Dynamo headlight for a bicycle

Abstract

Dynamo headlight (1) for a bicycle (3), comprising - a housing (4), - several lighting units (5) which can be operated with direct current, - an optical system (2) for directing the light emitted by the lighting units (5) into an illumination area (46) in front of the dynamo headlight (1), - a first electrical contact element (35) and a second electrical contact element (36) for input alternating current from an input alternating current generating power generator (32) as a dynamo (32) with a rotor (34) for supplying the dynamo headlight (1) with electrical energy from input alternating current with a variable alternating voltage (U) and a variable alternating current (I) at the first and second electrical contact element (35, 36) due to a variable speed of the rotor (34) of the power generator (32), - a rectifying means (39) for converting the input alternating current from the first and second electrical contact elements into direct current, - a transformation means (40) for changing the electrical voltage (U) of the operating direct current with which the lighting units (5) can be operated, characterized in that the dynamo headlight (1) comprises a control and / or regulating means (42) designed such that the input alternating current is limited to an upper limit value as the maximum value of the variable alternating current (I) and / or with the dynamo headlight (1) mounted on a bicycle (3) with a power generator (32) driven by a wheel of the bicycle (3) as a dynamo (32) for supplying the dynamo headlight (1) with electrical energy, so that the dynamo headlight (1) can be operated with electrical energy from the power generator (32), a method according to one or more of claims 9 to 14 can be carried out.

Description

[0001] The present invention relates to a dynamo headlight according to the preamble of claim 1, a method for operating a dynamo headlight according to the preamble of claim 9 and a bicycle according to the preamble of claim 15.

[0002] Dynamo headlights are used as components on bicycles to illuminate the area in front of the bicycle while the bicycle is moving, or to be recognized by the bicycle itself. A power generator is installed on the bicycle in the form of a dynamo. The dynamo is designed, for example, as a follower dynamo or a hub dynamo. The follower dynamo is in mechanical contact with a tire of the bicycle wheel. The hub dynamo is built into the hub or axle of, for example, the front wheel of the bicycle. The dynamo is designed as a permanent magnet alternating current generator for power generation with self-regulation.

[0003] The dynamo headlight is powered by electrical energy from the power generator. For historical reasons, the dynamo is designed to function primarily as a current source rather than a voltage source. Due to its design, the dynamo attempts to deliver an alternating current I of approximately 500 mA as input alternating current to the dynamo headlight at all times. At very low speeds, the alternating current can be less than 500 mA. With a legally specified electrical resistance of 12 ohms for the dynamo headlight, this results in an alternating voltage of approximately 6 V at a bicycle speed of approximately 15 km / h. This results in an upper limit of electrical power of 3 W, which is generally not exceeded even at much higher speeds.If the speed of the bicycle is increased further, for example to 20 km / h, the alternating current I and the alternating voltage U of the input alternating current do not increase significantly, so that the electrical power remains essentially constant at 3 W. At higher speeds, however, slightly higher values for the alternating voltage U and the alternating current I can occur, for example 6.2 V at 30 km / h. The historical reason for this design is to prevent bulbs in the dynamo headlight from burning out without the need for electronic control. The disadvantage, however, is that even at speeds above 15 km / h, no greater electrical power is available to operate the dynamo headlight. At higher speeds, it is sensible to enable stronger illumination with the dynamo headlight by increasing the electrical power of the dynamo headlight.

[0004] EP 1 549 108 A2 shows a lighting arrangement for a two-wheeler, in particular a bicycle, with a main light source, with a connection for a power generator supplying an alternating voltage and a rectifying means generating a direct voltage of a first voltage level from the alternating voltage and / or a connection for an energy store supplying a direct voltage of a first voltage level, with at least one transformation means which can transform the direct voltage of the first voltage level into a direct voltage of a second voltage level, wherein the main light source comprises at least one light-emitting diode and the second voltage level is greater than the forward voltage of the at least one light-emitting diode.

[0005] EP 2 757 674 B1 discloses a vehicle lamp comprising: a plurality of light source sections, a circuit board, and a lighting circuit including a DC / DC converter configured to operate the plurality of light source sections, wherein the DC / DC converter includes a plurality of converter sections.

[0006] WO 2013 / 174 363 A1 shows a bicycle headlight with LED light source, plastic housing and actively controlled input circuit, whereby the power semiconductors of the input circuit enable low-loss regulated power extraction from free-floating alternating voltage.

