JP5139237B2 - Lamp lighting control circuit and bicycle lamp - Google Patents

Description

  The present invention mainly relates to a bicycle lamp, and more particularly to a bicycle lamp that emits a lamp body by electric power generated according to the vehicle speed.

  In recent years, LEDs (Light Emitting diodes) have been increased in brightness and price, and LEDs have been adopted for bicycle lamps that have conventionally employed light bulbs. In a bicycle lamp that is lit by electric power generated according to the speed of the bicycle, the LED driving method is a resistance current limiting type that limits the current flowing through the LED using a resistor, and an input current or voltage. The switching constant current type that controls the current flowing in the LED by switching the connection on and off in the switching cycle is roughly divided into two.

  The switching constant current type is, for example, a circuit that uses a known switching power supply dedicated IC that periodically switches on and off the energization of the LED based on the current flowing through the LED. However, many of the inexpensive dedicated ICs that can be used in the circuit according to the method generally have a withstand voltage of 40 V or less, the voltage generated by power generation is unstable, and the LED (light) for a bicycle having a wide power generation voltage range is wide. Dedicated ICs that are not suitable for the body and can handle voltages up to about 60V exceeding 40V are expensive and have a demerit that they are not commensurate with the cost of lighting control circuits for bicycle LEDs.

  On the other hand, the resistance current limiting equation limits the voltage applied to the light emitting diode by, for example, a circuit configuration as shown in FIG. The lighting control circuit 9 includes a rectifier circuit 20 that rectifies the alternating current generated by the generator 10, an electric field capacitor C9 that smoothes the current output from the rectifier circuit 20, a light emitting diode LED, and the light emitting diode LED in series. And a connected resistor R90. The electric field capacitor C9 is connected between the high potential side output terminal and the low potential side output terminal of the rectifier circuit 20. The resistor R90 and the light emitting diode LED connected in series are connected in the forward direction to the rectifier circuit 20 in parallel with the electric field capacitor C9. With the configuration described above, a voltage obtained by dividing the voltage output from the rectifier circuit 20 by the resistor R90 is applied to the light emitting diode LED.

Further, as in the circuit described in FIG. 1 of Patent Document 1, when the voltage exceeds a predetermined voltage value, a circuit that bypasses the current and shunts the current flowing through the LED (FIG. 1 of Patent Document 1), etc. There is an advantage that it can be configured at a relatively low cost.
JP 2007-112172 A

  However, in the above-described resistance current limiting circuit (FIG. 11 and FIG. 1 of Patent Document 1), since electric power is supplied from the generator whose power generation amount increases according to the vehicle speed of the bicycle, low speed (10 km / h If the resistance value of the resistor connected in series with the LED is set so that the LED emits light sufficiently from about 5V, the generated voltage becomes 50V to 60V at high speed (about 40km / h). There is a problem that the current flows and breaks and deteriorates the LED, the heating of the lighting control circuit, and the voltage exceeding the withstand voltage of the lighting control circuit.

  The present invention has been made to solve the above-described problem, and its purpose is to apply a current that does not exceed the maximum rated current value of the lamp body even when the voltage value generated by the generator is high. An object of the present invention is to provide a lighting control circuit for a lamp.

(1) In order to solve the above problem, the present invention outputs the applied input voltage when the applied input voltage is equal to or lower than a predetermined threshold voltage, and the applied input voltage is A protection circuit that divides and outputs the applied input voltage when a predetermined threshold voltage is exceeded, and a lamp body drive circuit that applies a voltage output from the protection circuit to the lamp body, body driving circuit includes a switching element connected in series to the lamp body, have a first transistor connected to said switching element, along with provided between the ground potential the lamp body driving circuit, external A lightness detection circuit that turns off the switching element when the amount of light input from the light source is greater than a predetermined amount of light, and the protection circuit has a first connection point to which the input voltage is applied and one end of the protection circuit. Contact A first resistor connected to an output terminal for applying a voltage to the lamp driving circuit through a second connection point, an emitter connected to the first connection point, and a collector connected to the first connection point. A second transistor connected to a second connection point; a second resistor connected between an emitter of the second transistor and a base of the second transistor; and an emitter connected to the first connection. A third transistor having a collector connected to the base, a collector connected to the base of the second transistor, a first end connected to the base of the second transistor, and a second end connected to the third connection point. 3 resistor, one end connected to the first connection point, the other end connected to the base of the third transistor, and the cathode connected to the base of the third transistor The first Zener diode And a fifth resistor having one end connected to the anode of the first Zener diode and the other end connected to the third connection point. The third connection point includes the brightness detection circuit. And the threshold voltage is determined by the breakdown voltage of the first Zener diode, and when the input voltage is lower than the breakdown voltage of the first Zener diode, the threshold voltage is input via the second transistor. A voltage is output to the lamp driving circuit, and when the input voltage is higher than the breakdown voltage of the first Zener diode, the voltage divided by the first resistor is output to the lamp driving circuit. This is a lighting control circuit for a lamp.
With this configuration, the lighting control circuit applies the divided voltage to the lamp driving circuit when the protection circuit exceeds a certain voltage, and the lamp transistor according to the current flowing through the lamp in the first transistor of the lamp driving circuit. By switching on and off the current flowing through the body, the current flowing per unit time can be kept constant, and it is possible to prevent the overvoltage and overcurrent from being applied to the lamp body.

The configuration of this, the lighting control circuit, when the external (ambient) is bright, it is possible to suppress the power consumption of without supplying current to the lamp body.

The configuration of this protection circuit in accordance with the breakdown voltage of the first zener diode, the voltage applied to the lamp body driving circuit can press the minute, it is possible to reduce the power consumed by the lamp body driving circuit .

( 2 ) Further, according to the present invention, in the above-described invention, the lamp driving circuit includes: a first diode in which a voltage applied by the protection circuit to an anode is applied via the fourth connection point; A sixth resistor having one end connected to the cathode of the first diode and the other end connected to a fifth connection terminal; a seventh resistor having one end connected to the fourth connection point; Is connected to the other end of the eighth resistor, and the light emitting diode as the lamp body has an anode other than the seventh resistor. The first transistor has a base connected to the cathode of the first diode, an emitter connected to the other end of the seventh resistor, and a collector connected to the other end of the ninth resistor. A field-effect transistor connected and the switching element The base is connected to the other end of the eighth resistor, the drain is connected to the cathode of the light emitting diode, the source is grounded, and the fifth connection point is connected to the third connection point. And the predetermined voltage is a voltage obtained by stepping down the voltage applied from the protection circuit by the first diode.
With this configuration, the lamp driving circuit can set a threshold value for switching on and off the field effect transistor according to the forward voltage drop characteristic of the first diode, and the current corresponding to the lamp rated current can be set. It can flow.

