Lights

The Wogster said:

Wouldn't take much to add over-voltage protection, just need the right
sized voltage regulator put it between the generator and the light, and
voila, no more over voltages..... There might be room inside the light
for the chip, it needs three connections, INPUT (from the generator),
output (to the light) and ground (steel or aluminum bike frame usually).
Would be easy enough to take the chip, add a wire on each side, and a
screw to attach it, the ground terminal could be connected to the screw.

Sounds like you might be talking about a voltage regulator made for DC.
Bike generators put out AC (and high frequency AC at that). You can
buy voltage regulators for them (visit www.electralite.com IIRC) but I
don't think the standard unit you'd buy at Radio Shack would work
properly. Admittedly, I haven't tried, so I'd be interested in a
real-world report.

The usual voltage regulating scheme for a generator light is way, way
simpler. Almost everyone just puts two Zener diodes in parallel with
the lamp. The zeners will chop the top off the voltage curve.

More technical detail: Since generator systems are nominally six volt,
you might think you'd want six volt zeners - but that's not the case.
First, halogen generator bulbs can handle up to about 10% overvoltage
just fine, so you might want 6.6 volts... but it's the RMS value that
counts, not the peak.

This gets difficult to measure (you need a true RMS meter, not a
standard AC voltmeter) but IIRC a set of 8 volt zeners works well.
That's what I've got on my headlight, anyway, and it's been good for
many years.

Quoted message said:

Small over voltages are probably okay, a 3V lamp with a 4V or 5V
regulator is probably as good as a 3V regulator. The regulator needs to
be able to handle a large over voltage, like 40V.

The only way you'll get 40 volts out of a bike generator is if you run
it at high speed with no load - that is, with no headlight or
taillight. This could happen, I suppose, if you burnt out both bulbs
on a 30 mph descent. But the simple zener regulator would handle it
fine, provided you picked zeners capable of handling the generator's
current. Standard current is half an amp.

- Frank Krygowski

Quoted message said:

The Wogster said:

Wouldn't take much to add over-voltage protection, just need the right
sized voltage regulator put it between the generator and the light, and
voila, no more over voltages..... There might be room inside the light
for the chip, it needs three connections, INPUT (from the generator),
output (to the light) and ground (steel or aluminum bike frame usually).
Would be easy enough to take the chip, add a wire on each side, and a
screw to attach it, the ground terminal could be connected to the screw.

Sounds like you might be talking about a voltage regulator made for DC.
Bike generators put out AC (and high frequency AC at that). You can
buy voltage regulators for them (visit www.electralite.com IIRC) but I
don't think the standard unit you'd buy at Radio Shack would work
properly. Admittedly, I haven't tried, so I'd be interested in a
real-world report.

That link did not work....

Quoted message said:

The usual voltage regulating scheme for a generator light is way, way
simpler. Almost everyone just puts two Zener diodes in parallel with
the lamp. The zeners will chop the top off the voltage curve.

I stand corrected, would seem to be even cheaper, and you could probably
just put them somewhere along the wire with some solder and shrink wrap
wire tubing.....

Quoted message said:

More technical detail: Since generator systems are nominally six volt,
you might think you'd want six volt zeners - but that's not the case.
First, halogen generator bulbs can handle up to about 10% overvoltage
just fine, so you might want 6.6 volts... but it's the RMS value that
counts, not the peak.

This gets difficult to measure (you need a true RMS meter, not a
standard AC voltmeter) but IIRC a set of 8 volt zeners works well.
That's what I've got on my headlight, anyway, and it's been good for
many years.

The only way you'll get 40 volts out of a bike generator is if you run
it at high speed with no load - that is, with no headlight or
taillight. This could happen, I suppose, if you burnt out both bulbs
on a 30 mph descent. But the simple zener regulator would handle it
fine, provided you picked zeners capable of handling the generator's
current. Standard current is half an amp.

