Newbie Question -- running two headlamps and a taillight from one generator hub

My lighting system is a SON 20 dynohub which runs an Edelux headlight and a Supernova taillight. I tried a Supernova E3 triple to this in hopes of having more lighting for downhill or faster riding. Just riding along I could not get all 3 of the E3's LEDs to light up, instead only one did. To get all 3 to light up, I had to switch the Edelux off. I have 2 other dynohub wheels that I could try, one is a SON 28 and the last is a Supernova Infinity S. All of these are 6V, 3W.

.... I'm still looking for a question in that posting....

In the old days of incandescent bulbs, it was pretty normal to be able to wire two bulbs or lights in series and have it work. The bulbs were 12 ohms, and they would have 6 or 7 volts across them.

With LED headlights, I'm not sure if manufacturers are still sticking to that standard. You might try using each headlight separately and measuring the voltage across the headlight when at normal speeds. It might be that the E3 triple has a higher voltage drop across it than the standard 6 or 7v.

The SON28 is pretty beefy and can provide a bit more power than a SON20, as I understand it. Since it is designed for smaller wheels, it's reasonably to assume that it puts out less voltage than the SON28 at a given speed.

As I see it, both the SON20 and that E3 could be the source of the problem. You might try trading the E3 for a second Edelux. The Edelux has a better beam pattern, making better use of the light (right?). My guess is that it will be easier to drive two Edeluxes in series than the Edelux and E3.

Steve K--Thanks for the advice. I'll try the same 2 lights with the SON 28 next and see if it provides more power.

I used Son deluxe hub with Cyo + E3 triple + taillight in PBP. I don't think E3 ever had enough power. Even in 50 km/h+ downhills it didn't reach maximum output. 2x Cyo or 2x Luxos work better.