JP2006196318A - Lighting device and luminaire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure various control of a lighting device by a low power supply voltage detection circuit by preventing the operation of the low power supply voltage detection circuit after power shutdown to be improperly delayed to allow the power shutdown to be surely detected in a short time when various kinds of control of the lighting device are executed by detecting drop of an output voltage of a full-wave rectifier circuit in power-off. <P>SOLUTION: This lighting device comprises: the full-wave rectifier circuit DB for full-wave rectifying commercial AC power supply AC; a lighting circuit for lighting and controlling a lamp La by receiving the output voltage of the full-wave rectifier circuit DB; a capacitor C4 connected between output ends of the full-wave rectifier circuit DB; and the low power supply voltage detection circuit 2 for detecting drop of the output voltage of the full-wave rectifier circuit DB. In the lighting device, a path for grounding one end or both ends of an input-side line of the full-wave rectifier circuit DB through one or more capacitive elements C5 and C6 is formed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a lamp lighting device, and more particularly to an improvement of a lighting device that can be used as a commercial power source in combination of a three-wire power source or a four-wire power source and a one-way switch.

  As a lighting device that uses a commercial power supply as a power source and controls lighting of a lamp (for example, a discharge lamp), the power supply voltage of the commercial power supply is detected and the power supply voltage is abnormally lowered, or the power is cut off by a switch means. Some of them detect the lamp and control various lamps. A typical example is shown in FIG. In this lighting device, the commercial power source AC is connected to the input end of the line filter LF1 via the power switch element SW. The input end of the full-wave rectifier circuit DB is connected to the output end of the line filter LF1 via the normal filter LF2.

  A filter capacitor C4 is connected to the output terminal of the full-wave rectifier circuit DB. Further, a ground circuit that is grounded to the ground is connected to one end of the full-wave rectifier circuit DB through a series circuit of two capacitors C5 and C6. Further, a chopper circuit including an inductor L1, a switching element Q3, a rectifier diode D1, and an electrolytic capacitor C1 is connected to the output terminal of the full-wave rectifier circuit DB.

  The chopper circuit converts the output pulsating voltage of the full-wave rectifier circuit DB into a DC voltage, and generates a smoothed DC voltage at both ends of the electrolytic capacitor C1. The DC voltage is converted into a high-frequency AC voltage by an inverter circuit including switching elements Q1 and Q2 and a coupling capacitor C2, and further a discharge lamp as a load via a resonance circuit including an inductor L2 and a capacitor C3. Electric power is supplied to La, and the discharge lamp La is lit at a high frequency.

  The inverter control unit 1 supplies driving signals to the switching element Q3 constituting the chopper circuit and the switching elements Q1 and Q2 constituting the inverter circuit, and controls the driving of the chopper circuit and the inverter circuit.

  A voltage dividing circuit using resistors R1 and R2 is connected to the output terminal of the full-wave rectifier circuit DB, and the output voltage value of the full-wave rectifier circuit DB is monitored by monitoring the divided voltage with the low power supply voltage detection circuit 2. Is monitoring. In the lighting device provided with such a low power supply voltage detection circuit 2, for example, a stop signal is generated in the inverter control unit 1 by detecting a decrease in the output voltage of the full-wave rectification circuit DB, and the discharge lamp La is supplied to the discharge lamp La. By stopping the supply of power, circuit protection is realized when the power supply voltage drops abnormally. Further, by stopping the supply of electric power to the discharge lamp La when the power is cut off by the switch element SW, the supply of electric power to the discharge lamp La is continued by the residual charge of the electrolytic capacitor C1 after the power supply is cut off. Can be prevented and safety can be improved.

  Further, as a conventional example to which such a low power supply voltage detection circuit is applied, for example, there is a technique described in Japanese Patent Laid-Open No. 2001-15276 (Patent Document 1). In Patent Document 1, a discharge lamp, a discharge lamp lighting device capable of lighting the discharge lamp and controlling the power supplied to the discharge lamp, and lighting for measuring the power feeding time to the discharge lamp lighting device as the lighting time of the discharge lamp. An illuminance correction device for instructing the discharge lamp lighting device to supply power to the discharge lamp according to the lighting time measured by the lighting time timer so as to suppress a decrease in luminous flux associated with the lapse of the lighting time of the discharge lamp; A lighting device is disclosed that is provided in one fixture. Thus, in a discharge lamp lighting device having a timekeeping timer for storing the discharge lamp lighting time, it is necessary to reset the value of the lighting time stored at the time of replacement of the discharge lamp to an initial value. According to the technique of Patent Document 1, as a means for resetting the lighting time timer, an illuminating device including a power switch for turning on / off the power supply and a reset control unit for resetting the lighting time timer when the power on / off is a prescribed procedure Is disclosed. For example, when the power is turned on after 2 seconds on, 2 seconds off, 2 seconds on, and 2 seconds off, the lighting time stored in the lighting time timer is determined to have been instructed to reset the lighting time. It is configured to reset.