How about some part numbers or specs? Planning on new bike, thinking
generator lamp, and wouldn't mind doing it this way....

W

SMS said:

mark said:

When I win the lottery I'm upgrading to the Schmidt with an E6 secondary

Me too. I could have a dynamite dynamo system on my commute bike for
only $500 or so. That's only about 167 gallons of gasoline!

$500? What you smoking, dude? I bought a system last year when the
dollar hit its low vs the euro. $400 for a Schmidt hub based wheel, a
Schmidt E6 (as good of a light as it gets), a Lumotec, and all the
mounting hardware. You need a wheel anyway, so deduct the cost of
spokes and a rim and we are now running close to $300.

Cost of a top notch dynamo hub/light system: $400
Value of being able to continue riding and not worry about dead
batteries and chargers when riding through the Pyrenees/Alps:
Priceless.

- rick

Chuck said:

Jasper Janssen said:

Chuck said:

My kid's RC car broke and I had these 2 battery pack laying around so I
figured I play around with the soldering iron and rig up a battery pack.
I hooked together 15 AA size Ni-cads and soldered on a radio shack end
that's the same as the original. I couldn't believe how well it worked.
3:45 before it died and the pack size is smaller than the original.

How do you plan on recharging a 15-nicd cell pack? Or d'you use those
battery holder things?

Jasper

I taped and soldered them together in a series-paralell circuit then
soldered on the same end that the Cygo light came with. I then cut a
water bottle to half size and put the pack in it just like the original,
only smaller. What I did was take 5 batteries in series and mounted 3
packs of those paralell. The original pack put out 6.5 volt and this one
puts out 6.2 volt and charges overnight with the original charger that
came with the light.

I sure hope that you're not charging the packs in parallel! Connecting
them in parallel for discharging is okay, at least with NiMH batteries.

SMS said:

Chuck said:

Jasper Janssen said:

On Tue, 06 Sep 2005 22:00:46 GMT, Chuck <[email hidden]> wrote:

>My kid's RC car broke and I had these 2 battery pack laying around so I
>figured I play around with the soldering iron and rig up a battery pack.
>I hooked together 15 AA size Ni-cads and soldered on a radio shack end
>that's the same as the original. I couldn't believe how well it worked.
>3:45 before it died and the pack size is smaller than the original.

How do you plan on recharging a 15-nicd cell pack? Or d'you use those
battery holder things?

Jasper

I taped and soldered them together in a series-paralell circuit then
soldered on the same end that the Cygo light came with. I then cut a
water bottle to half size and put the pack in it just like the original,
only smaller. What I did was take 5 batteries in series and mounted 3
packs of those paralell. The original pack put out 6.5 volt and this one
puts out 6.2 volt and charges overnight with the original charger that
came with the light.

I sure hope that you're not charging the packs in parallel! Connecting
them in parallel for discharging is okay, at least with NiMH batteries.

Why would they not be okay to charge in parallel but ok to discharge.
It's not that they are a resistive circuit. Anyways, they've worked fine
so far and if they mess up I'm out of $1.25.

The Wogster said:

Quoted message said:

Sounds like you might be talking about a voltage regulator made for DC.
Bike generators put out AC (and high frequency AC at that). You can
buy voltage regulators for them (visit www.electralite.com IIRC) but I
don't think the standard unit you'd buy at Radio Shack would work
properly. Admittedly, I haven't tried, so I'd be interested in a
real-world report.

That link did not work....

Sorry. Not nearly enough sleep last night. That should be
www.reflectalite.com and you can hit the link to the regulator at the
bottom of the page.

Quoted message said:

Quoted message said:

The only way you'll get 40 volts out of a bike generator is if you run
it at high speed with no load - that is, with no headlight or
taillight. This could happen, I suppose, if you burnt out both bulbs
on a 30 mph descent. But the simple zener regulator would handle it
fine, provided you picked zeners capable of handling the generator's
current. Standard current is half an amp.

