JP2023160643A - Lighting device and emergency illumination device - Google Patents

Abstract

To stabilize the circuit operation while sharing circuit elements.SOLUTION: A lighting device 1 includes: an ordinary lighting circuit section 10; an emergency lighting circuit section 11; a charging circuit section 12; a switching circuit section 13; and a control circuit section 14. The switching circuit section 13 switches a power supply line W1 from the ordinary lighting circuit section 10 to an LED2 between a continuity state and a shut-down state. The control circuit section 14 controls the switching circuit section 13 to selectively switch the power supply line W1 between the continuity state and the shut-down state. The ordinary lighting circuit section 10 and the charging circuit section 12 share a transformer T1 and a switching element Q1. The ordinary lighting circuit section 10 is configured so as to operate, when the power supply line W1 is in the continuity state, to match the current flowing through the LED 2 to a target current, and when the power supply line W1 is in the shutdown state, to match output voltage V1 of the ordinary lighting circuit section 10 to the target voltage.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a lighting device and an emergency lighting fixture, and more particularly to a lighting device that controls a constant current supplied to a light source, and an emergency lighting fixture including the lighting device.

As a conventional example, a guide light device (emergency lighting device) and a light emitting device (lighting device) described in Patent Document 1 are illustrated. The light emitting device described in Patent Document 1 (hereinafter referred to as the conventional example) includes a DC/DC conversion circuit that generates DC power and lights up a light source using the generated DC power, and a DC/DC conversion circuit that detects the current flowing through the light source and outputs a feedback signal. and a current detection circuit that generates the current. The DC-DC conversion circuit adjusts the current value of the generated DC power based on the feedback signal generated by the current detection circuit. Thereby, the DC-DC conversion circuit operates as a constant current circuit that supplies a constant current to the light source.

Japanese Patent Application Publication No. 2012-003991

By the way, the light emitting device (lighting device) used in the guide light system can, in principle, turn on the light source both at all times (when the AC power supply is not out of power) and in emergencies (when the AC power supply is out of power). However, in exceptional cases, the light source may be turned off. For example, a light emitting device (lighting device) used in a guide light system installed at the entrance/exit of a movie theater turns off the light source of the guide light device while the charging circuit continues to charge the secondary battery while a movie is being shown. There are cases. However, even when the light source is turned off, the storage battery, which serves as an emergency power source, must continue to be charged.

In addition, in a lighting device, some circuit elements, such as a switching element that constitutes a switching power supply circuit, include a lighting circuit that is supplied with power from an AC power source to light the light source, and a charging circuit that is supplied with power from an AC power source and charges a storage battery. etc. may be shared. In such a case, the lighting circuit is subjected to constant current control when the light source is turned on, but if constant current control is continued when the light source is turned off, the circuit operation may become unstable.

An object of the present disclosure is to provide a lighting device and an emergency lighting fixture that can stabilize circuit operation while sharing circuit elements.

A lighting device according to one aspect of the present disclosure includes a regular lighting circuit section, an emergency lighting circuit section, a charging circuit section, a switching circuit section, and a control circuit section. The regular lighting circuit section lights up the light source using regular power supplied from a regular power source. The emergency lighting circuit section lights up the light source using emergency power supplied from an emergency power source. The charging circuit unit charges the emergency power source with the regular power. The switching circuit section switches a power supply path from the regular lighting circuit section to the light source between a conductive state and a cutoff state. The control circuit unit controls the switching circuit unit to selectively switch the power supply path between the conduction state and the cutoff state. The regular lighting circuit section and the charging circuit section share at least some circuit elements. The normal lighting circuit unit matches the current flowing through the light source with a target current when the power supply path is in the conduction state, and adjusts the output voltage of the normal lighting circuit unit when the power supply path is in the cutoff state. Operates to match the target voltage.

An emergency lighting device according to an aspect of the present disclosure includes a lighting device, the light source lit by the lighting device, the emergency power source, and a container housing the lighting device, the light source, and the emergency power source. Equipped with a body.

A lighting device and an emergency lighting fixture according to one aspect of the present disclosure have the effect of stabilizing circuit operation while sharing circuit elements.

FIG. 1 is an external perspective view of an emergency lighting device according to an embodiment of the present disclosure. FIG. 2 is an exploded perspective view of the emergency lighting device same as above. FIG. 3 is a circuit diagram of a lighting device according to an embodiment of the present disclosure. FIG. 4 is a circuit diagram of main parts including a current detection section and a voltage detection section in the above lighting device.

A lighting device 1 and an emergency lighting fixture A1 according to an embodiment of the present disclosure will be described in detail with reference to the drawings. However, each figure described in the following embodiments is a schematic diagram, and the respective ratios of the sizes and thicknesses of each component do not necessarily reflect the actual size ratios. Note that the configuration described in the embodiments below is only an example of the present disclosure. The present disclosure is not limited to the following embodiments, and various changes can be made depending on the design etc. as long as the effects of the present disclosure can be achieved.

(1) Overview The lighting device 1 according to the embodiment includes a regular lighting circuit section 10, an emergency lighting circuit section 11, a charging circuit section 12, a switching circuit section 13, and a control circuit section 14.

The regular lighting circuit section 10 lights up the light source (LED2) with the regular power supplied from the regular power source (commercial AC power source P1). The emergency lighting circuit section 11 lights up the LED 2 with emergency power supplied from an emergency power source (battery unit B1). The charging circuit section 12 charges the battery unit B1 with common power. The switching circuit unit 13 switches the power supply path W1 from the regular lighting circuit unit 10 to the LED 2 between a conductive state and a cutoff state. The control circuit unit 14 controls the switching circuit unit 13 to selectively switch the power supply path W1 between a conductive state and a cutoff state.

