Yep that's it, I'm not having any success for a German distributor. I was hoping someone here may have a contact they can nudge. Ideally one of the bigger shops would be better as I want to pitch the D1 against the big boys.

PS) As for this other German product's efficiency, you'll find it's electrically impossible using today's technology to get better efficiency than the D1. Evidence is better than talk...

https://www.igaro.com/res/route.main.d1/efficiency.pdf

Will include a B&M USB Werk next week. I expect it to be slaughtered (but we shall see).

I guess your problem could be, that you contacted retailers and no companies with a focus on distribution.

Did you send them a sample to test it? No one will buy items for his shops as long as he really thinks it can be a success! Give them a chance to test your products function, quality, handling, ...

Axel

The reference is the Forumslader.

http://www.forumslader.de/typo3temp/pics/590d4cd9bb.png
http://fahrradzukunft.de/22/steckdose-unterwegs-5/
http://fahrradzukunft.de/21/steckdose-unterwegs-4/
http://fahrradzukunft.de/13/steckdose-unterwegs-3/
http://fahrradzukunft.de/12/steckdose-unterwegs-2/
http://fahrradzukunft.de/11/steckdose-unterwegs/

I would have thought rose.de, bike-discount.de were wholesalers as well as distributors?

I send a D1 to SJSCycles in the UK (a well known Touring specialist) and they took it. I've not got to that point with a German company. I'm pretty sure the English email is just ignored, and/or because there's so many in Germany they may think it's yet another typical converter (which isn't true - the efficiency is way ahead and it has things like a titanium case and lifetime warranty). It should be easily accepted if I can get it noticed.

Thanks,
Andrew

The point is, you are not the only person with new inventions and great ideas. Those companies receive loads of "inventions" and ideas. The bicycle industry is crowded with inventors, because everyone has a relation to bicycles, and everyone knows one special thing to change and make the bike better.

You must be different to get in touch with businesses.

For resellers your product has a risk: you are providing lifetime warranty. But WHO knows how long your company will survive? When you have to close your business, there will be angry customers to be served by the german distributor.

In fact there is a number of USB converters on the german market, and compete with very strong names and brands... customers will mostly buy those.

The price of your product is quite high compared to other USB chargers. And it does not seem to have THAT special USP to divide from others. In fact it seems more simple and less funtions than others. And in the end a distributor needs a good margin to take in your product.

Maybe it could be a way to provide a direct marketing to some bike shops in Germany. As your product is a success, after a while you may find a company to distribute your gadget for the german market.

Axel

I do not consider that an accurate method to compare efficiency - you should measure wattage in -v- wattage out rather than just speed (which also differs on wheel size, tyres etc), however that being said, I'd be up for comparing against it.

The D1 would track the pink line or better (I know 3W at 12kph is possible with a 700c wheel) but I've not ramped up the load at this speed to get the max wattage. Maybe it would be the same, maybe it would beat it. It certainly wouldn't loose, I'm sure of it.

Feel free to send me one and I'll add it to the database. I'll send it back for free.

D1 max amps out is 3A, but I guess the dynamo in this test was fully saturated.

The only way to gain further efficiency is using mosfets on the bridge rectifier, but these pass current both ways which can interfere with any device which does frequency detection (i.e B&M rear light that goes bright when you brake). D1 also has frequency detection to prevent pulsing so this method couldn't be utilised.

Andrew

Superaxle -> I could offer a standard B&M 2yr warranty instead if that makes you happy?

The price could be lowered by using a plastic case, not sealing it properly (hello B&M Luxos) etc

D1 has a life-time warranty not for the fun of it, if it were to fail I'd be loosing a lot of money. It has it because it's quality is better so I can accept the very small risk of something going wrong (titanium case, IP67 rated (epoxy not gasket sealed like the plastic B&M), 25yr life internal electronics, 10x main capacitor working life over those found in the German units).

As you can see, I'm convinced that quality isn't the problem - just that it's not being picked up. Everyone that's bought one loves them. Also, to date I've had no returns (or failed units).

I may have to pay somebody in German to try and make contact for me...

Andrew

@acharnley, not sure if you are aware of the Eurobike 2016 trade fair in Friedrichshafen from August 31st to September 4th, which sounds like a great opportunity to get in contact with basically everybody in the German bicycle business.

It's probably too late and too expensive to set up your own booth there, but maybe you can find a company that is willing to host you. At least you could go there an try to talk to the distributors at their booths.

Cheers
tadzio


PS: the Forumslader is not your direct competitor, as it incorporates "cache" batteries. But Jens and his team put a lot of effort into optimizing it, and the diagram you saw is only a very small portition of the results of their measurements.

Btw, what is that black blob on the output cable - a capacitor that was too big to fit into the housing?

You will run up hart against EU laws. It is basically illegal to sell stuff without a specific basic warranty in the EU. Apple lost millions over this. Additional warranties are of course welcome.

