JP2014165014A - Lighting circuit and illumination light source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting circuit that is small in circuit scale and low in cost.SOLUTION: A lighting circuit 30 connected to an AC power supply 20 and configured to lighten an LED unit 38, comprises: a capacitor 32 and a bridge diode 34 supplied with an AC power from the AC power supply 20, and connected in series to each other; a Zener diode 36 connected in series to the LED unit 38, and connected to the bridge diode 34 so that a DC voltage from the bridge diode 34 is applied to the Zener diode 36 and the LED unit 38 connected in series.

Description

  The present invention relates to a lighting circuit for lighting a solid light emitting element such as a light emitting diode (LED) and an illumination light source using the lighting circuit.

  Solid light-emitting elements such as LEDs (Light Emitting Diodes) are expected to be new illumination light sources including various lamps because of their high efficiency and long life.

  Conventionally, various technologies have been proposed as LED lighting circuits (see, for example, Patent Document 1).

  FIG. 7 is a circuit diagram of the lighting circuit 10 disclosed in Patent Document 1. In FIG. The lighting circuit 10 is a circuit that is connected to the AC power source 20 and lights the LED unit 15, and includes input terminals 11 a and 11 b, a capacitor 12, a bridge diode 13, a diode 14, and the LED unit 15. The AC voltage from the AC power supply 20 is applied to the capacitor 12 and the bridge diode 13 connected between the input terminals 11a and 11b. A DC voltage obtained by rectification by the bridge diode 13 is applied to the LED unit 15, a current flows through the LED unit 15, and the LED unit 15 is lit. The diode 14 connected in parallel with the LED unit 15 circulates the current to the power supply side when a current flowing in the reverse direction of the LED unit 15 is generated due to a failure of the bridge diode 13 or the like.

  According to such a circuit, the AC voltage from the AC power supply 20 is dropped by the capacitor 12, and the AC voltage after the voltage drop (that is, a voltage suitable for light emission of the LED unit 15) is applied to the bridge diode 13. Applied. As a result, only the series resistance of the capacitor 12 acts as a heat generation factor with respect to the voltage drop of the AC voltage. Therefore, compared with the case where the same voltage drop is realized using a heat-generating electronic component such as a resistor, Wasteful power consumption).

JP-A-7-273371

  However, in the conventional lighting circuit 10 described above, a voltage drop is realized only by the capacitor 12 in order to obtain an AC voltage suitable for the LED unit 15 (AC voltage applied to the bridge diode 13). Therefore, a capacitor 12 that generates a large voltage drop is required, and the capacitor 12 is required to have a large capacity and a large withstand voltage. As a result, there is a problem that the capacitor 12 is large and expensive, and consequently, the size of the lighting circuit is increased and the cost of the lighting circuit is increased.

  In particular, when the AC power supply 20 is supplied with a high AC voltage such as AC 230 V instead of a low AC voltage such as AC 100 V, this problem becomes particularly significant.

  Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide a lighting circuit that has a small circuit scale and is inexpensive and an illumination light source that uses such a lighting circuit.

  In order to achieve the above object, a lighting circuit according to an embodiment of the present invention is a lighting circuit that is connected to an AC power source and lights a solid-state light emitting element, and receives a supply of AC power from the AC power source. And a constant voltage diode connected in series with the solid state light emitting element, and a DC voltage from the rectifying element is applied to the constant voltage diode and the solid state light emitting element connected in series. A constant voltage diode connected to the rectifier element.

  Here, the rectifying element may have two output terminals, and only the constant voltage diode and the solid state light emitting element may be connected between the two output terminals.

  Furthermore, a resistor connected in series with the constant voltage diode and the solid state light emitting device may be included.

  Further, a resistor connected in parallel to the capacitor may be provided.

  Furthermore, you may provide the resistance connected in series with the said capacitor | condenser and the said rectifier.

  The solid state light emitting device may be an LED.

  The present invention can be realized not only as a lighting circuit but also as an illumination light source including a solid-state light emitting element and the above-described lighting circuit that is connected to an AC power source and lights the solid-state light emitting element.

  According to the present invention, an inexpensive lighting circuit having a small circuit scale and an illumination light source using such a lighting circuit are realized. In particular, when the present invention is applied as a lighting circuit and an illumination light source that operate at a high AC voltage such as AC 230 V, a greater effect is achieved.