The regular lighting circuit section 10 and the charging circuit section 12 share at least some circuit elements (transformer T1, switching element Q1). The regular lighting circuit section 10 makes the current flowing through the LED 2 match the target current when the power supply path W1 is in a conductive state, and makes the output voltage V1 of the regular lighting circuit section 10 match the target current when the power supply path W1 is in a disconnected state. works to match.

In the lighting device 1 according to the embodiment, the regular lighting circuit section 10 and the charging circuit section 12 share some circuit elements (transformer T1, switching element Q1). always operate at the same timing. That is, when turning off the LED 2 while charging the battery unit B1, it is not possible to stop only the regular lighting circuit section 10 and operate the charging circuit section 12. Therefore, the lighting device 1 according to the embodiment can turn off the LED 2 while operating the charging circuit 12 and charging the battery unit B1 by switching the power supply path W1 to the cutoff state using the switching circuit 13.

Here, the regular lighting circuit section 10 continues to operate even while the power supply path W1 is in the cut-off state, and during this period, the regular lighting circuit section 10 operates to make the current flowing through the LED 2 match the target current. circuit operation is unstable.

Therefore, the lighting device 1 according to the embodiment operates the regular lighting circuit section 10 so that the output voltage V1 of the regular lighting circuit section 10 matches the target voltage when the power supply path W1 is in the cutoff state. As a result, the lighting device 1 according to the embodiment can stabilize the circuit operation of the regular lighting circuit section 10 while sharing some circuit elements between the regular lighting circuit section 10 and the charging circuit section 12.

Moreover, the emergency lighting fixture A1 according to the embodiment includes the lighting device 1 according to the embodiment and a light source (LED 2) lit by the lighting device 1 according to the embodiment. The emergency lighting fixture A1 according to the embodiment includes an emergency power source (battery unit B1), and a container body A10 that accommodates the lighting device 1, the LED 2, and the battery unit B1 according to the embodiment.

Since the emergency lighting fixture A1 according to the embodiment includes the lighting device 1 according to the embodiment, the regular lighting circuit section 10 and the charging circuit section 12 share some circuit elements, and the circuit operation of the regular lighting circuit section 10 is controlled. can be stabilized.

(2) Details of the emergency lighting fixture according to the embodiment The emergency lighting fixture A1 (hereinafter abbreviated as emergency lighting fixture A1) according to the embodiment will be described in detail with reference to the drawings. The emergency lighting fixture A1 described below is an evacuation exit guide light installed at an evacuation exit or a passageway to an evacuation exit of a building such as an office or a store. However, the emergency lighting equipment according to the embodiment is not limited to the evacuation exit guide light, and may, for example, be a stairway guide light installed in a stairwell in a building, or an emergency light installed on the ceiling of a room, etc. It doesn't matter. In the following description, unless otherwise specified, the vertical, longitudinal, and horizontal directions shown by arrows in FIG. 1 are defined as the vertical, longitudinal, and horizontal directions of the emergency lighting device A1.

The emergency lighting fixture A1 includes a lighting device 1 (hereinafter abbreviated as the lighting device 1) according to the embodiment, a vessel body A10, a light source unit A11, a display block A12, a battery unit B1, etc. (see FIGS. (see 2).

The container body A10 is made of a synthetic resin material and is formed into a rectangular box shape having an opening on the front surface (see FIG. 2). The container body A10 accommodates the lighting device 1, the battery unit B1, the terminal block 90, the mounting plate 91, and the like.

The mounting plate 91 is formed into a plate shape from a metal material (see FIG. 2). The mounting plate 91 is screwed to the inner bottom surface of the container body A10. The lighting device 1 and the terminal block 90 are screwed to a mounting plate 91 and housed in the housing A10. Further, the lighting device 1 and the terminal block 90 are electrically connected. The terminal block 90 is electrically connected to a power line drawn in from a power hole 96 (see FIG. 2) provided on the bottom of the container body A10. That is, the lighting device 1 is electrically connected to the commercial AC power source P1 through the terminal block 90 and the power line.

The battery unit B1 is detachably attached to the attachment plate 91. Note that the battery unit B1 is electrically connected to the lighting device 1 while being attached to the mounting plate 91.

The display block A12 includes a display panel 92, a light guide plate 93, and a holder 94 (see FIG. 2).

The display panel 92 is formed into a rectangular flat plate shape using a transparent synthetic resin material such as acrylic resin or polycarbonate resin. However, the display panel 92 may be formed of a translucent material other than synthetic resin, such as quartz glass. A pictogram 921 for evacuation guidance is displayed on the front surface (display surface 920) of the display panel 92 (see FIG. 1).

The light guide plate 93 is formed into a rectangular flat plate shape using a transparent synthetic resin material such as acrylic resin or polycarbonate resin. The light guide plate 93 is arranged behind the display panel 92 so that its front surface faces the rear surface of the display panel 92 (see FIG. 2). Light emitted from the light source unit A11 is incident on the upper surface (incidence surface 930) of the light guide plate 93. Light entering from the entrance surface 930 is guided through the light guide plate 93 and exits from the front surface of the light guide plate 93. Then, the display panel 92 is illuminated by the light emitted from the output surface of the light guide plate 93.

The holder 94 is made of a non-transparent synthetic resin material and is formed into a rectangular box shape (frame shape) with an open front and top surface. The holder 94 holds the display panel 92 and the light guide plate 93 so that the display panel 92 is placed in front of the light guide plate 93 (see FIG. 2).

