JPH0323380Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a bicycle headlight device that lights the headlight by a generator.

[Conventional technology]

Conventionally, bicycles have been equipped with a generator that generates electricity through the rotation of the front wheel and a headlight that is directly connected to the generator.When riding at night, etc., the upright generator is tilted down to generate electricity. By pressing the generator roller of the machine against the front tire, the generator generates alternating current power with a voltage proportional to rotation, and the generated power turns on the headlights, allowing safe driving.

Note that when driving during the daytime, there is no need to turn on the headlights; in this case, the generator is kept upright and the headlights are kept off.

[Problem that the invention attempts to solve]

By the way, as mentioned above, since the headlights are directly connected to the generator, it is necessary to raise and lower the generator in order to turn on and off the headlights.

If it becomes necessary to turn on the headlights while driving in the evening, etc., it is necessary to operate the generator with one hand to turn on the headlights. There is a problem in that this leads to inattentive driving and makes it impossible to drive safely.

[Means for solving problems]

This invention was made with the above points in mind, and includes a rectifier circuit that rectifies the power generated by a generator, a headlamp and a switching element that are connected in series between both output terminals of the rectifier circuit. A bicycle headlamp device includes a photosensitive element that receives ambient light, and a lighting control circuit that turns on the switching element when the illuminance of light received by the photosensitive element falls below a predetermined value.

[Effect]

Therefore, even if the generator is turned down all the time, the switching element will turn off and keep the headlights turned off during the daytime when there is no need to turn on the headlights, and the headlights will not turn on at night. While it is necessary to turn on the generator, the switching element is turned on and the headlights are turned on, and the headlights can be turned on and off without having to raise or lower the generator.

〔Example〕

Next, this invention will be explained in detail with reference to drawings showing one embodiment thereof.

In FIG. 1, 1 is a generator, and 2 is a rectifier circuit for rectifying the power generated by the generator 1, which is formed by a bridge circuit of full-wave rectification of diodes. 3 is a headlamp whose one input terminal is connected to the positive output terminal p of the rectifier circuit 2; 4 is a first NPN transistor forming a switching element;
The collector is connected to the other input terminal of the headlamp 3, and the emitter is connected to the negative output terminal n of the rectifier circuit 2.

5 is a cadmium sulfide element (hereinafter referred to as Cds) whose resistance value decreases almost in proportion to the received light illuminance, and forms a photosensitive element, one end of which is connected to the positive output terminal p, and the other end for bias. The first resistor 6 is connected to the negative output terminal n.

7 is a second transistor of NPN type, the collector of which is connected to the positive output terminal p via a second resistor 8 for current limiting.
The emitter is connected to the negative output terminal n, and the base is connected to the connection point x between Cds5 and the first resistor 6. 9 is a lighting control circuit having a circuit configuration shown by a broken line.

In addition, Cds5 has a light receiving characteristic where the resistance values are 20MΩ and 20KΩ respectively when the light receiving illuminance is OLx and 10Lx, and the resistance values of the first and second resistors 6 and 8 are 10K.
Ω and 500Ω, respectively.

Further, as shown in Fig. 2, the headlight 3 has a light bulb 3b built into a case 3a, a lens 3c provided in front of the light bulb 3b, and a mounting plate 3d protruding downward from the case 3a in front of the bicycle body. Attached to the top of the hawk. In addition, the light bulb 3b is, for example, 6V-3W.
(0.5A).

The Cds 5 is attached to the upper surface of the case 3a as shown in FIG. 2 so as not to be affected by the light from the light bulb 3b.

The generator 1 is always tilted down and pressed against the front tires, and when the front wheels rotate while driving, alternating current power with a voltage proportional to the rotation is generated, and the positive and negative output terminals p of the rectifier circuit 2, DC power with a voltage proportional to the voltage of the generated power is generated between n.

On the other hand, the resistance value of Cds5 changes depending on the received light intensity, and during the daytime when there is no need to turn on the headlight 3, that is, when the received light intensity is 10Lx or more, the resistance value of Cds5 is a low resistance value of 20KΩ or less. When the headlight 3 needs to be turned on at night, that is, when the received light intensity is less than 10Lx, the resistance value of Cds5 is 20KΩ.
The resistance value becomes higher than that.

Then, when the resistance value of Cds 5 becomes a low resistance value of 20KΩ or less while driving, the voltage at the connection point x increases and the second transistor 7 is turned on, and the second transistor 7 is turned on, which turns off the first transistor 4. do.

Conversely, when the resistance value of Cds 5 becomes a high resistance value of 20KΩ or more while driving, the voltage at the connection point x decreases and the second transistor 7 is turned off. turns on.

Therefore, while the ambient light is bright while driving and there is no need to turn on the headlight 3, the first transistor 4 is kept off, and both output terminals p, n of the headlight 3 and the rectifier circuit 2 are turned off. The connection between the
remains off.

On the other hand, when the ambient light during driving becomes dark and it becomes necessary to turn on the headlight 3, the first transistor 4 is turned on and both output terminals p of the headlight 3 and the rectifier circuit 2 are turned on.
n is closed, the rectified output of the rectifier circuit 2 is supplied to the headlamp 3, and the headlamp 3 is turned on.

By turning on and off the first transistor 4, the headlights 3 are automatically turned on and off without having to raise or lower the generator 1, so the generator 1 can be raised or lowered while the vehicle is running. There is no need,
Driving safety in the evening is significantly improved.

By the way, while the first transistor 4 is off and the headlight 3 is off, the headlight 3 does not consume the power generated by the generator 1, so the generator 1 falls down and is pressed against the front tire. However, the load placed on the pedals is light, especially when the generator 1 is a tire top press-contact type that generates electricity by press-contacting the tire tread surface, as described in Japanese Patent Publication No. 57-59110.
There is almost no load on the pedals, and there is no increase in driving effort.

In the above embodiment, the Cds 5 is attached to the case 3a, but it is of course possible to attach the Cds 5 to a location other than the case 3a where only ambient light can be received.

Furthermore, instead of using Cds5 as the photosensitive element, it is of course possible to use various photoelectric conversion elements such as solar cells.

[Effect of idea]

As described above, according to the bicycle headlight device of this invention, the switching element is turned on and off depending on the change in the illuminance received by the photosensitive element to control opening and closing between the rectifier circuit 2 and the headlight 3. As a result, the headlights 3 can be turned on and off without raising or lowering the generator 1, and driving safety can be significantly improved.

[Brief explanation of the drawing]

The drawings show one embodiment of the bicycle headlight device of this invention, with FIG. 1 being a circuit block diagram and FIG. 2 being a perspective view of the headlight. 1... Generator, 2... Rectifier circuit, 3... Headlight, 5... Cds, 9... Lighting control circuit.

Claims (1)

[Scope of utility model registration request] It has a rectifier circuit that rectifies the power generated by the generator, a headlamp and a switching element connected in series between both output terminals of the rectifier circuit, and a photosensitive element that receives ambient light. A bicycle headlight device comprising: a lighting control circuit that turns on the switching element when light illuminance falls below a predetermined value.