How about some part numbers or specs? Planning on new bike, thinking
generator lamp, and wouldn't mind doing it this way....

I'm going to be only limited help. I just spent half an hour looking
through my notes on generators without finding exact specs or part
numbers on the zeners I'm using. And I couldn't make out any markings
on the diodes themselves.

I do have notes indicating that they're 8.2 volt zeners, and notes from
my measurements that they keep the RMS output voltage from my Soubitez
bottom bracket generator below 6.6 volts without affecting its low
speed output.

I don't see any 8.2 volt zeners in the Radio Shack catalog. That
probably means I got these at the 1940s era electronic store downtown.
They have all sorts of goodies. You might try one of the online
electronic catalogs, like www.newark.com

BTW, there are lots of generator links at
http://www.nscl.msu.edu/~daniel/regulator.html#lgtlnk

and you might enjoy the article on generators at
http://www.ihpva.org/HParchive/PDF/hp49-1999.pdf
although some of the figures don't show up properly in that archive.

- Frank Krygowski

Quoted message said:

I do have notes indicating that they're 8.2 volt zeners, and notes from
my measurements that they keep the RMS output voltage from my Soubitez
bottom bracket generator below 6.6 volts without affecting its low
speed output.

Assuming that the generator output is at least roughly sinusoidal, peak
value is (just as roughly) SQRT2 of RMS, so a zener about 8.5-9 would
probably do best without cutting off too much.

Jasper

Chuck said:

SMS said:

Chuck wrote:

Quoted message said:

Quoted message said:

Quoted message said:

>How do you plan on recharging a 15-nicd cell pack? Or d'you use those
>battery holder things?

Quoted message said:

Quoted message said:

Quoted message said:

I taped and soldered them together in a series-paralell circuit then
soldered on the same end that the Cygo light came with. I then cut a
water bottle to half size and put the pack in it just like the original,
only smaller. What I did was take 5 batteries in series and mounted 3
packs of those paralell. The original pack put out 6.5 volt and this one
puts out 6.2 volt and charges overnight with the original charger that
came with the light.

Was the original battery a NiCD or an SLA? NiCds on SLA chargers are not
particularly healthy.

Jasper

Jasper Janssen said:

Chuck said:

SMS said:

Chuck wrote:

Quoted message said:

Quoted message said:

>>How do you plan on recharging a 15-nicd cell pack? Or d'you use those
>>battery holder things?

Quoted message said:

Quoted message said:

> I taped and soldered them together in a series-paralell circuit then
> soldered on the same end that the Cygo light came with. I then cut a
> water bottle to half size and put the pack in it just like the original,
> only smaller. What I did was take 5 batteries in series and mounted 3
> packs of those paralell. The original pack put out 6.5 volt and this one
> puts out 6.2 volt and charges overnight with the original charger that
> came with the light.

Was the original battery a NiCD or an SLA? NiCds on SLA chargers are not
particularly healthy.

It doesn't say what kind of battery. The charger say 500mA 6V. It
charges both packs fine and neither the battery nor the charger heats
up.

Rick said:

SMS said:

mark said:

When I win the lottery I'm upgrading to the Schmidt with an E6 secondary

Me too. I could have a dynamite dynamo system on my commute bike for
only $500 or so. That's only about 167 gallons of gasoline!

$500? What you smoking, dude? I bought a system last year when the
dollar hit its low vs the euro. $400 for a Schmidt hub based wheel, a
Schmidt E6 (as good of a light as it gets), a Lumotec, and all the
mounting hardware. You need a wheel anyway, so deduct the cost of
spokes and a rim and we are now running close to $300.

I was calcultating the cost of the Schmidt wheel, two headlights and a
tail light. Yes, with a single headlight, the $400 you came up with is
about right. But you really can't deduct the value of your old wheel,
that's pushing it!