The display block A12 is attached to the container body A10 so as to cover the remaining part of the opening of the container body A10 except for the upper part where the light source unit A11 is attached (see FIG. 1).

The light source unit A11 includes an LED 2 (see FIG. 3) serving as a light source, a light guide that guides light emitted from the LED 2, and a housing 95 that houses the LED 2 and the light guide. (see Figure 2).

The housing 95 is formed into a long box shape with an open bottom and rear surface. The LED 2 is mounted on a board and housed in one end (right end) of the housing 95 in the longitudinal direction. The light guide is formed in a long prismatic shape, with one end surface (right end surface) in the longitudinal direction facing the LED 2, and the side surface (lower surface) along the longitudinal direction facing the opening in the lower surface of the housing 95. It is housed in the casing 95 in a facing state. Note that a part of the board on which the LED 2 is mounted (hereinafter referred to as a protruding piece 97) protrudes from the rear surface of the housing 95 (see FIG. 2).

The light source unit A11 is attached to the container body A10 so as to be fitted into the upper front surface of the container body A10. At this time, by inserting and connecting the protruding piece 97 to the connector 98 installed at the upper right corner of the device body A10, the light source unit A11 (LED2) and the lighting device 1 are connected via the connector 98 and the electric wire (not shown). electrically connected.

Thus, in a state where the light source unit A11 is attached to the vessel body A10, the entrance surface 930 of the light guide plate 93 and the exit port of the light source unit A11 face each other in the vertical direction. Therefore, almost all of the light emitted from the exit of the light source unit A11 enters the light guide plate 93 from the incident surface 930 of the light guide plate 93. The light incident on the light guide plate 93 is totally reflected at the rear surface of the holder 94 while traveling through the light guide plate 93 and can be emitted forward from the output surface of the light guide plate 93 to illuminate the display panel 92 .

(3) Details of the lighting device according to the embodiment Next, the lighting device 1 will be described in detail with reference to the circuit diagrams of FIGS. 3 and 4.

The lighting device 1 includes a regular lighting circuit section 10, an emergency lighting circuit section 11, a charging circuit section 12, a switching circuit section 13, and a control circuit section 14. The lighting device 1 further includes a rectifier circuit 40, an input capacitor 41, a control power supply section 42, a power failure detection section 43, and the like.

Rectifier circuit 40 is a diode bridge. The rectifier circuit 40 performs full-wave rectification on an AC voltage (for example, a sine wave voltage with a frequency of 50 Hz or 60 Hz and an effective value of 100 V) input from the commercial AC power supply P1. The pulsating voltage output from the rectifier circuit 40 is smoothed by an input capacitor 41 made of an electrolytic capacitor. Then, the DC voltage smoothed by the input capacitor 41 is input to the regular lighting circuit section 10.

(3-1) Regular lighting circuit section The regular lighting circuit section 10 has a switching power supply circuit including a transformer T1, a switching element Q1, a diode D1, and a smoothing capacitor C1, a so-called isolated flyback converter.

The first end of the primary winding N11 of the transformer T1 is electrically connected to the high potential side terminal of the input capacitor 41, and the second end of the primary winding N11 is electrically connected to the drain terminal of the switching element Q1. be done. Switching element Q1 is an N-channel field effect transistor. The source terminal of switching element Q1 is electrically connected to the low potential side terminal of input capacitor 41. Further, a gate terminal of switching element Q1 is electrically connected to converter control section 30.

The transformer T1 has two secondary windings N21 and N22. One end of the one secondary winding N21 is electrically connected to the anode of the diode D1, and the other end of the one secondary winding N21 is electrically connected to the low potential side terminal of the smoothing capacitor C1. Further, the high potential side terminal of the smoothing capacitor C1 and the cathode of the diode D1 are electrically connected. Furthermore, the high potential side terminal of the smoothing capacitor C1 is electrically connected to the anode of the LED2 via the power supply path W1. Further, the low potential side terminal of the smoothing capacitor C1 is electrically connected to the cathode of the LED 2 via two detection resistors R21 and R22 electrically connected in series. That is, the voltage across the smoothing capacitor C1 becomes the output voltage V1 of the switching power supply circuit (normal lighting circuit section 10).

Converter control section 30 is composed of an integrated circuit. Converter control unit 30 performs feedback control, specifically PWM (pulse width modulation) control, on switching element Q1 so that the current flowing through LED 2 matches the first target value. However, converter control section 30 and switching element Q1 may be configured as one integrated circuit.

The current flowing through the LED 2 is detected by a current detection section 44 included in the feedback circuit. The current detection unit 44 outputs a voltage (first detection voltage Vx1) proportional to the current flowing through the LED 2 by differentially amplifying the voltage across the detection resistor R21 on the high potential side.

The first detection voltage Vx1 is input to the reference terminal of the shunt regulator U1 included in the feedback circuit. The anode terminal of the shunt regulator U1 is electrically connected to the low potential side terminal of the smoothing capacitor C1. A cathode terminal of the shunt regulator U1 is electrically connected to a low potential side input terminal of a photocoupler 31 and one end of a resistor R2, which are also included in the feedback circuit. A high potential side input terminal of the photocoupler 31 is electrically connected to the other end of the resistor R2 and one end of the resistor R1. The other end of the resistor R1 is electrically connected to a constant voltage circuit 32 included in the feedback circuit. Note that the resistor R2 connected between the two input terminals of the photocoupler 31 plays a role in causing the minimum cathode current to flow through the shunt regulator U1.

