JP2012227331A - Power supply device and lighting fixture having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a leakage magnetic flux and reduce loss in a transformer 500 and loss in a circuit in a power supply device 200 by winding a primary coil T1 and a secondary coil T2 of the transformer 500 with efficiency.SOLUTION: The transformer 500 of the power supply device 200 has: a first primary layer P1 obtained by winding two rows of the primary coil T1 to a center core 522; a first secondary layer S1 obtained by winding two rows of the secondary coil T2 to the first primary layer P1; a second primary layer P2 obtained by extending the primary coil T1 wound to the first primary layer P1 and further winding two rows of the extended primary coil T1 to the first secondary layer S1; and a second secondary layer S2 obtained by extending the secondary coil T2 wound to the first secondary layer S1 and further winding two rows of the extended secondary coil T2 to the second primary layer P2. By winding the primary coil T1 and the secondary coil T2 of the transformer 500 with efficiency, the leakage magnetic flux can be reduced, and loss in the transformer 500 and loss in the circuit in the power supply device 200 can be reduced.

Description

  The present invention relates to a lighting device that lights, for example, a light emitting diode (hereinafter referred to as “LED”) or organic electroluminescence (hereinafter referred to as “organic EL”).

  Reduction of useless light in recent lighting fixtures is important for energy saving and power saving. For this reason, light-emitting diodes (hereinafter referred to as LEDs) have attracted attention as lighting devices that control lighting of LEDs with excellent energy saving performance.

  A technique for reducing the leakage flux of a transformer used in a switching power supply device has been found (for example, see Patent Document 1).

  According to this Patent Document 1, it is possible to efficiently control the lighting of the LED by reducing the leakage magnetic flux, and further energy saving can be promoted.

Japanese Patent No. 4631529

  However, since the feedback winding is provided between the primary winding and the secondary winding, the coupling between the primary winding and the secondary winding is weak.

  Further, when the number of turns of the secondary winding is increased to increase the L value of the inductor, the coupling between the primary winding and the secondary winding may be weakened.

  The transformer of the power supply device according to the present invention includes a center core, a first primary layer in which one or two rows of primary windings are wound around the center core, and two rows of secondary windings relative to the first primary layer. The first secondary layer wound, the primary winding wound around the first primary layer extended with respect to the first secondary layer, and the second primary layer wound further in two rows, and the second primary layer On the other hand, a secondary winding wound around the first secondary layer is extended, and further has a second secondary layer wound in one or two rows.

  According to the power supply device of the present invention, by efficiently winding the primary winding and the secondary winding of the transformer, the leakage magnetic flux can be reduced, and the loss of the transformer and the loss of the circuit in the power supply device can be reduced. it can.

1 is a perspective view showing a lighting fixture of Embodiment 1. FIG. It is sectional drawing which shows the AA cross section of the lighting fixture of FIG. It is a circuit diagram which shows the circuit of the power supply device of FIG. FIG. 3 is a perspective view showing a transformer according to the first embodiment. It is sectional drawing which shows the BB cross section of the trans | transformer of FIG. It is sectional drawing which shows the state of the coil | winding of the transformer of FIG. It is a wave form diagram which shows the electric current which flows into MOS-FET of the power supply device of FIG. 3, and the voltage concerning MOS-FET. It is the schematic which shows the relationship between the coil | winding of the transformer of Embodiment 2, and the terminal connected. It is the schematic which shows the relationship between the coil | winding of the transformer of Embodiment 3, and the terminal connected. FIG. 6 is a cross-sectional view showing a cross section of a transformer according to a fourth embodiment. It is sectional drawing which shows the state of the coil | winding of the transformer of FIG. It is the schematic which shows the relationship between the coil | winding of the transformer of FIG. 11, and the terminal connected. FIG. 10 is a cross-sectional view illustrating a state of windings of a transformer according to a fifth embodiment. FIG. 10 is a cross-sectional view illustrating a state of a winding of a transformer according to a sixth embodiment.

Embodiment 1 FIG.
FIG. 1 is a perspective view of the lighting fixture of the present embodiment, and FIG. 2 is a cross-sectional view showing a cross section AA of the lighting fixture of FIG.

  The lighting fixture 1000 includes a main body 100, a switching power supply device 200 (hereinafter also simply referred to as a power supply device 200) attached to the main body 100, an LED module 300 attached to the main body 100, and a power supply device attached to the main body 100. 200 and the instrument cover 400 which covers the LED module 300 are provided.

