Construction Details

I decided to put the batteries into a holder, in order to be able to replace the batteries one by one if needed. I combined 3- and 2-battery aluminium holders made by Keystone. Note: a typical plastic holder is unsuitable for a bicycle as the batteries would pop out.

Unfortunately, the holder required quite a bit of space. Additionally, I could not find a commercial box that would be optimal sizewise for the holder, board and the other elements. Thus, I ended up using quite a large 2" x 3" x 3 1/2" interlocking aluminum box. In closing the box, I use two thumbscrews from the top and bottom.

I attached the battery holder to the back of the box and the rest to the front. The printed board is separated by hexagonal computer spacers from the box.

For connecting the dynamo and lights, I use a 4-position speaker compression terminal block. Such a block worked very well with my first electric regulator. Another tested solution was an arc out of a threaded rod, dipped in Plasti-Dip, surrounding the switch toggle. With no such arc, on the bike the switch would frequently get toggled accidentally and the toggle might get broken. Further details can be seen in the photographs which follow. (I had a series of decent photographs taken during construction but my family managed to put vacation shots on top. What I have at the moment are quick emergency shots; once I get something better again I'll substitute those shots.)

The box ended up pretty empty, mostly filled with wires. I ran a bead of silicon caulk along the joint of the two parts of the box to prevent water from getting in.