Thus, when the cathode current flowing into the cathode terminal is equal to or higher than the minimum cathode current, the shunt regulator U1 becomes conductive, and a forward current flows through the light emitting diode of the photocoupler 31. The forward current flowing through the light emitting diode is proportional to the voltage value of the first detection voltage Vx1 (the magnitude of the current flowing through the LED 2). Further, the output current of the photocoupler 31 (collector current of the phototransistor) is proportional to the forward current of the light emitting diode.

Here, the output terminal of photocoupler 31 is electrically connected to converter control section 30 through capacitor C3. That is, the output current of the photocoupler 31 is converted into a voltage (feedback signal Vfb) by the capacitor C3 and input to the converter control section 30.

Accordingly, the converter control unit 30 feedback-controls the switching element Q1 in accordance with the feedback signal Vfb input through the photocoupler 31 so that the first detection voltage Vx1, which is proportional to the current flowing through the LED 2, matches the target voltage. . As a result, the regular lighting circuit section 10 can make the current flowing through the LED 2 match the first target value.

(3-2) Current Detection Unit The current detection unit 44 includes an amplifier circuit 440 that differentially amplifies the voltage across the resistor R21 electrically connected in series with the LED 2 for the regular lighting circuit unit 10; A buffer circuit 441 provided on the output side (see FIG. 4).

The amplifier circuit 440 includes an operational amplifier OP1, four resistors R31, R32, R33, and R34, two capacitors C31 and C32, and the like.

The non-inverting input terminal (plus terminal) of the operational amplifier OP1 is electrically connected to the connection point between the cathode of the LED2 and the resistor R21 via the resistor R31. Further, a positive terminal of the operational amplifier OP1 is electrically connected to one end of a resistor R33 and a capacitor C31, respectively. Note that the other ends of the resistor R33 and the capacitor C31 are electrically connected to the ground of the circuit (one end on the low potential side of the resistor R22).

An inverting input terminal (minus terminal) of the operational amplifier OP1 is electrically connected to a connection point between two resistors R21 and R22 via a resistor R32. Further, the negative terminal of the operational amplifier OP1 is electrically connected to the output terminal of the operational amplifier OP1 via a resistor R34. Further, a capacitor C32 is electrically connected in parallel with a resistor R34 between the negative terminal and the output terminal of the operational amplifier OP1.

Here, assuming that the resistance values of the two input resistors R31 and R32 are equal, and the resistance values of the resistor R33 and feedback resistor R34 are equal, the output voltage of the operational amplifier OP1 is determined by the resistance ratio of the input resistor R32 and the feedback resistor R34. This is the voltage multiplied by the voltage across the resistor R21. In other words, the amplifier circuit 440 can differentially amplify the voltage across the resistor R21.

The buffer circuit 441 includes a voltage follower circuit in which the output terminal and the negative terminal of the operational amplifier OP2 are electrically connected, and a diode D31 whose anode is electrically connected to the output terminal of the operational amplifier OP2. Note that the output terminal of the buffer circuit 441 (the cathode of the diode D31) is electrically connected to the reference terminal of the shunt regulator U1 via a resistor R4.

Thus, by electrically connecting the output terminal of the amplifier circuit 440 to the reference terminal of the shunt regulator U1 through the buffer circuit 441, the current detection unit 44 suppresses fluctuations in the first detection voltage Vx1 while increasing the voltage of the shunt regulator U1. A necessary and sufficient current can be supplied to the reference terminal.

(3-3) Charging Circuit Section The charging circuit section 12 has a switching power supply circuit including a transformer T1, a switching element Q1, a diode D2, and a smoothing capacitor C2, a so-called isolated flyback converter. However, the charging circuit section 12 shares the transformer T1 and the switching element Q1 with the regular lighting circuit section 10.

One end of the other secondary winding N22 of the transformer T1 is electrically connected to the anode of the diode D2, and the other end of the secondary winding N22 is electrically connected to the low potential side terminal of the smoothing capacitor C2. Further, the high potential side terminal of the smoothing capacitor C2 and the cathode of the diode D2 are electrically connected. Further, the high potential side terminal of the smoothing capacitor C2 is electrically connected to the constant voltage circuit 32, the constant current circuit 33, and the power failure detection section 43. Further, the low potential side terminal of the smoothing capacitor C2 is electrically connected to the cathode of the LED 2 via two detection resistors R21 and R22. That is, the voltage across the smoothing capacitor C2 becomes the output voltage V2 of the switching power supply circuit (charging circuit section 12). Note that the voltage required to charge the storage battery (battery unit B1) that is the load of the charging circuit section 12 is higher than the forward voltage when the LED 2 is turned on. Therefore, the number of turns of the secondary winding N22 is greater than the number of turns of the secondary winding N21, and the output voltage V2 of the charging circuit section 12 is higher than the output voltage V1 of the regular lighting circuit section 10.

The constant current circuit 33 uses the voltage across the smoothing capacitor C2 (output voltage V2 of the charging circuit section 12) as a power source to supply a constant charging current to the battery unit B1. The battery unit B1 is charged with a charging current supplied from the constant current circuit 33.

(3-4) Voltage Detection Unit The voltage detection unit 45 outputs a second detection voltage Vx2 proportional to the output voltage V1 of the regular lighting circuit unit 10. The second detection voltage Vx2 is input to the reference terminal of the shunt regulator U1. However, the voltage detection unit 45 is configured to make the second detection voltage Vx2 lower than the first detection voltage Vx1 when the regular lighting circuit unit 10 lights the LED 2.