The second problem is the paperwork related to CE . This might entail additional certificates from third parties regarding electrical safety. (For me, CE resulted in serious tests of each individual device we sold. But you don't have 230V AC inside.)

German distributors will definitely ask about these two points.

The next biggy is importing into the EU. UKs "maybe,maybe-not,maybe-soon" exit means you have to deal with EU import taxes at some point. That will cause problems and distributors want stable and steady supply guaranties. I don't think they want a new startup from UK right now.

Most of these things disappear if you sell self assembly sets privatly (like Jens does)... ask him directly.

Outright claiming your stuff is better then the device developed by the local resident electrical guru and only successful startup was also a not-so-bright idea. It might be the case, but do a test first.

Sorry, I don't see how that relates to this case. Two years warranty normally is sufficient, there is now law (in Germany) requiring more than that! Also the problem would not really affect the producer but the dealer.




All quite speculative. But as a consumer that wants the charger can just order it in UK without any problem anyway (in the foreseable future) I would recomend more focusing on trying to send test samples to magazines. If there are german magazine articles some distributors might show interest.

It would be interesting to test D1 up 100 km/h and see how it performs in terms of high voltage at AC terminals (100V approx at no-load conditions) and overall efficiency.
Furthermore don't forget that a very common 3W6V dynohub can easily deliver up to 5 to 6W at 20km/h. So an output of 2.5W at 20 km/h is roughly the same as most of other similar devices on the market.

Cheers

Flachländer -> I think you need to re-read the original thread in which the writer complained that the D1 comes with a lifetime warranty.. He said this could be a problem, so I said he can reduce it to two years for free.

Flachländer -> you really need to re-read the original thread. The designer of the other product (that's not you by chance?) immediately said his product was more efficient than the Igaro D1.

This was silly of him, because I then pulled the efficiency results (as I'll relink below). These are the most accurate measurements done (more so than driving a wheel). I will gladly add his unit to the results, along with the B&M USB Werk next week - he can send me one without the batteries and I'll send it back for free.

https://www.igaro.com/res/route.main.d1/efficiency.pdf

I'd prefer to mimic real-life riding conditions. This does not involve riding at 100KM/h without a device plugged in. Most people buy dynamo hubs to power things, most dynamo hub owners are tourers, and most tourers don't ride at 100Km/h.

If your point is high speed protection, an Audax rider in Scotland a few week back maintained 60kph for 4.5 minutes. It's a lot faster than I can go, and yes, his D1 continues to work.

The D1 produces more than 2.5W at 20km/h. Although I've not tested it in this manor, I've had 4.88V/0.76A at 17kph when testing a Sony smartphone a few weeks back. Perhaps a variable resistive load could have pulled more.

Presuming no device limitations, efficiency dictates what will be given out, and the efficiency chart above shows the D1 is class leading. It's exactly what is needed when touring under arduous conditions - not everyone can sustain 20kph all the time.

Back to the original topic, if anyone does have a contact at one of the bike shops do let me know. I'd be willing to offer a full buy back on unsold units so there's no risk to the reseller.

Thanks, Andrew

... exactly as any other similar device on the market, so why should I buy yours one?

Perhaps what I should have said is if you take another device, but a resistive load of an appropriate value across it, do the same for the D1, and keep the speed the same - you'll get more wattage from the D1. You can't make energy, only convert it. The D1 converts more and the figures in the chart posted above prove it.

I'm quite happy to compare with one of the devices mentioned earlier. I don't need the batteries (they lessen efficiency), just the circuit board will be enough to produce the figures.

If you're not after efficiency, perhaps the ultra small size, the titanium case, the epoxy IP69 inner, the resilience (components are 25yr rated, the outside capacitor has a 10x increase in working life over standard). The lifetime warranty. The rebuildable USB port...

The price is much less than a Supernova The Plug, a bit less than an eWerk and a bit more than USB Werk (at least in the UK). Read the igaro.com website and if it still doesn't blow your skirt up... let me know why.


A.

Limited lifetime warranty does not nessarily cover what the law requires. I have been at that point too, trust me it is complex. The simplified version is 6 months warranty, no-questions-asked + 18 months warranty during which the customer has to prove the product was faulty at sale. Depending on your terms, "limited" is a deal breaker. If you bail out, the local dealer has to take over responsibility for your product. Guess why the big guys don't like startups...

About the forumslader. I own one, it is slightly better then the test results at speeds around 20 kph (26 wheel but 28" dynamo...), measured over longer distances. I would not dismiss losing against it. The team behind it did not comment so far. PN JensD, he does not read every thread here.

The D1 can't loose when it's being used to charge, it's electrically impossible.

Where it will loose if the rider goes very fast and doesn't have anything plugged in - at that point the protection kicks in and begins generating heat. The titanium case takes care of it. This is the downside from not using an inline darlington shunt, but it gives much higher efficiency when stuff is plugged in.

