The last headlight you will ever need

Sir Ridesalot wrote:
Frank Krygowski wrote:
Jeff Liebermann wrote:
Also, I blundered into this article on using a bicycle to generate
electricity. I haven't read it in detail, but basically the author
suggests it's a lousy idea.
http://www.lowtechmagazine.com/2011/05/bike-powered-electricity-generators.html

It's certainly a lousy idea if the intent is to use electricity to drive
devices that can reasonably be driven mechanically. Consider what it
would take to generate and store electricity to run an electric can
opener, vs. just cranking a manual can opener for 15 seconds.
Many years ago, we were asked to donate appliances, etc. to an
impoverished immigrant family that had moved to our area. Among our
donations was a manual can opener. The woman accepting donations was
astonished - "Do those things still work?" etc. She'd used only an
electric one for years. But earlier still, when we were given an
electric one as a gift, we returned it to the store.
Bicycling for transportation does have very high efficiency, but that's
the result of a different factor. When a person rides a bike, they're
not hauling around 3000 pounds of metal, plastic, rubber and glass. The
moving mass is almost all payload.
Related: http://www.bicyclinglife.com/Effecti...cacy/bacon.htm

In the rticle from the first link they talk about dead zones in the pedal cycle when using a bicycle to power a generator on a bicycle type trainer. I wonder if BioPace or other oval chainrings would help there?

'Dead zone' is a common comment when non-cyclists analyze
cycling. In theory maybe, but in practice not so much.



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

On Wednesday, March 26, 2014 1:37:46 PM UTC-4, AMuzi wrote:
Sir Ridesalot wrote:

Frank Krygowski wrote:

Jeff Liebermann wrote:

Also, I blundered into this article on using a bicycle to generate

electricity. I haven't read it in detail, but basically the author

suggests it's a lousy idea.

http://www.lowtechmagazine.com/2011/05/bike-powered-electricity-generators.html



It's certainly a lousy idea if the intent is to use electricity to drive

devices that can reasonably be driven mechanically. Consider what it

would take to generate and store electricity to run an electric can

opener, vs. just cranking a manual can opener for 15 seconds.

Many years ago, we were asked to donate appliances, etc. to an

impoverished immigrant family that had moved to our area. Among our

donations was a manual can opener. The woman accepting donations was

astonished - "Do those things still work?" etc. She'd used only an

electric one for years. But earlier still, when we were given an

electric one as a gift, we returned it to the store.

Bicycling for transportation does have very high efficiency, but that's

the result of a different factor. When a person rides a bike, they're

not hauling around 3000 pounds of metal, plastic, rubber and glass. The

moving mass is almost all payload.

Related: http://www.bicyclinglife.com/Effecti...cacy/bacon.htm



In the rticle from the first link they talk about dead zones in the pedal cycle when using a bicycle to power a generator on a bicycle type trainer. I wonder if BioPace or other oval chainrings would help there?



'Dead zone' is a common comment when non-cyclists analyze

cycling. In theory maybe, but in practice not so much.







--

Andrew Muzi

www.yellowjersey.org/

Open every day since 1 April, 1971

Yes, many people including a lot of casual bicyclist think in terms of pistons rather than pedaling in circles.

Cheers

On Wed, 26 Mar 2014 18:53:41 +1100, James
wrote:

On 26/03/14 16:02, Jeff Liebermann wrote:

http://www.myra-simon.com/bike/dynotest.html

SP claims 72% for theirs.

This claims 67% for a SON.
http://www.ctc.org.uk/file/public/fe...ub-dynamos.pdf

See the description of how the hubs were tested on Pg 61.

"...electrical output is monitored with a 12 ohm resistance,
since that’s how it’s always been done, as bulbs are also
resistors."

Ummm... bulbs are not constant resistance, which varies with applied
voltage. Same with LED lamps that have built in current regulators.

"...his apparatus mounts the hubshell in a lathe chuck and
turns it at a set speed whilst measuring the drag force on
a lever attached to the axle."

It kinda looks like they measured the hub drag, and used that to
calculate efficiency (and ignored maybe 0.05 watts of bearing drag).
For example, the Son hub shows a difference in drag (with and without
a load) of:
6.39 - 1.05 watts = 5.34 watts (at 30 km/hr)
yet the graph shows that at 30 km/hr, it will only output 4.0 watts.
If you believe those numbers, then the efficiency should be the power
delivered divided by the drag under load or:
4.0 / 6.39 = 63%
which is close enough to the claimed 67% for the SON that I would
guess(tm) that's how it was done. I would feel better if they had
measured the input torque with a force guage to get the input power,
and used a load resembling a real LED light. I know I'm reading
between the lines, but I'm somewhat suspicious since there are no
details on the methods, no intermediate results, and no calculations
used to obtain their results.

Hmmm... I think I need to get some sleep.

Yep, you do.