Quoted message said:

Cost of a top notch dynamo hub/light system: $400
Value of being able to continue riding and not worry about dead
batteries and chargers when riding through the Pyrenees/Alps:
Priceless.

I agree. For touring, the high cost, and relatively illumination of a
dynamo system is of little concern. For commuting, it is often a big
concern. I have both types of lighting systems. It'd be out of the
question to do my commute with a dynamo system, as it isn't nearly
bright enough.

The Wogster said:

Wouldn't take much to add over-voltage protection, just need the right
sized voltage regulator put it between the generator and the light, and
voila, no more over voltages..... There might be room inside the light
for the chip, it needs three connections, INPUT (from the generator),
output (to the light) and ground (steel or aluminum bike frame usually).
Would be easy enough to take the chip, add a wire on each side, and a
screw to attach it, the ground terminal could be connected to the screw.

Overvoltage protection is easy, but a simple voltage regulator will not
work properly. You'd need to rectify the AC out of the dynamo first. All
of this involves losses.

What you really want is not just over-voltage protection, since this
simply dumps off the excess energy as heat, reducing the effiency. A
dynamo such as the LightSpin would be ideal, as it does not lose
effiency by dumping off excess energy as heat.

SMS said:

Overvoltage protection is easy, but a simple voltage regulator will not
work properly. You'd need to rectify the AC out of the dynamo first. All
of this involves losses.

What you really want is not just over-voltage protection, since this
simply dumps off the excess energy as heat, reducing the effiency.

One should not overstate the problem. Bike generators are
self-regulating to a very large degree. Many people use NO voltage
regulation with them, and do not blow bulbs. With a well-designed
generator, additional regulation is valuable only for extended high
speed riding. That additional regulation is adequately provided by two
simple zener diodes. This is standard practice among people who ride
their bikes hundreds of miles in randonneur events.

Quoted message said:

A
dynamo such as the LightSpin would be ideal, as it does not lose
effiency by dumping off excess energy as heat.

Like all such things, the Lightspin has advantages and disadvantages
over other generators. One can get a perfectly satisfactory system for
far, far less money than the Lightspin.

And if you want a top end system, you might do well to consider the
inherently elegant hub dynamos, rather than the bundle of unrepairable
electronics in the Lightspin. The efficiency is essentially the same.

- Frank Krygowski

SMS said:

The Wogster said:

Wouldn't take much to add over-voltage protection, just need the right
sized voltage regulator put it between the generator and the light,
and voila, no more over voltages..... There might be room inside the
light for the chip, it needs three connections, INPUT (from the
generator), output (to the light) and ground (steel or aluminum bike
frame usually). Would be easy enough to take the chip, add a wire on
each side, and a screw to attach it, the ground terminal could be
connected to the screw.

Overvoltage protection is easy, but a simple voltage regulator will not
work properly. You'd need to rectify the AC out of the dynamo first. All
of this involves losses.

Acceptable losses though. Just don't go for the 'simple'.

Quoted message said:

What you really want is not just over-voltage protection, since this
simply dumps off the excess energy as heat, reducing the effiency.

Yeah, you have to pedal harder to make that heat to waste. Not a good
method.
A

Quoted message said:

dynamo such as the LightSpin would be ideal, as it does not lose
effiency by dumping off excess energy as heat.

Then it has to have a regulator mechanism. Car alternators are regulated
by changing the amount of current that goes to the magnetizing windings
so you can put in about 3 amps and get back 100 (my alternator).
It's electronics and I am an engineer in you know what field so it can
be done, but anyone doing it might be price gouging.
Bill

Quoted message said:

Bill said:

Quoted message said:

Overvoltage protection is easy, but a simple voltage regulator will
not work properly. You'd need to rectify the AC out of the dynamo
first. All of this involves losses.

Acceptable losses though. Just don't go for the 'simple'.

