JP2002127960A - Lighting system for bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting system for a bicycle capable of improving illuminance of an electric bulb at the time of low speed traveling and preventing burn-out of the bulb at the time of high speed traveling by an inexpensive and simple additional structure. SOLUTION: This lighting system for the bicycle constituted of a circuit for connecting a generator 1 and load R of the electric bulb 2 is characterized by disposing a capacitor C in parallel with the load R. High illuminance is secured by increasing an output of the generator by generating a magnetic increasing action by self-excitation in a coil of the generator up to a prescribed number of revolution, burn-out of the bulb can effectively be prevented by lowering the output for a high speed region exceeding the prescribed number of revolution and the service life of the load R of the electric bulb can be improved, by only the additional structure of the simple capacitor C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle light comprising a circuit for connecting a generator and a load such as a light bulb (not only a light bulb but also a display device, an alarm, a microcomputer, a drive source of a transmission, etc.). Related to the device.

[0002]

2. Description of the Related Art Hitherto, in a bicycle lighting device comprising a circuit connecting a generator and a load such as a light bulb, the output of the generator has been used as it is by directly connecting it to a load such as a light bulb.
Therefore, when the power of the generator is used particularly for a light bulb such as a headlight, the output voltage is low and the illuminance is dark at the start of traveling when the operation speed of the generator is small, and the output power of the generator increases. At the time of high-speed running, there was a possibility that the bulb of the bulb could be cut, which would break the filament. Various proposals have been made to solve such problems of low output and running out of balls.

For example, as disclosed in Japanese Utility Model Laid-Open Publication No. 50-64379, at a high speed when the output voltage is higher than a predetermined value, a resistor having a predetermined load is connected by the operation of the switching transistor to prevent the ball from breaking. As described in Japanese Utility Model Laid-Open Publication No. Sho 62-67840, a low-speed light bulb having different rated values and a high-speed For selectively using electric bulbs, or Japanese Patent Application Laid-Open No. H2-15588.
As disclosed in Japanese Patent No. 3 gazette, an inductance is inserted into a circuit connecting a generator and a light bulb to reduce the reactance of the inductance and to use a relatively small-capacity light bulb at a low speed for practical use. In some cases, sufficient illuminance is ensured, the current during high-speed running is suppressed, and even when a small-capacity light bulb is used, the bulb is prevented from running out. Although not illustrated, there has also been proposed one configured to receive replenishment of battery power during low-speed traveling.

[0004]

However, in such a conventional illuminating device, the above-mentioned Japanese Utility Model Application Laid-Open No. Sho.
In the device disclosed in Japanese Patent No. 79, it is necessary to use a large number of expensive transistors in a switching circuit, which has led to an increase in cost. In addition, the aforementioned Japanese Utility Model Laid-Open No. 62-67840
In the device disclosed in Japanese Patent Laid-Open Publication No. H11-157, the cost is similarly increased, for example, it is necessary to prepare threshold value judgment means, switch means, and at least two bulbs having different ratings.
Furthermore, in the device disclosed in Japanese Patent Application Laid-Open No. 2-155883, since an inductance is provided separately from the generator, an increase in weight and a slight increase in cost cannot be avoided. Furthermore, when the battery power is replenished during low-speed running, various equipment for mounting the battery is required, which is uneconomical.

Therefore, the present invention solves the above-mentioned problems of the conventional bicycle lighting device, and improves the illuminance of the electric bulb at low speed traveling and reduces the breaking of the ball at high speed traveling by an inexpensive and simple additional structure. It is an object of the present invention to provide a lighting device for a bicycle which can be prevented.

[0006]

Therefore, the present invention provides a bicycle lighting device comprising a circuit connecting a generator and a load such as a light bulb, wherein a capacity is arranged in parallel with the load. I do. Further, the present invention is characterized in that the constant of the capacity is changed according to the generator speed. Further, the present invention is characterized in that a plurality of capacitors are arranged in parallel with the load, and the plurality of capacitors are sequentially opened in accordance with an output from a speed detection circuit of the generator. These are the means for solving the problems.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show a first embodiment of a bicycle lighting device according to the present invention. FIG. 1 (A) is an equivalent circuit diagram of the lighting device according to the present invention, and FIG. 1 (B) is for comparison. FIG. 2 is an equivalent circuit diagram of a conventional ordinary lighting device, FIG. 2 is a transfer function diagram of an output voltage showing a relationship between the number of revolutions of a generator and amplification degree in the lighting device of the present invention, and FIG. Graph showing the relationship between the generator speed and the generated voltage without considering the noise, FIG.
FIG. 4 is a diagram showing the relationship between the number of revolutions of the generator and the generated voltage in the lighting device of the present invention as compared with the conventional device. As shown in FIG. 1 (A), the lighting device of the present invention is a bicycle lighting device including a circuit connecting a generator 1 and a load R such as a light bulb 2 or the like. (A capacitive element such as the excitation capacitor 3).