The LED module 300 is electrically connected to the power supply device 200 and is lit by power supplied from the switching power supply device 200.
The LED module 300 includes ten light emitting diodes 310 (hereinafter also referred to as LEDs 310), an LED substrate 320 on which the LEDs 310 are mounted, and two attachment portions 330 that fix the LED substrate 320 to the main body 100. .

  The LED module 300 in this embodiment will be described with respect to a case where ten LEDs 310 are mounted on the LED substrate 320. However, the number of LEDs 310 may be nine or less, or may be eleven or more. Good.

  FIG. 3 is a circuit diagram showing a circuit configuration of the switching power supply device of FIG.

  The power supply apparatus 200 includes an AC / DC conversion circuit 210 that converts an input AC power supply AC into a DC voltage, a DC power supply circuit 220 that is connected to the AC / DC conversion circuit 210 and supplies a constant current to the connected LED module 300, An activation circuit 230 that activates the DC power supply circuit 220 is provided.

  The AC / DC converter circuit 210 includes a rectifier circuit DB that converts the AC power supply AC into a pulsating rectified voltage, and a capacitor C1 that smoothes the rectified voltage converted by the rectifier circuit DB.

  The DC power supply circuit 220 is a so-called flyback type constant current circuit, and includes a primary winding T1, a secondary winding T2, and a feedback winding T3, and one end side of the primary winding T1 is an AC / DC conversion circuit 210. A transformer 500 connected to the diode 500, a diode D10 whose anode terminal is connected to one end of the secondary winding T2 of the transformer 500, and an electrolytic capacitor C10 (hereinafter referred to as smoothing) whose positive electrode is connected to the cathode terminal of the diode D10. A capacitor C10), a detection resistor R10 connected to the smoothing capacitor C10 via the LED module 300 and detecting the LED current flowing through the LED module 300, and the other end of the primary winding T1 of the transformer 500. MOS-FET Q1 (hereinafter, also referred to as switching element Q1) connected to, and the on-state of the MOS-FET Q1 A control circuit IC for controlling ON / OFF, a current limiting circuit 221 connected to one end of the feedback winding T3 of the transformer 500, and a control power supply Vcc (hereinafter referred to as control) of the control circuit IC connected to the current limiting circuit 221. (Also referred to as a voltage Vcc) is connected to a control power supply circuit 222 and a current limiting circuit 221, and information such as a voltage value output to the transformer 500 is transmitted to the control circuit IC when the MOS-FET Q1 is switched. A switching control detection circuit 223 and a snubber circuit 224 that is connected to both ends of the primary winding T1 and absorbs switching noise generated when the MOS-FET Q1 is switched are provided.

In the transformer 500, when the MOS-FET Q1 is on, a current flows through the primary winding T1, and the core 520 is magnetized. When the MOS-FET Q1 is off, no current flows through the primary winding T1, and the transformer 500 is magnetized. A voltage corresponding to the energy of the core 520 thus generated is generated in the secondary winding T2. The voltage generated in the secondary winding T2 is smoothed by the electrolytic capacitor C10 via the diode D10, and a current flows through the LED module 300.
Further, a voltage corresponding to the voltage (secondary voltage) generated in the secondary winding T2 (voltage corresponding to the turn ratio between the secondary winding T2 and the feedback winding T3) is generated in the feedback winding T3. Therefore, based on the voltage generated in the feedback winding T3, the control circuit IC can detect the timing when the MOS-FET Q1 is turned on or off.

  Note that the transformer 500 shown in FIG. 3 includes numbers of terminals (pin1, pin3 to which winding start and winding end of the primary winding T1, the secondary winding T2, and the feedback winding T3 are connected. pin5, pin7, pin9) are shown for convenience of explanation, but the order of the terminals to be connected is not specified. The structure of the transformer 500 will be described later.

  The current limiting circuit 221 includes a resistor R2. The resistor R2 limits (suppresses) the current that instantaneously flows from the feedback winding T3 into the control power supply circuit 222 and the switching control detection circuit 223.

  The control power supply circuit 222 includes a diode D1 connected to the feedback winding T3 of the transformer 500 and a control capacitor C2 connected to the cathode of the diode D1.

  The switching control detection circuit 223 includes a diode D2 connected to the feedback winding T3 of the transformer 500 via the current limiting circuit 221. The diode D2 has an anode connected to the current limiting circuit 221 and a cathode connected to the control circuit IC.