  Therefore, the present invention has an extremely high practical value in the present day when lighting fixtures equipped with solid light emitting elements have become widespread.

Circuit diagram of lighting circuit in an embodiment of the present invention (A) is the phasor diagram of the voltage at the main part of the lighting circuit in the embodiment of the present invention, and (b) is the phasor diagram of the voltage at the main part of the conventional lighting circuit not including the Zener diode. Diagram for explaining the experimental results regarding resistance to spike current The circuit diagram of the lighting circuit in the modification of embodiment of this invention Sectional drawing of the lightbulb-shaped lamp in embodiment of this invention The figure explaining the example which applied the light source for illumination which concerns on this invention to the refrigerator interior lighting apparatus Circuit diagram of conventional lighting circuit

  Hereinafter, embodiments of a lighting circuit and a light source for illumination according to the present invention will be specifically described with reference to the drawings. Note that each of the embodiments and modifications described below is a specific example of the present invention. The numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of the constituent elements, operation timings, and the like shown in the following embodiments and modifications are merely examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments and modifications, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements.

  FIG. 1 is a circuit diagram of a lighting circuit 30 according to an embodiment of the present invention. In this figure, not only the lighting circuit 30 but also the AC power source 20 for supplying AC power to the lighting circuit 30 and a solid state light emitting device (here, the LED unit 38) to be lit are shown together. Yes.

  The lighting circuit 30 is a lighting circuit that is connected to the AC power source 20 and lights the LED unit 38, and includes input terminals 31a and 31b, a capacitor 32, resistors 33a and 33b, a bridge diode 34, a resistor 35, a Zener diode 36, and Output terminals 37a and 37b.

  The AC power source 20 is a power source that supplies AC power, for example, an AC 230V power source.

  The input terminals 31 a and 31 b are a terminal pair that receives supply of AC power from the AC power supply 20.

  A capacitor 32, a bridge diode 34, and a resistor 35 connected in series are connected between the input terminals 31a and 31b. Further, two resistors 33 a and 33 b connected in series are connected in parallel with the capacitor 32.

  The capacitor 32 has a capacity for causing a voltage drop with respect to the AC voltage from the AC power supply 20. The capacitance of the capacitor 32 is set to a value that causes a predetermined voltage drop that satisfies the following. That is, an appropriate amount of AC voltage is applied to the bridge diode 34, and as a result, the DC voltage obtained at the bridge diode 34 substantially matches the voltage drop at the Zener diode 36 and the LED unit 38. Capacity has been determined.

  The resistors 33a and 33b are resistors for discharging the charge accumulated in the capacitor 32 when the lighting circuit 30 is removed from the AC power supply 20, and have extremely high resistance values (for example, about 300 KΩ each). . The two resistors 33a and 33b are configured to compensate for each of the resistors having a low withstand voltage (to increase the total withstand voltage).

  The resistor 35 is a resistor that functions as a fuse, and has an extremely low resistance value (for example, 100Ω).

  The bridge diode 34 is an example of a rectifying element that converts an AC voltage into a DC voltage, and has two input terminals to which the AC voltage is input and two output terminals that output the DC voltage after rectification.

  A Zener diode 36 and an LED unit 38 connected in series are connected between the two output terminals of the bridge diode 34.

  The zener diode 36 is an example of a constant voltage diode that generates a constant voltage drop (zener voltage). For example, the zener diode 36 is a constant voltage diode having a Zener voltage of 12V.

  The output terminals 37a and 37b are a terminal pair from which the lighting circuit 30 outputs a current. Here, the LED unit 38 is connected. The LED unit 38 is an example of a solid state light emitting device, and is, for example, a plurality of LED chips connected in series (for example, six LED chips having a forward voltage of 3 V and connected in series).

  The operation of the lighting circuit 30 in the present embodiment configured as described above is as follows.

  The AC voltage supplied from the AC power supply 20 is subjected to a voltage drop by the capacitor 32, and the AC voltage after the voltage drop is applied to the input terminal of the bridge diode 34.

  The resistance values of the resistors 33a and 33b are negligibly large compared to the impedance of the capacitor 32 at the power frequency of the AC power source 20. Therefore, the voltage drop at both ends of the capacitor 32 can be regarded as a voltage drop due to the capacitor 32 alone.

