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Is there an updated Dynotest somewhere?



 
 
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  #41  
Old September 15th 17, 08:34 AM posted to rec.bicycles.tech
John B.[_3_]
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Posts: 5,697
Default Is there an updated Dynotest somewhere?

On Fri, 15 Sep 2017 06:12:02 -0000 (UTC), bob prohaska
wrote:

John B. wrote:

Not to argue but why is the "clawpole armature" used in automotive
"alternators".
--


The power output of any given electrical machine is proportional to operating
frequency (within some rather broad limits). If you want high power, the
easiest way to get it is using high(er) frequency. Clawpole designs are
mechanically strong and relatively cheap to manufacture.

http://www.rle.mit.edu/per/wp-conten...pologies-I.pdf
states in part:
The salient pole synchronous generator has
the highest electrical output per pound per rpm among all
generators according to a NASA study published in 1965 [9].
It also has the lowest reactances and therefore its regulation
and transient performance are the best.


bob prohaska


Thanks for that.
--
Cheers,

John B.

Ads
  #42  
Old September 15th 17, 12:12 PM posted to rec.bicycles.tech
Sepp Ruf
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Posts: 454
Default Is there an updated Dynotest somewhere?

James wrote:
On 11/09/17 19:40, Sepp Ruf wrote:
James wrote:


My SP PV8 hub dynamo has been in service for a few years now. I guess
that means it's done near 30,000km already, with no issues to report.


Good to hear, good for you!

How many indoor/outdoor temperature cycles at 100% humidity,


I don't store my bicycle indoors.

how much frost,


Never had icicles forming on it.


There we go, dynamo hubs are lossy! They get so hot that any precipitation
just evaporates!!

road salt,


I don't think we get salted roads in Australia. At least none that I am
aware of.

Joerg-ific Wisconsin winters has it been exposed to?


None. I don't live there. We get some 100% humidity and some mornings
where the temperature drops to just below zero. Does that help?


No :-) I'm tempted to get one nice blue PV8 at the price of three dull,
heavy Shimano "thirtysomethings," but I only have a choice of keeping it
away from either winter-salted roads or subtropical coastal ones.
  #43  
Old September 15th 17, 01:55 PM posted to rec.bicycles.tech
Ralph Barone[_4_]
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Posts: 853
Default Is there an updated Dynotest somewhere?

Frank Krygowski wrote:
On 9/14/2017 10:26 AM, Ralph Barone wrote:
bob prohaska wrote:
Sepp Ruf wrote:

For Rob who might experience mental drag uphill from just having to see a
big, heavy, non-laminated hub slowly revolving in the front wheel, the
smallish Shimano DH-T780-1N, 1.5W 250mA class, might suffice[1] once he
grows sick of the Soubitez. Best price I see is 96 euros a pair from CNC
Hamburg on ebay, no overseas shipping available, though.
http://www.ebay.com/itm/253093811841

[1]
DRL does not require more than 100 lumens if you get the optics right.

It's a bit puzzling how folks seem to excuse poor design in dynamo hubs
when they're considerably more fanatic about optimizing every other part
of a bicycle.

In particular, the 3 watt standard is utterly archaic. Folks now are
starting to use dynamos to power electronics, and I suspect most would
opt for more than 3 watt lights if useful designs were available.

I still don't understand why high-end builders like Schmidt don't use
salient-pole armatures, which could be constructed from standard motor
laminations (instead of the custom clawpole monolith used now). That
would shorten the iron path dramatically, reducing reluctance, reduce
the length of copper, reducing resistance. The performance gains can
be traded for lighter weight, higher efficiency or higher power.
Every motor builder in the world does it that way, why not dyamo hub
builders? Maybe there _is_ a technical reason, but it certainly isn't
apparent to me. The use of incandescent bulbs may have set the tradition,
but it's certainly no reason to continue.

At this rate I won't "get sick" of the Soubitez, I'll wear it out.

bob prohaska


Machine theory is a bit of a black art for me, but I suspect that the "less
optimized" magnetics in hub dynamos provides the extra leakage inductance
required to make it self regulate into a 12 ohm load. I fully agree that a
less well regulated output plus a switching regulator could work very well
with modern electronics.


Is it feasible to use a switching regulator when you've got as much
inductance as a typical hub dynamo? I'd have thought that causes problems.

But then, I'm not an EE.