The voltage detection unit 45 includes a constant voltage element 450 and a resistor 451 that are electrically connected in series between the output terminals of the regular lighting circuit unit 10, and a buffer circuit 452 that receives the voltage across the resistor 451 as an input (see FIG. (see 4). Constant voltage element 450 is a Zener diode. The cathode of the Zener diode, which is the constant voltage element 450, is electrically connected to the high potential side output terminal of the regular lighting circuit section 10, and the anode is connected to the low potential side output terminal of the regular lighting circuit section 10 via the resistor 451. electrically connected. Further, a capacitor 453 is electrically connected to the resistor 451 in parallel. The voltage detection section 45 uses a voltage obtained by dividing the output voltage V1 of the regular lighting circuit section 10 by a voltage dividing circuit including a constant voltage element 450 and a resistor 451 as a second detection voltage Vx2. Note that the second detection voltage Vx2 is the voltage obtained by subtracting the voltage across the constant voltage element 450 (Zener voltage) from the output voltage V1 of the regular lighting circuit section 10, so if the output voltage V1 is a constant voltage, it is a constant voltage. Become.

The buffer circuit 452 includes a voltage follower circuit in which the output terminal and the negative terminal of the operational amplifier OP3 are electrically connected, and a diode D32 whose anode is electrically connected to the output terminal of the operational amplifier OP3. Note that the output terminal of the buffer circuit 452 (the cathode of the diode D32) is electrically connected to the reference terminal of the shunt regulator U1 via a resistor R4.

Thus, the voltage detection unit 45 suppresses fluctuations in the second detection voltage Vx2 by electrically connecting the connection point between the constant voltage element 450 and the resistor 451 to the reference terminal of the shunt regulator U1 through the buffer circuit 452. A necessary and sufficient current can be supplied to the reference terminal of the shunt regulator U1.

(3-5) Emergency lighting circuit section The emergency lighting circuit section 11 has a flyback converter equipped with a transformer and a switching element, and a converter control circuit that controls switching of the switching element, and is supplied from the battery unit B1. The DC voltage is boosted or stepped down and output. However, the emergency lighting circuit section 11 may include a forward converter instead of the flyback converter.

The high potential side output terminal of the emergency lighting circuit section 11 is electrically connected to the anode of the LED 2, and the low potential side output terminal of the emergency lighting circuit section 11 is electrically connected to the low potential side terminal of the detection resistor R22. connected to.

The converter control circuit takes in the voltage across the detection resistor R22 (third detection voltage Vx3) that is proportional to the current flowing through the LED 2, and performs feedback control on the switching element so that the magnitude of the current flowing through the LED 2 matches the second target value. (PWM control). However, the second target value of the emergency lighting circuit section 11 is a value smaller than the first target value of the regular lighting circuit section 10.

(3-6) Switching Circuit Unit The switching circuit unit 13 includes a drive circuit 130, a switching element 131, a capacitor 132, a resistor 133, a switching element 134, a diode D3, and the like.

Switch element 131 is a P-channel field effect transistor. A source terminal of the switch element 131 is electrically connected to a high potential side output terminal of the regular lighting circuit section 10 (a high potential side terminal of the smoothing capacitor C1). A drain terminal of the switch element 131 is electrically connected to the anode of the LED 2 via a diode D3. That is, the switch element 131 is inserted into the power supply path W1, and can selectively switch the power supply path W1 between a conductive state and a cutoff state.

Capacitor 132 and resistor 133 are electrically connected in parallel between the source terminal and gate terminal of switch element 131. That is, since the voltage across the capacitor 132 is applied between the source terminal and the gate terminal of the switch element 131, the impedance between the drain and source of the switch element 131 decreases as the voltage across the capacitor 132 increases.

The drive circuit 130 includes two transistors TR1 and TR2 and two resistors R11 and R12. The two transistors TR1 and TR2 are both pnp type bipolar transistors. The emitter of one transistor TR1 is electrically connected to the gate terminal of the switch element 131. The collector of transistor TR1 is electrically connected to the base of the other transistor TR2. The base of the transistor TR1 is electrically connected to the emitter of the transistor TR2 and one end of the resistor R11. The other end of the resistor R11 is electrically connected to the gate terminal of the switch element 131. The collector of the other transistor TR2 is electrically connected to the low potential side terminal of the detection resistor R22.

The drive circuit 130 configured as described above functions as a constant current circuit that causes a constant current to flow through the capacitor 132 or the resistor 133.

The switching element 134 is an npn type bipolar transistor. The collector of the switching element 134 is electrically connected to the collector of the transistor TR1 and the base of the transistor TR2 via a resistor R12. The emitter of the switching element 134 is electrically connected to the collector of the transistor TR2 and the low potential terminal of the detection resistor R22. A base of the switching element 134 is electrically connected to the control circuit section 14 . That is, the switching element 134 is turned on and off by the control circuit section 14 as described later. While the switching element 134 is on, the drive circuit 130 operates to maintain the switching element 131 in the on state (conducting state). On the other hand, while the switching element 134 is off, the drive circuit 130 is stopped and the switching element 131 is maintained in the off state (blocking state).

(3-7) Control circuit section The control circuit section 14 includes a microcontroller. The control circuit unit 14 operates by being supplied with a control voltage Vcc from the control power supply unit 42. The control power supply section 42 has a three-terminal regulator 420. The control power supply unit 42 is supplied with power from the charging circuit unit 12 and outputs the control voltage Vcc when the commercial AC power supply P1 is not out of power and the charging circuit unit 12 is operating. Furthermore, when the commercial AC power supply P1 is out of power and the emergency lighting circuit section 11 is operating, the control power supply section 42 is supplied with power from the emergency lighting circuit section 11 and outputs the control voltage Vcc.

