Portable active lighting device or same installed on a bicycle

A portable active lighting device, comprising:

• at least one power supply source;
• a first optical system with at least one first light source of variable intensity for long-distance illumination, said first light source being controlled by a control circuit connected to the power supply source;
• a second optical system with at least one second light source of variable intensity for short-distance illumination, said second light source being controlled by the control circuit connected to the power supply source;
• a light sensor configured to determine a light intensity of a location in which a vehicle with the lighting device is situated and to supply a measurement signal to the control circuit;
• a speed sensor configured to determine a speed of the vehicle on a path or road, and to supply a measurement signal to the control circuit;
• and
• the control circuit, which is configured to automatically activate the first optical system only when the determined speed of the vehicle exceeds a predetermined speed threshold, and determine a light intensity of the first source, when the first optical system is activated, based on a combination of both the light intensity determined by the light sensor and the speed determined by the speed sensor.