[0007] EP 1 577 202 A2 discloses a device for operating at least one light-emitting diode, wherein the power source is a dynamo of a two-wheeler and the current / voltage characteristic of the light-emitting diode requires current / voltage conversion for reliable operation, wherein a full-wave rectifier and a current / voltage converter are connected between the dynamo and the light-emitting diode. The light-emitting diode is connected in series with a measuring resistor. A first voltage measuring device is provided for measuring the voltage across the measuring resistor, and a second voltage measuring device is provided for measuring the voltage at the output of the full-wave rectifier. A control unit is provided to which the two voltages measured by the first and second voltage measuring devices are fed and which generates a control signal for the current / voltage converter therefrom.

[0008] The object of the present invention is therefore to provide a dynamo headlight for a bicycle, a method for operating a dynamo headlight for a bicycle and a bicycle in which the electrical power technically realizable by the power generator as a dynamo is available as electrical power for operating the dynamo headlight even at high speeds of the bicycle.

[0009] This object is achieved with a dynamo headlight for a bicycle, comprising a housing, several lighting units operable with direct current, an optical system for directing the light emitted by the lighting units into an illumination area in front of the dynamo headlight, a first electrical contact element and a second electrical contact element for input alternating current from a power generator generating input alternating current as a dynamo with a rotor for supplying the dynamo headlight with electrical energy from input alternating current with a variable alternating voltage U and a variable alternating current I at the first and second electrical contact element due to a variable speed of the rotor of the power generator, a rectifying means for converting the input alternating current from the first and second electrical contact element into direct current,a transformation means for changing the electrical voltage U of the operating direct current with which the lighting units are operable, wherein the dynamo headlight comprises a control and / or regulating means designed such that the input alternating current is limited to an upper limit as the maximum value of the variable alternating current I and / or with the dynamo headlight mounted on a bicycle with a power generator driven by a wheel of the bicycle as a dynamo for supplying the dynamo headlight with electrical energy, so that the dynamo headlight can be operated with electrical energy from the power generator, a method described in this patent application can be carried out. Preferably, a mechanical coupling between the wheel of the bicycle and the dynamo is formed with a mechanism,so that the dynamo is driven by the bicycle wheel. Preferably, the direct current converted from alternating current to direct current by the rectifying means can be changed in electrical voltage U by the transforming means as operating direct current for operating the lighting units.

[0010] In another variant, the upper limit of the variable alternating current is less than 500 mA, 600 mA or 900 mA.

[0011] In a supplementary embodiment, the upper limit of the variable alternating current is greater than 300 mA. Preferably, the upper limit of the variable alternating current is between 300 mA and 900 mA, in particular between 400 mA and 600 mA.

[0012] In a further embodiment, the electrical voltage U and / or the electrical current I of the operating direct current for the lighting units can be controlled and / or regulated as a function of the alternating voltage U and / or the alternating current I of the input alternating current, in particular with the control and / or regulating means.

[0013] Preferably, from the time the upper limit value of the alternating current I of the input alternating current is reached and the alternating voltage U of the input alternating current is increased at the same time beyond the value of the alternating voltage U of the input alternating current when the upper limit value of the alternating current I of the input alternating current is reached, the electrical voltage U and / or the electrical current I of the operating direct current can be increased, in particular by means of the control and / or regulating means.

[0014] In a supplementary embodiment, the electrical voltage U of the operating direct current remains substantially constant, and the electrical current I of the operating direct current can be increased. A substantially constant electrical voltage U of the operating direct current preferably means that the electrical voltage U of the operating direct current changes by less than 40%, 30%, 20%, 10%, or 5% during operation of the dynamo headlight.

[0015] In a further embodiment, the electrical power of the input alternating current corresponds substantially, in particular with a deviation of less than 30%, 20% or 10%, to the electrical power of the operating direct current of the lighting units.

[0016] The transformation means is expediently a DC / DC converter, and the DC / DC converter can convert the direct current generated by the rectification means into the operating direct current. The transformation means preferably comprises smoothing means, preferably at least one capacitor.

[0017] Inventive method for operating a bicycle with a dynamo headlight and a power generator as a dynamo for alternating current, comprising the steps of: Riding the bicycle so that, due to a mechanical coupling of the power generator to a wheel of the bicycle, a rotor of the power generator is set in rotation and an input alternating current with a variable alternating voltage U and a variable alternating current I is generated by the power generator depending on the variable speed of the rotor of the power generator, Conducting the input alternating current to a rectifying means, Converting the input alternating current into a direct current by means of the rectifying means,Conducting the direct current generated by the rectification means to a transformation means and changing the primary electrical voltage U and the primary electrical current I of the primary direct current at the input of the transformation means into a secondary electrical voltage U and a secondary electrical current I of a secondary direct current at the output of the transformation means as operating direct current; conducting the operating direct current output by the transformation means to lighting units and operating the lighting units with the operating direct current, so that light is emitted by the lighting units in the dynamo headlight, wherein the input alternating current is limited to an upper limit of the variable alternating current I, in particular upon reaching a limit speed of the rotor of the power generator. Preferably, the limit speed is variable for a fixed limit of the variable alternating current.in particular due to environmental conditions and / or load conditions. Preferably, the limit speed for a fixed limit of the variable alternating current is substantially constant, in particular with a deviation of less than 30%, 20%, or 10%, or variable.