( 3 ) Further, according to the present invention, in the invention described above, a second diode having an anode connected to a drain of the field effect transistor and connected to an anode of the light emitting diode, the light emitting diode, and the field effect transistor And a coil having one end connected to the cathode of the light emitting diode and the other end connected to the drain of the field effect transistor.
With this configuration, when the field effect transistor is turned off, the light emitting diode is energized by applying an induced voltage generated in the coil. Thus, the lighting control circuit can light the light emitting diode for a while even when the field effect transistor is turned off.

( 4 ) Further, according to the present invention, in the invention described above, the brightness detection circuit includes a tenth resistor to which the voltage output from the protection circuit is applied at one end, and a cathode other than the tenth resistor. A second Zener diode having an anode grounded, an eleventh resistor having one end connected to the other end of the tenth resistor, and one end connected to the other end of the eleventh resistor. A twelfth resistor whose other end is grounded, a base is connected to the other end of the eleventh resistor, a collector is connected to the third connection point and the fifth connection point, and an emitter is grounded. A fourth transistor, a capacitor having one end connected to the other end of the eleventh resistor, the other end grounded, a collector connected to the other end of the eleventh resistor, and an emitter grounded Characterized by comprising a transistor That.
With this configuration, the lighting control circuit can suppress power consumption without flowing current through the lamp when the surroundings are bright.

( 5 ) Further, the present invention applies to the lighting control circuit the lighting control circuit for the lamp described above, the lamp connected to the lighting control circuit, and a voltage generated according to the vehicle speed of the bicycle. A bicycle lamp comprising: a bicycle generator; and a rectifier circuit that rectifies alternating current generated by the bicycle generator and inputs the rectified current to the lighting control circuit.
With this configuration, the bicycle lamp can prevent application of overvoltage or current even when the voltage generated by the bicycle generator is high, and can prevent deterioration and breakage of the lamp.

( 6 ) Further, according to the present invention, a rectifier circuit connected to an AC generator and converting an AC voltage into a DC voltage, a DC voltage output from the rectifier circuit is detected, and a DC voltage generated by the rectifier circuit is A voltage detection circuit that generates a switching signal when a predetermined threshold value is exceeded; a first resistor; and a switch means connected in parallel to the first resistor; A switching circuit for turning off the switch means by a switching signal from a detection circuit, a lamp connected to the switching circuit, an output circuit having a switching element connected in series with the lamp, and the switching circuit; is connected to the connected and the output circuit, have a drive circuit that turns on control and oFF control of the switching elements of the output circuit, the switching means of the switching circuit has an emitter contact to said rectifier circuit And a collector connected to the drive circuit and a base connected to an emitter via a second resistor, and the voltage detection circuit has an emitter connected to the emitter of the second transistor. And a third transistor having a collector connected to the base of the second transistor, and a Zener diode connected to the base of the third transistor. .
When the voltage detection circuit generates the switching signal, it is possible to prevent the switch means from applying a voltage to the lamp body via the first resistor and applying a voltage exceeding the rated voltage.

( 7 ) Further, according to the present invention, in the above-described invention, the drive circuit includes a feedback resistor connected between the lamp body and the switching circuit, and an emitter connected to the feedback resistor. A collector is connected to the switching element, and a base has a first transistor connected to the switching circuit via a diode.
By having the first transistor, the switching element can be switched on and off according to the current flowing through the lamp body, and an average constant current can be applied to the lamp body.

Tsu by providing the E zener diode, a DC voltage rectifier circuit is generated, when it exceeds the breakdown voltage of the zener diode, when a voltage is applied to the fixture via the first resistor by the switch means, the rated Application of a voltage exceeding the voltage can be prevented.

( 8 ) Further, the present invention provides the brightness detection circuit which is connected in series to the drive circuit and controls the drive circuit to be off when the amount of light input from the outside exceeds a predetermined light amount. It is characterized by having.
As a result, when the surroundings are bright enough that the amount of light input to the lightness detection circuit exceeds a predetermined amount of light, the drive circuit can be turned off to reduce power consumption in the lamp.

( 9 ) Further, according to the present invention, in the invention described above, the brightness detection circuit is connected to the voltage detection circuit, and the voltage detection circuit is turned on when a light amount input from the outside exceeds a predetermined light amount. It is characterized by being turned off.
As a result, the voltage applied to the drive circuit can be suppressed when the surroundings are bright enough that the amount of light input to the brightness detection circuit exceeds a predetermined amount of light.

( 10 ) The lightness detection circuit includes a fourth transistor having a collector connected to a base of the first transistor of the drive circuit, and a phototransistor connected to a base of the fourth transistor. It is characterized by that.
By including the phototransistor, it is possible to detect a case where a light amount exceeding a predetermined amount is received from the outside.

( 11 ) Further, the present invention includes the lighting control circuit for the lamp described above, and a bicycle generator that applies a voltage generated according to the vehicle speed of the bicycle to the lighting control circuit. This is a bicycle lamp.
With this configuration, the bicycle lamp can prevent application of overvoltage or current even when the voltage generated by the bicycle generator is high, and can prevent deterioration and breakage of the lamp.

  According to this invention, the lighting control circuit includes a switching element (field effect transistor) that switches on and off of a current flowing through the lamp body (light emitting diode) by the lamp body driving circuit, and a first element that controls the switching element. By providing the transistor, the current flowing through the lamp body is made constant, and even when the voltage generated by the generator is high, a current that does not exceed the maximum rated current value of the lamp body can be passed through the lamp body.

  Hereinafter, a lighting control circuit according to an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a circuit diagram illustrating an outline of the connection between the lighting control circuit 1 and the generator 10 and the configuration of the lighting control circuit 1 according to the first embodiment.
The lighting control circuit 1 receives an AC voltage output from the generator 10 from input terminals G1 and G2. In addition, the lighting control circuit 1 includes a rectifier circuit 20 that rectifies the AC voltage generated by the generator 10, electric field capacitors C 1 and C 2, a protection circuit 30, a lamp driving circuit 40, and a brightness detection circuit 50. It has.