In FIG. 1A, X described in the circuit is the reactance of the armature in the generator, r is the resistance of the armature in the generator, and R is the output power of the generator. Indicates the load resistance of a light bulb or the like that is turned on. Generally, an equivalent circuit of a permanent magnet generator is shown in FIG.
On the left side of the dashed line. On the right is the load resistance. Here, E0: no-load induced electromotive force E: output voltage according to the present invention (load voltage) E ': output voltage of conventional example r: armature resistance X: armature reactance R: load resistance C: self-excitation induced It is a capacitor. In general, a generator tends to increase the exciting magnetic field due to a leading current, which is called a self-excitation phenomenon. Since a capacitive element induces a current, connecting an exciting capacitor or the like in parallel with the generator output increases the exciting magnetic field, thereby increasing the generator output.

The output voltage E in FIG. 1A is: E = R × E0 / (R + r + j (ωCRr + X) −ω ² C
XR) Here, X is considered as an inductive element, X = jωL, and s =
Substituting with jω, the transfer function (E / E0) of the output voltage is as follows. H (s) = 1 / LC (s ² + 1 / CR × s + 1 / LC) where r << R. This transfer function is ω0 = 1 / L
Assuming that C and ω0 CR <1, this is indicated by the solid line A in FIG.

On the other hand, in the case where the capacitance C of the excitation capacitor 3 and the like in FIG. 1A is removed and the configuration is as shown in FIG. 1B, a conventional illumination device having no self-excitation phenomenon is obtained. At this time, the output voltage E 'is as follows: E' = R / (R + r + jX) In the same manner as described above, when the transfer function of the output voltage is obtained, H '(s) = R / L / (s + R / L). This transfer function can be graphed as described above.
This is indicated by the dashed line B in FIG. From these, it is understood that by providing the capacitance C of the excitation capacitor 3 and the like, the amplification degree below ω0 is larger than that in the case where the capacitance C is not provided. This is because, at a frequency of ω <ω0 at which the rotational speed is equal to or less than the predetermined rotational speed, the presence of the capacitance C causes a current to flow through the coil of the generator to increase the magnetism.

In other words, the coil is self-excited to cause a magnetizing effect, and the amplification factor is increased as compared with the conventional product, so that the generator output is increased. On the other hand, ω exceeding a predetermined rotation speed
At ω0, the output of the generator is rapidly reduced by an LC filter (low-pass filter) including the reactance X of the armature coil and the capacitance C of the capacitor in the generator. The no-load induced electromotive force E0 of the generator is generally expressed as follows. _{E0 = ωK W φ U / 2} 1/2 where, K _W is the effective series winding number of the core, phi _U depends on the configuration of the generator in effective magnetic flux. Assuming that the effective magnetic flux does not depend on frequency, E0 is represented as shown in FIG. This is understood as a generator characteristic with no load connected. When this E0 is combined with the above-described transfer function (A and B in FIG. 2),
The output voltage is as shown in FIG.

As can be understood from FIG. 4, in the conventional output voltage E 'curve shown by the dashed line, the voltage increases gradually according to the rotation speed, and the generated power is small in the low speed range.
While the high generated power is shown in the high-speed region, the output voltage E rises to around ω0 and the output voltage E rises to around
It can be seen that it has been gradually decreasing since 0.
By making this ω0 correspond to the average cruising speed of the bicycle, it is possible to generate power at a higher output than the conventional generator from the start of rowing to the cruising, and secure high illuminance. On the other hand, the output can be reduced to effectively prevent the bulb from running out, and the life of the load such as a light bulb can be improved.

FIGS. 5 and 6 show a second embodiment of a bicycle lighting device according to the present invention. FIG. 5 is a circuit diagram of the lighting device, and FIG. 6 is a time table diagram of the lighting device. The present embodiment is characterized in that the constant of the capacity C is changed in accordance with the number of revolutions of the generator. As shown in FIG. Capacitors 3, 4 and 5 are provided, and these capacitors 4 and 5 are sequentially opened by changeover switches 6 and 7 by operation signals SA and SB according to the output from the speed detection circuit 8 of the generator. It is what was constituted. In the example shown in the figure, the plurality of capacitors 4 and 5 arranged in parallel with the load are configured to be sequentially opened, and the capacitance is switched stepwise. However, a variable capacitor or the like is used. Thus, the constant of the capacity C may be changed steplessly in accordance with the number of revolutions of the generator.