  The snubber circuit 224 includes a regenerative diode D3 whose cathode side is connected to the drain terminal of the MOS-FET Q1 (one end side of the primary winding T1 of the transformer 500), an anode side of the regenerative diode D3, and the primary winding T1. A resistor R3 connected to the other end side and a capacitor C3 connected to both ends of the primary winding T1 of the transformer 500 are provided.

  The snubber circuit 224 absorbs spike-like noise generated when the MOS-FET Q1 is switched.

  The control circuit IC is activated by receiving the activation power from the activation circuit 230, operates after the activation by the control power Vcc from the control power circuit 222, and based on the signal of the switching control detection circuit 223, the MOS-FET Q1. Controls switching (on / off).

  The starting circuit 230 includes a starting resistor R1, and this starting resistor R1 is connected to the power supply terminal portion of the rectifier circuit DB and the control circuit IC. The activation resistor R1 activates the control circuit IC until the AC power AC is input and power is stably supplied from the feedback winding T3 (control power circuit 222) to the control circuit IC.

Next, the structure of the transformer 500 will be described.
4 is a perspective view showing the structure of the transformer of FIG. 3, FIG. 5 is a schematic cross-sectional view showing the outline of the BB cross section of the transformer of FIG. 4, and FIG. 6 is each winding of the transformer of FIG. It is sectional drawing which shows the state of a line.

  The transformer 500 includes a bobbin 510, two cores 520 inserted from above and below the bobbin 510, a primary winding T1, a secondary winding T2, and a feedback winding T3 wound around the core portion 512 of the bobbin 510. Have.

The bobbin 510 has flange portions 511a and 511b provided on the upper and lower sides, and a core portion 512 that connects the upper and lower flange portions 511a and 511b, and the cross-sectional shape thereof is an “engine” shape.
The flange portion 511b has ten terminals pin1 to terminal pin10 (hereinafter, the terminals pin1 to pin10 may be collectively referred to as “terminal pin”), and the terminal pin is a substrate of the power supply device 200. Soldered (not shown).

  Note that ten terminals pin are not necessarily provided. To maintain an insulation distance between the terminals and to prevent erroneous insertion of the power supply device 200 into the substrate, teeth that do not have some terminals are provided. There may be a missing state.

  Moreover, although the number of terminals pin provided in the collar part 511b demonstrates the case of 10 in this Embodiment, 11 or more may be sufficient and it may be 9 or less.

  The core 520 has an E-shaped side surface, and includes an outer core 521 and a center core 522 provided at the center of the outer core 521. The center core 522 has a cylindrical shape and is fitted into the core portion 512 of the bobbin 510. Although not illustrated, when two cores 520 are attached to the bobbin 510, a gap (also referred to as a center gap) may exist.

  Next, the primary winding T1, the secondary winding T2, and the feedback winding T3 wound around the transformer 500 (the core portion 512 of the bobbin 510) will be described.

  The primary winding T1 connected to the terminal pin1 (winding start terminal) of the bobbin 510 is first wound around the core portion 512 (center core 522) of the bobbin 510 from the flange portion 511a to the flange portion 511b in a row. , Two rows are stacked to form the first layer. This first layer is referred to as a first primary layer P1. For convenience of explanation, the winding is wound from the flange part 511a to the flange part 511b of the bobbin 510, and the state where the wound winding is wound in two rows so as to overlap vertically with respect to the core part 512 is 2 It is called line winding, and the state wound in one line alignment so as not to overlap vertically is sometimes referred to as one line winding.

  Next, the secondary winding T2 connected to the terminal pin5 (winding start terminal) of the bobbin 510 so as to overlap the first primary layer P1 has 14 turns from the flange portion 511a to the flange portion 511b of the bobbin 510 in a row. Two rows are wound to form the second layer. This second layer is referred to as a first secondary layer S1.

  Further, the primary winding T1 wound around the first primary layer P1 is wound in two rows with 15 turns from the flange portion 511a to the flange portion 511b of the bobbin 510 so as to overlap the first secondary layer S1. A third layer is formed and wound around the terminal pin3 (winding end terminal) of the bobbin 510. This third layer is referred to as a second primary layer P2.

  Further, the secondary winding T2 wound around the first secondary layer S1 is wound in two rows with 14 turns from the flange portion 511a to the flange portion 511b of the bobbin 510 so as to overlap the second primary layer P2. The fourth layer is formed and wound around the terminal pin9 (winding end terminal) of the bobbin 510. This fourth layer is referred to as a second secondary layer S2.

