etherhuffer 

My SON hub with Edelux light stopped working. I check for continuity on the hub, looks good. Put a meter on the hub connections, spun the wheel, got power. Checked the lead/coaxial wire, got continuity. That leaves the wire up to the light. Question: How does one check an LED unit vs a bulb unit? This is LED, and not sure if you can just check continuity or not. I am pretty sure the issue will be in the soldered coaxial fitting having broken

2_i 

Most dynamo LED lamps will work straight off a DC source. Optimally this should be 6V, but those lamps normally tolerate significant voltage variations. I suspect that you could power your Edelux from a higher current USB port. I just tried it with IQ Cyo and the standlight came on for both voltage polarities. I could get the main light weakly working for one of the polarities off USB. Yes, obviously most power failures result from some mechanical connection problems.

Tourist in MSN

I have checked dyno powered taillights with a Li Ion battery from my phone that is roughly 4 volts. That should not be any problem at all.

And as noted above, higher voltage should be ok. The headlight has more voltage protection than taillights, so I would not go above 6 volts on a taillight. USB voltage is 5, should be good enough to test to see if it lights up.

Germany_chris

Did you check the ground wire?

noglider 

I'm pretty sure they work off AC. Of course the light might rectify it so it is effectively DC, but it definitely tolerates AC. I believe most dynamo lights will tolerate DC but perhaps not all. I've been thinking of setting up a 5V system to power dynamo-type lights.

Tourist in MSN

Try it first with just a light and some jumper wires. And after the light has been lit for several minuts to charge up the standlight, pull the plug and see how well the standlight works.

At 5 volt the lower voltage might reduce the standlight brightness and time. The lights I tested with 4 volt from a Li Ion battery had a very dim standlight.

I would not be surprised if the standlight only works with one polarity, not the other. So, if you do not get a standlight, try swapping the wires to reverse polarity.

Let us know how it worked.

2_i 

I ran, so far, only into one dynamo light that would not work off DC, B&M Eyc. Interestingly, I was unable to run that light off 60Hz AC transformed down to the vicinity of 6V. The only source that it reacted to was a dynamo. I have no idea what is happening inside that light. Regarding other propositions that have been mentioned I essentially run B&M Cyo off two lithium batteries in series. There may be a protective diode somewhere there on the way, but it is a Schottky, i.e., just 0.2V or so drop.

Tourist in MSN

I saw on a different forum that the Edelux light uses a magnetic switch, there is a magnet on the outside that pulls on another magnet inside the light to operate the switch. Not sure if that makes sense or not. But on the other forum, it was suggested to try using a stronger magnet to turn the light on and off.

unterhausen

There has to be someone in the Seattle area with a spare light. Probably someone with a spare dynohub wheel, but you don't need that if the hub is shown to work

steelbikeguy

I recall Jan Heine mentioning that a reed switch was used. A reed switch closes in the presence of a suitable/sufficient magnetic field. It's the same sort of switch that is used for the sensor in many (probably all) bike computers that have a magnet mounted to the spokes.

It's unlikely that the magnet decreased in strength. For the rare earth magnets, it takes a huge external magnetic field to demagnetize them... or a very high temperature that would likely melt the plastic that the magnet is contained in.

Steve in Peoria