  Further, the resistance value of the resistor 35 is small enough to be ignored as compared with the impedance of the capacitor 32 and the bridge diode 34. Therefore, the voltage drop at the resistor 35 is negligibly small compared to the voltage drop at the capacitor 32 and the bridge diode 34.

  The AC voltage applied to the input terminal of the bridge diode 34 is rectified by the bridge diode 34 and converted into a DC voltage. As described above, the DC voltage obtained by rectification by the bridge diode 34 due to the voltage drop at the capacitor 12 is substantially equal to the voltage drop at the Zener diode 36 and the LED unit 38. For example, the DC voltage obtained by rectification by the bridge diode 34 is about 30 V, which is the sum of the Zener voltage 12 V in the Zener diode 36 and the forward voltage 18 V in the LED unit 38. Such a DC voltage is applied to the Zener diode 36 and the LED unit 38 connected in series, whereby a current flows through the LED unit 38 via the output terminals 37a and 37b, and the LED unit 38 is lit.

  According to the lighting circuit 30 in the present embodiment as described above, the Zener diode 36 is connected in series with the LED unit 38. Therefore, a constant voltage drop is caused by the Zener diode 36 with respect to the DC voltage obtained by the bridge diode 34, and the DC voltage after the voltage drop is applied to the LED unit 38. Thus, according to the present embodiment, the voltage drop at the capacitor 32 can be smaller by the voltage drop at the Zener diode 36 than in the conventional lighting circuit that does not include such a Zener diode 36. That is, the capacitor 32 only needs to have a smaller capacity and a smaller withstand voltage than conventional ones. Therefore, the capacitor 32 is smaller and less expensive than the conventional one, and as a result, the size of the lighting circuit can be reduced and the cost of the lighting circuit can be reduced.

  In the lighting circuit 30 in the present embodiment, a Zener diode 36 that is not required in the conventional lighting circuit is added. However, the component size and cost of the Zener diode 36 are smaller than the reduction in the capacitance and size of the capacitor 32. Therefore, as a whole of the lighting circuit 30, according to the lighting circuit 30 in the present embodiment, the circuit scale can be reduced and the cost can be reduced as compared with the conventional lighting circuit.

FIG. 2A is a phasor diagram of the voltage at the main points of the lighting circuit 30 in the present embodiment. FIG. 2B is a phasor diagram of the voltage at the main points of a conventional lighting circuit that does not include the Zener diode 36. In FIG. 2, V _in is a voltage (input voltage) supplied from the AC power supply 20. V _cap is a voltage (voltage drop) across the capacitor 32. V _LED is a voltage (forward voltage) at both ends of the LED unit 38. V _zener is the voltage (Zener voltage) at both ends of the Zener diode 36.

As shown in FIG. 2A, in the lighting circuit 30 in the present embodiment, V _in is a component obtained by adding V _LED and V _Zener, and a component of V _cap that is 90 degrees out of phase with it. Separated. As shown in FIG. 2B, in the conventional lighting circuit that does not include the Zener diode 36, V _in is separated into a component of V _{LED and} a component of V _cap . As can be seen from the fact that the size of V _cap in FIG. 2 (a) is smaller than the size of V _cap in FIG. 2 (b), the lighting circuit 30 in the present embodiment has a conventional lighting circuit. In comparison, the voltage drop at the capacitor 32 can be small. Therefore, according to the lighting circuit 30 of the present embodiment, the capacitor 32 only needs to have a smaller capacity and a smaller withstand voltage than conventional ones. As a result, the circuit scale of the lighting circuit 30 is reduced and realized at low cost.

  In addition, the voltage drop in the capacitor | condenser 32 may be so small that the Zener diode 36 with a larger Zener voltage is employ | adopted. However, as the Zener voltage of the Zener diode 36 increases, the power consumption of the Zener diode 36 increases. Therefore, the Zener voltage of the Zener diode 36 needs to be determined to an optimum value from the viewpoint of the capacity and withstand voltage of the capacitor 32 and the power consumption of the Zener diode 36. In the present embodiment, when the AC voltage from the AC power supply 20 is 230 V AC and the voltage at both ends of the LED unit 38 is 18 V, the voltage drop at the capacitor 32 may be kept below the standard withstand voltage of 630 V. The possible Zener voltage was 12V or more and 18V or less. Here, as the most preferable mode, the Zener diode 36 having the smallest Zener voltage, that is, the Zener voltage of 12V is adopted. Of course, the optimum Zener voltage changes as appropriate according to the number of LED chips connected in series, and also changes depending on the input voltage.