[0018] In an additional embodiment, when the limit speed of the rotor of the power generator is exceeded, the upper limit value of the variable alternating current I is kept essentially constant, in particular with a deviation of less than 30%, 20% or 10%, and the variable alternating voltage U of the input alternating current is further increased.

[0019] In a further variant, once the limit speed of the rotor of the power generator is exceeded, the variable alternating voltage U of the input alternating current is increased as a function of the speed of the rotor of the power generator, in particular the variable alternating voltage U of the input alternating current is substantially, in particular with a deviation of less than 30%, 20% or 10%, directly proportional to the speed of the rotor of the power generator.

[0020] In particular, the electrical power of the operating direct current essentially corresponds, in particular with a deviation of less than 30%, 20%, or 10%, to the electrical power of the input alternating current. The rectification means and the transformation means exhibit electrical losses, so that the electrical power of the operating direct current is slightly lower than the electrical power of the input alternating current.

[0021] In a further embodiment, from the moment the limit speed of the rotor of the power generator is exceeded and the upper limit value of the variable alternating current I of the input alternating current is reached, during a further increase in the alternating voltage U of the input alternating current, the electrical current I of the operating direct current and / or the electrical voltage U of the operating direct current is increased, in particular substantially, in particular by at least 5%, 10%, 20%, 30%, 50% or 70%, the electrical current I of the operating direct current is increased and the electrical voltage U of the operating direct current is kept substantially constant, in particular with a deviation of less than 30%, 20% or 10%.

[0022] In an additional variant, once the limit speed of the rotor of the power generator is exceeded, the electrical current I of the operating current is increased as a function of the variable alternating voltage U of the input alternating current, in particular the electrical current I of the operating current is controlled and / or regulated essentially, in particular with a deviation of less than 30%, 20% or 10%, directly proportional to the variable alternating voltage U of the input alternating current.

[0023] A bicycle according to the invention, comprising a frame or a body, at least two wheels, a dynamo headlight, a power generator driven by a wheel as a dynamo and the dynamo headlight can be operated with electrical energy from the power generator, in particular exclusively with electrical energy from the power generator, wherein the dynamo headlight is designed as a dynamo headlight described in this patent application and / or a method described in this patent application can be carried out with the bicycle.

[0024] In a further variant, the first and / or second electrical contact element is designed as an electrical connector and / or as a fixing element for fastening the dynamo headlight to a frame of the bicycle.

[0025] Preferably, the current generator generates an alternating current with a variable and substantially constant alternating current I, in particular with a deviation of less than 50%, 40%, 30%, 20% or 10%, wherein in particular the substantially constant alternating current is the upper limit of the alternating current.

[0026] In an additional embodiment, the alternating current I and / or the alternating voltage U of the input alternating current is detected by a sensor.

[0027] In an additional embodiment, the alternating current I and / or the alternating voltage U of the operating direct current is detected by a sensor.

[0028] In a further embodiment, the control and / or regulation of the alternating current I of the input alternating current is carried out as a function of the detected alternating current I and / or the detected alternating voltage U of the input alternating current and / or the detected current I and / or the detected voltage U of the operating direct current. Corresponding data and / or functions for controlling and / or regulating the alternating current I and / or the alternating voltage U of the input alternating current as a function of the detected alternating current I and / or the detected alternating voltage U of the input alternating current and / or the detected current I and / or the detected voltage U of the operating direct current are stored in the control and / or regulation means.

[0029] In another variant, the upper limit of the alternating current I of the input alternating current is essentially constant, in particular with a deviation of less than 30%, 20%, or 10%. The upper limit is a fixed value that is subject to slight fluctuations during operation of the dynamo headlight and / or the bicycle.

[0030] In a further embodiment, the power generator or dynamo is designed as a follower dynamo (side-rotor dynamo) or as a hub dynamo or as a rim dynamo or as a spoke dynamo.

[0031] Preferably, the dynamo is designed as a permanent magnet alternating current generator and / or as a claw pole generator and / or as a generator with permanent magnets in the rotor and / or with self-regulation.

[0032] In another embodiment, the lighting units are LEDs.

[0033] The dynamo headlight is designed as a front dynamo headlight.