  Finally, the feedback winding T3 connected to the terminal pin5 (winding start terminal) of the bobbin 510 is wound 10 turns (one line) from the flange 511a to the flange 511b of the bobbin 510 so as to overlap the second secondary layer S2. Then, the fifth layer is formed and wound around the terminal pin4 (winding end terminal) of the bobbin 510. This fifth layer is called a feedback winding layer D.

  That is, the primary winding T1, the secondary winding T2, and the feedback winding T3 are wound around the core portion 512 of the bobbin 510, and in order from the core portion 512, the first primary layer P1, the first secondary layer S1, and the second winding. A primary layer P2, a second secondary layer S2, and a feedback winding layer D are formed.

  In this way, the primary winding T1 is divided into the first primary layer P1 and the second primary layer P2 to form a winding layer, and the secondary winding T2 is divided into the first secondary layer S1 and the second secondary layer A winding layer is formed by dividing the layer S2.

  At this time, the one-row winding and the two-row winding are respectively wound from the flange portion 511a to the flange portion 511b of the bobbin 510, and the rolled-up state after one-row winding and two-row winding is substantially flat.

  The windings wound in two rows have the same number of turns in the first row as the number of turns in the second row. Thus, by making the number of turns in the first and second rows of windings wound in two rows the same, the winding state when winding in two rows can be made almost flat. Thus, the contact area which each layer touches can be enlarged by making the winding of 1 row winding and 2 rows winding substantially flat.

  An insulating tape for insulating the electrical connection of each layer is wound between each of the first primary layer P1, the first secondary layer S1, the second primary layer P2, the second secondary layer S2, and the feedback winding layer D. And has an insulating layer Z. Further, the transformer 500 has an insulating layer Zo around which an insulating tape is wound around the outer periphery of the feedback winding D. The insulating layers Z and Zo are for maintaining insulation between the respective layers. However, when the thickness of the insulating tape used is reduced and the thickness of the insulating layers Z and Zo is reduced as much as possible, the bonding between the layers can be improved.

  Next, focusing on the first secondary layer S1, the first secondary S1 layer has two rows of windings, the inner row is the first primary layer P1, the outer row is the second primary layer P2, and the insulating tape ( Proximity through the insulating layer Z). Since the structure of the transformer 500 is transmitted to the secondary side using a magnetic field generated on the primary side, the first primary layer P1, the second primary layer P2, and the first secondary layer S1 are in contact with each other as much as possible. The higher the number, the better the transmission and the better the coupling between the primary winding T1 and the secondary winding T2. Accordingly, it is preferable that the first secondary layer S1 sandwiched between the first primary layer P1 and the second primary layer P2 has two windings. For example, when the first secondary layer S1 has three windings, the winding arranged in the middle is not close to either the first primary layer P1 or the second primary layer P2, and thus the coupling is poor. Become. On the other hand, when the winding of the first secondary layer S1 is wound in one row, the outer shape of the transformer 500 becomes large in order to wind the necessary number of turns for the circuit operation of the power supply device 200, so the winding of the first secondary layer S1 Is preferably two-row winding.

  Thus, the contact area where each layer (the first primary layer P1, the first secondary layer S1, the second primary layer P2, the second secondary layer S2) is in contact with each other (the first primary layer P1, the first secondary layer S1, the second primary layer P2, and the second secondary layer S2) is made substantially flat. And increasing the transmission efficiency for transmitting power from the primary side to the secondary side by bringing the winding of the first secondary layer S1 closer to the first primary layer P1 and the second primary layer P2. In addition, power loss due to the transformer 500 can be reduced.

  Also, the second primary layer P2 is preferably a two-row winding, as with the first secondary layer S1.

Next, power loss when using the transformer 500 in the present embodiment will be considered.
For example, when the primary-side inductor of the conventional transformer is 1 mH, the leakage inductor is 30 μH when the primary winding and the secondary winding are divided into two. Similarly, when the inductor on the primary side of the transformer 500 is 1 mH, the primary winding T1 and the secondary winding T2 are each divided into two and each layer (first primary layer P1, first secondary layer S1, Experiments have confirmed that the leakage inductor is 10 μH when the second primary layer P2 and the second secondary layer S2) are wound in two rows. Therefore, since the leakage inductor is 3%, it is reduced to 1%, so that the power consumption of the transformer 500 is improved to 0.48 W, for example, from 0.5 W.