  FIG. 3 is a diagram for explaining an experimental result regarding resistance to spike current. FIG. 3A is a circuit diagram of a comparative lighting circuit. In this comparative lighting circuit, a resistor 16 is connected in place of the Zener diode 36 of the lighting circuit 30 in the present embodiment. In this experiment, the operation was compared between a lighting circuit using a Zener diode 36 and a lighting circuit using a resistor 16 as a voltage divider for a DC voltage output from the bridge diode 34. Specifically, two types of commercial AC voltages (AC150V, AC230V) were supplied from the AC power supply 20, and the operation of each lighting circuit was observed.

  FIG. 3B is a diagram showing experimental results. Here, “Input Voltage” in the table shown in FIG. 3B is an AC voltage supplied from the AC power supply 20. Further, “Zener” in the “Voltage divider” column corresponds to the lighting circuit 30 in the present embodiment, and “Resister” corresponds to the lighting circuit for comparison. According to this experiment, when the input voltage was set to AC 150 V, both the lighting circuit 30 and the comparative lighting circuit in this embodiment operated normally. However, when the input voltage is set to AC 230 V, the lighting circuit 30 in this embodiment operates normally, but the LED unit 38 is damaged in the comparative lighting circuit.

  The waveform shown in (b) of FIG. 3 shows the waveform of the spike current flowing in the LED unit 38 in the lighting circuit 30 and the comparative lighting circuit in the present embodiment when the input voltage is AC 150V. “Zener / AC150V” indicates a spike current waveform in the lighting circuit 30 in the present embodiment, and “Resistor / AC150V” indicates a spike current waveform in the comparative lighting circuit. As can be seen from these waveforms, the spike current is generated in a shorter time in the lighting circuit 30 in the present embodiment. On the other hand, in the comparative lighting circuit, the spike current is generated for a longer time. Due to this difference, it is considered that the LED unit 38 is damaged in the comparative lighting circuit when the input voltage of AC 230 V is supplied.

  As described above, according to the lighting circuit 30 in the present embodiment, the circuit scale is reduced, and not only is it realized at low cost, but also the resistance to spike current is higher than that of the lighting circuit in which the voltage divider is configured by a resistor. It becomes higher and stable operation can be continued.

  Even if the resistor 16 is used instead of the zener diode as in the comparative lighting circuit shown in FIG. 3A, the LED unit 38 may be damaged if the input voltage is AC 150V. There was no. From this, it can be said that when the input voltage is AC 150 V or less, for example, AC 110 V or more and 127 V or less, or AC 100 V or more and 110 V or less, the lighting circuit can be configured with a small circuit scale and at low cost.

  The lighting circuit according to the present invention is not limited to the above embodiment. For example, the lighting circuit shown in FIG. 4 may be used. FIG. 4 is a circuit diagram of a lighting circuit 30a in a modification of the above embodiment. The lighting circuit 30a includes three LED units 38a to 38c connected in parallel instead of the LED unit 38 in the lighting circuit 30 of the above embodiment, and is further connected in series with the Zener diode 36. The resistor 39 is provided.

  According to the lighting circuit 30a in the present modification, not only the voltage drop in the Zener diode 36 but also the voltage drop in the resistor 39 occurs with respect to the DC voltage output from the bridge diode 34. Therefore, according to the lighting circuit 30a in the present modification, the voltage drop in the capacitor 32 can be smaller than that in the lighting circuit 30 in the above embodiment. That is, according to the lighting circuit 30a in the present modification, the capacitance and withstand voltage of the capacitor 32 can be smaller than those in the lighting circuit 30 in the above embodiment. As a result, the lighting circuit 30a in the present modification can be realized with a smaller circuit scale and at a lower cost.

  Further, according to the lighting circuit 30a in the present modification, since the three LED units 38a to 38c are driven, it is possible to drive an LED unit having a larger light emission amount than the lighting circuit 30 in the above embodiment.

  In this modification, since the power is consumed in the resistor 39, the resistance value of the resistor 39 is set in consideration of the balance between the demerit of increasing power consumption and the merit of reducing the capacitance and withstand voltage of the capacitor 32. It is necessary to decide.

  Next, an embodiment of an illumination light source according to the present invention having the above lighting circuit will be described.