[0034] In an additional embodiment, the dynamo headlight comprises a control and / or regulating unit for switching the at least two lighting units on and off, so that the dynamo headlight can be switched between the two radiation characteristics.

[0035] In a supplementary variant, the electrical power of the dynamo headlight and / or the power generator is greater than 5W, 7W, 10W or 12W.

[0036] In a further embodiment, the control and / or regulating unit and / or the control and / or regulating means is integrated into the dynamo headlight.

[0037] Preferably, the control and / or regulating unit additionally functions as a control and / or regulating means or vice versa.

[0038] In a supplementary variant, the alternating current of the input alternating current is the effective value or rectified value or peak value of the alternating current of the input alternating current.

[0039] In a supplementary variant, the alternating voltage of the input alternating current is the nominal value or effective value or rectified value or peak value of the alternating voltage of the input alternating current

[0040] In a further variant, the method described in this patent application is carried out with the dynamo headlight and / or bicycle described in this patent application.

[0041] Preferably, at least two lighting units can be separately activated and deactivated during operation, so that different radiation characteristics can be generated by means of the at least two separately activatable and deactivatable lighting units and the optical system.

[0042] Preferably, the interior is limited by the housing and / or the protective screen.

[0043] Preferably, the optical system is formed by a lens system and / or by at least one reflector.

[0044] In a supplementary variant, the lens system forms at least partially the protective screen.

[0045] In an additional embodiment, the lens system comprises at least one lens.

[0046] In a further variant, at least one lighting unit is dimmable. This advantageously allows individual beam characteristics to be adjusted in terms of illuminance. For example, the illuminance of the low beam or high beam can be adjusted to the luminous intensity of the ambient light by dimming the correspondingly assigned lighting units.

[0047] In particular, several, especially all, lighting units are dimmable.

[0048] In a further embodiment, the dynamo headlight is designed such that at least one lighting unit, preferably a plurality of lighting units, is / are assigned to each radiation characteristic. When operating at least one radiation characteristic, the at least one lighting unit, preferably the plurality of lighting units, is / are active, and the remaining unassigned at least one lighting unit is deactivated. To implement different radiation characteristics, only those lighting units assigned to the corresponding radiation characteristic are selectively activated, while the other lighting units are deactivated or switched off. A dimmed lighting unit is therefore also an active lighting unit.

[0049] Preferably, the at least one lighting unit is continuously dimmable and / or the electrical power and / or the radiant power of the dimmable at least one lighting unit is variable by at least 10%, 30%, 50%, 100% or 200%, preferably by means of the control and / or regulating unit.

[0050] In one variant, the dynamo headlight comprises a temperature sensor for detecting the temperature of the dynamo headlight, preferably on the lighting units and / or on a carrier plate and / or on the housing and / or in the area of the lighting units and / or in the area of the carrier plate and / or in the area of the housing, and / or the electrical power and / or the radiant power of the dimmable at least one lighting unit is controllable and / or adjustable as a function of a parameter, in particular as a function of the temperature detected by the temperature sensor, in order to avoid overheating of the lighting units.

[0051] In particular, the beam characteristics are low beam and / or high beam and / or cornering light and / or daytime running light and / or additional side illumination.

[0052] In a further embodiment, the lighting units are LEDs and / or light bulbs and / or a laser-phosphor system. In a laser-phosphor system, the electromagnetic radiation emitted by at least one laser strikes a phosphor, for example, phosphor, so that the phosphor, acting as a lighting unit, emits light.

[0053] In a supplementary variant, the lighting units are arranged on a carrier, in particular a carrier plate and / or circuit board.

[0054] In a further embodiment, the electrical power and / or light output of at least one lighting unit that can be dimmed depending on the temperature detected by the temperature sensor can be reduced once at least one temperature limit value detected by the temperature sensor has been reached. Only once the at least one temperature limit value has been reached is the electrical power and / or light output of the at least one lighting unit provided for this purpose reduced.

[0055] In an additional embodiment, the dynamo headlight is a front dynamo headlight.

[0056] Cooling fins are preferably formed on the outside of the housing, particularly in the area of the lighting units.

[0057] In a further embodiment, the lighting units and / or the control and / or regulating means and / or the control and / or regulating unit are operated, in particular exclusively, with electrical energy from the power generator.

[0058] The dynamo headlight expediently comprises at least one switching unit for switching the dynamo headlight on and off.

[0059] In a further embodiment, the control and / or regulating unit and / or the control and / or regulating means comprises a processor, preferably a microcontroller, and at least one data memory.