The rectifier circuit 20 includes four diodes D3 to D6 constituting a diode bridge, and full-wave rectifies the AC voltage generated by the generator 10 to convert it into a DC voltage and outputs the DC voltage. The electric field capacitor C1 is connected in the forward direction between the output terminal of the rectifier circuit 20 and the ground potential, and smoothes the pulsating current output from the rectifier circuit 20.
The protection circuit 30 includes a voltage detection circuit 31 and a switching circuit 32. In the protection circuit 30, the switching circuit 32 has a resistor R <b> 1 (first resistor), the voltage output from the rectifier circuit 20 is applied, and the voltage detection circuit indicates that the voltage has exceeded a predetermined threshold voltage. When a voltage divided by the resistor R1 (first resistor) is applied to the lamp body drive circuit 40 when the voltage output from the rectifier circuit 20 is equal to or lower than a predetermined threshold voltage, The voltage output from the rectifier circuit 20 is applied to the lamp drive circuit 40. The electric field capacitor C2 is connected in the forward direction between the output terminal of the protection circuit 30 and the ground potential, and smoothes the current output from the protection circuit 30.

The lamp driving circuit 40 includes a driving circuit 41 and an output circuit 42. The lamp driving circuit 40 performs control to turn on the light emitting diode LED, and applies the voltage applied from the protection circuit 30 to the light emitting diode LED. By switching on and off the current according to the current flowing through the light emitting diode LED, the current flowing through the light emitting diode LED is prevented from becoming excessive, and control is performed to flow a constant current through the light emitting diode LED.
The brightness detection circuit 50 detects ambient brightness, turns off the connection between the lamp drive circuit 40 and the ground potential when the detected brightness exceeds a predetermined threshold value, and the detected brightness is equal to or less than the threshold value. At this time, the connection between the lamp driving circuit 40 and the ground potential is turned on.

Next, the configurations of the protection circuit 30, the lamp driving circuit 40, and the brightness detection circuit 50 will be described.
The protection circuit 30 includes PNP transistors Q2 and Q3, resistors R1 to R5, and a Zener diode ZD1. The voltage detection circuit 31 includes a transistor Q3, resistors R2 to R5, and a Zener diode ZD1. The switching circuit 32 includes a transistor Q2 as a switch means and a resistor R1. The transistor Q2 (second transistor) has an emitter connected to the output terminal on the high potential side of the rectifier circuit 20 via the connection point J1, and a drive circuit via the connection point J2 whose collector is the output terminal of the protection circuit 30. 41, and the base is connected to the connection point J1 through the resistor R2 (second resistor). The resistor R1 (first resistor) is configured by connecting resistors R1a and R1b in series, one end is connected to the connection point J1, and the other end is connected to the connection point J2 that is the output end of the protection circuit 30. . The transistor Q2 and the resistor R1 are connected in parallel between the connection point J1 and the connection point J2.

The resistor R3 (third resistor) has one end connected to the base of the transistor Q2 and the other end connected to a connection point J3 that is an output terminal on the low potential side of the rectifier circuit 20.
The resistor R4 (fourth resistor) has one end connected to the connection point J1 and the other end connected to the base of the transistor Q3. The emitter of the transistor Q3 (third transistor) is connected to the connection point J1. That is, the emitter of transistor Q3 is connected to the emitter of transistor Q2. The collector of transistor Q3 is connected to the base of transistor Q2. That is, the collector of the transistor Q3 is connected to the connection point J3 through the resistor R3. The Zener diode ZD1 (first Zener diode) has a cathode connected to the base of the transistor Q3 and the other end connected to the connection point J3 via a resistor R5 (fifth resistor).

  The lamp driving circuit 40 includes a diode D1, resistors R6 to R9, a PNP transistor Q1 (first transistor), an NMOS field effect transistor Q5 (switching element), and a light emitting diode LED. The drive circuit 41 includes a diode D1, a transistor Q1, a resistor R6, and a resistor R7. The output circuit 42 includes a field effect transistor Q5, a resistor R8, and a resistor R9. The diode D1 is configured by diodes D1a and D1b connected in series in the forward direction, and the anode is connected to the connection point J2 that is the output terminal of the protection circuit 30 via the connection point J4 (fourth connection point). The cathode is connected to the connection point J5 (fifth connection point) through the resistor R6 (sixth resistor). The resistor R7 (seventh resistor) is a feedback resistor, and one end is connected to the switching circuit 32 via the connection point J4, and the other end is connected to the connection point R that connects the light emitting diode LED.

  The transistor Q1 has an emitter connected to the other end of the resistor R7, a collector connected to the base of the field effect transistor Q5 via the resistor R9 (9th resistor), a base connected to the cathode of the diode D1, and the diode D1. To the switching circuit 32 of the protection circuit 30. The field effect transistor Q5 has a drain connected to the connection point W connecting the light emitting diode LED, and a source grounded. The resistor R8 (eighth resistor) has one end connected to the base of the field effect transistor Q5 and the other end grounded. The light emitting diode LED has an anode connected to the connection terminal R and a cathode connected to the connection terminal W.

  The brightness detection circuit 50 includes resistors R10 to R12, a Zener diode ZD2, an NPN transistor Q4, a capacitor C3, and a phototransistor Q6. The Zener diode ZD2 (second Zener diode) has a cathode connected to a connection point J2 that is an output terminal of the protection circuit 30 via a resistor R10 (tenth resistor), and an anode grounded. The transistor Q4 has a collector connected to the protection circuit 30 via the connection point J3, is connected to the base of the transistor Q1 of the lamp driving circuit 40 via the connection point J5, the emitter is grounded, and the base is the resistor R12. (Twelfth resistor) is grounded. One end of the capacitor C3 (third capacitor) is connected to the base of the transistor Q4, and the other end is grounded. The phototransistor Q6 has an emitter grounded and a collector connected to the base of the transistor Q4. The resistor R11 (eleventh resistor) has one end connected to the cathode of the Zener diode ZD2 and the other end connected to the gate of the transistor Q4.

  Next, operations of the protection circuit 30, the lamp driving circuit 40, and the brightness detection circuit 50 will be described. In the description of the protection circuit 30 and the lamp driving circuit 40, the brightness detection circuit 50 connects the protection circuit 30 and the ground potential, and connects the lamp driving circuit 40 and the ground potential. Suppose that That is, it is assumed that the transistor Q4 is on. Moreover, the voltage dropped by the diodes D1a and D1b and the light emitting diode LED is the same voltage.

(1. Operation of protection circuit 30)
In the protection circuit 30, when the voltage applied from the rectifier circuit 20 is lower than the breakdown voltage of the Zener diode ZD 1 as a predetermined threshold voltage, the transistor Q 3 does not generate a potential difference between the emitter and the base. Become. At this time, the transistor Q2 is turned on because the voltage applied to the collector is higher than the voltage applied to the base by the voltage drop across the resistor R2. As a result, the protection circuit 30 applies the voltage applied from the rectifier circuit 20 to the lamp driving circuit 40 via the transistor Q2.