The control circuit section 14 receives a power outage detection signal from the power outage detection section 43. The power failure detection section 43 includes a Zener diode ZD1 and a resistor R31. The cathode terminal of the Zener diode ZD1 is electrically connected to the high potential side output terminal of the charging circuit section 12 (the high potential side terminal of the smoothing capacitor C2). The anode terminal of Zener diode ZD1 is electrically connected to the negative electrode of battery unit B1 via resistor R31. In other words, when the commercial AC power supply P1 is not out of power and the charging circuit section 12 is operating, the Zener diode ZD1 is conductive and the voltage across the resistor R31 exceeds the threshold value, so the output of the power outage detection section 43 is The voltage becomes high level. On the other hand, when the commercial AC power supply P1 is out of power and the charging circuit section 12 is not operating, the Zener diode ZD1 is not conductive and the voltage across the resistor R31 becomes zero, so the output voltage of the power outage detection section 43 is at a low level. becomes.

When the output signal of the power outage detection unit 43 is at a high level, the control circuit unit 14 determines that the commercial AC power supply P1 has not experienced a power outage, and operates in the normal operation mode. On the other hand, when the output signal of the power outage detection section 43 is at a low level, the control circuit section 14 determines that the commercial AC power supply P1 is out of power and operates in an emergency operation mode.

In the normal operation mode, the control circuit section 14 instructs the converter control section 30 to operate the normal lighting circuit section 10 and the charging circuit section 12, and turns on the switching element 134 to turn on the switching circuit section 13. (Switch element 131 is turned on). Note that the control circuit section 14 maintains the emergency lighting circuit section 11 in a stopped state in the normal operation mode. Thus, the LED 2 is turned on by the regular lighting circuit section 10 (normal lighting), and the battery unit B1 is charged by the charging circuit section 12.

In the emergency operation mode, the control circuit section 14 operates the emergency lighting circuit section 11, turns off the switching element 134, and switches the switching circuit section 13 to a cut-off state (switch element 131 is turned off). Note that the regular lighting circuit section 10 and the charging circuit section 12 enter a stopped state when the power supply from the commercial AC power source P1 is stopped. The LED 2 is then turned on (emergency lighting) by the emergency lighting circuit section 11.

By the way, in the lighting device 1 used for the emergency lighting device A1, there is a desire to turn off the LED 2 while operating the charging circuit section 12 when the commercial AC power source P1 is not out of power. Note that the Fire Service Act Enforcement Regulations, Article 28-3, Paragraph 4, Item 2 and the Guidelines state that guide lights, which are a type of emergency lighting equipment, can be turned off in places where darkness is required depending on the type of use. Directional lights are permitted to be turned off during performance hours at movie theaters.

Therefore, the control circuit section 14 has an operation mode in which the lights are turned off at all times, in addition to normal and emergency operation modes. When the control circuit unit 14 receives a lights-off signal from the signaling device in the normal-use operating mode, the control circuit unit 14 shifts from the normal-use operating mode to the always-off operation mode. Note that when the control circuit unit 14 receives a lighting signal from the signaling device in the always-off operation mode, it returns from the always-off operation mode to the normal operation mode.

In the always-off operation mode, the control circuit unit 14 instructs the converter control unit 30 to operate the regular lighting circuit unit 10 and the charging circuit unit 12, and turns off the switching element 134 to place the switching circuit unit 13 in the cut-off state. (switch element 131 is turned off). That is, since the regular lighting circuit section 10 and the charging circuit section 12 share one switching element Q1, when the charging circuit section 12 is operated, the regular lighting circuit section 10 also operates. However, since the switching circuit unit 13 switches the power supply path W1 to the cutoff state, the LED 2 is not turned on by the regular lighting circuit unit 10. Further, since the control circuit section 14 maintains the emergency lighting circuit section 11 in a stopped state, the LED 2 is not turned on by the emergency lighting circuit section 11. Therefore, when the control circuit section 14 operates in the always-off operation mode, the LED 2 can be turned off while continuing to charge the battery unit B1.

(4) Advantages of the lighting device according to the embodiment As described above, when the control circuit unit 14 operates in the normal operation mode, the feedback circuit outputs the feedback signal Vfb corresponding to the first detection voltage Vx1. do. Therefore, converter control section 30 performs PWM control on switching element Q1 according to first detection voltage Vx1 instead of second detection voltage Vx2.

On the other hand, when the control circuit section 14 operates in the always-off operation mode, the first detection voltage Vx1 is zero, so the feedback circuit outputs the feedback signal Vfb corresponding to the second detection voltage Vx2. Therefore, converter control section 30 performs PWM control on switching element Q1 according to second detected voltage Vx2.

However, when the switching circuit section 13 interrupts the power supply path W1 while causing the charging circuit section 12 to continue charging the battery unit B1 as described above, the power output from the regular lighting circuit section 10 is not supplied to the LED 2. . Therefore, when the converter control section 30 performs feedback control according to the first detection voltage Vx1 of the current detection section 44, the circuit operation becomes unstable and the output voltage V1 of the regular lighting circuit section 10 increases more than necessary. There is a possibility that it will happen.

Therefore, when the power supply path W1 is cut off by the switching circuit section 13, the converter control section 30 detects the output voltage V1 of the regular lighting circuit section 10 with the voltage detection section 45, and detects the second output voltage V1 detected by the voltage detection section 45. Feedback control is performed to match the output voltage V1 to the target voltage according to the detected voltage Vx2. Thereby, the lighting device 1 avoids that the output voltage V1 of the regular lighting circuit section 10 increases more than necessary when the LED 2 is turned off, and allows the regular lighting circuit section 10 and the charging circuit section 12 to It is possible to stabilize the circuit operation of the regular lighting circuit section 10 while sharing the same. Note that when the lighting device 1 receives a lighting signal from the outside, the control circuit unit 14 controls the switching circuit unit 13 to switch the power supply path W1 from the cutoff state to the conduction state, so the operation mode of the control circuit unit 14 is changed. can be controlled remotely.