Sure. If we can jam multiple GFLOPS of processing power into a phone, we
can surely make an SMPS that can handle the output of a hub dynamo. Hell,
we were able to make multi hundred MW AC-DC-AC converters in 1967 using
vacuum tubes.

  #44  
Old September 15th 17, 04:40 PM posted to rec.bicycles.tech
Andre Jute[_2_]
external usenet poster
 
Posts: 10,422
Default Is there an updated Dynotest somewhere?

On Friday, September 15, 2017 at 1:56:03 PM UTC+1, Ralph Barone wrote:
Hell,
we were able to make multi hundred MW AC-DC-AC converters in 1967 using
vacuum tubes.


Now you're speaking my language!

Andre Jute
Fidelista
(No, not that one, he's wormfood and good riddance to bad rubbish, too)
  #45  
Old September 15th 17, 05:43 PM posted to rec.bicycles.tech
Andre Jute[_2_]
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Posts: 10,422
Default Is there an updated Dynotest somewhere?

On Saturday, September 9, 2017 at 4:57:50 AM UTC+1, bob prohaska wrote:

...any guidance...


Bike lamps and particularly bike dynamo lamps are at the level of 6V VW dim/dip lamps, if you are venerable enough to remember those. They became that good, i.o.w. barely sufficient, only in the last ten years, with the advent of the reflector technology associated with the Busch & Muller Cyo. All the remaining failures of this lamp, and of hub dynamos in general, are traceable to silly regulations made by German legislators. In particular, the lamp doesn't throw high enough to see stop signs on country lane crossing where I live, because of the flat-top cutoff.

I have both high and low quality Shimano hub dynamos and SON. I wouldn't pay the premium for a SON, but the one I have was already on a bike I was getting a huge discount on, and I was already imposing on the dealer to swap out other parts more critical to my use of the bike. You don't need a better hub dynamo than the Shimano with replaceable bearings, whatever it's number is now. For city and town riding at night, and during the day if you want daylight running lamps, the Shimano is superior in that it comes up to speed faster than the very old-fashioned SON.

It's a mistake to think that daylight running lamps have a lesser requirement; DRL in fact have more stringent requirements. The BUMM lamps have DRL from separate LED, and miserable it is too, barely better than nothing, and perhaps worse it causes undue confidence in the rider. Since the main lamp LEDs have an essentially unlimited MTBF, I just switch my lamps on when the bike arrives and never switch them off again: I run the main lamps day and night. Careful: there's also an automatic day/night switching option, which looks like an extra cost, but the lamp with it is often the cheapest at the European discounters, so I buy that one, but carefully switch it out for good, forever, so that in daylight my lamps run full strength.

These BUMM lamps, front and rear, may be the best available at any reasonable price, and at least they aren't the sort of inadequate crap BUMM pushed until about ten years ago, but you should be aware that none of them have a blinking mode, another failure of imagination by the German legislators, though you can easily build electronics to add a flash mode. I used to run additional lamps for flash mode but no longer do because the Cyo lamps, running their nighttime mode in the day, are strong enough to be easily seen when the bike itself (it's British Racing Green) is nearly invisible in the shade of trees overhanging the road, a common condition here.

Finally, I have a Cateye taillight, No. TL-LD1100, which many thought the best battery rear lamp generally available, which runs 200 hours on a pair of AA batteries and has flashing modes. I never found anything that economical for the front of the bike, but a 200 hour life for even one of your lamps isn't a nuisance at the level of lamps that chew a set of batteries on every ride or every second or third ride.

On your question about the likelihood of improvements to hub dynamos, the answer is the sameoldsameold: The German legislators fixed the dynamo's output and there is no incentive whatsoever to improve it, only costs and protracted struggles with bureaucracy. In any event, BUMM and SON and the German lobbyists paid by Shimano and BUMM would be the big losers of any new legislative dispensation because currently by virtue of primacy they enjoy a near monopoly -- vide Sepp Ruf's sarcastic remarks about complaints that tests conducted on the products of competitors by the SON employee Andreas Oehler are at best suspect and more than likely worthless because of his involuntary bias: they wouldn't be so brazen about it in a better-regulated field with real competition. Nor can foreign competitors make radical innovations, because the German legislation results in certain expectations of OEM suppliers by all the big bike makers, who are the major market, not individuals like you'n'me. Sorry, but you're screwed before you start down that road -- and that also explains why James' hub dynamo is so little better than a SON or a Shimano, and why every tiny gain is shouted from the rooftops like they just discovered the Grand Unified Theory Einstein failed to discover: those designers had to keep looking over their shoulders at the German legislation.