On the other hand, when the voltage applied from the rectifier circuit 20 exceeds the breakdown voltage of the Zener diode ZD1, a current is supplied from the connection point J1 to the ground potential via the resistor R4, the Zener diode ZD1, the resistor R5, and the transistor Q4 of the brightness detection circuit 50. Flows. Along with this, the base potential of the transistor Q3 is lowered, so that a potential difference is generated between the emitter and the base of the transistor Q3, the transistor Q3 is turned on, and a collector current flows. Thus, the transistor Q2 has no potential difference between the emitter and the base, and the transistor Q2 is turned off. As a result, the protection circuit 30 steps down the voltage applied from the rectifier circuit 20 by the resistor R <b> 1, and the stepped down voltage is applied to the lamp drive circuit 40.
As described above, when the voltage applied to the protection circuit 30 exceeds the breakdown voltage (predetermined threshold voltage) of the Zener diode ZD1, the protection circuit 30 reduces the voltage (divided by the resistor R1 provided). Until the voltage applied to the protection circuit 30 reaches the breakdown voltage of the Zener diode ZD1, the applied voltage can be applied to the lamp drive circuit 40. .

(2. Operation of the lamp driving circuit 40)
In the lamp driving circuit 40, the voltage supplied from the protection circuit 30 is supplied to the emitter of the transistor Q1 via the resistor R7, and is stepped down by the diode D1 (D1a, D1b) and supplied to the base of the transistor Q1. The The transistor Q1 is turned on, and a collector current flows through the transistor Q1. The collector current of the transistor Q1 is supplied to the gate of the field effect transistor Q5 via the resistor R9. Then, electric charge is stored in the gate of the field effect transistor Q5, and the field effect transistor Q5 is turned on. As a result, a current flows through the light emitting diode LED connected to the drain of the field effect transistor Q5, and the light emitting diode LED is turned on.

  At this time, since the impedance of the emitter of the transistor Q1 is higher than the impedance of the light emitting diode LED, the emitter current flowing through the emitter of the transistor Q1 is about one digit smaller than the current flowing through the light emitting diode LED. For example, when the emitter current is several tens of mA, the current of the light emitting diode LED is several hundred mA. When the current flows through the light emitting diode LED, the current flowing through the resistor R7 increases, so that the potential of the emitter of the transistor Q1 decreases, the potential difference between the base and the emitter of the transistor Q1 decreases, and the transistor Q1 is turned off. The collector current of transistor Q1 stops flowing. When the collector current of the transistor Q1 stops flowing, no charge is supplied to the gate of the field effect transistor Q5, and the stored charge is discharged through the resistor R8, so that the field effect transistor Q5 is turned off. Thereby, no current flows through the light emitting diode LED, and the light emitting diode LED is turned off.

Subsequently, since the current does not flow to the light emitting diode LED, the voltage of the emitter of the transistor Q1 rises, the transistor Q1 is turned on again, the collector current of the transistor Q1 flows, and the field effect transistor Q5 is turned on again. Become.
Thereafter, the lamp driving circuit 40 repeats the above-described operation. In the lamp driving circuit 40, the transistor Q1 (first transistor) is controlled to be turned on and off in accordance with the current flowing through the light emitting diode LED. As a result, the field effect transistor Q5 (switching element) is turned on and off. By switching between the states, a constant current can flow on the light emitting diode LED on average.

(3. About the operation of the brightness detection circuit 50)
In the lightness detection circuit 50, the phototransistor Q6 is turned on when the amount of light received by the light receiving unit exceeds the threshold (predetermined amount of light) of the phototransistor Q6. Thereby, the base of the transistor Q4 becomes the ground potential, and the transistor Q4 is turned off. Further, the connection between the protection circuit 30 and the ground potential is turned off. In the lamp driving circuit 40, the voltage applied to the base of the transistor Q1 rises to the voltage applied to the emitter, and the transistor Q1 is always in the off state. As a result, the field effect transistor Q5 is always off, and no current flows through the light emitting diode LED.

On the other hand, when the light received by the light receiving portion of the phototransistor Q6 is darker than the threshold, the phototransistor Q6 is turned off and the transistor Q4 is turned on. As a result, the connection between the protection circuit 30 and the ground potential is turned on via the transistor Q4. The transistor Q1 of the lamp driving circuit 40 is applied with a voltage that is stepped down by a diode D1 from the voltage at which the lamp driving circuit 40 is applied to the base. As a result, the lamp driving circuit 40 performs the above-described operation and causes a constant current to flow through the light emitting diodes LED on average.
By providing the lightness detection circuit 50 in the lighting control circuit 1, it is possible to perform control so that the light-emitting diode LED is not lit in a bright place.

(4. Relationship with voltage generated by generator 10)
Next, FIG. 2 shows the relationship between the voltage applied to the lighting control circuit 1, that is, the voltage generated by the generator 10, the current flowing through the light emitting diode LED, and the power consumed by the lighting control circuit 1. It is a schematic diagram. Here, the voltage V0 is a voltage at which a current starts to flow through the light emitting diode LED, and is determined by the threshold voltage of the transistor Q1, the forward voltage drop characteristics of the diodes D1a and D1b, and the resistance value of the resistor R7. The voltage V1 is a voltage at which the current that flows to the light emitting diode LED becomes the rated current value of the light emitting diode LED. The voltage V2 is the maximum output voltage of the generator 10. The voltage V3 is a breakdown voltage of the Zener diode ZD1.

FIG. 2A is a schematic diagram showing the relationship between the voltage generated by the generator 10 and the current flowing through the light emitting diode LED. When the voltage generated by the generator 10 is higher than the voltage V1, the lighting control circuit 1 keeps the current flowing through the light emitting diode LED constant by the operation of the transistor Q1 and the field effect transistor Q5 without exceeding the maximum rated current value. Current can flow.
FIG. 2B is a schematic diagram showing the relationship between the voltage generated by the generator 10 and the power consumption of the lamp driving circuit 40. When the voltage generated by the generator 10 is greater than the voltage V3, the lighting control circuit 1 applies the voltage divided by the resistor R1 (resistors R1a and R1b) of the protection circuit 30 to the lamp driving circuit 40, The power consumption of the drive circuit 40 can be suppressed, and the heat generation of the lamp drive circuit 40 can be suppressed.