  Further, when the MOS-FET Q1 is switched due to the influence of the leakage inductor of the transformer 500, a vibration waveform is generated when the voltage applied to the drain terminal of the MOS-FET Q1 rises from zero. This vibration waveform will be described.

  FIG. 7 shows a drain current waveform (broken line portion) flowing through the MOS-FET Q1 and a drain voltage waveform (solid line portion) applied to the MOS-FET Q1.

When the MOS-FET Q1 is turned on (t _on ), a drain current flows between the drain terminal and the source terminal of the MOS-FET Q1 so that the current gradually increases from the on time, and the MOS-FET Q1 is turned off (t _off). ), No drain current flows through the MOS-FET Q1, and a drain voltage is applied to the drain terminal of the MOS-FET Q1.

  The drain voltage includes a flyback voltage VFB generated on the primary winding T1 side corresponding to the secondary voltage generated on the secondary winding T2 side of the transformer 500 when the MOS-FET Q1 is off, and a capacitor C1. The output voltage VDC is added.

  When the MOS-FET Q1 is switched off, the instantaneously high drain voltage (the voltage VFB for the flyback is added to the output voltage VDC of the capacitor C1, and the leakage magnetic flux component that is the voltage across the primary winding) Is generated for a predetermined time (tfo) such that the instantaneous amplitude of the high drain voltage gradually decreases, and the output voltage VDC of the flyback is output to the output voltage VDC of the capacitor C1. It settles to the added drain voltage.

  When the MOS-FET Q1 is switched from on to off, theoretically, the drain current flowing through the MOS-FET Q1 is cut off at the moment when the MOS-FET Q1 is turned off, and the drain voltage applied to the MOS-FET Q1 is generated. Actually, when the MOS-FET Q1 is turned from ON to OFF, or when a drain current is instantaneously flowing through the MOS-FET Q1, a timing for applying a drain voltage to the MOS-FET Q1 occurs. At this time, electric power generated by multiplying the drain current and the drain voltage is generated in the MOS-FET Q1. Since the generated electric power is consumed as heat, it leads to power loss. Therefore, the higher the peak of the oscillation voltage generated in the drain voltage, the higher the power loss of the MOS-FET Q1. However, the leakage flux can be reduced by dividing the primary winding T1 and the secondary winding T2 of the transformer 500 into two and alternately forming winding layers, and the drain generated in the MOS-FET Q1. Since voltage oscillation (peak voltage) can be suppressed, power loss in the MOS-FET Q1 can be reduced.

This vibration waveform affects the voltage applied to other switching elements (for example, diodes D1 and D3), coils and capacitors (for example, capacitor C3) in addition to the MOS-FET Q1, and the vibration waveform becomes large. The power loss in each element increases.
Therefore, if the leakage inductor of the transformer 500 can be reduced, the vibration waveform generated when the MOS-FET Q1 is switched can be reduced, and the power loss in each element can be suppressed. Circuit efficiency can also be improved.

  In addition, although the case where the DC power supply circuit 220 of the present embodiment is a flyback method has been described, the DC power supply circuit 220 may be other methods such as a forward method.

  In the present embodiment, the primary winding T1 and the secondary winding T2 of the transformer 500 are each divided into two to form each layer. However, the primary winding T1 and the secondary winding are described. Each layer may be formed by dividing the line T2 into three or more.

  In view of efficiency, theoretically, it may be desirable that each layer of the primary winding T1 and the secondary winding T2 is wound in one row, but the number of layers increases, so that the manufacture is difficult, Manufacturing efficiency is inferior and manufacturing cost is high.

  Therefore, the number of turns of each layer (first primary layer P1, first secondary layer S1, second primary layer P2, second secondary layer S2) of primary winding T1 and secondary winding T2 is set to two rows. It is possible to obtain almost the same efficiency performance as when each layer of the primary winding T1 and the secondary winding T2 is wound in one row, and to suppress an increase in the number of layers (P1, P2, S1, S2). Manufacturing efficiency can be improved and manufacturing costs can be reduced.

  In the present embodiment, the number of turns of the (primary winding T1) of the first primary layer P1 and the second primary layer P2 is 15 turns, but it is other than 15 turns (less than 15 turns and more than 15 turns). It doesn't matter.

  In the present embodiment, the number of windings (secondary winding T2) of the first secondary layer S1 and the second secondary layer S2 is 14 turns, but other than 14 turns (less than 14 turns, more than 14 turns) ).