However, in order to make the output voltage V2 of the charging circuit section 12 higher than the voltage required for charging the battery unit B1 when the LED 2 is turned off (when the power supply path W1 is cut off), the converter control section 30 sets the second detection voltage Vx2 to the output voltage V2 of the charging circuit section 12. It is preferable that the target value of the output voltage V1 when feedback control is performed accordingly be higher than the voltage value of the output voltage V1 when feedback control is performed according to the first detection voltage Vx1. Thereby, the lighting device 1 can maintain the output voltage V2 of the charging circuit section 12 at a level necessary and sufficient for charging the battery unit B1 while suppressing the output voltage V1 of the regular lighting circuit section 10 from increasing excessively. I can do it.

Here, the output terminal of the current detection section 44 (output terminal of the buffer circuit 441) and the output terminal of the voltage detection section 45 (output terminal of the buffer circuit 452) are electrically connected to the reference terminal of the shunt regulator U1 via the resistor R4. (See Figure 4). That is, converter control section 30 controls switching of switching element Q1 based on the higher detection voltage of first detection voltage Vx1 and second detection voltage Vx2. The voltage detection unit 45 is configured to set the second detection voltage Vx2 to be lower than the first detection voltage Vx1 output from the current detection unit 44 when the control circuit unit 14 is operating in the normal operation mode. It is configured. However, when the switching circuit section 13 switches the power supply path W1 to the cutoff state, the first detection voltage Vx1 of the current detection section 44 becomes zero, so the second detection voltage Vx2 becomes higher than the first detection voltage Vx1. . As a result, converter control section 30 controls switching of switching element Q1 based on first detection voltage Vx1 when control circuit section 14 is operating in the normal operation mode. On the other hand, when the control circuit section 14 operates in the always-off operation mode, the converter control section 30 performs switching control on the switching element Q1 based on the second detection voltage Vx2.

Therefore, since the lighting device 1 causes the converter control unit 30 to perform switching control on the switching element Q1 based on the higher voltage of the first detection voltage Vx1 and the second detection voltage Vx2, the circuit configuration can be simplified. I can do it.

In addition, the current detection section 44 differentially amplifies the voltage (first detection voltage Vx1) proportional to the current supplied to the LED 2 from the regular lighting circuit section 10 in the amplifier circuit 440, so that the rated current of the LED 2 is relatively low. Even when the current is small, the current detection accuracy can be improved. Moreover, since the current detection unit 44 is provided with a buffer circuit 441 on the output side of the amplifier circuit 440, the influence on the first detection voltage Vx1 when connected to another circuit (shunt regulator U1) is reduced and detected. Further improvement in accuracy can be achieved.

Further, the voltage detection section 45 includes a constant voltage element 450 and a resistor 451 that are electrically connected in series between the output terminals of the regular lighting circuit section 10, and a buffer circuit 452 that receives the voltage across the resistor 451 as input. . Therefore, by providing the buffer circuit 452 in the voltage detection section 45, the lighting device 1 reduces the influence on the second detection voltage Vx2 when connected to another circuit (shunt regulator U1) and improves detection accuracy. It is possible to achieve further improvements.

(5) Summary The lighting device (1) according to the first aspect of the present disclosure includes a regular lighting circuit section (10), an emergency lighting circuit section (11), a charging circuit section (12), and a switching circuit section. (13) and a control circuit section (14). The regular lighting circuit section (10) lights up the light source (LED2) with the regular power supplied from the regular power source (commercial AC power source P1). The emergency lighting circuit unit (11) lights up the light source with emergency power supplied from an emergency power source (battery unit B1). The charging circuit section (12) charges the emergency power source with regular power. The switching circuit section (13) switches the power supply path (W1) from the regular lighting circuit section (10) to the light source between a conductive state and a cutoff state. The control circuit unit (14) controls the switching circuit unit (13) to selectively switch the power supply path (W1) between a conductive state and a cutoff state. The regular lighting circuit section (10) and the charging circuit section (12) share at least some circuit elements (transformer T1, switching element Q1). The regular lighting circuit section (10) matches the current flowing through the light source with the target current when the power supply path (W1) is in a conductive state, and adjusts the current flowing through the light source to match the target current when the power supply path (W1) is in a cutoff state. ) to match the output voltage (V1) with the target voltage.

The lighting device (1) according to the first aspect stabilizes the circuit operation of the regular lighting circuit section (10) while sharing some circuit elements between the regular lighting circuit section (10) and the charging circuit section (12). can be achieved.

The lighting device (1) according to the second aspect of the present disclosure can be realized in combination with the first aspect. In the lighting device (1) according to the second aspect, the regular lighting circuit section (10) includes a switching power supply circuit including a switching element (Q1), and a control circuit (converter control section 30) that controls switching of the switching element (Q1). ), a current detection section (44), and a voltage detection section (45). The current detection section (44) preferably outputs a first detection voltage (Vx1) corresponding to the magnitude of the current supplied to the light source. It is preferable that the voltage detection section (45) outputs a second detection voltage (Vx2) corresponding to the magnitude of the output voltage (V1) of the switching power supply circuit. The second detection voltage (Vx2) output by the voltage detection section (45) is lower than the first detection voltage (Vx1) when the light source is on, and the first detection voltage when the light source is off. It is preferable that the voltage is higher than the voltage (Vx1). It is preferable that the control circuit performs switching control on the switching element (Q1) based on the higher detection voltage of the first detection voltage (Vx1) and the second detection voltage (Vx2).