As described above, the lighting control circuit 1 includes the lamp driving circuit 40 so that the current flowing through the light emitting diode LED is constant and the light emitting diode LED has a maximum current even when the voltage generated by the generator 10 is high. A constant current below the rated current value can flow. Further, since the lighting control circuit 1 stably energizes without exceeding the level necessary for lighting the light emitting diode LED (rated current), cogging generated in the generator 10 can be reduced.
Furthermore, the lighting control circuit 1 can change the voltage applied to the lamp body driving circuit 40 according to the voltage value generated by the generator 10 by providing the protection circuit 30. By changing the voltage applied to the lamp driving circuit 40, the power consumption of the lamp driving circuit 40 can be suppressed, heat generation can be reduced, and deterioration of the lamp driving circuit 40 and the light emitting diode LED can be prevented.

(Second Embodiment)
FIG. 3 is a circuit diagram schematically illustrating the connection between the lighting control circuit 1A and the generator 10 and the configuration of the lighting control circuit 1A according to the second embodiment. The lighting control circuit 1A includes a rectifier circuit 20, a protection circuit 30, a lamp body drive circuit 40a, and a brightness detection circuit 50, as illustrated. In addition,
Parts corresponding to the respective parts of the first embodiment in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. The circuit shown in the figure is different from the first embodiment in that a coil L1 connected in series with the light emitting diode LED is provided, and a diode D2 is provided between the resistor R7 and the drain of the field effect transistor Q5. It is. The cathode of the diode D2 is connected to the other end of the resistor R7, and the anode of the diode D2 is connected between the drain of the field effect transistor Q5 and the coil L1. One end of the coil L1 is connected to the cathode of the light emitting diode LED via the connection point W, and the other end is connected to the drain of the field effect transistor Q5.

  According to this configuration, when the field effect transistor Q5 is turned off, the lighting control circuit 1A applies the induced electromotive force generated in the coil L1 to the light emitting diode LED through the diode D2, and turns on the light emitting diode LED. You can continue. As a result, the lighting control circuit 1A can lengthen the lighting time when the light emitting diode LED is repeatedly turned on and off, as compared with the lighting control circuit 1 of the first embodiment. As a result, when the field effect transistor Q5 is switched on and off at high speed, the light-emitting diode LED can be lit at a constant brightness.

  Next, FIG. 4 and FIG. 5 are graphs showing simulation results of the current value flowing through the light emitting diode LED in the circuit configuration of the second embodiment. The horizontal axis direction represents time, and the vertical axis direction represents the current value (0 to 140 mA) flowing through the light emitting diode LED and the voltage value (0 to 18 V or 35 V) in a part of the circuit. .

FIG. 4 shows the current flowing through the light emitting diode LED when the voltage generated by the generator 10 is 20 V, the voltage at the emitter of the transistor Q3, the voltage at the collector of the transistor Q2, and the voltage at the drain of the field effect transistor Q5. Show. At this time, the frequency at which the field effect transistor Q5 is switched on and off by the transistor Q1 is 28.47 Hz.
5 shows the current flowing through the light emitting diode LED when the voltage generated by the generator 10 is 35 V, the voltage at the emitter of the transistor Q3, the voltage at the collector of the transistor Q2, and the drain at the drain of the field effect transistor Q5. The voltage is shown. At this time, the frequency at which the field effect transistor Q5 is switched on and off by the transistor Q1 is 56.93 Hz.

  As shown in the two graphs, in the lighting control circuit 1, even when the voltage applied from the generator 10 is different, the current flowing through the light emitting diode LED causes the transistor Q1 to switch the field effect transistor Q5 on and off. Thus, it can be stabilized at about 140 mA which is the rated current value.

(Third embodiment)
FIG. 6 is a circuit diagram schematically illustrating the connection between the lighting control circuit 1B and the generator 10 and the configuration of the lighting control circuit 1B according to the third embodiment. The lighting control circuit 1B includes a rectifier circuit 20, a protection circuit 30, a lamp driving circuit 40b, and a brightness detection circuit 50a. In the lighting control circuit 1B, portions corresponding to the respective portions of the second embodiment in FIG. Further, as shown in the drawing, the lighting control circuit 1B is different from the second embodiment in a lamp driving circuit 40b and a brightness detection circuit 50a.

The lamp body driving circuit 40b includes a driving circuit 41b and an output circuit 42b. The lamp driving circuit 40b performs control to turn on the light emitting diode LED, and applies the voltage applied from the protection circuit 30 to the light emitting diode LED. By switching on and off the current according to the current flowing through the light emitting diode LED, the current flowing through the light emitting diode LED is prevented from becoming excessive, and control is performed to flow a constant current through the light emitting diode LED.
The lightness detection circuit 50a stops applying a current to the drive circuit 41b of the lamp body drive circuit 40b when the light quantity input from the outside exceeds a predetermined light quantity, and the light emitting diode LED does not light up. Like that.

Next, the structure of the lamp driving circuit 40b and the lightness detection circuit 50a will be described.
The lamp driving circuit 40b includes a driving circuit 41b, an output circuit 42b, and a light emitting diode LED. The drive circuit 41b includes a diode D7, an NPN transistor Q9 (first transistor), and resistors R18 and R19. The output circuit 42b includes a field effect transistor Q5 (switching element) and a resistor R20.
One end of the resistor R19 is connected to the lightness detection circuit 50a via the connection point J6, and the other end is grounded via the resistor R18. Transistor Q9 has a collector connected to the other end of resistor R19, an emitter grounded, and a base connected to the cathode of diode D7. The diode D7 has an anode connected to the output circuit 42b and is connected to the source of the field effect transistor of the output circuit 42b. The light emitting diode LED has an anode connected to the lightness detection circuit 50a via the connection point J7, a cathode connected to the drain of the field effect transistor Q5, and a source grounded via the resistor R20.

The brightness detection circuit 50a includes resistors R21 to R23, a capacitor C4, a PNP transistor Q10, a phototransistor Q11, and a Zener diode ZD4.
The Zener diode ZD4 has a cathode connected to the connection point J2 that is the output terminal of the protection circuit 30, and an anode grounded via the resistor R23. The resistor R21 has one end connected to the connection point J2 and the other end connected to the anode of the Zener diode ZD4 via the resistor R22. The capacitor C4 has one end connected to the connection point J2 and the other end connected to the other end of the resistor R21. The phototransistor Q11 has a collector connected to the connection point J2, and an emitter connected to the other end of the resistor R21. That is, the capacitor C4 and the phototransistor Q11 are connected in parallel to the resistor R21. The transistor Q10 has an emitter connected to the connection point J2, a collector connected to the lamp driving circuit 40b via the connection point J6, and a base connected to the other end of the resistor R21.