The real reason others use darlington shunts is the cheap plastic cases which can't handle the dissipation. Aluminium (or Titanium as with the D1) costs more $.

On warranty, the limited warranty only applies to the USB port. This is clear - if the user allows water to sit in the port it will eventually corrode (as will with any device) and in this case a small charge is applied to replace it. As it's rebuildable the cable won't be shortened or spliced and heat shrinked.

The rest of the unit is warrantied for life - if it breaks anywhere in the world it will be replaced. Obviously we'd prefer some sort of proof rather than subject ourselves to consumer fraud, but if it looks honest that's enough. We can offer this because each D1 is hand built and the quality is of such that it should never fail. 100's have now been sold all around the globe (many the previous aluminium cased design). Not a single warranty request has come in so far.

It's easy to be skeptical in our throw-away world, but as a long-time round the world tourer myself, there are those that prefer reliability and performance above all else.

I feel like a salesman now, that's quite enough!

Andrew

Dynamos are constant current sources. The trick to higher power is more volt and tuning capacities. Jens based his current design on this: http://www.forumslader.de/Schaltplan.236.0.html and pulls up to 10 watt out of a "3 watt" dynamo. What about your way? 2, 4 or more tuning capacities settings? Input voltage seems to be limited to 21V in your case?

The efficiency input-output you measure does not matter that much to the user. Common riders do not feel a 2-3 watt difference. Even tire presure can have more influence then that. But they will complain if the phone/gps/camera... is not fully charged at the end of the day. That's why Jens does not publish efficiency but wh per km or watt vs speed. I can quantify my needs in wh/day, but I cannot tell you if the dynamo is pushing a significant load or is idling. So... do you have a full plot of wh per km or watt vs speed for a commonly used dynamo?

About warranty: the EU legislation about this is published here: http://eur-lex.europa.eu/legal-content/EN/TXT/?uri=URISERV:l32022 . It basically requires you to add a small paragraph to your warranty stating that you do acknowledge this state garantied warranty. (Like scott does it here https://www.scott-sports.com/global/en/support/warranty/ in the second last paragraph or Apple in the 2 colum of the first table here http://www.apple.com/ie/legal/statutory-warranty/ ) It is a very good idea to tell dealers how you will honor this required stuff because in the worst case they have to pay back the full price to the customer. Promoting a different warranty, no matter how good, will not solve this problem. This is a problem between you and the dealer, not between you and the customer and it is a question I was asked about. The fines related to this are considerable in Germany.

Higher voltage is irrelevant, if the load is high enough and the converter has no limits then the dynamo will stay at it's nominal voltage (6V) regardless of speed. There is misconception that as you go faster the dynamo speed will be greater - only true if no load is upon the dynamo.

You are absolutely incorrect in your method of measure but completely correct in expectation. What matters is whether the phone is charged - correct, how well it charges depends upon how much power comes out of the dynamo and how much is lost in conversion (the efficiency).

Where this matters is that hard long day in wind, uphill, on a bad road. Your cache battery is dead and your speed is much lower than normal. The dynamo wattage is lower. The converter offering the higher efficiency rating has the best possible chance of device charging.

Cache batteries lower efficiency by 30% but enhance convenience. Better to use a USB powerbank with passthrough because you only get 500 recharge cycles, if you're lucky.

D1 protection begins at 21V.

Minimum loss from using an inline darlington shunt (Jen's design) is 0.7V/8.4V = 8.3%

This is the trade off between efficiency at lower speeds with a device attached and higher speeds with no device attached. I began with the latter and it wasn't enough for arduous touring conditions.

Saying a dynamo is constant current doesn't hold value unless you say it "with a resistive load", most USB devices use switch mode regulators to poll the voltage and switch load accordingly - they are not resistive loads.

The Sony M4 Aqua I mentioned earlier, it cycles between 100mA, 500mA, 0.74A and 1.2A, hence the graph of W v kph is not indicative of reality.

I'll stick with the math rather than a drill.

https://en.wikipedia.org/wiki/Electrical_efficiency

Warranty

If a German distributor required that in print it would be added to every unit. It is not a requirement of the legislation that it is stated from what I can tell - it is a obligatory to be able to sell within the EU? Anyhow not a problem.

Tuning

On one of the forumslader pages it is talked about adding a capacitor on the input to tune efficiency. He uses 220uF (have to stay within the protected range because a 100v 220uF is too large!).

To answer your question about the black blob, that's a Nicholan 470uF 35V 10X life capacitor, and it's doing what the forumslader page discusses. Obviously 470uF is better than 220uF (assuming same ESR) but there is the size consideration. I tried multiple MLCC's (rather expensive!) in order to fit the capacitance inside the case but the performance wasn't up to it.

Output

Is 3A / 15W maximum. I doubt this condition will ever happen.

