Dynamo Lighting - fit and forget?

[Mick F]

WOW indeed, I've had mine so long I sometimes forget just how bright it is, it's good to be reminded.
But my standlight, although bright isn't anything like as bright as the main beam.

Only seen it in daylight of course, though it was indoors.

The front light seems very very bright and white, and when the wheel stops, it doesn't go to half brilliance like the Spanniga did, in fact it didn't seem to dim at all though it does after a short while as it fades. As I say, this test was in daylight, so a real dark road test is required to confirm.

I suppose the rear light is brighter - MUCH brighter - due to a higher voltage being sent aft. I would have thought that the voltage would have been a "Standard Voltage" to rear lights ............. obviously not the case.

May have to get out on a ride at 5am tomorrow. Not going out in this evening because I'll have had a glass (or two or three or maybe four) of beer.

[Des49]

Does anyone have experience of both Supernova lights and the Edelux to give a comparison? The price of the latter is much more attractive than the Supernova.

Yes
viewtopic.php?f=5&t=120923#p1220341

Though depending on the model of yours my comparison might not be relevant.
Mine are original Supernova E3* Lefty mount from 2009 with the LED upgraded in 2011 and MK1 Edelux as linked above.
The E3 has the symmetrical beam and even with the upgrade the LED is at least one generation behind current models.
They're chalk and cheese, the E3 the equivalent of a high beam, a bit anti social to other road users but superb on the dark lanes and it reduces that feeling of riding through a tunnel. The Edelux is far more civil, the dipped equivalent, it puts more light on the road where you actually need it most of the time, but you don't see much beyond that. It's hard to say which I prefer, though I've fitted the Edelux to the most used bike so I obviously consider it the more practical. I've ridden both through the night without feeling I need anything else, though just for fun I also have a super bright battery light which gets used on the darkest lanes when there's no one about to blind. I'm likely to use this more with the Edelux than the E3. they both have superb build quality in different ways, the Edelux wins on features, the reed switch mentioned earlier and of course the clever reflector, as an object of desire the Supernova has it, jewel like engineering.
I'd have no hesitation in recommending either, though I'd be interested to see the latest version of the E3

* I had the original original Supernova, bought in Germany, sold before it was really properly tested, it went back three times, twice for a poor quality toggle switch. the light was unreliable though the service was excellent, I ended up feeling like their guinea pig but in the end came out of it rather well.

That's very useful thanks. May be worth trying an Edelux.

My Supernova headlights are the E3 Triple, I haven't been using them as long as you have, but did have a fairly old one that had the LEDs upgraded at one point that I brought directly from the UK distributor that I can't remember. I do aim them very carefully and find the wide beam very useful as much of my night riding can be in unlit narrow lanes. We have 6 bikes set up for their lights, a couple bikes have handlebar mounted lights that can be moved easily from one bike to another, though I would prefer to have an additional headlight to avoid having to do this.

I did buy a new E3 Triple last year, about to fit it to a bike for my wife any day. Be interesting to see if it seems brighter than the older ones. I also have a box with 3 rear LED lights and headlight to be returned for repair, they haven't been problem free and reinforce the need to have good backups when away from home.

[Gattonero]

Out riding this morning on Moulton. It was a bit drizzly and dank, so I switched on the lights.
They came on, just like they always do. I checked the front by sticking my hand in front, and looked down between my legs to check the rear.

All well and good and nice and bright.

An hour later, I noticed that the front on wasn't on, and neither was the rear. I switched off and back on a couple of times, but no lights at all.

I stopped and checked all the connections. Still no good.
Back home, I disconnected the dynohub and put my multimeter on, spun the wheel and it went up to 20v ac.

It seems I have a defective front light again. Last one the switch broke and they sent me a new one free of charge and told me to keep the defective one ............... which I still have.

Stopped for lunch, and I'll get back to the case later. Looks like I'll be swapping the lights over.

