt
and end up with:
650 * 0.85 / 5 * 1.1 = 553 / 5.5 = 100 lumens/watt

Can you see where this is going? In the end, the lumens/watt value
for the end product is the light output including all the optics,
divided by the power input as measured from the battery, and derated
by the chip junction temperature.

A dynamo can produce more than 3 watts at high speeds.


I don't ride at high speeds. I'm slowly converting one of my machines
to a "comfort" bicycle.

In the olden days
of incandescent dynamo lights there was protection circuitry to limit
the power to the bulb by cutting off the voltage over 6V. But these high
power LEDs can handle 15W so there's no need to limit the power.


Yep. So why do many dynamos still use the increased inductive
reactance at higher speeds (and higher frequencies) to provide this
voltage limiting? It would be easy enough to reduce the winding
inductance and allow the voltage to increase linearly instead of
flat-topping. The manufacturer might be afraid of blowing something
up with too much voltage at high speeds.

This light http://supernova-lights.com/en/supernova-e3-triple-2 claims
640 lumens at 4.5W. 4.5W is definitely possible from a nominal 3W
dynamo. It claims 800 lumens peak.


640 lumens / 4.5 watts = 142 lumens/watt measured "warm".
If they start out with a 200 lumens/wall LED, that might be possible.
Ok, I stand corrected, but I'm also suspicious.

I couldn't find any test reports or method used on the Supernova site.
I did find this test of the M99 model:
http://supernova-lights.com/en/blog/supernova-blog-1/post/first-test-performance-supernova-m99-pro-br-36
1100 lumens / 16 watts = 68.7 lumens/watt. Hmmm...

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Frank Krygowski[_4_] March 7th 17 05:00 AM

More About Lights
 
On 3/6/2017 4:33 PM, Joerg wrote:

The real McCoy would be a worryfree system like in a car where it
recharges while riding. If I ever switch the road bike front wheel to
one with a hub dynamo I will do that. Right now it only has a bottle
dynamo, too much drag and it eats the left side wall of "modern" tires.


I've done well with a bottle dynamo whose drive wheel has an added
circumferential groove to hold a thick O-ring. That O-ring runs on the
rim's braking surface, not on the tire. Zero tire wear, and it runs
very smoothly. I've experienced no slipping - but it's not been tested
in the rain.


--
- Frank Krygowski

Frank Krygowski[_4_] March 7th 17 05:05 AM

More About Lights
 
On 3/6/2017 1:47 PM, wrote:

I notice that a large number of the people in our group have flashing red rear lights and it isn't long before these batteries run down enough that the taillight even blinking is almost entirely unnoticeable. So I don't have much respect for battery power for a great deal of use.


When the first twinkling LED taillights (by Vistalight) came out in the
1990s, people were very impressed by how visible they made a bike.
Bikes were visible up to half a mile away, and AA batteries in those
units last months.

Since then, "safety inflation" has proclaimed that they're insufficient
because they're too dim. Now you need a taillight so bright that it
blinds following riders. Of course those consume much more electricity.

--
- Frank Krygowski

Jeff Liebermann March 7th 17 05:10 AM

More About Lights
 
On Mon, 6 Mar 2017 16:57:41 +1100, James
wrote:

What if I don't want to play with batteries?


Then play with calcium carbide (produces acetylene gas) instead:
https://www.google.com/search?q=acetylene+bicycle+lamp&tbm=isch

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Frank Krygowski[_4_] March 7th 17 05:11 AM

More About Lights
 
On 3/6/2017 9:37 PM, sms wrote:

This light http://supernova-lights.com/en/supernova-e3-triple-2 claims
640 lumens at 4.5W. 4.5W is definitely possible from a nominal 3W
dynamo. It claims 800 lumens peak.

Note that his light, while sold in Germany, is not "road legal."
because, according to reviews, it doesn't suffer the problems of StVZO
lights, "It has a very broad light output that is closer to a floodlight
than a focused beam, and so doesn’t give the ‘tunnel’ effect of some of
the powerful battery-powered lights. This means it’s great for
illuminating branches and hazards above you and off to the side." As we
all know, the problem with StVZO legal lights are related to the
extremely focused spot beam.


Here's an example of an StVZO headlamp (2013 model) with the "extremely
focused spot beam" the Scharf complains about.
http://peterwhitecycles.com/images/p...lux-II-800.jpg

See that tiny spot? ;-)


--
- Frank Krygowski

Jeff Liebermann March 7th 17 05:29 AM

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On Mon, 6 Mar 2017 23:11:26 -0500, Frank Krygowski
wrote:

Here's an example of an StVZO headlamp (2013 model) with the "extremely
focused spot beam" the Scharf complains about.
http://peterwhitecycles.com/images/p...lux-II-800.jpg

See that tiny spot? ;-)


Here's the same photo with brightness converted to pseudo colors:
http://802.11junk.com/jeffl/pics/bicycles/Front-Light-False-Color/sch-edelux-II-800.jpg
No obvious hot spot.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

DATAKOLL MARINE RESEARCH March 7th 17 07:08 AM

More About Lights
 
never experiencing dyna lighting, the White photo bears no relation to anything I've read here.

I aaside the cycle is moving at 35 mph.

