Decreasing Electrical Load on Dynamo

If I can't make the dynamo put out more current, maybe I can reduce the electrical load of the bike and try to make the best use of the available current that the dynamo will produce.  That means replacing some of the high load incandescent bulbs with some modern LED technology.  Of course 6 volt positive ground LED lamps are not commonplace, so I will have to create them.

Here's the general idea.  The trick will be to diffuse the light enough that it doesn't look like they are LEDs.  The other trick will be to separate the high and low intensity "filaments" on the tail / brake light so they don't feed back into the system.  That's easily done with some regular signal diodes, and two different resistors.  With both resistors running in parallel, I'll set their combined resistance at the maximum current of the LEDs.  With only one running, I'll see what percentage of max current still gives a decent output for the tail light "filament" circuit.

The running lamp bulb in the headlight should be even easier.  I can just use some white LEDs and pile them into the bayonet base of a dead lamp.  Diffusing this lamp will probably prove to be more difficult since there's nothing to hide the fabricated LED lamp assembly in the big headlamp housing.  Maybe a piece of plastic diffuser or reflector from something else will work.

I did sacrifice an ultra-bright LED that I had in my junk box from an old project to prove a concept.  Most LEDs have a rather narrow view angle.  I took the file to the lens of one of these LEDs and ground it flat.  Then I used some fine emory paper and polished it up.  I'll have to refine the technique, but essentially it works.  It diffuses the light into a wider area, rather than focusing it into a beam.  I did get a weird halo effect, but I think I just need to polish the edges a little more.

I don't plan to run the bike in the dark if at all possible, so If I can just reliably run the running lamp circuit without the main beam I should be fine.  The main headlamp is a HUGE 30w draw on the dynamo, and it just doesn't keep up.

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The running light in the head lamp was easy.  6 Ultra-Bright White LED's soldered into a bayonet lamp base.  The rear tail light lamp was a little more challenging, per the above diagram.

Dang! that's BRIGHT!

Both these replacement bulbs LED assemblies draw less than half an amp and put out MORE light than the original incandescent bulbs.

Rear Fender and indicator lamps

I decided to only replace the wires that needed replacing at the moment to keep it as original as possible.  Some wires had already been spliced, so those may need attention depending on the security of the splice.  So far what I've seen they are just wrapped together and taped up.  I prefer solder and shrink tube if I have to splice.

I took off the rear fender for the first time last night.  There was 50 years worth of dirt and grease under there that had to be mucked out.  It was much easier to run the wiring with the fender off.  Anticipating the need to remove the fender to change the rear tire, I used two barrel connectors to attach the stop and tail light wires; naturally installed in opposite directions so I don't mix up the wires.

The horn and brake light switch got hooked up too.  I modified the wiring slightly from stock and ran the stop light wire down between the electrical boxes to the switch rather than in the right one and back out again.  Because of the heavy insulation 105'C MTW wire I'm using it just made more sense.  BEEP BEEP!  That works.

The adventure came when trying to get the oil and charge indicators to work.  The charge indicator had a spring left in there by someone who thought they were going to fix it.  It ended up shorting out the connection inside the bulb holder and kept the light from coming on.  With that removed and cleaned out with a little bare hookup wire wrapped around the bulb for extra contact along the sides the red charge indicator worked fine.  (Is it supposed to be the red one?)

The oil indicator threw me for a little while before I realized that the bulbs are only 2.5v and there is an integral dropping resistor wrapped around the bulb holder fixture.... and that some genius while trying to test the bulb (me) had vaporized the end of the resistor wire.  They say its the same bulb holder used on a Rover P4 (Like I'll ever find one of those in the states).  A dab of solder fixed that up and I have an operational oil pressure switch light.  It felt re-assuring to turn on the new key, and see indicators lamps smiling at me.

The next step is the scary part.  When I fire it up, will the indicators go out?  Will it charge the battery and is there enough oil pressure.  I'll try that this weekend.