Andre Jute
Luminous
  #46  
Old September 15th 17, 06:03 PM posted to rec.bicycles.tech
Joerg[_2_]
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Posts: 6,016
Default Is there an updated Dynotest somewhere?

On 2017-09-14 12:15, Frank Krygowski wrote:
On 9/14/2017 10:26 AM, Ralph Barone wrote:
bob prohaska wrote:
Sepp Ruf wrote:

For Rob who might experience mental drag uphill from just having to
see a
big, heavy, non-laminated hub slowly revolving in the front wheel, the
smallish Shimano DH-T780-1N, 1.5W 250mA class, might suffice[1] once he
grows sick of the Soubitez. Best price I see is 96 euros a pair
from CNC
Hamburg on ebay, no overseas shipping available, though.
http://www.ebay.com/itm/253093811841

[1]
DRL does not require more than 100 lumens if you get the optics right.

It's a bit puzzling how folks seem to excuse poor design in dynamo hubs
when they're considerably more fanatic about optimizing every other part
of a bicycle.

In particular, the 3 watt standard is utterly archaic. Folks now are
starting to use dynamos to power electronics, and I suspect most would
opt for more than 3 watt lights if useful designs were available.

I still don't understand why high-end builders like Schmidt don't use
salient-pole armatures, which could be constructed from standard motor
laminations (instead of the custom clawpole monolith used now). That
would shorten the iron path dramatically, reducing reluctance, reduce
the length of copper, reducing resistance. The performance gains can
be traded for lighter weight, higher efficiency or higher power.
Every motor builder in the world does it that way, why not dyamo hub
builders? Maybe there _is_ a technical reason, but it certainly isn't
apparent to me. The use of incandescent bulbs may have set the
tradition,
but it's certainly no reason to continue.

At this rate I won't "get sick" of the Soubitez, I'll wear it out.

bob prohaska


Machine theory is a bit of a black art for me, but I suspect that the
"less
optimized" magnetics in hub dynamos provides the extra leakage inductance
required to make it self regulate into a 12 ohm load. I fully agree
that a
less well regulated output plus a switching regulator could work very
well
with modern electronics.


Is it feasible to use a switching regulator when you've got as much
inductance as a typical hub dynamo?



Yes.


I'd have thought that causes problems.



Nope :-)


But then, I'm not an EE.


If charging a battery plus driving a light (which is the proper setup,
like in a motor vehicle) it is advantageous to run the converter in
"maxiumum power point tracking" or MPPT mode. That is what solar
converters mostly do as well. A small processor dithers the "conversion
factor" (input to output voltage) slightly around while constantly
calculating the output power, indicating whether the maximum power point
is drifting higher, lower, or remains constant. Mostly depending on
riding speed in this case. When the load demand is met, the battery full
and lights at full brightness, it has to back off in the direction of
causing the least amount of mechanical load. The latter isn't a concern
with solar panels.

On a bicycle one would like a few more features, for example an
uphill-disable that sheds the load unless the bus voltage is or becomes
critically low. Another potential feature could be energy harvesting
downhill by maximizing the power output during those times. 3-axis
sensors could help determining such conditions automatically. Endless
possibilities but, of course, there will come a point where it becomes
"technology looking for a home" and more does not make sense.

As usual don't expect to see this at bike shops anytime soon.

Sort of OT but funny: Yesterday I stood at a red traffic light in the
middle of the lane and my road bike started making a wee-wee. A puddle
formed underneath the BB, meaning below where the saddle is ...
embarrassing. Turns out my water bottle had developed a circumferential
hair-crack.

--
Regards, Joerg

http://www.analogconsultants.com/
  #47  
Old September 15th 17, 06:33 PM posted to rec.bicycles.tech
Joerg[_2_]
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Posts: 6,016
Default Is there an updated Dynotest somewhere?

On 2017-09-14 14:42, Frank Krygowski wrote:
On 9/14/2017 4:43 PM, Radey Shouman wrote:
Frank Krygowski writes:

On 9/14/2017 10:26 AM, Ralph Barone wrote:
bob prohaska wrote:
Sepp Ruf wrote:

For Rob who might experience mental drag uphill from just having
to see a
big, heavy, non-laminated hub slowly revolving in the front wheel,
the
smallish Shimano DH-T780-1N, 1.5W 250mA class, might suffice[1]
once he
grows sick of the Soubitez. Best price I see is 96 euros a pair
from CNC
Hamburg on ebay, no overseas shipping available, though.
http://www.ebay.com/itm/253093811841

[1]
DRL does not require more than 100 lumens if you get the optics
right.