Not a joke this time. I had 2 hrs sleep the night before and have
been working continuously on a project that finally escaped my desk
late last night. By the time I posted my messages, I was a zombie.
I'm taking the day off today to recover. A large truck decided to
roll over on the local highway this morning, so I have another excuse
to not go to the office and do nothing today. Back to sleep, I guess.



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

On Wed, 26 Mar 2014 11:28:00 -0400, Frank Krygowski
wrote:

On 3/26/2014 1:02 AM, Jeff Liebermann wrote:
Also, I blundered into this article on using a bicycle to generate
electricity. I haven't read it in detail, but basically the author
suggests it's a lousy idea.
http://www.lowtechmagazine.com/2011/05/bike-powered-electricity-generators.html

It's certainly a lousy idea if the intent is to use electricity to drive
devices that can reasonably be driven mechanically.

Ummm... I was talking about bicycle lamps. I suppose I could conjure
a mechanically driven bicycle lamp, but electric power seems to be
more convenient and practical.

Ah, got it. Instead of a dynamo, I install a hollow steel flywheel.
Around the outer edge, I attach an array of cigarette lighter flints.
When turning, the flints will produce highly visible sparks. Add a
reflector and I have a mechanical headlight that just might be more
efficient than an electrically driven headlight. I'll leave the
details, such as how to keep the sparks from setting my clothes on
fire, to production engineering.

Consider what it
would take to generate and store electricity to run an electric can
opener, vs. just cranking a manual can opener for 15 seconds.

Hmmm... I haven't seen any bicycle powered can openers, but I suppose
one could be designed. Speed reduction seems to be the major problem,
so I would suggest an outboard worm gear, driving a sprocket, with the
power transmitted to the can opener via a speedometer cable. I'm not
sure there's a market, but if you label it "high efficiency" and
"ecologically correct", it should bring in some sales.

Many years ago, we were asked to donate appliances, etc. to an
impoverished immigrant family that had moved to our area. Among our
donations was a manual can opener. The woman accepting donations was
astonished - "Do those things still work?" etc. She'd used only an
electric one for years. But earlier still, when we were given an
electric one as a gift, we returned it to the store.

Chuckle. I still use a manual can opener. I tried an electric opener
but found that it was slow and required disassembly for cleaning. When
the stress of opening some bent rim cans (50% off at the local market)
destroyed the plastic case, I gave up on it. Why anyone would want an
electric can opener is beyond my limited imagination.

Bicycling for transportation does have very high efficiency, but that's
the result of a different factor. When a person rides a bike, they're
not hauling around 3000 pounds of metal, plastic, rubber and glass. The
moving mass is almost all payload.
Related: http://www.bicyclinglife.com/Effecti...cacy/bacon.htm

Nice story, but the answer is obvious. We are a nation of convenience
addicts. It doesn't matter if it's economical, efficient,
ecologically correct, or even in fashion. If it's not convenient, to
won't sell. If you price modern convenience devices back to where the
raw materials were excavated from the ground, literally everything
that we do and buy can be done better, cheaper, and with less damage
to the environment if done manually or mechanically. It's much like
the old labor union joke, where the union guy complains that a steam
shovel has replaced 100 men with hand shovels, and where the business
owner retorts "why not 1000 men with teaspoons". It's difficult to
roll back progress, especially when the automobile is considered an
advancement over the bicycle.

Anyway, hauling around 3000 lbs of automobile is not very efficient or
economical, but it sure is convenient, especially if the bacon is far
away.

Ugh... topic drift... need sleep...




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

On 3/26/2014 12:29 PM, Jeff Liebermann wrote:

snip

Hmmm... I haven't seen any bicycle powered can openers, but I suppose
one could be designed. Speed reduction seems to be the major problem,
so I would suggest an outboard worm gear, driving a sprocket, with the
power transmitted to the can opener via a speedometer cable. I'm not
sure there's a market, but if you label it "high efficiency" and
"ecologically correct", it should bring in some sales.

You need to work on a bicycle driven coffee grinder. For bicycle
tourists without access to electric power the present options suck
because the manual grinders are extremely slow. Contrary to what was
shown in the movie City Slickers, there are no battery powered coffee
grinders. The closest I've come is this:
http://nordicgroup.us/bikecoff/bcimages/batterygrinder.JPG but this
12VDC grinder has been discontinued.

On 3/26/2014 4:22 PM, sms wrote:
On 3/26/2014 12:29 PM, Jeff Liebermann wrote:

snip

Hmmm... I haven't seen any bicycle powered can openers, but I suppose
one could be designed. Speed reduction seems to be the major problem,
so I would suggest an outboard worm gear, driving a sprocket, with the
power transmitted to the can opener via a speedometer cable. I'm not
sure there's a market, but if you label it "high efficiency" and
"ecologically correct", it should bring in some sales.

You need to work on a bicycle driven coffee grinder. For bicycle
tourists without access to electric power the present options suck
because the manual grinders are extremely slow. Contrary to what was
shown in the movie City Slickers, there are no battery powered coffee
grinders. The closest I've come is this:
http://nordicgroup.us/bikecoff/bcimages/batterygrinder.JPG but this
12VDC grinder has been discontinued.