[0060] An embodiment of the invention is described in more detail below with reference to the accompanying drawings. They show: Fig. 1 one half of a dynamo headlight cut along a central plane, Fig. 2 a view of a carrier plate with light units of the dynamo headlight according to Fig. 1, Fig. 3 a view of a reflector of the dynamo headlight according to Fig. 1, Fig. 4 the cross-section of the carrier plate according to Fig. 2 and additionally partially the housing of the dynamo headlight according to Fig. 1, Fig. 5 a side view of a bicycle and Fig. 6 a highly simplified electrical diagram of the bicycle with a dynamo headlight and a power generator as a dynamo.

[0061] In Fig. 5 shows a bicycle 3. To illuminate an illumination area 46 in front of the bicycle 3, the bicycle 3 has a dynamo headlight 1 as a front dynamo headlight 29, and also a rear light 30 and a brake light 31 at the rear.

[0062] The dynamo headlight 1 has a housing 4 made of plastic and / or metal, in particular aluminum. On a rear area of the housing 4, a retaining stud 20 is formed as a holding device 19 with a holding opening 21. The holding device 19 serves to directly or indirectly fasten the dynamo headlight 1 to the frame of the bicycle 3. The pot-shaped housing 4 and a protective screen 18 thus enclose or delimit an interior space 49, and within the interior space 49, a control and / or regulating unit 15 is arranged as an electronics unit 16, a reflector 14, and a carrier plate 7 as a circuit board 8 with lighting units 5. The lighting units 5 ( Fig. 2) are attached to the carrier plate 7 as the circuit board 8, and furthermore, the lighting units 5 are designed as LEDs 6. To supply the control and / or regulating unit 15 and the lighting units 5 with electrical energy or electrical current, the housing 4 has at least one opening 28 for the passage of two power lines 38. The openings 28 are sealed by means of sealing elements (not shown), so that no moisture or dirt can penetrate into the interior space enclosed by the housing 4. A front end region of the interior space enclosed by the housing 4 is sealed fluid- and dust-tight by the protective screen 18. The light reflected by the reflector 14 is radiated outward through the protective screen 18 into the illumination space 46. However, the protective screen 18 has no optical effect and serves merely to protect the interior of the dynamo headlight 1 from environmental influences.The dynamo headlight 1 can be switched on and off using a switching unit 37 integrated into the dynamo headlight 1. Furthermore, the switching unit 37 can be used to manually switch between high beam and low beam.

[0063] The reflector 14 made of plastic ( Fig. 1 and Fig. 3) has a reflection surface 13 for reflecting the light emitted by the lighting units 5. The reflection surface 13 comprises a plurality of mirror elements 26. The number of mirror elements 26 is approximately 90 to 110. The reflector 14 is formed symmetrically to a vertical center plane in the longitudinal direction and in the center, as shown in Fig. 3 between two steps 27, the mirror elements 26 between the two steps 27 are formed raised with respect to the other mirror elements 26 to the left and right of the step 27 as shown in Fig. 3.

[0064] The carrier plate 7 has two fastening openings 10, and the carrier plate 7 is fastened to the housing 4 by means of fastening elements 11 in the form of screws 12, each arranged in the fastening openings 10. For this purpose, fastening bores 9 are designed as blind holes 9 with an internal thread on the housing 4. The screws 12 have a shaft with an external thread and also a screw head. The external thread of the screw shaft engages with the internal thread on the fastening bore 9, and the screw head rests on an outer side of the carrier plate 7, so that the carrier plate 7 is fastened to the housing 4 in a form-fitting and / or force-fitting manner. A temperature sensor 17 is fastened to the carrier plate 7. The temperature sensor 17 serves to detect the temperature of the dynamo headlight 1 in the area of the lighting units 5.The temperature sensor 17 can also be arranged at a different location, for example between the carrier plate 7 and the housing 4. A thermally conductive gel is arranged between the carrier plate 7 and the housing 4 in order to increase the thermal conductivity from the carrier plate 7 to the housing 4. The carrier plate 7 is preferably made of a material with high thermal conductivity, for example metal, in particular aluminum or steel. The control and / or regulating unit 15 is additionally designed such that, for at least one dimmable lighting unit 5, the electrical power and / or light output is dependent on the temperature detected by the temperature sensor 17 and, simultaneously, for at least one lighting unit 5, the electrical power and / or light output is substantially independent of the temperature detected by the temperature sensor 17.When a temperature limit is reached, some of the lighting units 5 are operated essentially unchanged in accordance with the radiation characteristic requirements, and another part of the lighting units 5 that is less important for the illumination is operated in dimmed mode, i.e. with reduced electrical power and / or light output, so that the dimmed lighting units 5 emit less heat or waste heat. This prevents an unacceptable increase in the temperature of the dynamo headlight 1 in the area of the lighting units 5. The lighting units 5 that are less important for the illumination area in terms of a radiation characteristic are selected for dimming, so that the important illumination area, such as the illumination space 46, is illuminated essentially unchanged with a high illuminance.The lighting units 5 can also be operated in such a way that the higher the temperature detected by the temperature sensor 17, the more lighting units 5 are operated dimmed and vice versa.