(5. Operation of the lamp driving circuit 40b)
Here, the transistor Q10 of the brightness detection circuit 50a is in an on state, and the voltage output from the protection circuit 30 is applied to the lamp driving circuit 40b through the transistor Q10 and the connection point J6. The operation of the lamp driving circuit 40b will be described.
In the lamp driving circuit 40b, the field effect transistor Q5 is turned on when the current applied from the protection circuit 30 via the transistor Q10 and the connection point J6 is applied to the gate. As a result, a current flows through the light emitting diode LED connected to the drain of the field effect transistor Q5, and the light emitting diode LED is turned on.

  When the field effect transistor Q5 is turned on, the transistor Q9 is turned on when a current is applied to the base via the diode D7, and the potential applied to the gate of the field effect transistor Q5 is set to the ground potential. Transistor Q5 is turned off. Thereby, no current flows through the light emitting diode LED, and the light emitting diode LED is turned off. When the field effect transistor Q5 is turned off, no current is applied to the base of the transistor Q9, and the transistor Q9 is turned off. Then, a voltage is again applied to the gate of the field effect transistor Q5 to turn it on.

As described above, the lamp driving circuit 40b repeats the above-described operation thereafter. In the lamp driving circuit 40b, the transistor Q9 (first transistor) switches the field effect transistor Q5 (switching element) between the on state and the off state in accordance with the current flowing through the light emitting diode LED (lamp body). And a constant current can be passed through the light emitting diode LED (lamp) on average.
Note that, when the transistor Q10 of the brightness detection circuit 50a is in an off state, the field effect transistor Q5 and the transistor Q9 are not in an on state, so that no current flows through the light emitting diode LED and it does not light up.

(6. Operation of brightness detection circuit 50a)
In the lightness detection circuit 50a, the phototransistor Q11 is turned on when the amount of light received by the light receiving unit exceeds the threshold value (predetermined amount of light) of the phototransistor Q11. As a result, the voltage output from the protection circuit 30 is applied to the base of the transistor Q10 via the phototransistor Q11, the transistor Q10 is turned on, and current is applied to the lamp drive circuit 40b via the connection point J6.

(Fourth embodiment)
FIG. 7 is a circuit diagram showing an outline of the connection between the lighting control circuit 1C and the generator 10 of the fourth embodiment and the configuration of the lighting control circuit 1C. As illustrated, the lighting control circuit 1C includes a rectifier circuit 20, a protection circuit 30, a lamp driving circuit 40c, and a brightness detection circuit 50a. In the lighting control circuit 1C, portions corresponding to the respective portions of the third embodiment in FIG. Further, as shown in the figure, the lighting control circuit 1C is provided with a coil L2 between the anode of the light emitting diode LED and the connection point J7 in the lamp driving circuit 40c, as compared with the third embodiment. The difference is that a diode D8 is provided between the cathode and the connection point J7.

The diode D8 has an anode connected to the cathode of the light emitting diode, and a cathode connected to the coil L2 via the connection point J7.
According to this configuration, when the lighting control circuit 1C field effect transistor Q5 is turned off, the induced electromotive force generated in the coil L2 is applied to the light emitting diode LED via the diode D8, and the light emitting diode LED is continuously lit. be able to. As a result, the lighting control circuit 1C can lengthen the lighting time when the light emitting diode LED is repeatedly turned on and off, as compared with the lighting control circuit 1B of the third embodiment. As a result, when the field effect transistor Q5 is switched on and off at high speed, the light-emitting diode LED can be lit at a constant brightness.

(Fifth embodiment)
FIG. 8 is a circuit diagram showing an outline of the connection between the lighting control circuit 1D and the generator 10 of the fifth embodiment and the configuration of the lighting control circuit 1D. As illustrated, the lighting control circuit 1D includes a rectifier circuit 20, a protection circuit 30a, a lamp driving circuit 40b, and a brightness detection circuit 50a. In the lighting control circuit 1D, portions corresponding to the respective portions of the third embodiment in FIG. Further, as shown in the drawing, the lighting control circuit 1D is different from the third embodiment in the configuration of the protection circuit 30a, and the resistor R13 (first resistor) is not an output on the high potential side of the rectifier circuit 20, but is low. It is connected to the ground potential on the potential side.
The protection circuit 30a includes a voltage detection circuit 31a and a switching circuit 32a. The voltage detection circuit 31a detects whether the voltage applied by the rectifier circuit 20 is higher than a predetermined voltage, and the switching circuit 32a. Switches the voltage applied to the lamp drive circuit 40b.

The voltage detection circuit 31a includes resistors R14 to R17, a Zener diode ZD3, and a transistor Q8. The switching circuit 32a includes a transistor Q7 (second transistor) and a resistor R13 (first resistor) as switching means. The resistor R13 includes a resistor R13a and a resistor R13b connected in series.
One end of the resistor R14 is connected to the high-order output end of the rectifier circuit 20 via the connection point J8, and the other end is connected to the cathode of the Zener diode ZD3. The anode of the Zener diode ZD3 is grounded via the resistor R15. Transistor Q8 has a collector connected to connection point J8 via resistor R16, an emitter grounded, and a base connected to the anode of Zener diode ZD3. Resistor R17 has one end connected to the emitter of transistor Q8 and the other end connected to the base of transistor Q7. The transistor Q7 has a collector connected to the lamp driving circuit 40b via the connection point J9, and an emitter grounded. One end of the resistor R13 is connected to the lamp driving circuit 40b via the connection point J9, and the other end is grounded. The transistor Q7 and the resistor R13 are connected in parallel between the connection point J9 and the ground, and the transistor Q7 is turned on and off according to the voltage output from the rectifier circuit 20, and the transistor Q7 and the resistor R13 are connected. A current flows through either of R13.

(7. Operation of protection circuit 30a)
In the protection circuit 30a, when the voltage applied from the rectifier circuit 20 is lower than the breakdown voltage of the Zener diode ZD3 as a predetermined threshold voltage, the transistor Q8 is turned off without causing a potential difference between the emitter and the base. It becomes a state. At this time, the transistor Q7 is turned on due to a potential difference between the emitter and the base. As a result, the current flowing from the lamp driving circuit 40b via the connection point J9 bypasses the resistor R13 and flows to the ground potential via the transistor Q7.
On the other hand, when the voltage applied from the rectifier circuit 20 is higher than the breakdown voltage of the Zener diode ZD3 as a predetermined threshold voltage, the voltage is connected to the ground potential from the connection point J8 through the resistor R14, the Zener diode ZD3, and the resistor R15 in this order. Current flows. Accordingly, the transistor Q8 is turned on due to a potential difference between the emitter and the base. As a result, the transistor Q7 has the emitter and base at the same potential and is turned off. As a result, the current flowing from the lamp driving circuit 40b via the connection point J9 flows to the ground potential via the resistor R13.

