John's cycle lighting

I got fed up with problems with existing lighting systems, and eventually built my own (and occasionally get fed up with that, too, although it's reasonably robust by now). I use halogen lamps run from 6 large (full D-cell) NiCd batteries which are mounted in a box with some electronics attached (I'll do a circuit diagram here sometime soon) to regulate the voltage when running from the optional dynamo, and the charging current. The box plugs into the wiring of either the trike or the bike, or into a main transformer to recharge at home. I use an 8-pin Bulgin connector (the kind used for disco light shows etc) with the following pinout:

1low-voltage AC in (and chassis)
2low-voltage AC in
3switched +
4(no connection yet)
5battery +
6(no connection yet)
7negative common
8positive out (to switch)

The ``switched'' line comes from a switch on the front light, and goes to the back lights, so they can all be switched on and off from the front. It goes into the electronics box in case I want to add some new feature, such as turn signals for the trike that will only run at night, for example.

The ``battery +'' line lets me check the voltage conveniently (and were the output electronics to fail, in an emergency I could re-wire the connector to run the lights straight from the battery output).

In the past, I've had a connection to run trailer lights from bike or trike, but that's no longer working -- I'll do a better version of it some time soon. This will have the same kind of Bulgin connector as the rest of the system, so I can put the batteries on the back of the trike or in the trailer for a change.

Turn indicators on the trike would probably be very nice -- it's good to keep both hands on the handlebars around corners!

I'm adding some smaller batteries to the battery box, with a robust switch, to give some backup when the main NiCds run down (NiCds run down quite suddenly, and it's generally reckoned to be a bad idea to run them as a ``float'' and better to let them discharge and recharge fairly deeply, so I don't like to keep doing small top-ups to them.) I wanted to get a switch which would be hard to throw by accident, such as a transformer mains voltage selector, but those are no longer available so I got an ordinary toggle switch and cut its dolly off, so it needs a pointy stick to throw it.

I'm currently working on a combined front lamp mounting and battery box holder to go on the front carrier of the trike; it also has a socket like the one on the battery box, to connect a rectifier and regulator between the dynamo and the lights so I still have some lighting if I forget to take the battery box with me.

John C. G. Sturdy
[John's home] Last modified: Sun Jun 10 22:09:51 GMT Daylight Time 2007