1. I want to see a plot [Power] vs [Speed], possibly based on a 28" wheel
2. Your claimed 2.34255W at 20km/h seems pretty low and however not enough to decently power-up even a very common gps such as a Garmin Montana 600 at its max backlight illumination
3. IP69 is irrilevant if I have a look to the IP00 usb connector
4. A minimum of a cache battery is fundamental to allow continuous and regular functioning of connected devices
5. Voltage protection (21V) is too low, you must accept the fact that not always you have a connected load
6. Pricewise it doesn't look to be much attractive

CONCLUSIONS
1. Test it in a more scientific way, not just on the handlebar of your bike keeping a multimeter in your hand.
2. Test it at multiple speeds with different types of load.
3. Test it varying among different dynohubs in such a way to see how it performs with different power generators.
4. Test it in parallel with some led headlight switched-on (with built-in overvoltage protection)
5. Finally make public in a clear way all the results of your tests, show your test set-up and plots obtained

Thank you.

I think only apple truly tested the limits by selling without acknowledging 99/44/EC. They payed about 3 millions Euro in Italy, something of similar in Netherlands and backpedaled very, very fast in Germany. In your case, the dealer will also be involved in the lawsuit.



He uses several sets and switches depending on speed. Basically a discrete form of MPP-tracking.

Assuming you have the CE paperwork and include the mandatory state warranty into your terms... what about german product liability ? Maximal fine is 85 million Euro, realistic fines in your case are about the value of the phone charged by the device or maybe the bikeframe if it goes all wrong. It is independent of product value and it applies by default. There are insurances against this, but they are only valid if the other paperwork is absolutely correct and documented. In practice, the british CPA should have similar worst case scenarios. I guess that's why you registered a Limited in UK?

And read https://fahrradzukunft.de/archiv/ , the "Steckdose" series. Sending them a sample would help your case a lot.

ConRAD -> you can't seem to grasp the completely scientific efficiency figures I posted earlier. Here they are again:

https://www.igaro.com/res/route.main.d1/efficiency.pdf

I never said it does 2.34W @ 20km/h. I don't know where you read that.

You'll find my results are public, this dataset is linked on the website.

Thank you for your "Test it" conclusions, but the D1 is already tested with all 3W dynamo hubs, and with many LED headlights, and with many, many USB devices at different loads.

There's a few on youtube, and more are upcoming.

Click reviews, a current user has kindly posted some comments.

https://www.sjscycles.co.uk/dynamos/igaro-d1-dynamo-usb-power-converter/

After speaking to a German at a dynamo manufacturing company it appears the Forumslader is the #1 unit to beat. I like a challenge.

England -v- Germany

Match accepted!

Can somebody contact the developer of the Forumslader and ask them if they'd be willing to provide a sample (without batteries) and I'll do the same. We can swap back afterwards if it is desired. I'll be testing the Forumslader under lab conditions, 6V AC @ 250Hz, 10ohm (0.5A) load as per the detailed spreadsheet posted earlier. Hopefully they can add the D1 to the speed test.

You can contact JensD by yourself. His email address is in the user profile.

The Forumlader is not a commercial product. You can only obtain it from Jens.

I think you are wrong in assuming 20km/h.

The published tests (first linked pdf in this thread) are run at 500Hz. Shimanos have 28 pulses per revolution (SON: 26 pulses). 500Hz / 28 pulses corresponds to:
=> 17.8 revolutions per second.
=> 1071 revolutions per min.
=> 64285 revolutions per hour.

My bike (26x0.75 tires) is traveling ~ 2m per revolution => 128 km/h for 2.5-something watts according to posted tests (144 km/h for 47-622, YMMV). The high-speed Forumslader option with velogical dynamo outputs 15 - 22W at 60 km/h. It will shutdown well before reaching 128 km/h.

See? He did run tests well beyond your requested 100km/h. You should have asked about lower speeds.

… ah, you are perfectly right, actually I was asking to run a test at 100 km/h because I erroneously was assuming that he was using a real hub generator.
But reading better the pdf file at the beginning of this thread I’m discovering now that “a signal generator with an amplifier had been used instead”, regulated at 500hz/6.05V/0.445A !!!
That’s simply a nonsense, if he wants to make comparisons he must use real generators and not “signal generators” at 500 Hz !!!
Furthermore please be careful because in your calculations you considered 28 poles but in the reality you must consider them as 14 “couples of poles” since you need a couple N-S to produce an hertz and not just a single pole, so 500 Hz makes 256/288 km/h (26”/28” respectively) !!!!
To make tests in this way is a nonsense !!

Here below a picture showing frequency and voltage from a standard Shimano dynohub at 20km/h on a 28” wheel.
Do you see?? 20km/h is 20000/3600 m/s that divided by 2.150 m (28” wheel) makes 2.58 turns per second, i.e. 2.58 X 14 (couples of poles) = 36 Hz (approx)

Ups, sorry, my typical back-of-the-envelope mistake.