[0065] With the dynamo headlight 1, different beam characteristics, namely a low beam, a high beam, a daytime running light, and a cornering light, can be provided or implemented. For this purpose, corresponding light units 5 are assigned to the different beam characteristics. Thus, light units 22 for the low beam, light units 23 for the high beam, light units 24 for the daytime running light, light units 25 for the cornering light, and light units 33 for a wide and close-up illumination range are arranged on the carrier plate 7 ( Fig. 2). Fig. The upper light units 24 for the daytime running lights shown in Figure 2 can optionally also be used as light units 23 for the high beam. To switch on or activate only the low beam, only the light units 22 for the low beam are activated, and the remaining unassigned light units 5 are deactivated or switched off by means of the control and / or regulating unit 15 and the electronics 16. This applies analogously to the high beam, so that when the high beam is switched on, the light units 23 for the high beam are active, and usually also the light units 22 for the low beam.During travel with the bicycle 3 or the e-bike 32, the control and / or regulating unit 15 is thus switched such that when the high beam is activated to illuminate a long-distance illumination area as the high beam space 48, it is naturally necessary that a close-up illumination area as the low beam space 47 is also illuminated by the lighting units 22 for the low beam. Due to the different alignment of the lighting units 5 to the reflection surface 13 of the reflector 14, the different radiation characteristics can thus be achieved simply by activating different lighting units 5 due to the reflection of the light emitted by the lighting units 5 at the reflection surface 13 in accordance with the laws of reflection, i.e. the angle of incidence equals the angle of emission.Each of the lighting units 5 essentially completely illuminates the reflection surface 13, but with a different illuminance on the reflection surface 13, so that, for example, when only the lighting units 22 for the low beam are operated, the majority of the light serves to illuminate the close-up illumination area as the low beam area, but to a lesser extent the remaining illumination area, for example the long-distance illumination area, is also illuminated as the high beam area.

[0066] In Fig.Figure 6 shows a highly simplified electrical circuit diagram of the bicycle 3 with the dynamo headlight 1. A power generator 32, in the form of a dynamo, is installed as a hub dynamo 32 in a front wheel of the bicycle 3. A rotor 34 with permanent magnets is installed in the power generator 32. Two power lines 43 are led from the power generator 32 to a first electrical contact element 35 and a second electrical contact element 36. The first and second electrical contact elements 35, 36 are formed at one end or an end region of the power line 38 of the dynamo headlight 1. The power lines 38 are led to a rectifying means 39, in the form of a rectifier 39. In the rectifying means 39, the alternating current generated by the power generator 32 is converted into direct current and passed through the two power lines 44 to an input 47 of a transformation means 40. The transformation means 40 is designed as a DC / DC converter 41.At the DC / DC converter 41, the direct current with a primary electrical voltage U and a primary current I at the input 47 is converted into a direct current with a secondary electrical voltage U and a secondary current I at an output 48 of the DC / DC converter 41. The direct current at the output 48 of the DC / DC converter 41 is conducted as operating direct current via the power lines 45, for example as conductor tracks on the circuit board 8, to the lighting units 5 as LEDs 6. The lighting units 5 are generally or partially electrically connected in parallel with electrical series resistors. The control and / or regulating unit 15 of the dynamo headlight 1 additionally functions as a control and / or regulating means 42 for controlling and / or regulating an input alternating current at the first and second electrical contact elements 35, 36, i.e., on the power line 38 of the dynamo headlight 1.