  Moreover, since the winding can be uniformly wound over the entire width of the bobbin 510 (the width from the flange portion 511a to the flange portion 511b), it is possible to easily wind the winding without any special equipment. The transformer 500 can be used.

  In the present embodiment, since the leakage inductance is particularly small, the case where the center core 522 has a cylindrical shape has been described. However, any shape such as a prismatic shape may be used.

  In the present embodiment, the case where the transformer 500 includes two E-type cores 520 has been described. However, a combination of an E-type core and an I-type core may be used.

Embodiment 2. FIG.
The present embodiment is a modification of the transformer of the first embodiment.
In the present embodiment, description of the same configuration as that of the first embodiment will be omitted, and a configuration of a transformer different from that of the first embodiment will be described.

FIG. 8 is a schematic diagram showing the relationship between the transformer windings of the present embodiment and the terminals to be connected.
In the first embodiment, the case where the primary winding T1 of the transformer 500 is wound from the terminal pin1 to the terminal pin3 to form the first primary layer P1 and the second primary layer P2 has been described.

  In the transformer 500a of this embodiment, the primary winding T1 is wound from the terminal pin1 to the terminal pin2 to form the first primary layer P1, and the primary winding T1 is wound from the terminal pin2 to the terminal pin3. The second primary layer P2 is configured.

  In this way, when the primary winding T1 is wound around the terminal pin2 and the first primary layer P1 and the second primary layer P2 are wound, the transformer 500a is further obtained while obtaining the same effect as in the first embodiment. Is easy to manufacture.

Embodiment 3 FIG.
The present embodiment is a modification of the transformer of the second embodiment.
In the present embodiment, description of the same configuration as that of the second embodiment will be omitted, and a configuration of a transformer different from that of the second embodiment will be described.

FIG. 9 is a schematic diagram showing the relationship between the transformer windings of the present embodiment and the terminals to be connected.
In the transformer 500b, the secondary winding T2 is wound from the terminal pin7 to the terminal pin8 to form the first secondary layer S1, and the secondary winding T2 is wound from the terminal pin8 to the terminal pin9, S2 is configured.

  As described above, when the secondary winding T2 is wound around the terminal pin8 and the first secondary layer S1 and the second secondary layer S2 are wound, the transformer 500b is further obtained while obtaining the same effect as in the second embodiment. Is easy to manufacture.

  As in the transformer 500 of FIG. 3 of the first embodiment, the primary winding T1 is wound from the terminal pin1 to the terminal pin3 to form the first primary layer P1 and the second primary layer P2. It doesn't matter.

Embodiment 4 FIG.
The present embodiment is a modification of the transformer of the first embodiment.
In this embodiment, since the structure of the lighting fixture and the circuit configuration of the switching power supply device are the same, the description thereof is omitted. Further, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted as appropriate, and the shape of the transformer different from that in the first embodiment will be described.

  10 is a schematic cross-sectional view showing an outline of the transformer of the present embodiment, FIG. 11 is a cross-sectional view showing a state where a winding is wound around the transformer of FIG. 10, and FIG. It is the schematic which shows the relationship between the coil | winding of a transformer and the terminal connected.

  The transformer 500c includes a bobbin 510, two E-type cores 520 inserted from the top and bottom of the bobbin 510, a primary winding T1 wound around the core 512 of the bobbin 510, and a first secondary winding T2a. The second secondary winding T2b and the feedback winding T3 have a wire diameter almost twice the wire diameter of the first secondary winding T2a.

  In the first secondary winding T2a connected to the terminal pin7 (winding start terminal) of the bobbin 510, first, a row of 20 turns is wound around the core part 512 of the bobbin 510 from the collar part 511a to the collar part 511b. , Connected to the terminal pin8 to form the first layer. This first layer is referred to as a third secondary layer S3.

  Next, the primary winding T1 connected to the terminal pin1 (winding start terminal) of the bobbin 510 so as to overlap with the third secondary layer S3 is arranged in a row with 14 turns from the flange part 511a to the flange part 511b of the bobbin 510. It is rolled and two rows are stacked to form the second layer. This second layer is referred to as a first primary layer P1.

  Further, the second secondary winding T2b connected to the terminal pin8 of the bobbin 510 is arranged in a row with 10 turns from the flange part 511a to the flange part 511b of the bobbin 510 so as to overlap the first primary layer P1. Are wound in two rows to form the third layer. This third layer is referred to as a first secondary layer S1.