It's a bit puzzling how folks seem to excuse poor design in dynamo
hubs
when they're considerably more fanatic about optimizing every other
part
of a bicycle.

In particular, the 3 watt standard is utterly archaic. Folks now are
starting to use dynamos to power electronics, and I suspect most would
opt for more than 3 watt lights if useful designs were available.

I still don't understand why high-end builders like Schmidt don't use
salient-pole armatures, which could be constructed from standard motor
laminations (instead of the custom clawpole monolith used now). That
would shorten the iron path dramatically, reducing reluctance, reduce
the length of copper, reducing resistance. The performance gains can
be traded for lighter weight, higher efficiency or higher power.
Every motor builder in the world does it that way, why not dyamo hub
builders? Maybe there _is_ a technical reason, but it certainly isn't
apparent to me. The use of incandescent bulbs may have set the
tradition,
but it's certainly no reason to continue.

At this rate I won't "get sick" of the Soubitez, I'll wear it out.

bob prohaska

Machine theory is a bit of a black art for me, but I suspect that
the "less
optimized" magnetics in hub dynamos provides the extra leakage
inductance
required to make it self regulate into a 12 ohm load. I fully agree
that a
less well regulated output plus a switching regulator could work
very well
with modern electronics.

Is it feasible to use a switching regulator when you've got as much
inductance as a typical hub dynamo? I'd have thought that causes
problems.


Happens all the time. Google "h-bridge", and notice all those diodes in
parallel with the switching components, allowing current always to
continue to circulate through some path. Typically the diodes are
in the same package as the switching component, eg MOSFET.


So spikes, etc. from switching inductors get to sort of bleed off
through diodes? Is that the idea? Again, electronics isn't my thing.


Not for switching inductors because those are handled inherently by the
design of the switching regulator. However, there will be other
inductive spikes due to generator inductance and cabling inductance.
You'll have to muffle spikes that could exceed any absolute maximum
ratings of components either via capacitance or a transient voltage
suppressor (TVS). A TVS is essentially a fat glorified zener diode.
Important is to also consider the case of an erratic cable connection
which should not cause the electronics to fry.

Easy to do.

--
Regards, Joerg

http://www.analogconsultants.com/
  #48  
Old September 15th 17, 06:54 PM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 6,016
Default Is there an updated Dynotest somewhere?

On 2017-09-14 12:26, Frank Krygowski wrote:
On 9/14/2017 1:46 AM, bob prohaska wrote:
Sepp Ruf wrote:

For Rob who might experience mental drag uphill from just having to
see a
big, heavy, non-laminated hub slowly revolving in the front wheel, the
smallish Shimano DH-T780-1N, 1.5W 250mA class, might suffice[1] once he
grows sick of the Soubitez. Best price I see is 96 euros a pair from
CNC
Hamburg on ebay, no overseas shipping available, though.
http://www.ebay.com/itm/253093811841

[1]
DRL does not require more than 100 lumens if you get the optics right.


It's a bit puzzling how folks seem to excuse poor design in dynamo hubs
when they're considerably more fanatic about optimizing every other part
of a bicycle.

In particular, the 3 watt standard is utterly archaic. Folks now are
starting to use dynamos to power electronics, and I suspect most would
opt for more than 3 watt lights if useful designs were available.


Well, dynamos are not limited to 3 Watts. As James and others have
discussed, they'll put out more power if presented with bigger loads,
i.e. more resistance.



Ummm, not quite. More resistance doesn't always mean bigger load, it
only does so if you let the voltage rise. For any speed there is a
resistance that will result in a maximum of the delivered electrical
power. That resistance and the maximum power vary with speed.


... They're essentially constant current devices. I
used to occasionally drive two halogen headlamps from my Soubitez roller
dynamo. Others do it with hub dynos. (It doesn't work well with a bottle
dyno, though, because the smaller drive roller is more prone to slipping.)


What happens is that the current isn't very constant. Many dynamos will
go to 700mA and higher if you put the coals on. That was the reason I
constantly blew light bulbs as a teenager until I finally
"electronicized" my bikes and installed a recharcheable battery.