  FIG. 5 is a cross-sectional view of the light bulb shaped lamp 40 in the embodiment of the present invention. The light bulb shaped lamp 40 is an example of an illumination light source including a solid light emitting element (here, an LED unit) and the lighting circuit described above. More specifically, the light bulb shaped lamp 40 includes a translucent globe 41, an LED unit 42 that is a light source, a base 43 that receives electric power from the outside of the lamp, a support 44, a support plate 45, a resin case 46, The lead wire 47 and the lighting circuit 48 are provided.

  The globe 41 is a translucent cover that houses the LED unit 42 and transmits light from the LED unit 42 to the outside of the lamp. The light of the LED unit 42 that has entered the inner surface of the globe 41 passes through the globe 41 and is extracted to the outside of the globe 41.

  The LED unit 42 is the LED unit 38 described above or the LED units 38 a to 38 c connected in parallel, and emits light when a current is supplied to the LED chip via the lead wire 47. The LED unit 42 is held in the globe 41 by a support 44. By arranging the LED unit 42 at the center position of the globe 41, the light distribution characteristic of the light bulb shaped lamp 40 becomes a light distribution characteristic similar to a general incandescent light bulb using a conventional filament coil.

  More specifically, the LED unit 42 includes a translucent substrate, a plurality of LED chips disposed on the main surface of the substrate, a wavelength conversion material, and a sealing member that seals the plurality of LED chips. Consists of As the LED chip, for example, a blue LED chip that emits blue light is employed. The wavelength conversion material is a member that converts the wavelength of light emitted from the LED chip, and is, for example, a phosphor-containing resin containing phosphor particles. For example, YAG (yttrium, aluminum, garnet) -based yellow phosphor particles are employed as the phosphor particles. The yellow phosphor particles emit yellow light when excited by blue light from the LED chip. As a result, white light obtained by the yellow light and the blue light from the LED chip is emitted.

  The base 43 is a power receiving unit that receives power for causing the LED unit 42 to emit light from the outside of the light bulb shaped lamp 40. The base 43 receives an AC voltage such as AC 230 V through two contacts, and the power received by the base 43 is input to the lighting circuit 48 via a lead wire.

  The column 44 is a metal stem (metal column) provided so as to extend from the vicinity of the opening of the globe 41 toward the inside of the globe 41. The support 44 functions as a support member that supports the LED unit 42 in the globe 41 and also functions as a heat dissipation member for radiating heat generated in the LED unit 42 toward the base 43 side.

  The support plate 45 is a member that supports the support column 44 and is fixed to the resin case 46. The support plate 45 is disposed so as to close the opening of the globe 41. The support plate 45 is made of a metal material having a high thermal conductivity such as aluminum, like the support 44.

  The resin case 46 is an insulating case (circuit holder) for electrically insulating the support column 44 and the base 43 and accommodating the lighting circuit 48.

  The two lead wires 47 are a pair of lead wires for supplying power for lighting the LED unit 42 from the lighting circuit 48 to the LED unit 42.

  The lighting circuit 48 is the lighting circuit 30 according to the embodiment or the lighting circuit 30a according to the modification.

  The light bulb shaped lamp 40 according to the present embodiment configured as described above is used with its base 43 screwed into a socket of a lighting device to which AC power is supplied. As described above, the lighting circuit 48 included in the light bulb shaped lamp 40 includes the capacitor 32 having a smaller capacity and withstand voltage than the conventional one, so that the circuit scale is small and inexpensive. Therefore, the light bulb shaped lamp 40 is also small in size and can be realized at low cost.

  The illumination light source including the lighting circuit according to the present invention can be realized not only as the lamp as described above but also as an illumination device for various electronic devices.

  FIG. 6 is a diagram illustrating an example in which the illumination light source according to the present invention is applied to a refrigerator interior lighting device. 6A is a front view of the refrigerator in a state where the door of the refrigerator provided with the illumination light source according to the present invention is opened, and FIG. 6B is a cross-sectional view taken along the line AA in FIG. FIG.

  As shown in FIG. 6A, the refrigerator main body 50 is divided into a plurality of sections to form a storage room. A refrigerator compartment 51 is arranged at the top of the refrigerator main body 50, an ice making room 52 and a first freezing room 53 are arranged side by side immediately below, followed by a vegetable compartment 55, and a second room at the bottom. A freezer compartment 54 is arranged.

