1. Field of the Invention
The invention relates to a tail light for a bicycle with semiconductor light sources.
2. Description of the Prior Art
Conventional tail lights are operated with incandescent light bulbs. These bulbs emit light nearly homogeneously over a large spatial angle. This makes it possible to construct a tail light with sufficient light intensity in backward, upward and lateral directions using a single light bulb. Such a wide distribution of emitted light is required by legal security regulations (see e.g. Section 67, TA 14 of the German StVZO).
The bulbs that are used in conventional tail lights have a nominal operation voltage of approximately 6 V and a power consumption of 0.6 W. They show an average life time of approximately 100 hours because the filaments are damaged easily. It would be preferable, however, to reduce power consumption such that sufficient illumination is generated at a slow bicycle speed and part of the dynamo power can be used for charging an accumulator at high bicycle speed. It should also be possible to operate the light plant when the bicycle has stopped. At the same time, the life time of the light source should be increased.