There goes your commission!

--
- Frank Krygowski

On Wed, 26 Mar 2014 11:28:00 -0400, Frank Krygowski
wrote:

On 3/26/2014 1:02 AM, Jeff Liebermann wrote:


Also, I blundered into this article on using a bicycle to generate
electricity. I haven't read it in detail, but basically the author
suggests it's a lousy idea.
http://www.lowtechmagazine.com/2011/05/bike-powered-electricity-generators.html

It's certainly a lousy idea if the intent is to use electricity to drive
devices that can reasonably be driven mechanically. Consider what it
would take to generate and store electricity to run an electric can
opener, vs. just cranking a manual can opener for 15 seconds.

Many years ago, we were asked to donate appliances, etc. to an
impoverished immigrant family that had moved to our area. Among our
donations was a manual can opener. The woman accepting donations was
astonished - "Do those things still work?" etc. She'd used only an
electric one for years. But earlier still, when we were given an
electric one as a gift, we returned it to the store.

Bicycling for transportation does have very high efficiency, but that's
the result of a different factor. When a person rides a bike, they're
not hauling around 3000 pounds of metal, plastic, rubber and glass. The
moving mass is almost all payload.

Related: http://www.bicyclinglife.com/Effecti...cacy/bacon.htm

The Army had pedal generated generators in WW II. Supposed to provide
emergency power for radios or some such use.

The problem is that human power is not very effective. About the
smallest auxiliary generator I see these days is a 600 watt unit,
Little 2 stroke engine will put out a continuous 600 watts all day on
a tank of gas :-)
--
Cheers,

John B.

On Wed, 26 Mar 2014 13:22:45 -0700, sms
wrote:

On 3/26/2014 12:29 PM, Jeff Liebermann wrote:

snip

Hmmm... I haven't seen any bicycle powered can openers, but I suppose
one could be designed. Speed reduction seems to be the major problem,
so I would suggest an outboard worm gear, driving a sprocket, with the
power transmitted to the can opener via a speedometer cable. I'm not
sure there's a market, but if you label it "high efficiency" and
"ecologically correct", it should bring in some sales.

You need to work on a bicycle driven coffee grinder. For bicycle
tourists without access to electric power the present options suck
because the manual grinders are extremely slow. Contrary to what was
shown in the movie City Slickers, there are no battery powered coffee
grinders. The closest I've come is this:
http://nordicgroup.us/bikecoff/bcimages/batterygrinder.JPG but this
12VDC grinder has been discontinued.


My goodness but you Americans seem so inapt. One can easily pound
coffee beans into a powder with a mortar and pestle. Just like the old
folks used to. But of course, you probably can't figure out how to
operate one of those.
--
Cheers,

John B.

On 3/26/2014 3:07 PM, Jeff Liebermann wrote:
On Wed, 26 Mar 2014 18:53:41 +1100, James
wrote:

On 26/03/14 16:02, Jeff Liebermann wrote:

http://www.myra-simon.com/bike/dynotest.html

SP claims 72% for theirs.

This claims 67% for a SON.
http://www.ctc.org.uk/file/public/fe...ub-dynamos.pdf

See the description of how the hubs were tested on Pg 61.

"...electrical output is monitored with a 12 ohm resistance,
since that’s how it’s always been done, as bulbs are also
resistors."

Ummm... bulbs are not constant resistance, which varies with applied
voltage. Same with LED lamps that have built in current regulators.

I wondered about that when I read it. Personally, I think a fixed 12
Ohm resistor was a good enough load for comparing generators back in the
days of halogen bulbs. But we are pretty thoroughly in the LED era.

I just put one of my bikes on my workstand. It's got a Shimano hub
dynamo (DH-3N30) and a Busch & Muller IQ Cyo LED headlamp. There's also
a homebrew LED taillight.

Anyway, I hooked up a voltmeter and spun the wheel at 9.5 mph (15.3 kph)
and at 30 mph (48 kph), using an electric drill fitted with two
different diameter sanding disks. At both those speeds, the voltage was
only 3.9 Volts. That's significantly less than what would result with a
12 Ohm load. (Knowing the characteristics of dynamos, it's pretty
certain the hub was still putting out half an amp, so that hub was
putting out only about 2 Watts. )

That tells me that LED lights don't need to consume even 3 Watts. My
riding experience tells me that, with decent optics, those 2 Watts give
plenty of light for any reasonable riding. It also means that the drag
would be even less than what they measured with the 12 Ohm load.

--
- Frank Krygowski

Jeff Liebermann wrote:

:Chuckle. I still use a manual can opener. I tried an electric opener
:but found that it was slow and required disassembly for cleaning. When
:the stress of opening some bent rim cans (50% off at the local market)
:destroyed the plastic case, I gave up on it. Why anyone would want an
:electric can opener is beyond my limited imagination.

Arthritis.

--
sig 114