I see an Vpp of around 25V on your oscilloscope, so the 6V amplifier setting is the next big no-go? He is limiting to 21V anyhow and probably wasting addition energy that way. Now i understand the need for a metal heatsink.

YES, good point ... so better not to exaggerate with resin impregnation to make the thing IP69!!!
Here below:
Picture 1 shows Voltage and Frequency at no-load conditions at 20 km/h on a 28" wheel.
Picture 2 shows Voltage and Frequency on a 12 Ohm resistor at 20 km/h on a 28" wheel.
Below data are referred to Shimano DH-3D32-QR hub dynamo.

6V is the real-life voltage once you apply a load, there is no point in testing 20V, 40V, 60V which indicates there is no load attached.

As the pdf shows, the testing begins at 500Hz. This value was chosen because the The Plug 3 cycles off at 250Hz. The D1 will work at a lower value but I wanted to keep the test equal for all devices if possible.

In other words, this test is not a quantative test of a converters output at a given speed, but rather when there is enough power supplied to provide a 500mA output, what is the efficiency transfer of the converter.

IT DEPENDS ON THE LOAD, OBVIOUSLY !!!

Just for your information:

- Picture 1 shows Voltage and Frequency at no-load conditions at 20 km/h on a 28" wheel.
- Picture 2 shows Voltage and Frequency on a 12 Ohm resistor at 20 km/h on a 28" wheel.
- Picture 3 shows Voltage and Frequency on a 40 Ohm resistor at 20 km/h on a 28" wheel.

All below data are referred to Shimano DH-3D32-QR hub dynamo.
As you can see all values are referred to 20 km/h, if you go at 40 km/h then frequency will double and voltage will tend to increase significantly.
Cheers.

You limit to 21V, so you will convert additional energy into heat (unloaded/partial loaded case). A lot of heat at faster speeds, which explains why you need the metal heat sink while most of the others work fine without. It also severely limits the lifetime of all components within the case. Elkos lose half of their lifetime with every 10°K increase. Your 25-year-stuff can and will die faster then expected.



The Plug was designed to work with hubdynamo, not an amplifier. I guess that triggers various safeguards. Looking at a real signal and comparing to the amplifier output might show why.



My bike can accelerate with ~9.81 m/s² if i drop it of a cliff. I would not take that as a test of my ability to it accelerate on a flat road.

I use 10ohm/ 0.5A indicative of a typical smartphone.

There are no electrolytic capacitors inside the case. The D1 design requires the 21V limit, which isn't as efficient at higher speeds without a load attached BUT offers significant efficiency gain at lower speed and/or with a suitable load. That is the trade off, and one I was happy to make because the majority of tourers and commuters are not doing 35kph+ on a constant basis and they tend to buy dynamo hubs to power things. I've already done the alternatives; load dependant darlington shunt, and high voltage PWM (crap at low voltage, low output, less efficiency - Igaro D1 PWM is 95%).

On heat, here's how much it generates from an actual user (see last post):

https://www.lfgss.com/conversations/289960/

The Plug monitors the output voltage and cuts off if it drops. It does not have the capacitance or efficiency to continue over the transients hence it's poor performance at low speed. The ability to function at differing speeds is outside the scope of my pdf test.

@acharnley

I'm not totally sure whether you're joking or not!
In your pdf you say "For this test mains frequency (50Hz) is too low to guarantee 500mA".
Can you explain?
I'm testing dozens of converters (e.g. e-werk, usb-werk, Luxos-U, etc.) and believe me I've no problems to get 500mA at 34Hz (i.e. 20km/h on a 28" wheel).

The 500mA must stay within USB spec (4.75v). The D1 can't do it at 50Hz. The Plug 3 can't do it at 250Hz. I can't say for other units.

Test with a 6V transformer and a high VA rating. 10ohm across the converter. Mains is 50Hz in Europe.

Use a pure sine wave rather than test results based upon a specific dynamo design.

I know that mains is 50Hz in Europe, but unfortunately a standard hub dynamo delivers roughly 34Hz at 20km/h, twice at 40 km/h, three times that frequency at 60 km/h ... and so on so forth. Furthermore I'm a bit afraid that using a "pure sine wave" as you're doing with your lab generator is a sort of a fancy approach not reflecting at all a real dynamo output that, as far as I can see, isn't a perfect sinusoidal shape at all. In conclusion ... I suspect that your tests are simply an overall nonsense, sorry for that.

You might as well remind me how I and the rest of the world go about calculating efficiency again? What's the equation?

Exactly the one you've been using: W(out)/W(in).
The problem is that your fake signal generator is NOT a dynamo, please repeat all your tests with real dynamos and related real frequencies. Cheers.