  As described above, when the voltage applied to the protection circuit 30a exceeds the breakdown voltage (predetermined threshold voltage) of the Zener diode ZD3, the protection circuit 30a applies the voltage divided by the provided resistor R13 to the lamp body. The applied voltage is applied to the lamp drive circuit 40b until the voltage applied to the drive circuit 40b and the voltage applied to the protection circuit 30a reaches the breakdown voltage of the Zener diode ZD3.

(Sixth embodiment)
FIG. 9 is a circuit diagram showing an outline of the connection between the lighting control circuit 1E and the generator 10 and the configuration of the lighting control circuit 1E according to the sixth embodiment. As illustrated, the lighting control circuit 1E includes a rectifier circuit 20, a protection circuit 30a, a lamp driving circuit 40c, and a brightness detection circuit 50a. In the lighting control circuit 1E, portions corresponding to the respective portions of the fifth embodiment in FIG. Further, as illustrated, the lighting control circuit 1E is different from the fifth embodiment in that the lamp driving circuit 40c of the fourth embodiment of FIG. 7 is used instead of the lamp driving circuit 40b. Is a point.
According to this configuration, when the field effect transistor Q5 is turned off, the lighting control circuit 1C applies the induced electromotive force generated in the coil L2 to the light emitting diode LED via the diode D8, and turns on the light emitting diode LED. Can continue to. As a result, the lighting control circuit 1C can lengthen the lighting time when the light emitting diode LED is repeatedly turned on and off, as compared with the lighting control circuit 1B of the third embodiment. As a result, when the field effect transistor Q5 is switched on and off at high speed, the light-emitting diode LED can be lit at a constant brightness.

(Seventh embodiment)
FIG. 10 is a circuit diagram schematically illustrating the connection between the lighting control circuit 1F and the generator 10 and the configuration of the lighting control circuit 1F according to the seventh embodiment. As illustrated, the lighting control circuit 1F includes a rectifier circuit 20, a protection circuit 30, a lamp driving circuit 40d, and a brightness detection circuit 50b. In the lighting control circuit 1F, portions corresponding to the respective portions of the fourth embodiment in FIG. As shown in the drawing, the lighting control circuit 1F is different from the fourth embodiment in that a part of the lamp driving circuit 40c and the brightness detection circuit 50a are configured by one integrated circuit IC1.

The lamp driving circuit 40d includes an integrated circuit IC1, a resistor R24, a diode D9, a coil L3, and a light emitting diode LED. One end of the resistor R24 is connected to the connection point J2, which is the output end of the protection circuit 30, and the other end is connected to the anode of the light emitting diode LED. In the integrated circuit IC1, the voltage input terminal _VIN is connected to one end of the resistor R24, the current detection terminal I _SENSE is connected to the other end of the resistor R24, the terminal LX is connected to the cathode of the light emitting diode via the coil L3, The terminal ADJ is grounded via the brightness detection circuit 50a, and the ground terminal GND is grounded. The diode D9 has an anode connected to the terminal LX of the integrated circuit IC1 and a cathode connected to one end of the resistor R24.

The integrated circuit IC1 performs an operation of switching whether or not to connect the terminal LX and the ground terminal GND in accordance with a current input to the current detection terminal I _SENCE .
The brightness detection circuit 50b includes a phototransistor Q12 and a capacitor C5. One end of the capacitor C5 is connected to the terminal ADJ of the integrated circuit IC1 provided in the lamp driving circuit 40d, and the other end is grounded. The phototransistor Q12 has a collector connected to one end of the capacitor C5 and an emitter grounded.

In the first to seventh embodiments, the lighting control circuits 1 to 1F are configured to include the light emitting diode LED. However, the light emitting diode LED is provided outside the lighting control circuit 1, and the connection point R, The light emitting diode LED may be connected via W.
In the first to seventh embodiments, the resistor R1 of the switching circuit 32 and the resistor R13 of the switching circuit 32a are configured to connect two resistors in series. In order to adjust the current value applied to 40d, a plurality of resistors may be connected in parallel.

It is a circuit diagram which shows the outline of the structure of the connection of the lighting control circuit of 1st Embodiment, and a generator, and a lighting control circuit. It is the schematic which showed the relationship between the voltage applied to a lighting control circuit, the electric current which flows into a light emitting diode, and the electric power which a lighting control circuit consumes. It is a circuit diagram which shows the outline of the structure of the connection of the lighting control circuit of 2nd Embodiment, and a generator, and a lighting control circuit. 5 is a graph showing a simulation result of a current value flowing through a light emitting diode in the circuit configuration of the second embodiment. 5 is a graph showing a simulation result of a current value flowing through a light emitting diode in the circuit configuration of the second embodiment. It is a circuit diagram which shows the outline of the structure of the connection of the lighting control circuit of 3rd Embodiment, and a generator, and a lighting control circuit. It is a circuit diagram which shows the outline of the structure of the connection of the lighting control circuit of 4th Embodiment, and a generator, and a lighting control circuit. It is a circuit diagram which shows the outline of the connection of the lighting control circuit of 5th Embodiment, and a generator, and the structure of a lighting control circuit. It is a circuit diagram which shows the outline of the connection of the lighting control circuit of 6th Embodiment, and a generator, and the structure of a lighting control circuit. It is a circuit diagram which shows the outline of the structure of the connection of the lighting control circuit of 7th Embodiment, and a generator, and a lighting control circuit. It is a circuit diagram which shows the structure of the resistance current limiting type | formula in a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1A, 1B, 1C, 1D, 1E, 1F ... Lighting control circuit 10 ... Generator, 20 ... Rectifier circuit 30, 30a ... Protection circuit 31, 31a ... Voltage detection circuit 32, 32a ... Switching circuit 40, 40a, 40b , 40c, 40d ... Lamp drive circuit 41, 41a, 41b, 41c ... Drive circuit 42, 42b ... Output circuit 50, 50a, 50b ... Lightness detection circuit C1, C2 ... Electric field capacitor C3, C4, C5 ... Capacitor D1, D1a , D1b, D2, D3, D4, D5, D6, D7, D8, D9 ... Diode LED ... Light emitting diode L1, L2, L3 ... Coil Q1, Q2, Q3, Q4, Q7, Q8, Q9, Q10 ... Transistor Q5 ... Field effect transistors,
Q6, Q11, Q12 ... Phototransistors R1, R1a, R1b, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R13a, R13b, R14, R15, R16, R17, R18, R19, R20, R21, R22, R23, R24 ... Resistors ZD1, ZD2, ZD3, ZD4 ... Zener diodes

