Schmidt ~ secondary headlamp problem

[Nick]

I've recently fitted a secondary E6Z headlamp, but find that since doing so, the standlight on my rear light no longer works (well there is a faint glimmer from the LEDs). This is regardless as to whether or not i have been using the secondary headlamp.

The problem coincided directly with fitting the 2ndary headlamp, and it would thus be very unlikely that anything else has caused it. Any suggestions/ comments would be greatly appreciated!

[RJC]

How is the rear light wired into the system?
It should always be in parallel with the first headlamp.
If you have connected it in parallel with both front lights
then the 6V rear lamp will be driven with 12V when both front
lights are operating which could damage it.

Robin

[Nick]

Thanks for that Robin.

I have no idea how the back light is wired I'm afraid!. It is earthed through the bike frame, and powered from one of the spade connectors on the Primary B&M front light (the top right hand connector when looking at the light at from the front).

None of the 3 lights came with any instructions to indicated how they should be wired, and the front B&M light did not included any instructions to say what the 4  terminals were for.

[Nick]

As a PS, I have now tried completely 'unwiring' the secondary headlight to see if it made any difference, but the rear standlight still does not work. It would thus seem that the rear standlight has been irreparably damaged by fitting the secondary headlamp.

[RJC]

Which B&M light are you using?
There are instructions which you can download from
http://www.bumm.de
You should check the earth connection through the
frame at both ends.

[Dave Whittle Thorn Workshop]

 Acording to Schmidt this is how to wire the lamps correctly.

[Dave Whittle Thorn Workshop]

I e-mailed Schmidt to ask them some questions regarding secondary lights, here are the answers! [^]

>>I was after some information regarding the secondary lights you do, a
>>lot
>>of our customers are asking about these and I would like to inform them
>>correctly,

It's good you ask. I planned to write instructions for the "E6-Z" (E6 secondary headlamp) during the holidays but didn't found the time...

>>Do they work in series or parallel?

The E6-Z works in series to the normal headlamp (or the combination headlamp and rear lamp).

The last information leaflet in German is www.nabendynamo.de/pdf/12vinfo5.pdf - which shows the wiring sheme.

A good practical guide (in English) on how to wire the E6-Z together with an existing headlamp (or the E6) is shown on www.peterwhitecycles.com/wiringinstructions.htm

Hints and pictures about mounting two headlamps on a fork are shown on www.peterwhitecycles.com/dualsetupfork.htm

>>If you are running two headlamps up front then should you use 2 x 2.4w
>>bulbs or 2 x 3w bulbs?

E6 and E6-Z won't be damaged if you use 2.4W bulbs, but for maximum light output 3W works best.

>>Can you still have a back light running?

If you run a back light in parallel with the "primary" headlamp, you should use a 2.4W lamp there (and a 3W in the secondary headlamp).



The rear lamp should be connected in parallel to the primary headlamp as usual. To run the E6-Z remove one plug of the primary headlamp from the SON connetors, plug in the mating plug of the E6-Z instead and connect the two loose connectors like shown in the Peter

>>And does it need wiring in any
>>clever sort of way?

White links mentioned above. The E6-Z has no connection to ground potential and no rear light connector.

The wiring is really easy done - mounting of two headlamps on a bicycle can be a bigger problem. The secondary lamp is best placed on or near the handlebar because in hilly terrain it might be neccessary to switch it on and off reltive often.

>>Sorry to ask so many questions would just like to get my facts
>>straight
>>before I tell customers what to do.

It is much appreciated that you ask - we are guilty of not providing neccessary information early enough! Feel free to ask if you are not shure in any aspect of dynamo lighting.

[PeLu]

There is not much to add, just: If you use a rear light, take a 3W bulb for the second light. If you take a 2.4W, the excessive current will be just turned to heat in the second light's over voltage protection (assuming you use the Schmidt E6-Z). Not a very big difference....
And the E6-Z includes a capacitor for raising the voltage at medium speed (they call it low speed .-) .

BTW, if you want anything translated, just give me a message.

A little bit is also here:
http://www.m-gineering.nl/sondualg.htm
and a translation from the document mentioned above:
http://www.m-gineering.nl/son12vg.htm

[Nick]

Many thanks to all for your advice and research. Fitted a replacement rear light last night and took it to work and back today with the secondary lamp sometimes on and sometimes off. I took no chances and ran both an earth and a live from the Primary headlight to the rear light...and all seems to be working fine.

It would seem as though I should be replacing the 2.4W bulb in my secondary headlight with a 3W bulb...so down to the bike shop tomorrow...the wiring diagarm was helpful..but my German is not very good!

Many thanks again

[Dave Whittle Thorn Workshop]

Hi,

Thats exactly the way to set it up, double wire the rear, Schmidt dont recomend that you use the frame for the earth as it dosn't always give a decent earth, Shimano headsets for instance dont conduct electricity!

3W bulbs are hard to come by in some areas, don't be tempted by the reflectalite ones they don't seem to last very long, we stock Phillips bulbs, if you need one give me a ring.

Dave Whittle SJS Returns/Warranty

01278 441542

[PeLu]

The good things abozt bulbs taht they are easy to mail in an envelope.
I just remembered an other possibility to mount a light on the fork:

http://www.klickfix.com/minimounte.htm

The Minimount should be easier to get here than the overseas solution.

I've changed all my bikes to double wires in the seventies. German bicycle light enthusiasts checked the resistance with real current (don't trust your DMM in this case!) and got horrible numbers.
When you have a dynamo on your rear wheel and feed the main current through it, the loss might be significant.
As almost all dynamos are constant current sources, the front light may not be dimmer in such a case (sufficient speed assumed), but it will kill the backlight.

Also some mudguars with built in wires should be avoided (as wires not as mudguards). They are very unrelyable.