Il problema dell'alimentazione elettrica per chi usa la bicicletta, sia nell'uso quotidiano che per viaggi di più giorni, sta diventando sempre più impegnativo. Serve sempre più energia elettrica non solo per illuminare la strada nelle buie ore della notte ma anche per alimentare il sempre crescente numero di dispositivi elettronici a cui non sappiamo più rinunciare. Questo sito vuole essere un primo passo per provare ad orientarsi nella non sempre facile scelta degli strumenti necessari per gestire in modo possibilmente autonomo le proprie necessità.

The electric power supply problem for people who like to cycle either in everyday use and along trips of several days, it's becoming increasingly challenging. More and more electricity is indeed required not only to illuminate the road in the dark hours of the night but also to feed the ever growing number of electronic devices that we can't live without. This site aims to be just a first step in the attempt to orientate the user in the not always easy commitment to choose the most appropriate tools.

Thursday, 17 May 2018

Lighting-up from 3.9W to 5.4W using a common 6V-3W dynohub

Based on some tests performed on a common 6V-3W dynohub (Shimano DH-3D32) span at an equivalent of 20 km/h on a 28” wheel and connected to a variable resistive load, I plotted Power vs Load Resistance getting a maximum of power at about 30 Ohm load.
At this point I tried several filament lamp configurations aimed to get closer as much as possible to the above indicated optimal resistance.
In the WIRING DIAGRAM below all labelled powers and relevant resistances are the nominal ones whereas in the next table all reported numbers are actually measured values.
CONCLUSION: using a 3-ways single pole selector (S1) it seems to be possible to have the following lighting modes:
S-0 - OFF
S-1 - Common Head and Rear Light combination mode (normal mode)
S-2 - Reinforced double front light configuration mode (flood mode)

REMARK: as said above all tests have been performed with very common tungsten filament, it’d be interesting to repeat same test either with alogen filament lamps and led lights.




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