Patent ID: 7119707

Claim:
A circuit for providing electrical current to a bicycle lighting device that provides external illumination to an area around the bicycle, wherein the circuit comprises: a current supply circuit that supplies DC current from a power supply to the bicycle lighting device along a current path, wherein the current supply circuit comprises a first transistor having input and output current flowing terminals structured to flow current from the power supply through the bicycle lighting device in response to signals applied to a control terminal of the first transistor; and a current limiting circuit comprising: a second transistor having input and output current flowing terminals and a control terminal, wherein current flowing through the input and output current flowing terminals is communicated to the control terminal of the first transistor for controlling current flowing through the input and output current flowing terminals of the first transistor; and a resistance coupled in series with the input and output current flowing terminals of the first transistor and with the control terminal of the second transistor; wherein a voltage from the power supply is input to the resistance and to one of the input and output current flowing terminals of the second transistor such that a voltage applied to the control terminal of the second transistor through the resistance remains substantially constant in response to voltage fluctuations of the power supply so that substantially constant current flows through the input and output terminals of the first transistor.