Well at least we've cleared up that your method is unable to demonstrate efficiency.

I'd be more than happy to carry out a similar test to your own, but the hub would be different and different wheel size so results would be incomparable.

Since we've agreed that my method does calculate true efficiency by the process of Math, you are in a better position to produce universal results.

Please repeat all your tests to conform to the recognized efficiency equation rather than for a specific dynamo hub.

Dear Acharnley please don't be silly, Math???
Sorry my dear but efficiency is just Wout/Win!!
But it's OK, you won, therefore I finally give-up and prefer to get out of this totally useless discussion.
Cheers.

It only became total useless once you jumped on it, ignoring the original subject matter.

Let's talk about a different kind of efficiency: this thread is on page one of Google.de results about your loader. It contains a link to a thread were you basically offer free stuff for positive reviews. You demonstrate a very interesting method of communication and little understanding how electricity generation works. This forum has several commercial, tech-savvy participants (manfacturing and dealers).

Good luck marketing this one away.

On the technical side: your amplifier is probably not a 4 quarant model (high VA and ~kHz with 4q does not come cheap), meaning your results will depend strongly on the amplifier. You cannot even replicate the same input current for 2 loaders. And it is not related at all to hub dynamos. Phi will be way off, no matter which amplifier you use.

" were you basically offer free stuff for positive reviews"

Please stay clear of defamatory comments. Nobody has ever been paid for a positive review nor has any review ever been pre-edited.

I'll exit this conversation now that it is becoming one of hate.

Because the construction of the loading device influence the output of the generator related to speed.

If one device get a input of 3W at 20 km/h and have a efficiency of 80 percent and the other device get a input of 5W at 20 km/h and have a efficiency of 75 percent, than the second device is the better device, in spite of lower efficiency.

The same using rechargeable battery. It may lower efficiency. But if your navigation device battery is full and the loading device produce more energy than the navigation device needs, you can save energy for the times, when the loading device produce too little energy.

So with a rechargeable battery and lower efficiency you can produce more useable energy than without a rechargeable battery and higher efficiency.

Very good points, thank you !!

That would help, but not totally solve the problem. He measures W(in) using a multimeter, ignoring the power factor.

He might hit a harmonic at 500Hz and has no chance to truly measure it using his equipment. So reported W(in) might be bogus, the system boundary is very unfortunate/irrelevant and the current source is unrelated to the real world application.

I understand startups are looking for a fortunate testcase for promotion. I even think giving out samples for reviews is ok if the review includes that information. But this efficiency claim is way too far off. He might have a case promoting the form factor (it looks tiny) or the support-local-guys route. IP69 might be a seller, if the resin can really resist a high pressure washer and he does something about the USB port (IP67 USB ports exist. IP67 only while closed, of course...).

You could of course implement the minimal loader design and put it into a fancy case. I'm pretty sure it would be the most ecofriendly system around from the raw materials point of view. And very, very cheap to produce.

I'm quite happy to replicate the wheel test and publish these results. I only have a Shimano 3N80 (XT) hub, the 3N30 is obsolete.

What was used for the variable resistive load?

... ahhh, I knew very well the story of harmonic distorsion and the fact that to make reliable mesurements he was supposed to use a power analyzer and not just a multimenter, but intentionally I preferred to ignore this aspect just for not complicate too much an already very critical discussion.
Here below the "scrappy sinewave" of the dynamo output when you connect it to an e-werk.

I'm done with arguing this.

I have sent a request to https://fahrradzukunft.de

I'm confident the Igaro D1 has greater efficiency and thus will offer greater output at any given speed, but they can test it and we'll see.

Do you have a wattmeter? Those solve several problems in one go and will give you power in and power out, DC and AC.

You are expecting a maximum output of roughly 20W at 5V. I would use 2, maybe more heavy heating 10 Ohm resistors and do several combinations to get the maximal power. One testrun in parallel, one serial, one with just one resistor. Thick cables, proper soldering,... tedious work, but doable. And easily comparable results.

Resistors, even those made out of Konstantan, drift with temperature, sometimes as a function of the material, sometimes due to thermoelectric effects. Using just one multimeter, that drift can influence the result as the resistor heats up. A really big resistor with a large cooling area does not heat up that much from 3-5-20W and should be safe. Ridiculously big ones are available and cost less then a proper second multimeter.

With a wattmeter (or if you only do output and assume pure DC: 2 multimeter) a series of small 20W resistors should be enough. They do heat up, so put them somewhere safe. Or use variable, manual resistors. (I would pick a ~100W model, 2 multimeter minimum)

Electronic loads would be total overkill, but offer the most flexible setup. Pick one that can do MPP-tracking, it saves a lot of work.