  As shown in FIG. 6B, the refrigerator compartment 51 has a door 58 on the front surface. The refrigerator compartment 51 is provided with a plurality of storage shelves 57 for organizing and storing stored items without overlapping. A specific low temperature chamber 56 is provided at the lowermost stage of the refrigerator compartment 51.

  The interior lighting device is an example of an illumination light source including a solid-state light emitting element (here, an LED unit) and the lighting circuit described above, and here, as shown in FIGS. 6A and 6B. It comprises two LED units 60a and 60b and a control circuit 59. The two LED units 60a and 60b correspond to the LED unit 38 or 38a to 38c described above. These two LED units 60a and 60b have a plurality of LEDs on the left wall surface and the right wall surface in front of the front end of the storage shelf 57, respectively, when viewed from the front side of the door 58 in the depth direction in the refrigerator 51. The chips are arranged in the vertical direction. The control circuit 59 corresponds to a circuit in which the lighting circuit 30 or 30a described above is added with a circuit for detecting the opening / closing operation of the door 58 and controlling the energization of the LED units 60a and 60b, and is provided on the back surface of the refrigerator main body 50. It has been.

  According to the interior lighting device configured as described above, the lighting circuit included in the control circuit 59 includes the capacitor 32 having a smaller capacity and withstand voltage than the conventional one, so that the circuit scale is small and inexpensive. Therefore, a compact and inexpensive interior lighting device is realized.

  Although the lighting circuit and the illumination light source according to the present invention have been described based on the embodiments and the modifications thereof, the present invention is not limited to these embodiments and modifications. As long as it does not deviate from the gist of the present invention, various modifications conceived by those skilled in the art are applied to the present embodiments and modifications, and forms constructed by combining components in different embodiments and modifications are also included in the present invention. Within one or more embodiments.

  For example, the LED unit 38 driven by the lighting circuit 30 in the above embodiment is composed of a single row of LED chips in which a plurality of LED chips are connected in series, but a plurality of rows of LEDs connected in parallel. It may be composed of a chip. Furthermore, one LED chip may be connected in series.

  In the lighting circuit 30a in the above modification, the resistor 39, the Zener diode 36, and the LED units 38a to 38c are connected in series in this order. However, the connection order of these three components is not limited to this order. May be.

  In the above embodiment, the LED is used as the solid light emitting element, but a solid light emitting element such as a semiconductor laser, an organic EL (Electro Luminescence), or an inorganic EL may be used.

  In addition, in the above-described lighting devices for various electronic devices, examples applied to the refrigerator interior lighting device have been described. However, the lighting devices for various electronic devices are not limited to this, and all other types of microwave ovens and the like can be used. It can also be applied as a lighting device for electronic equipment.

20 AC power supply 30, 30a, 48 Lighting circuit 31a, 31b Input terminal 32 Capacitor 33a, 33b, 35, 39 Resistance 34 Bridge diode 36 Zener diode 37a, 37b Output terminal 38, 38a-38c, 42, 60a, 60b LED unit 40 Light bulb shaped lamp 41 Globe 43 Base 44 Support column 45 Support plate 46 Resin case 47 Lead wire 50 Refrigerator body 51 Refrigeration room 52 Ice making room 53 First freezing room 54 Second freezing room 55 Vegetable room 56 Special low temperature room 57 Storage shelf 58 Door 59 Control circuit

Claims (7)

A lighting circuit connected to an AC power source and lighting a solid state light emitting device,
A capacitor and a rectifying element connected in series, which are supplied with AC power from the AC power source;
A constant voltage diode connected in series with the solid state light emitting element, the direct current voltage from the rectifier element being applied to the constant voltage diode connected in series and the solid state light emitting element; A lighting circuit comprising a connected constant voltage diode. The rectifying element has two output terminals,
The lighting circuit according to claim 1, wherein only the constant voltage diode and the solid state light emitting element are connected between the two output terminals. The lighting circuit according to claim 1, further comprising a resistor connected in series with the constant voltage diode and the solid state light emitting device. The lighting circuit according to claim 1, further comprising a resistor connected in parallel to the capacitor. The lighting circuit according to claim 1, further comprising a resistor connected in series to the capacitor and the rectifying element. The lighting circuit according to claim 1, wherein the solid-state light emitting element is an LED. A solid state light emitting device;
An illumination light source comprising: the lighting circuit according to claim 1, wherein the lighting circuit is connected to an AC power source and lights the solid state light emitting element.

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