International Bicycle Travel Forum
International Bicycle Travel Forum
Who's Online
21 registered (Holger, FordPrefect, borstolone, 14 invisible), 71 Guests and 191 Spiders online.
Details
Advanced
About this forum
Rules
The Rules for this forum
Terms of use
Agreements for the use
The Team
Who's behind the forum?
Involved Homepages
Bicycle-travel sites already using the forum
Participate!
Use this forum in your Homepage
RSS feeds RSS
Overview of public RSS feeds
Shoutbox
A small chat area
Partner Sites
Statistics
25650 Members
85477 Topics
1295824 Posts

During the last 12 months 3963 members have been active.The most activity so far was at 01.03.11 11:21 with 1172 users online.
more...
Page 3 of 3  < 1 2 3
Topic Options
#1233248 - 09/04/16 12:34 PM Re: Hilfe einen Verteiler für Igaro D1 in Deutschl [Re: ConRAD]
acharnley
Commercial Participant
Topic starter
Offline Offline
Posts: 31
Originally Posted By: ConRAD
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. frown

Edited by acharnley (09/04/16 12:39 PM)
Top   Email Print
#1233358 - 09/04/16 09:10 PM Re: Hilfe einen Verteiler für Igaro D1 in Deutschl [Re: acharnley]
ConRAD
Member
Offline Offline
Posts: 206
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!!

Edited by Keine Ahnung (09/09/16 11:56 AM)
Top   Email Print
#1233372 - 09/04/16 10:26 PM Re: Hilfe einen Verteiler für Igaro D1 in Deutschl [Re: ConRAD]
acharnley
Commercial Participant
Topic starter
Offline Offline
Posts: 31
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.
Top   Email Print
#1233441 - 09/05/16 09:05 AM Re: Hilfe einen Verteiler für Igaro D1 in Deutschl [Re: acharnley]
Flachländer
Member
Offline Offline
Posts: 491
Originally Posted By: acharnley
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 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.
Top   Email Print
#1236194 - 09/19/16 03:35 PM Re: Hilfe einen Verteiler für Igaro D1 in Deutschl [Re: Flachländer]
acharnley
Commercial Participant
Topic starter
Offline Offline
Posts: 31
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.
Top   Email Print
#1237017 - 09/24/16 09:02 AM Re: Hilfe einen Verteiler für Igaro D1 in Deutschl [Re: acharnley]
acharnley
Commercial Participant
Topic starter
Offline Offline
Posts: 31
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.
Top   Email Print
Page 3 of 3  < 1 2 3


www.bikefreaks.de