The state of power generation during traveling in the lighting device of the present embodiment will be described with reference to the time table of FIG.
The vehicle starts traveling and increases the speed. When the speed reaches SP1, the switch 6 is switched by the operation signal SA from the speed detection circuit 8, and the exciting capacitor 4 is opened. As a result, the output voltage P0 that is decreasing from V1 to the peak is switched in the increasing direction. When the traveling speed reaches SP2 by further increasing the speed, the operation signal SB from the speed detection circuit 8 is output.
Switches the switch 7 to open the exciting capacitor 5. As a result, the output voltage P0, which is decreasing at the peak of V2, is switched in the increasing direction. When the traveling speed further increases, P0 peaks at V3 and P0 decreases to protect the load 2 such as a light bulb. When the traveling speed decreases, an output voltage P0 is output by an operation opposite to the above-described behavior. With such a configuration, the output power according to the speed can be more finely controlled.

The embodiments of the present invention have been described above. However, within the scope of the present invention, the shape and type of the generator (rim generator, hub generator, etc.), and the shape of the load such as a light bulb, etc. , Type, shape of capacity, type, change form of constant of the capacity, shape, type, number of capacity of speed detection circuit, form of sequential opening of multiple capacity according to output from speed detection circuit of generator, etc. Needless to say, can be adopted as appropriate.

[0016]

As described above in detail, the present invention relates to a bicycle lighting device comprising a circuit connecting a generator and a load such as a light bulb, wherein a capacity is arranged in parallel with the load. With only a simple additional structure, up to a predetermined number of revolutions, the coil of the generator generates a magnetizing effect by self-excitation, increasing the output of the generator, ensuring high illuminance,
In a high-speed range exceeding a predetermined number of revolutions, the output can be reduced to effectively prevent the ball from running out, and the life of a load such as a light bulb can be improved. When the constant of the capacity is changed according to the number of revolutions of the generator, the output power according to the speed can be more finely controlled.

Further, when a plurality of capacities are arranged in parallel with the load and these capacities are sequentially opened according to the output from the speed detection circuit of the generator, the cost is relatively low. Only by preparing a few capacitive elements, it is possible to control the minimum required increase or decrease of the output voltage corresponding to the speed. Thus, according to the present invention, there is provided a bicycle lighting device capable of improving the illuminance of a light bulb during low-speed running and preventing the ball from running out during high-speed running with an inexpensive and simple additional structure.

[Brief description of the drawings]

1 shows a first embodiment of a lighting device for a bicycle according to the present invention, FIG. 1 (A) is an equivalent circuit diagram of the lighting device of the present invention, and FIG. 1 (B) is a conventional ordinary lighting device for comparison. It is an equivalent circuit diagram of a lighting device.

FIG. 2 is a transfer function diagram of an output voltage showing a relationship between a rotation speed of a generator and an amplification degree in the lighting device of the present invention as compared with a conventional one.

FIG. 3 is a diagram showing the relationship between the number of revolutions of the generator and the generated voltage without taking into account the load.

FIG. 4 is a diagram showing the relationship between the number of revolutions of the generator and the generated voltage in the lighting device of the present invention as compared with the conventional device.

FIG. 5 is a circuit diagram of a lighting device for a bicycle according to a second embodiment of the present invention.

FIG. 6 is a time table diagram of the lighting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Generator 2 Light bulb (load) 3 1st excitation capacitor (capacity) 4 2nd excitation capacitor (capacity) 5 3rd excitation capacitor (capacity) 6 Changeover switch 7 Changeover switch 8 Speed detection circuit E0 No-load induced electromotive force E book Output voltage (load voltage) according to the invention E 'Output voltage of conventional example r Armature resistance X Armature reactance R Load resistance C Self-excitation inducing capacitor (capacitance) P0 Generator output voltage SA Operation signal (for changeover switch 6) SB Operation signal (for changeover switch 7) V1 Maximum output voltage 1 V2 Maximum power voltage 2 V3 Maximum power voltage 3

Claims (3)

[Claims] 1. A bicycle lighting device comprising a circuit connecting a generator and a load such as a light bulb, wherein a capacity is arranged in parallel with the load. 2. The lighting device for a bicycle according to claim 1, wherein the constant of the capacity is changed according to the number of revolutions of a generator. 3. A plurality of capacitors are arranged in parallel with the load, and the plurality of capacitors are sequentially opened according to an output from a speed detection circuit of the generator. 3. The lighting device for a bicycle according to 2.