  Further, the primary winding T1 wound around the first primary layer P1 is wound in two rows with 14 turns as one row from the flange portion 511a to the flange portion 511b of the bobbin 510 so as to overlap the first secondary layer S1. The third layer is formed and wound around the terminal pin3 (winding end terminal) of the bobbin 510. This fourth layer is referred to as a second primary layer P2.

  Further, two rows of 10 turns from the flange portion 511a to the flange portion 511b of the bobbin 510 so that the second secondary winding T2b wound around the first secondary layer S1 overlaps the second primary layer P2. It is wound to form the fifth layer, and is wound around the terminal pin9 (winding end terminal) of the bobbin 510. This fifth layer is referred to as a second secondary layer S2.

  Finally, the feedback winding T3 connected to the terminal pin5 (winding start terminal) of the bobbin 510 is wound 10 turns (one line) from the flange 511a to the flange 511b of the bobbin 510 so as to overlap the second secondary layer S2. Then, the sixth layer is formed and wound around the terminal pin4 (winding end terminal) of the bobbin 510. This sixth layer is called a feedback winding layer D.

  That is, the primary winding T1, the first secondary winding T2a, the second secondary winding T2b, and the feedback winding T3 are wound around the core portion 512 of the bobbin 510, and in order from the core portion 512, the third winding A secondary layer S3, a first primary layer P1, a first secondary layer S1, a second primary layer P2, a second secondary layer S2, and a feedback winding layer D are formed.

  It should be noted that the electrical connection of each layer is insulated between the third secondary layer S3, the first primary layer P1, the first secondary layer S1, the second primary layer P2, the second secondary layer S2, and the feedback winding layer D. Insulating tape is wound and has an insulating layer Z. Further, the transformer 500 has an insulating layer Zo around which an insulating tape is wound around the outer periphery of the feedback winding D.

  If attention is paid to the third secondary layer S3 and the first secondary layer S1 (second secondary layer S2), the third secondary layer S1 is wound in one row, and the first secondary layer S1 (second secondary layer S2) is wound. The wire is formed in two rows. The first secondary winding T2a forming the third secondary layer S3 is approximately half the wire diameter of the second secondary winding T2b forming the first secondary layer S1 (second secondary layer S2). is there. Therefore, the third secondary layer S3 and the first secondary layer S1 (second secondary layer S2) have the same number of turns.

  Since the current flowing through the secondary windings T2a and T2b is distributed to the secondary layers S1 to S3, the wire diameters of the windings are the third secondary layer S3 and the first secondary layer S1 (second secondary layer S2). There is no problem even if it changes.

  Further, the third secondary layer S3 is increased by one layer as compared with the transformer 500 of FIG. 5 of the first embodiment. This is because the primary layers P1 and P2 and the secondary layers S1 to S3 are excellent in transmission when the contact area is as large as possible, so that the primary winding T1 and the secondary windings T2a and T2b are well coupled. It is preferable to increase the number of divided winding layers. However, since the shape of the transformer 500c increases as the number of divided winding layers increases, the total of the primary layers P1 and P2 and the secondary layers S1 to S3 is preferably about 5 layers.

Embodiment 5 FIG.
The present embodiment is a modification of the transformer of the first embodiment.
In this embodiment, since the structure of the lighting fixture and the circuit configuration of the switching power supply device are the same, the description thereof is omitted. Further, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted as appropriate, and the shape of the transformer different from that in the first embodiment will be described.

FIG. 13 is a cross-sectional view showing a state in which a winding is wound around the transformer of the present embodiment.
The transformer 500d does not wind the feedback winding layer D to the full width of the bobbin 510 (from the flange portion 511a to the flange portion 511b), and has a gap d1 between the flange portions 511a and 511b. The larger the contact area between the feedback winding layer D and the second secondary layer S2, the easier it is to transmit the power of the secondary winding T2 to the feedback winding T3, but the coupling between the primary winding T1 and the secondary winding T2 As a result, a preferable voltage is also generated in the feedback winding T3. Therefore, there may be a gap d1 between the feedback winding T3 and the flange portions 511a and 511b.

Embodiment 6 FIG.
The present embodiment is a modification of the transformer of the fifth embodiment.
In the present embodiment, the same components as those in the fifth embodiment are denoted by the same reference numerals, description thereof will be omitted as appropriate, and the shape of the transformer different from that in the fifth embodiment will be described.