By all means go for the simple. Use a Simple Switcher (tm). Plug in the
values at "http://www.national.com/appinfo/power/" and account for the
actual DC voltage from the output of the dynamo, after it is rectified.

You can use a buck/boost switching regulator, and do it pretty cheaply,
at least in volume.

Note that "High Efficiency" is in comparison to linear regulators.
You're still going to be at around 80% efficiency, which may not be
acceptable to some.

SMS said:

Bill said:

Quoted message said:

Overvoltage protection is easy, but a simple voltage regulator will
not work properly. You'd need to rectify the AC out of the dynamo
first. All of this involves losses.

Acceptable losses though. Just don't go for the 'simple'.

By all means go for the simple. Use a Simple Switcher (tm). Plug in the
values at "http://www.national.com/appinfo/power/" and account for the
actual DC voltage from the output of the dynamo, after it is rectified.

You can use a buck/boost switching regulator, and do it pretty cheaply,
at least in volume.

Note that "High Efficiency" is in comparison to linear regulators.
You're still going to be at around 80% efficiency, which may not be
acceptable to some.

Some of the switchers can go up to 95% but that may be too much
circuitry and money to throw at the problem. It does make sense tome
though that the faster I am going at night the more light I want so I
don't blast into a big pothole.
Bill

Bill said:

Some of the switchers can go up to 95% but that may be too much
circuitry and money to throw at the problem.

I was including the losses from the bridge rectifier to convert the AC
out of the dynamo, to DC. You'd be right around 80%, with a good design.
So with a 6W dynamo, you're losing 1.2W, which is unacceptable.

I submit that on or about Thu, 08 Sep 2005 02:20:11 GMT, the person
known to the court as "mark" <[email hidden]> made a statement
(<[email hidden]> in Your
Honour's bundle) to the following effect:

Quoted message said:

Not reliable, no over voltage protection, difficult to attach, lousy optics.
Just what are they sufficient for?

Millions of Dutch people, according to my observations :-)

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

85% of helmet statistics are made up, 69% of them at CHS, Puget Sound

I submit that on or about Sun, 11 Sep 2005 21:53:34 GMT, the person
known to the court as SMS <[email hidden]> made a statement
(<[email hidden]> in Your Honour's bundle) to
the following effect:

Quoted message said:

I was calcultating the cost of the Schmidt wheel, two headlights and a
tail light.

All gold plated, obviously. Either that or your LBS *really* don't
want your custom!

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

85% of helmet statistics are made up, 69% of them at CHS, Puget Sound

Just zis Guy said:

I submit that on or about Thu, 08 Sep 2005 02:20:11 GMT, the person
known to the court as "mark" <[email hidden]> made a statement
(<[email hidden]> in Your
Honour's bundle) to the following effect:

Quoted message said:

Not reliable, no over voltage protection, difficult to attach, lousy optics.
Just what are they sufficient for?

Millions of Dutch people, according to my observations :-)

This is true. The riding conditions in the Netherlands are such that you
can get away with a lot less in terms of lighting.

Just zis Guy said:

I submit that on or about Sun, 11 Sep 2005 21:53:34 GMT, the person
known to the court as SMS <[email hidden]> made a statement
(<[email hidden]> in Your Honour's bundle) to
the following effect:

Quoted message said:

I was calcultating the cost of the Schmidt wheel, two headlights and a
tail light.

All gold plated, obviously. Either that or your LBS *really* don't
want your custom!

You cannot buy any of this at an LBS in the U.S., except perhaps Harris
Cyclery.

The other person stated $400, but he was referring to one headlight and
no tail light. With two headlights and a tail light, it'd be around
$500, depending on which headlights you choose it could be a little more
or a little less. I.e. Peter White charges between $296 and $380 for a
wheel with a Schmidt dynamo. Lumotec headlights range from $41 to $89. A
4DToplight Senso Multi is $55.

But of course you knew all this, you're just being stupid, for a change.