The lighting device (1) according to the second aspect causes the control circuit to control switching of the switching element (Q1) based on the higher voltage of the first detection voltage (Vx1) and the second detection voltage (Vx2). , the circuit configuration can be simplified.

The lighting device (1) according to the third aspect of the present disclosure can be realized in combination with the second aspect. In the lighting device (1) according to the third aspect, the current detection unit (44) differentially detects the voltage across the resistor (R21) electrically connected in series with the light source with respect to the regular lighting circuit unit (10). It is preferable to include an amplifier circuit (440) for amplification and a buffer circuit (441) provided on the output side of the amplifier circuit (440).

The lighting device (1) according to the third aspect can improve the accuracy of current detection by the current detection section (44) even when the rated current of the light source is relatively small.

The lighting device (1) according to the fourth aspect of the present disclosure can be realized in combination with the second or third aspect. In the lighting device (1) according to the fourth aspect, the voltage detection section (45) includes a constant voltage element (450) and a resistor (451) electrically connected in series between the output terminals of the regular lighting circuit section (10). ) and a buffer circuit (452) that receives the voltage across the resistor (451) as input.

The lighting device (1) according to the fourth aspect can further improve detection accuracy by the voltage detection section (45).

The lighting device (1) according to the fifth aspect of the present disclosure can be realized in combination with any one of the first to fourth aspects. In the lighting device (1) according to the fifth aspect, the control circuit section (14) controls the switching circuit section (13) while operating the charging circuit section (12) when receiving the lights-off signal from the outside. It is preferable to switch the power supply path (W1) from a conductive state to a cutoff state. When the control circuit section (14) receives a lighting signal from the outside, it is preferable that the control circuit section (14) controls the switching circuit section (13) to switch the power supply path (W1) from the cutoff state to the conduction state.

The lighting device (1) according to the fifth aspect can remotely control the operation mode of the control circuit section (14).

An emergency lighting fixture (A1) according to a sixth aspect of the present disclosure includes a lighting device (1) according to any one of the first to fifth aspects, a light source lit by the lighting device (1), and an emergency lighting device (A1) according to a sixth aspect of the present disclosure. A container body (A10) that accommodates a lighting device (1), a light source, and an emergency power source.

The emergency lighting device (A1) according to the sixth aspect shares some circuit elements between the regular lighting circuit section (10) and the charging circuit section (12), and controls the circuit operation of the regular lighting circuit section (10). Stabilization can be achieved.

A1 Emergency lighting equipment A10 Body B1 Battery unit (emergency power supply)
W1 Power supply path P1 Commercial AC power supply (normal power supply)
Q1 Switching element (switching power supply circuit)
T1 Transformer V1 Output voltage of regular lighting circuit section Vx1 First detection voltage Vx2 Second detection voltage R21 Resistor 1 Lighting device 2 LED (light source)
10 Normal lighting circuit section 11 Emergency lighting circuit section 12 Charging circuit section 13 Switching circuit section 14 Control circuit section 30 Converter control section (control circuit)
44 Current detection unit 45 Voltage detection unit 440 Amplification circuit 441 Buffer circuit 450 Constant voltage element 451 Resistor 452 Buffer circuit

Claims (6)

a regular lighting circuit section that lights up the light source with regular power supplied from a regular power supply;
an emergency lighting circuit unit that lights up the light source with emergency power supplied from an emergency power source;
a charging circuit unit that charges the emergency power source with the regular power;
a switching circuit unit that switches a power supply path from the regular lighting circuit unit to the light source between a conductive state and a cutoff state;
a control circuit unit that controls the switching circuit unit to selectively switch the power supply path between the conduction state and the cutoff state;
Equipped with
The regular lighting circuit section and the charging circuit section share at least some circuit elements,
The normal lighting circuit unit matches the current flowing through the light source with a target current when the power supply path is in the conduction state, and adjusts the output voltage of the normal lighting circuit unit when the power supply path is in the cutoff state. operates to match the target voltage,
lighting device. The regular lighting circuit section is
a switching power supply circuit including a switching element;
a control circuit that controls switching of the switching element;
a current detection unit that outputs a first detection voltage corresponding to the magnitude of the current supplied to the light source;
a voltage detection unit that outputs a second detection voltage corresponding to the magnitude of the output voltage of the switching power supply circuit;
has
The second detection voltage output by the voltage detection section is lower than the first detection voltage when the light source is on, and lower than the first detection voltage when the light source is off. high,
The control circuit controls switching of the switching element based on the higher detection voltage of the first detection voltage and the second detection voltage.
The lighting device according to claim 1. The current detection section includes:
an amplifier circuit that differentially amplifies a voltage across a resistor electrically connected in series with the light source for the regular lighting circuit section;
a buffer circuit provided on the output side of the amplifier circuit;
has,
The lighting device according to claim 2. The voltage detection section is
a constant voltage element and a resistor electrically connected in series between the output terminals of the regular lighting circuit section;
a buffer circuit whose input is the voltage across the resistor;
has,
The lighting device according to claim 2 or 3. When the control circuit unit receives a light-off signal from the outside, the control circuit unit operates the charging circuit unit and controls the switching circuit unit to switch the power supply path from the conduction state to the cut-off state, and receives a light-off signal from the outside. is received, controlling the switching circuit unit to switch the power supply path from the cutoff state to the conduction state;
The lighting device according to any one of claims 1 to 3. A lighting device according to any one of claims 1 to 3,
the light source lit by the lighting device;
the emergency power source;
a container housing the lighting device, the light source, and the emergency power source;
Equipped with
Emergency lighting equipment.

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