Are you sure that the model you've linked is ok ? from its instructions manual, chapter#2 I read:
#2. DESCRIPTION OF THE INSTRUMENT
- The measurement range concerning the fundamental frequency is 40 to 70 Hz.
- Voltage/Current: Sinusoidal signal (THD < 0.1%)
- Power: Sinusoidal signal, PF = 1, Frequency 50 Hz, Measuring range 10.00 W...999.9 W

NOTES:
- at 20 km/h you might expect 32-36 Hz
- expected THD is well above 20%
- Power measuring range has a minimum starting from 10W

It is using a internal 2kHz sampling and calculates based on the instantaneous values. It is not the high end option, but it did work reasonably well here (PWM for heating, 100Hz, 25 - 500W). It does not really need a low THD (Current (THD = 40%), typical error 0,2%) and it does not stop working completely outside the usual 40 - 70Hz window. Just don't trust it at 200Hz. But i never tested it at lower power ...

The better option (Fluke) is officially limited to the same frequency rage. But that one does work at higher frequencies.

Digital 2 channel oscilloscope is the better option, but more complex in use. I used one to check the cheaper wattmeter. You don't really need the wattmeter if a oscilloscope is available ...

The pdf I used earlier explains the resistor type and time, 5ohm 10W ceramic. Not kept on long enough for heat to be an issue.

A wattmeter/voltmeter+ampmeter can only measure within good accuracy a pure sin wave - at least, I don't have a model that can sample wave energy and average it. The signal was read using a digital oscilloscope to ensure the amp wasn't overloading and distorting the signal. The amp I use to boost the signal generator is a class A/B 100W. I also use a class D 100W and get the same figures.

I hope your man isn't using the built in li-ions to skew the output results as the German translation is not clear. This would be very unfair.

I'm presently using FLUKE 43 (not 43B) but my limit seems to be the current clamp that starts from 500A (url) ... too much I think !!

Check voltage and current, at the same time if possible. Class AB and D give similar results if the output lowpass filter on the class D matches the system well. I can't really comment on that for your system.



That's why you test over longer times and cycle the batteries completely...

It is possible to display the current power flow (batteries, consumer, generator) with a smartphone app to check for obvious test design problems.

Hey, during the last days I have read this topic with great interest. My point of view ist the one from a potential buyer of a Dynamo to USB-Adapter within the next year.
I would like to add few thought, but not to offend or argue against you or your product, but to explain why people here behave how they behave... and maybe even give you a hint how to improve your product and specially your "marketing" But please keep in mind that my technical knowledge for this topic is limited.

1)People here in this Forum are researching and developing since ages how to use the power of the dynamos for different solutions. Here a random old thread topic to show you since how long this topic is present here. Since then the knowledge and experience have expand, and later several more ore less commercial solutions (most of them bad, some even usable, a few quite good) have come up and most of the vanished since then. But people here still used to build there "own" stuff to satisfy the specific needs of different travellers.
To find ways to compare this totally different solutions for different tasks and needs is even more complicated. The Forumslader is just one of a few dozen solutions that has been developed, tested and compared here. True, the Forumslader is the most famous on, because it meets the needs of most of the travellers here (and have a few extra gimmicks like an extra 12V output, speedometer, odometer bluetoot, Android-App etc), but there are many different other solutions that work quite good to.
Now, you came across claiming you found the estimative solution, the philosopher's stone, people here even may "find it's electrically impossible using today's technology to get better efficiency than the D1 !!!!!!111!!!" (yes I added the exclamation marks to your quote) you may understand that people now a at least a bit sceptical. So people ask questions about it and how your test are done.
They even try to show your what kind of testing are done with other solutions, so you can do the same to have some comparable solutions, or just sent your device there so it can be tested with their experimental Setup. But first you doubt the test setting and repeat that your solution _must_ be the best of all and "blow your skirt", "England -v- Germany,Match accepted!" etc....
People here a bit allergic to such kind of exaggerations and marketing phrasing.
These kind of marketing has often be used to push bad products, so people become even more sceptical when you use even more aggressive marketing blabla.

so at the end


This was the best (and I think the only) way to show what (or what not) is your device
capable of. I (and many others) will certainly notice how your device will perform well compare to other solutions. Just keep in mind the Fahrradzukunft people do this as a hobby in there free time and wont get paid for this. This means that it actually may take quite a while if they decide to test it.

Otherwise you may still find a few people here that are still not annoyed (annoyed, pissed overstrained - all this word are to "hard" to describe what I mean -Im still searching for the right word)*by you in the who have the knowledge and the good reputation to test your device and will write a report about it when you ask them, and send you back your device afterwards...

*yes people here in germany (and also specially in this forum) can be easily offended if you hit the right spots, you already found a few

Btw: the fact that you only have a reseller from GB is not a Dealbreaker for german buyers- at least while GB is still in the EU. 10€ Shipping could be better but is still ok. People here actually like small one person solutions once they have been proven the be working and provide solutions that the "big company’s" don't provide (examples: Rohloff, Grobox, Reisegabel, Forumslader, ...)