I've fitted a B&M Cyo are the front and a Secula at the rear, driven by a SON28 front hub.
Right yesterday that I've used the bike for some shopping and I had no lights, it was a pleasure as always to flick the rotary switch to get some very bright lights on. In particular, I'm impressed by how bright the Secula works at the rear, if forms a circle or red light that is very visible from distance, but does not dazzle like all the battery lights do.

It's a combination I'd highly recommend.

[Gattonero]

My Edelux arrived the other day, and I've just spent an hour or two fitting it and running the rear light cable.
https://www.sjscycles.co.uk/lighting/36 ... -polished/

Two things:
WOW and WOW!

Four more things:
One, the front light is bright and the standlight is the same brightness as the "normal" light.
Two, the rear light is bright too - far brighter than it was before with the Spanninga.
Three, the lights come on bright with a single spin of the front wheel.
Four, the quality is superb.

If I can get up early enough tomorrow morning, I'm off on a test ride.

I guess you've seen where the price paid goes

[Gattonero]

call me a luddite but I think that 'simple is good' and I have eschewed standlights and the ilk; one mode of standlight failure results in the light not working at all......

You may also ride on solid tyres for the fear of punctures?

The standlight function is a MASSIVE improvement in safety, been able to see a stationary bicycle in the dark shouldn't even be discussed.
OTOH, capacitors should be of good quality in the first place (=long lifespan) and replaceable.

[Mick F]

Still not managed to get up early enough to test the light out yet, but I aim to try tomorrow 5am.

I checked out the standlight brightness, and it does indeed dim to about half brilliance. I am amazed how quickly the capacitor is charged, and I'm looking forward (pun) to going down the drive and having the standlight on so I can open and close the gate. The Spanninga 60 wouldn't charge in that time and I had to take a torch with me.

One thing that's puzzling me slightly, is why the rear light is very bright now. I think it might be TOO bright and be a little inconsiderate to following traffic.

I would have thought that there was a standard voltage feed to the rear, but this obviously varies with different headlamps.
Anyone got any knowledge or experience of this?
Is my rear light likely to be over-driven?

It's a B+M toplight flat.
https://www.rosebikes.com/article/b--m- ... aid:450592

[robc02]

I would have thought that there was a standard voltage feed to the rear, but this obviously varies with different headlamps.
Anyone got any knowledge or experience of this?
Is my rear light likely to be over-driven?

Without seeing a circuit diagram it is difficult to be sure, but the only light that I know of that "processes" the supply to the rear light is the Supernova. It supplies a regulated DC supply so the dedicated rear light consists of 3 LEDs each with its own series resistor. As far as I am aware, all others provide a switched AC supply, straight from the generator and in parallel with the front light circuitry.

For your rear light to be brighter it suggests that the supply voltage is higher than before, but I would have expected its circuitry to rectify and regulate to the correct voltage for the LED - unless it was previously not high enough and now the rear light circuit is now able to work properly? A circuit diagram and/or some measurements are needed here.

The supply voltage would be higher than before if the new front light is drawing less current than the old one. (On "no load" a typical generator will supply many tens of volts at typical riding speeds, this is "pulled down" by the load of the light).

As mentioned before, there is a lot of information about this sort of thing on candlepower forums.

[andrew_s]

I am amazed how quickly the capacitor is charged,

That's because the standlight turns off on a timer, rather than running the capacitor down to flat.
Even knocking the wheel round a couple of magnet poles provides enough "on" time to reset the timer, and the capacitor will normally have enough charge left from the previous ride to light up the standlight.

As for the brighter rear light, it could be that it is getting a higher voltage than with the old front light. A dynohub is more like a 0.5 A generator than a 6 V generator, and a way to get extra power out of it is for the light to present an apparent impedance of more than 12 Ω. It's not unlikely that the dynamo is giving 7 or 8 volts.
As for following drivers/riders, the area from which the light comes is important, with a light with a small emitting area (like the Supernova) being more dazzling than one with a large emitting area (like a Toplight), even if the brightness is the same.