Second, despite the current fashion for mega-lumen lights, I've seen no
evidence that road cyclists need them, and I've seen the disadvantages.
IME, a good B&M LED headlight lights up a stop sign nearly 1/4 mile way.
It also illuminates the road very well; and with ever-improving LEDs,
the current models are probably better than the ones I own.

And it's a little ironic that the mega-lumen fans choose to ignore poor
optical design in their headlights, leading to inferior illumination
while blinding others. I think that's a bigger problem than a few
percent less theoretical efficiency in the dynamo.


There are people who disagree with you on that, such a yours truly.


Finally, there are devices which will power a phone or a GPS unit from a
hub dyno. Personally, I'd prefer to limit people from (say) playing
their stereo speakers while they ride!



My MP3 player is really helpful when riding boring stretches of prairie
on the MTB or long lone climbs on the road bike. Plus it helps drown out
the constant din of traffic when riding on roads. I used it for 2-1/2h
of the 4h ride yesterday.


At this rate I won't "get sick" of the Soubitez, I'll wear it out.


I've got two that are working very well. They're decades old. One was a
gift, from a friend who ripped out its output wire. A little solder
fixed that.


Nowadays you'll have to run them on the rim or the tire's road surface
though. Sidewalls have become too flimsy, they'd likely even wear with
your o-ring trick.

--
Regards, Joerg

http://www.analogconsultants.com/
  #49  
Old September 15th 17, 06:58 PM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 6,016
Default Is there an updated Dynotest somewhere?

On 2017-09-14 13:02, jbeattie wrote:
On Thursday, September 14, 2017 at 12:26:34 PM UTC-7, Frank Krygowski
wrote: snip

Finally, there are devices which will power a phone or a GPS unit
from a hub dyno. Personally, I'd prefer to limit people from (say)
playing their stereo speakers while they ride!
At this rate I won't "get sick" of the Soubitez, I'll wear it
out.


Careful, there . . . Joerg runs speakers. The noise keeps the
mountain lions away.

I wan't to slap the dopes with speakers on their bikes -- make them
crash into the guys with earbuds who then domino into the guys
talking or texting on their iPhones. I wish the great heel of Yahweh
would come down and crush all those devices -- at least while in use
on bikes.


One has to use them judiciously and not too loudly. As for animals: Once
I was gently herding a cow back to her pasture, playing cowboy with my
MTB. At the end she shoved herself through the fence she probably busted
out from, so fast that it seemed like it wasn't her first "excursion".
This caused the fence to make loud twanging noises and that made the
herd nervous. Singing calms herds but I can't sing at all. So I turned
on the MP3 player and set it to a smooth African tune. That did it.

[...]

--
Regards, Joerg

http://www.analogconsultants.com/
  #50  
Old September 15th 17, 07:05 PM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 6,016
Default Is there an updated Dynotest somewhere?

On 2017-09-14 18:48, sms wrote:
On 9/13/2017 10:46 PM, bob prohaska wrote:
Sepp Ruf wrote:

For Rob who might experience mental drag uphill from just having to
see a
big, heavy, non-laminated hub slowly revolving in the front wheel, the
smallish Shimano DH-T780-1N, 1.5W 250mA class, might suffice[1] once he
grows sick of the Soubitez. Best price I see is 96 euros a pair from
CNC
Hamburg on ebay, no overseas shipping available, though.
http://www.ebay.com/itm/253093811841

[1]
DRL does not require more than 100 lumens if you get the optics right.


It's a bit puzzling how folks seem to excuse poor design in dynamo hubs
when they're considerably more fanatic about optimizing every other part
of a bicycle.


There's little competition in dynamo hubs and an extremely limited
market for higher efficiency hubs that would require different lights.

If someone could build a 6W hub that could be rectified and power and
charge a decent commute light then it'd be great, but most riders that
need that much light for commuting have already moved on.



I did, simply mounting a Li-Ion battery block on each bike. The MTB has
four 18650 cells, the road bike has eight. That turned out to be
sufficient for my usual rides.

In the old days (70's and up) I also had a dynamo that charged the
battery. Back then lead-acid, later NiCd. Now with the Li-Ion I didn't
feel that urge because they pack so much energy. When my front rim is up
I might consider a new wheel with a hub dynamo if one is available at
not much more than a wheel sans dynamo. Then I could drop to two or four
18650 cells for the road bike.

--
Regards, Joerg

http://www.analogconsultants.com/
 




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