FIG. 14 is a cross-sectional view showing a state where a winding is wound around the transformer of the present embodiment.
The transformer 500e does not wind the feedback winding D layer to the full width of the bobbin 510 (from the flange part 511a to the flange part 511b), and has a gap d1 between the flange parts 511a and 511b.

  Further, the transformer 500e does not wind the first primary layer P1, the second primary layer P2, the first secondary layer S1, and the second secondary layer S2 to the full width of the bobbin 510 (from the flange portion 511a to the flange portion 511b). A gap d2 is provided between the flange portions 511a and 511b.

  The gaps d1 and d2 are provided to secure a predetermined insulation distance between the primary layers P1 and P2, the secondary layers S1 and S2, the feedback winding layer D, and the flange portions 511a and 511b of the bobbin 510.

  The coupling is improved by increasing the contact area of each primary layer P1, P2, each secondary layer S1, S2, and the feedback winding layer D, but there may be gaps d1, d2. At this time, each layer is provided with gaps d1 and d2, and the windings are wound closely without any gaps, so that the windings in the next row and the windings in the next layer can be easily wound, and the contact area can be easily increased. Can improve the bonding.

  DESCRIPTION OF SYMBOLS 1000 Lighting fixture, 100 main body, 200 Switching power supply device (power supply device), 210 AC / DC conversion circuit, 220 DC power supply circuit, 221 Current limiting circuit, 222 Control power supply circuit, 223 Switching control detection circuit, 224 Snubber circuit, 230 Starting circuit, 300 LED module, 310 Light emitting diode (LED), 320 LED substrate, 330 mounting part, 400 instrument cover, 500, 500a to 500e transformer, 510 bobbin, 511a, 511b collar part, 512 core part, 520 core, 521 outer core, 522 Center core, DB rectifier circuit, C1 capacitor, D1 diode, C10 electrolytic capacitor, R10 detection resistor, Q1 MOS-FET, IC control circuit, D1 diode, C2 control capacitor, D2 diode , D3 regenerative diode, R3 resistor, C3 capacitor, R1 starting resistor, AC AC power supply, Vcc control power supply, T1 primary winding, T2, T2a, T2b secondary winding, T3 feedback winding.

Claims (7)

In a power supply device using a transformer having a primary winding and a secondary winding,
The transformer is
A center core, a first primary layer in which the primary winding is wound in one or two rows with respect to the center core, and a first secondary layer in which the secondary winding is wound in two rows with respect to the first primary layer; The primary winding wound around the first primary layer is extended with respect to the first secondary layer, and further, the second primary layer wound in two rows, and the second primary layer with respect to the first primary layer. A secondary secondary layer in which the secondary winding wound around one secondary layer is extended and further wound in one or two rows;
A power supply device comprising: In a power supply device using a transformer having a primary winding and a secondary winding,
The transformer is
A center core, a third secondary layer in which the secondary winding is wound in one or two rows with respect to the center core, and a first primary layer in which the primary winding is wound in two rows with respect to the third secondary layer; The first secondary layer is extended from the secondary winding wound around the third secondary layer and further wound in two rows, and the first secondary layer, A second primary layer that is extended from the primary winding wound around the first primary layer and is further wound in two rows, and the second primary layer is wound around the first secondary layer. A second secondary layer extending from the secondary winding and further wound in one or two rows;
A power supply device comprising: The secondary winding has a first secondary winding and a second secondary winding having a wire diameter twice as large as the wire diameter of the first secondary winding,
The third secondary layer is wound with the first secondary winding,
The power supply device according to claim 2, wherein the first secondary layer and the second secondary layer are wound with a second secondary winding. The power supply device
A switching element connected to the primary winding of the transformer;
A control unit for controlling the switching of the switching element,
4. The power supply device according to claim 1, wherein the transformer includes a feedback winding wound around the center core and supplying power to the control unit. 5. The transformer has a bobbin having two flanges;
The power supply device according to any one of claims 1 to 4, wherein the primary winding and the secondary winding are wound up to the flange portion of the bobbin. The transformer has a bobbin having two flanges;
5. The power supply device according to claim 1, wherein the primary winding and the secondary winding are wound around the flange portion of the bobbin with a predetermined space therebetween. The power supply device according to any one of claims 1 to 6,
While this power supply device is attached, a main body that houses an LED module fed from the power supply device,
A lighting apparatus comprising:

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