[Mick F]

Test ride complete.
Ten miles of dark pre-dawn lanes, and I'm impressed.
It is bright and white with a good beam-shape ........... and with a stop once or twice, I managed to get the aim correct. Yes, very pleased.

The light comes on bright with hardly a turn of the wheel, and at walking speed, there's no flicker or hesitation whatsoever.

This last point seems to ring true with what robc02 says. The current draw must be quite small and that's why the light comes on easily with only a turn of the wheel, plus allowing for a brighter rear light.

The more current you take out of a hub dynamo, the lower the voltage available. Power = Voltage x Current
http://www.spanninga.com/products/headlamps/axendo-60/#
https://www.sjscycles.co.uk/lighting/36 ... -polished/
What current do these draw?
Anyone got any info?

[ConRAD]

... anyone got any info?

The info I've got is that things are a little bit more complicate than "Power = Voltage x Current".
________________________________________________________________________________

Dynohubs are commonly regarded, within certain limits, basically as “current generators” but this is true till the applied external resistive load is negligible compared to the inductive component of the generator its own internal impedance.
Under such a circumstance indeed the inductive reactance of the generator prevails and either speeding up the generator (i.e. more speed, more voltage, more frequency and more reactance) or varying the load (not too much !!) the circuit current will tend to remain constant.
But what happens in the reality is well documented in the table below.



And here below some tests performed with real lights.
For the tests I’ve been using:
- Dynamo: Shimano DH-3D32
- Headlight: B&M Lumotec N, alogen lamp with built-in overvoltage protection
- Rearlight: B&M D-Toplight XS Plus

PICTURE 1: 20km/h, OPEN CIRCUIT



PICTURE 2: 20km/h, ONLY FRONT LIGHT IS ON, voltage is cut-off by overvoltage protection at 7.61V, all power (4.25W) is going to the front light



PICTURE 3: 20km/h, BOTH FRONT and REAR LIGHTS ARE ON, voltage drops to 5.62V and shows to be well below the preset cut-off value, the overall power decreases to 3.23W and goes, proportionally, either to front and rear light. Now the front light shines much less than when it was “alone”.

[Mick F]

Thanks for that. Very interesting.

My original thought was that the front light somehow exports the power aft and each make of front light would be different in this regard perhaps.

Maybe my original thought is correct and they aren't in parallel?

[ConRAD]

... each make of front light would be different in this regard perhaps ... maybe my original thought is correct and they aren't in parallel?

Sure, each make will likely to act in a different way ... but your "original" thought is correct I think (as far as I understand), front a rear lights are definitely in parallel, in parallel downstram the overvoltage protection that is built-in and becomes "active" only once you switch-on the front light.

[PH]

Test ride complete.
Ten miles of dark pre-dawn lanes, and I'm impressed.
It is bright and white with a good beam-shape ........... and with a stop once or twice, I managed to get the aim correct. Yes, very pleased.

The light comes on bright with hardly a turn of the wheel, and at walking speed, there's no flicker or hesitation whatsoever.

Glad to hear it
This thread has reminded me to appreciate mine more. I was riding in the dark for a few hours on Saturday and have an overnighter next weekend, they wouldn't have been so pleasant a few years ago before good LED dynamo lights.

[Mick F]

This thread has reminded me to appreciate mine more. I was riding in the dark for a few hours on Saturday and have an overnighter next weekend, they wouldn't have been so pleasant a few years ago before good LED dynamo lights.

One comment I have now, and one comment I would make in the pre-LED days, is that the long range illumination isn't enough.

I had a BB dynamo for many years with an ever-so-bright Xenon bulb in the front in an excellent front light, and it was as good as the Edelux is now IMHO.

I would ideally like a main beam and a dipped beam. Riding along the dark lanes that swoop up and down and round and round, you need a full beam like you would use one in a car. I can manage fine on a straightish main road though, and that was the very sort of roads I was commuting along in my BB dynamo days.

[Mick F]

This is the way dynamos used to be wired.
Why not now?

Dynamo Wiring 1.jpg (13.96 KiB) Viewed 656 times