[0067] While riding the bicycle 3 with the dynamo headlight 1 switched on, the dynamo headlight 1 is powered by electrical energy generated by the power generator 32. Due to its structural design, the dynamo 32 attempts, based on legal requirements, to supply an alternating current I of approximately 500 mA as input alternating current to the dynamo headlight 1 at any time. Under other legal requirements, the dynamo headlight 1 could, for example, strive to supply an alternating current I of approximately 800 mA as input alternating current to the dynamo headlight 1 at any time. The dynamo headlight 1 includes a sensor (not shown) for detecting the alternating current I and / or the alternating voltage U of the input alternating current.The rectification means 39 and the transformation means 40 are controlled by the control and / or regulating means 42 as a function of the alternating voltage U and / or alternating current I of the input alternating current detected by the sensor in such a way that the alternating current I of the input alternating current is limited to an upper limit value of, for example, 450 mA. Even if the speed of the bicycle 3 increases, the alternating current I of the input alternating current does not rise above this upper limit value of 450 mA. An increase in the speed of the bicycle 3 and thus the rotational speed of the rotor 34 of the power generator 32 only causes an increase in the alternating voltage U of the input alternating current to values above 6 V, for example a voltage of 9 V or 12 V of the input alternating current, once the upper limit value of 450 mA is reached at a certain limit speed of the rotor 34.The electrical power at the first and second electrical contact elements 35, 36 can thus be increased further even after the upper limit of 450 mA is reached, because the electrical power is ideally calculated from the product of voltage U and current I. At higher speeds of the bicycle 3, larger electrical powers of, for example, 10 W or 15 W can thus be generated by the power generator 32 and delivered to the dynamo headlight 1, and the dynamo headlight 1 can be operated with these larger electrical powers of, for example, 10 W or 15 W. This larger electrical power of, for example, 10 W or 15 W is transferred to the lighting units 5 by means of the DC / DC converter 41 by the current I being increased significantly and the voltage U being increased only slightly at the operating direct current.The lighting units 5, as LEDs, have a low electrical resistance, so that despite the sharply increasing current I of the operating direct current, the voltage U of the operating direct current only increases slightly. The electrical power required to operate all lighting units 5 of the dynamo headlight 1 essentially corresponds to the electrical power of the input alternating current. However, the electrical power of the operating direct current is slightly lower than the electrical power of the input alternating current due to losses in the rectification means 39 and the transformation means 40.

[0068] Overall, significant advantages are associated with the dynamo headlight 1 according to the invention, the method according to the invention for operating the bicycle 3 with the dynamo headlight 1 and the power generator 2, and the bicycle 3 according to the invention. The power generator 32 is preferably designed in accordance with German legal regulations, for example, Section 67 of the German Road Traffic Licensing Regulations (StVZO) and the test regulations for bicycle alternators (TA24), so that, due to its design, the alternating current I of the input alternating current does not exceed a limit of approximately 500 mA, even at higher speeds.The control and / or regulation of the alternating current I of the input alternating current at the dynamo headlight 1 is carried out by the control and / or regulation means 42 such that the alternating current I of the input alternating current does not reach the limit value of 500 mA. As a result, even at higher speeds of the bicycle 3, once a limit speed of the rotor 34 of the power generator 32 is reached, the limit value of 500 mA is not reached. This circumvents self-regulation of the power generator 32, so that at higher speeds of the bicycle 3, the alternating voltage U of the input alternating current can increase almost indefinitely. Due to this design of the dynamo headlight 1, the electrical power provided by the power generator 32 is not limited to, for example, 3 W, but can reach significantly higher values of, for example, 12 W or 15 W.The dynamo headlight 1 thus has a variable internal resistance with the effect that the electrical power output of the power generator 32 is not limited and thus also not the electrical power for the dynamo headlight 1.