[email protected] March 7th 17 08:58 AM

More About Lights
 
On Tuesday, March 7, 2017 at 5:11:29 AM UTC+1, Frank Krygowski wrote:
On 3/6/2017 9:37 PM, sms wrote:

This light http://supernova-lights.com/en/supernova-e3-triple-2 claims
640 lumens at 4.5W. 4.5W is definitely possible from a nominal 3W
dynamo. It claims 800 lumens peak.

Note that his light, while sold in Germany, is not "road legal."
because, according to reviews, it doesn't suffer the problems of StVZO
lights, "It has a very broad light output that is closer to a floodlight
than a focused beam, and so doesn’t give the ‘tunnel’ effect of some of
the powerful battery-powered lights. This means it’s great for
illuminating branches and hazards above you and off to the side." As we
all know, the problem with StVZO legal lights are related to the
extremely focused spot beam.


Here's an example of an StVZO headlamp (2013 model) with the "extremely
focused spot beam" the Scharf complains about.
http://peterwhitecycles.com/images/p...lux-II-800.jpg

See that tiny spot? ;-)


--
- Frank Krygowski


That is the headlight I use and it looks exactly the same on a pitch dark street. So again I don't understand why people find this amount of light insufficient.

Lou

John B.[_3_] March 7th 17 01:06 PM

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On Mon, 6 Mar 2017 11:15:54 -0800 (PST), jbeattie
wrote:

On Sunday, March 5, 2017 at 9:57:44 PM UTC-8, James wrote:
On 06/03/17 10:22, Barry Beams wrote:


Burn time: What if you had five or ten hours battery time at your
generator's brightness? My Oculus gives at least that much
brightness, and a quickly field replaceable battery so you can put in
a fresh battery. Other rechargeables leave you out of light and out
of luck when the battery drains. Oculus also comes with a spare
battery included.


What if I don't want to play with batteries?


Then you're done with the battery light discussion and may move on to helmets.

-- Jay Beattie.


I thought that chain-lube was next on the agenda?
--
Cheers,

John B.


John B.[_3_] March 7th 17 02:00 PM

More About Lights
 
On Mon, 06 Mar 2017 20:10:21 -0800, Jeff Liebermann
wrote:

On Mon, 6 Mar 2017 16:57:41 +1100, James
wrote:

What if I don't want to play with batteries?


Then play with calcium carbide (produces acetylene gas) instead:
https://www.google.com/search?q=acetylene+bicycle+lamp&tbm=isch


Ahem! I don't think you should suggest acetylene gas devices to some
of the folks here. After all the safe limit for acetylene gas is 15
psi, above which it tends to go BOOM! :-)

(but maybe if you wear a helmet and have a bright light... :-)
--
Cheers,

John B.


Joerg[_2_] March 7th 17 05:37 PM

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On 2017-03-06 20:00, Frank Krygowski wrote:
On 3/6/2017 4:33 PM, Joerg wrote:

The real McCoy would be a worryfree system like in a car where it
recharges while riding. If I ever switch the road bike front wheel to
one with a hub dynamo I will do that. Right now it only has a bottle
dynamo, too much drag and it eats the left side wall of "modern" tires.


I've done well with a bottle dynamo whose drive wheel has an added
circumferential groove to hold a thick O-ring. That O-ring runs on the
rim's braking surface, not on the tire. Zero tire wear, and it runs
very smoothly. I've experienced no slipping - but it's not been tested
in the rain.


May main issue isn't rain but mud. Often the Soubitez bottle dynamo on
my road bike mutates into a clump of drying clay.

Back in Europe slush and ice was the main issue. Typically on a night
ride back home when a cold front rushed in. The slush accumulated at the
dynamo, gradually froze up there and at some point ... phseeeee ... no
more light on our bikes except on mine because that had a battery.

--
Regards, Joerg

http://www.analogconsultants.com/

Jeff Liebermann March 7th 17 07:38 PM

More About Lights
 
On Tue, 07 Mar 2017 20:00:47 +0700, John B.
wrote:

On Mon, 06 Mar 2017 20:10:21 -0800, Jeff Liebermann
wrote:

On Mon, 6 Mar 2017 16:57:41 +1100, James
wrote:

What if I don't want to play with batteries?


Then play with calcium carbide (produces acetylene gas) instead:
https://www.google.com/search?q=acetylene+bicycle+lamp&tbm=isch


Ahem! I don't think you should suggest acetylene gas devices to some
of the folks here. After all the safe limit for acetylene gas is 15
psi, above which it tends to go BOOM! :-)


I once found a patent for an acetylene lantern design that used the
heated gas pressure from the burning acetylene to pressurize a reed
and thus act as a horn. I don't recall if it had a built in red tail
light.

What keeps an acetylene lantern from blowing up and ruining a ride is
that the drip of water into the calcium carbide chamber is regulated
by the back pressure produced by the reaction. No water means no gas
is produced. It's a gravity fed affair, that's quite reliable and
should never raise the internal pressure anywhere near 15 psig.

(but maybe if you wear a helmet and have a bright light... :-)


The light isn't for me. It's for James who wants an alternative to
changing batteries. I solved my lighting problem long ago:
http://802.11junk.com/jeffl/pics/bicycles/slides/bicycle-flashlight.html

The big problem with an acetylene bicycle lantern is that a typical
lantern only delivers about 30 to 50 lumens (my measurements).

If you need a project, build an acetylene lamp that screws into an
aluminum water bottle.
http://www.4bobandbob.com/pages/pics/PremierDia.gif

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558


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