So far, as very well suggested above, sometimes “EFFICIENCY” is not a top priority. What is most important is indeed the effective power that a certain AC/DC converter can draw from the AC side (generator) of a system and deliver to the DC side (load) at a certain speed.
To make it clear once again: “if one device gets an input of 3.0 W at 20 km/h and has an efficiency of 80% and the other device gets a input of 3.5 W at 20 km/h and has an efficiency of 75%, than the second device is the better device, in spite of its lower efficiency”.
To make evaluations on how good an AC/DC is, I personally do not even need very sophisticated laboratory instruments since I make all relevant measurements directly on DC side.
To do that I use a real generator, a real AC/DC converter (the one under test) and an adjustable ohmic load made-up of calibrated ceramic resistors.
The wheel/generator speed is controlled and finely tuned via an asynchronous motor powered by a 3-phase inverter. At this point the test method is extremely simple: I adjust (sink) the load till to get the maximum transferred DC power to the load taking care of course that the voltage doesn’t go below a certain “low limit”.
For instance for usb 5V voltage I’d set this limit to 4.75V.
The results seem to be pretty reliable so far.
The basic estimate criteria would be that an AC/DC converter is as better as bigger is the amount of ACTIVE POWER that it will let to flow from the generator to the load.
The test system I use is THIS ONE, home made but pretty well performing.
Here below a couple of sample plots based on a Shimano DH-3D32-QR hub dynamo and an e-werk respectively set at 4.9V (1st plot) and 5.6V (2nd plot).
As you can see at 20 km/h it doesn’t seem to be able to transfer more that 2.75W:

You're now referring to current limit. Probably the eWerk (which uses a buck and boost) has a 500mA limit for one or both of it's chipsets. This is normal for high voltage PWM chipsets (and another reason why I don't use them in the D1).

I believe efficiency is more important because most tourers are not riding at a constant 20kph. The time a tourer really needs the most power is on a bad road in central Asia, with a wind, going up a hill, at 10kph.

Evidently a device should support a full 500mA output and ideally 0.75A as this is what many smartphones use as there 2nd level input (1st being 1.5-2A for a wall charger).

Igaro D1 is 3A / 15W limited. It's advertised as 2A because the chance of getting 15W out of a dynamo is very low and I don't want to give an impression that it's achievable in real world riding.

I'm aware of the techniques uses to smooth the input to assist in high current output; mosfets with capacitors, back to back electrolytic on the AC. I ended up with an expensive Japanese electrolytic outside the case (so it's replaceable should it be necessary after 10-20 years) and MLCC's to further reduce ESR.

PS) my request for the Igaro D1 to be tested and compared to your device has been ignored.

Originally Posted By: acharnley

... you're now referring to current limit. Probably the eWerk (which uses a buck and boost) has a 500mA limit for one or both of it's chipsets. This is normal ...

ABSOLUTELY NO!!! - Dear Mr. Acharnley, very frankly speaking I'm becoming more and more convinced that you might not understand very much of electricity. I'm a bit afraid too that you don't even know anything about other products you want to compete with. So please, and of course I do apologize for that, accept my suggestion: simply try to find a different strategy for marketing your D1!!

Right you are. As expected, you believe the eWerk's current limit (which you say it has) is due to some magical effect other than either the input wattage or the devices ability to convert it.

You've already established efficiency is unimportant, which just shows that you haven't ridden with a dynamo hub and a USB power converter in some of the more arduous parts of our world.

I should have exited the conversation earlier but I had hoped your German rag would agree to pitch the D1 against your device so that the borderline hate and idiocy could be put to rest.

I have not a care for marketing, I put all my time into maximising quality, electrical efficiency and customer service - people buy D1's, and so far they love them - there's the marketing ploy for you right there.

Now exiting.

I have never seen somebody riding a Class-A/B amplifier across the difficult parts. And yet you developed the Igaro D1 to be optimized for amplifiers and leave it untested on dynamos in the lab. And you expect volunteers to test your device right-now after this thread.

My remarks on German and EU law still stand.

I would usually wish you good luck, but i will rather wish for patience in your business partners. They need it.

To correct these two untruths, a) the D1 was not optimized for amplifiers and b) it has been extensively tested (and it's digital monitoring optimized) for dynamo hubs in real world conditions within some of the more ardious regions of the world.

Cheers, A.

I feel obliged to meet the demands of the community therefore I've configured a Shimano 3N-80 for a speed test. I've began initial testing and you can see the results below.

(please discredit the Vdrop for now, I need to get my meter closer to the load)

This time I have an e-Werk and like ConRad I found the same 2.75w limitation.

Feel free to provide your critique on the method used to calculate any of the figures.

https://www.igaro.com/misc/efficiency.ods

I've ordered some higher wattage resistors for the high power tests and will make improvements to it next week.