Claims (11)

When the applied input voltage is equal to or lower than a predetermined threshold voltage, the applied input voltage is output, and when the applied input voltage exceeds the predetermined threshold voltage, the applied input voltage A protective circuit that divides and outputs
A lamp driving circuit that applies a voltage output from the protection circuit to the lamp, and
The lamp driving circuit is:
A switching element connected in series to the lamp body;
Have a first transistor connected to said switching element,
A lightness detection circuit that is provided between the lamp driving circuit and the ground potential and that turns off the switching element when the amount of light input from the outside is greater than a predetermined amount of light;
The protection circuit is
A first resistor having one end connected to the first connection point to which the input voltage is applied and a second resistor connected to an output end for applying a voltage to the lamp driving circuit via a second connection point; ,
A second transistor having an emitter connected to the first connection point and a collector connected to the second connection point;
A second resistor connected between the emitter of the second transistor and the base of the second transistor;
A third transistor having an emitter connected to the first node and a collector connected to a base of the second transistor;
A third resistor having one end connected to the base of the second transistor and the other end connected to a third connection point;
A fourth resistor having one end connected to the first connection point and the other end connected to the base of the third transistor;
A first Zener diode having a cathode connected to a base of the third transistor;
A fifth resistor having one end connected to the anode of the first Zener diode and the other end connected to the third connection point;
With
The third connection point is grounded through the brightness detection circuit,
The threshold voltage is determined by a breakdown voltage of the first Zener diode;
When the input voltage is lower than the breakdown voltage of the first Zener diode, the input voltage is output to the lamp driving circuit via the second transistor, and the input voltage is the breakdown of the first Zener diode. When the voltage is higher than the voltage, the lamp lighting control circuit outputs the voltage divided by the first resistor to the lamp driving circuit. The lamp driving circuit is:
A first diode having an anode connected to a fourth connection point disposed at the same potential as the second connection point of the protection circuit;
A sixth resistor having one end connected to the cathode of the first diode and the other end connected to a fifth connection point disposed at the same potential as the third connection point;
A seventh resistor having one end connected to the fourth connection point;
An eighth resistor with one end grounded;
A ninth resistor having one end connected to the other end of the eighth resistor;
The light emitting diode as the lamp body has an anode connected to the other end of the seventh resistor,
The first transistor has a base connected to the cathode of the first diode, an emitter connected to the other end of the seventh resistor, a collector connected to the other end of the ninth resistor,
The field effect transistor as the switching element has a base connected to the other end of the eighth resistor, a drain connected to the cathode of the light emitting diode, and a source grounded.
The lamp lighting control circuit according to claim 1 , wherein the fifth connection point is grounded via the lightness detection circuit. A second diode having an anode connected to the drain of the field effect transistor and a cathode connected to the anode of the light emitting diode;
A coil provided between the light emitting diode and the field effect transistor, having one end connected to the cathode of the light emitting diode and the other end connected to the drain of the field effect transistor. The lighting control circuit of the lamp body according to 2 . The brightness detection circuit includes:
A tenth resistor applied with a voltage output from the protection circuit at one end;
A second Zener diode having a cathode connected to the other end of the tenth resistor and an anode grounded;
An eleventh resistor having one end connected to the other end of the tenth resistor;
A twelfth resistor having one end connected to the other end of the eleventh resistor and the other end grounded;
A fourth transistor having a base connected to the other end of the eleventh resistor, a collector connected to the third connection point and the fifth connection point, and an emitter grounded;
A capacitor having one end connected to the other end of the eleventh resistor and the other end grounded;
A collector connected to the other end of the resistor of the eleventh, the lighting control circuit of the fixture according to claim 2 or claim 3 emitter characterized in that it comprises a phototransistor which is grounded. A lighting control circuit for a lamp body according to any one of claims 1 to 4 ,
A lamp connected to the lighting control circuit;
A bicycle generator for applying a voltage generated according to the speed of the bicycle to the lighting control circuit;
A bicycle lamp, comprising: a rectifying circuit that rectifies alternating current generated by the bicycle generator and inputs the alternating current to the lighting control circuit. A rectifier circuit connected to an AC generator for converting AC voltage to DC voltage;
A voltage detection circuit that detects a DC voltage output from the rectifier circuit and generates a switching signal when a DC voltage generated by the rectifier circuit exceeds a predetermined threshold;
A switch circuit connected to the rectifier circuit, having a first resistor and a switch means connected in parallel to the first resistor, and for switching off the switch means by a switch signal from the voltage detection circuit;
A lamp connected to the switching circuit;
An output circuit having a switching element connected in series with the lamp body;
Which is connected with the switching circuit and is connected to the output circuit, it has a drive circuit that turns on control and OFF control of the switching elements of the output circuit,
The switching means of the switching circuit includes a second transistor having an emitter connected to the rectifier circuit, a collector connected to the drive circuit, and a base connected to the emitter via a second resistor,
The voltage detection circuit includes a third transistor having an emitter connected to the emitter of the second transistor, a collector connected to the base of the second transistor, and a Zener connected to the base of the third transistor. A lamp lighting control circuit comprising a diode . The drive circuit includes a feedback resistor connected between the lamp body and the switching circuit, an emitter connected to the feedback resistor, a collector connected to a switching element of the output circuit, and a base via the diode. The lamp lighting control circuit according to claim 6 , further comprising a first transistor connected to the switching circuit. The lamp body according to claim 7, further comprising a brightness detection circuit that is connected in series to the drive circuit and that controls the drive circuit to be off when the amount of light input from the outside exceeds a predetermined amount of light. Lighting control circuit. The brightness detection circuit is connected to the voltage detection circuit, according to claim 8, characterized in that said voltage detection circuit in the OFF state when exceeding the amount of light quantity of light input from the outside predetermined Lighting control circuit for lamps. The brightness detection circuit includes a fourth transistor having a collector connected to a base of the first transistor of the drive circuit, and a phototransistor connected to a base of the fourth transistor. The lighting control circuit of the lamp body according to claim 8 or 9 . A lighting control circuit for a lamp body according to any one of claims 6 to 10 ,
A bicycle generator for applying a voltage generated according to the speed of the bicycle to the lighting control circuit;
A bicycle lamp characterized by comprising:

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