Claims

[1] Dynamo headlight (1) for a bicycle (3), comprising - a housing (4), - several lighting units (5) which can be operated with direct current, - an optical system (2) for directing the light emitted by the lighting units (5) into an illumination area (46) in front of the dynamo headlight (1), - a first electrical contact element (35) and a second electrical contact element (36) for input alternating current from an input alternating current generating power generator (32) as a dynamo (32) with a rotor (34) for supplying the dynamo headlight (1) with electrical energy from input alternating current with a variable alternating voltage (U) and a variable alternating current (I) at the first and second electrical contact element (35, 36) due to a variable speed of the rotor (34) of the power generator (32), - a rectifying means (39) for converting the input alternating current from the first and second electrical contact elements into direct current, - a transformation means (40) for changing the electrical voltage (U) of the operating direct current with which the lighting units (5) can be operated, characterized by that the dynamo headlight (1) comprises a control and / or regulating means (42) designed such that the input alternating current is limited to an upper limit value as the maximum value of the variable alternating current (I) and / or with the dynamo headlight (1) mounted on a bicycle (3) with a power generator (32) driven by a wheel of the bicycle (3) as a dynamo (32) for supplying the dynamo headlight (1) with electrical energy, so that the dynamo headlight (1) can be operated with electrical energy from the power generator (32), a method according to one or more of claims 9 to 14 can be carried out. [2] Dynamo headlight according to claim 1, characterized by that the upper limit of the variable alternating current (I) is less than 500 mA, 600 mA or 900 mA. [3] Dynamo headlight according to claim 1 or 2, characterized by that the upper limit of the variable alternating current (I) is greater than 300 mA. [4] Dynamo headlight according to one or more of the preceding claims, characterized by that the electrical voltage (U) and / or the electrical current (I) of the operating direct current for the lighting units (5) can be controlled and / or regulated as a function of the alternating voltage (U) and / or the alternating current (I) of the input alternating current, in particular with the control and / or regulating means (42). [5] Dynamo headlight according to one or more of the preceding claims, characterized bythat from the time the upper limit value of the alternating current (I) of the input alternating current is reached and the alternating voltage (U) of the input alternating current is increased at the same time beyond the value of the alternating voltage (U) of the input alternating current when the upper limit value of the alternating current (I) of the input alternating current is reached, the electrical voltage (U) and / or the electrical current (I) of the operating direct current can be increased, in particular by means of the control and / or regulating means (42). [6] Dynamo headlight according to claim 4 or 5, characterized by that the electrical voltage (U) of the operating direct current remains essentially constant and the electrical current (I) of the operating direct current can be increased. [7] Dynamo headlight according to one or more of the preceding claims, characterized bythat the electrical power of the input alternating current essentially corresponds to the electrical power of the operating direct current of the lighting units (5). [8] Dynamo headlight according to one or more of the preceding claims, characterized by that the transformation means (40) is a DC / DC converter (41) and with the DC / DC converter (41) the direct current generated by the rectification means (39) can be converted into the operating direct current. [9] Method for operating a bicycle (3) with a dynamo headlight (1) and a power generator (32) as a dynamo (32) for alternating current, comprising the steps: - Riding the bicycle (3) such that, due to a mechanical coupling of the power generator (32) to a wheel of the bicycle (3), a rotor of the power generator (32) is set in a rotational movement and an input alternating current with a variable alternating voltage (U) and a variable alternating current (I) is generated by the power generator (32) depending on the variable speed of the rotor of the power generator (32), - conducting the input alternating current to a rectifying means (39), - converting the input alternating current into a direct current by means of the rectifying means (39), - conducting the direct current generated by the rectifying means (39) to a transformation means (40) and changing the primary electrical voltage (U) and the primary electrical current (I) of the primary direct current at the input (47) of the transformation means (40) into a secondary electrical voltage (U) and a secondary electrical current (I) of a secondary direct current at the output (48) of the transformation means (40) as operating direct current, - conducting the operating direct current output by the transformation means (40) to lighting units (5) and operating the lighting units (5) with the operating direct current, so that light is emitted by the lighting units (5) in the dynamo headlight (1), characterized by that the input alternating current is limited to an upper limit value of the variable alternating current (I), in particular when a limit speed of the rotor of the current generator (32) is reached. [10] Method according to claim 9, characterized by that when the limit speed of the rotor of the current generator (32) is exceeded, the upper limit value of the variable alternating current (I) is kept substantially constant and the variable alternating voltage (U) of the input alternating current is further increased. [11] Method according to claim 9 or 10, characterized by that from the moment the limit speed of the rotor of the power generator (32) is exceeded, the variable alternating voltage (U) of the input alternating current is increased as a function of the speed of the rotor of the power generator (32), in particular the variable alternating voltage (U) of the input alternating current is substantially directly proportional to the speed of the rotor of the power generator (32). [12] Method according to one or more of claims 9 to 11, characterized by that the electrical power of the operating direct current essentially corresponds to the electrical power of the input alternating current. [13] Method according to one or more of claims 9 to 12, characterized by that from the moment the limit speed of the rotor of the current generator (32) is exceeded and the upper limit value of the variable alternating current (I) of the input alternating current is reached, during a further increase in the alternating voltage (U) of the input alternating current, the electrical current (I) of the operating direct current and / or the electrical voltage (U) of the operating direct current is increased, in particular the electrical current (I) of the operating direct current is substantially increased and the electrical voltage (U) of the operating direct current is kept substantially constant. [14] Method according to one or more of claims 9 to 13, characterized bythat, when the limit speed of the rotor of the power generator (32) is exceeded, the electrical current (I) of the operating current is increased as a function of the variable alternating voltage (U) of the input alternating current, in particular the electrical current (I) of the operating current is controlled and / or regulated essentially directly proportional to the variable alternating voltage (U) of the input alternating current. [15] Bicycle (3), comprising - a frame or body, - at least two wheels, - a dynamo headlight (1), - a wheel-driven power generator (32) as a dynamo (32) and the dynamo headlight (1) is operable with electrical energy from the power generator (32), in particular exclusively with electrical energy from the power generator (32), characterized by , that the dynamo headlight (1) is designed according to one or more of claims 1 to 8 and / or a method according to one or more of claims 9 to 14 can be carried out with the bicycle (3).

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