As a similar conventional example, for example, there is a technique described in Japanese Patent Application Laid-Open No. 2004-247225 (Patent Document 2). In Patent Document 2, the stored lamp lighting time is reset to the initial value based on the no-load detection information after the power is turned on as means for resetting the lighting time timer when replacing the discharge lamp in Patent Document 1 described above. It is what I did. For example, when the user wants to reset the lighting time intentionally, the operation of turning off the power after turning on the lighting device in the no-load state with the discharge lamp removed is continuously performed three times. It is possible to reset the lighting time for the first time by repeating the operation. This conventional example prevents an unintended lighting time from being reset by turning the power on and off during normal use.
JP 2001-15276 A JP 2004-247225 A

  However, in the circuit configuration of FIG. 8 described in the conventional example, for example, a single-phase three-wire power source may be used as a commercial power source. The single-phase three-wire power source is a power source voltage obtained by using a transformer as shown in FIG. 9, and the primary winding (between terminal 1 and terminal 2) of the transformer has, for example, 6,000V. Single phase power supply is connected. There are two windings (between A-N and NB) on the secondary side of the transformer, and the respective windings are connected in series with each other. Here, the connection point (terminal N) of the two windings is called a neutral wire and is grounded to the ground. A single-phase voltage of 100 V that is stepped down by a transformer is generated in each winding (between terminal A and terminal N and between terminal N and terminal B), so that between two windings (between terminal A and terminal B) ), A total single-phase voltage of 200V can be obtained. Power is supplied to the load via the switch SW from a single-phase voltage of 200 V generated between the terminal A and the terminal B. As the switch SW, a double cut-off switch that cuts off both the terminal A side and the terminal B side is also used. Here, a case where a single cut-off switch that cuts off only the terminal A side is used will be considered.

  FIG. 10 shows an operation explanatory diagram when the circuit of FIG. 8 described in the conventional example is driven by such a combination of a single-phase three-wire power source and a one-way switch. In FIG. 10, the two secondary windings of the single-phase three-wire power source are illustrated as AC1 and AC2, respectively. In addition, FIG. 11 shows operation waveforms when the power is shut off.

  According to FIG. 10, even when the switch SW shifts from the on state to the off state, the voltage AC2 generated in one of the secondary windings of the single-phase three-wire power source is used as the power source, and the path indicated by the dotted line in the figure. (AC2 → LF1 → DB → C4 → C5 → C6 → Ground → AC2) The current continues to flow. For this reason, as shown in FIG. 11, since charges are accumulated in the filter capacitor C4 connected to the output terminal of the full-wave rectifier circuit DB, the voltage of the filter capacitor C4 drops to zero even when the power supply is shut off. A constant voltage is maintained without doing so. When the time further elapses, the voltage of the electrolytic capacitor C1 is lower than the voltage of the filter capacitor C4, so that the charge of the filter capacitor C4 is discharged through the rectifier diode D1, and the voltage of the filter capacitor C4 starts to decrease. . Usually, as the electrolytic capacitor C1, a capacitor having a relatively large capacity is used, so that the time during which the voltage of the electrolytic capacitor C1 is lowered is relatively long.

  Therefore, when the threshold value for the low power supply voltage detection circuit 2 to detect a drop in the power supply voltage is lower than the detection voltage due to the residual voltage of the filter capacitor C4 charged by the power supply AC2, the switch SW is cut off. Regardless, it takes a considerable time for the low power supply voltage detection circuit 2 to operate.

  As described in the conventional example, the time until the low power supply voltage detection circuit 2 operates after the switch SW is cut off is inadvertently increased by the combination of the single-phase three-wire power supply and the one-way switch. In such a configuration, the stop of the power supply to the discharge lamp when the power is shut off is delayed, and the power supply to the discharge lamp is inadvertently continued even after the power is shut off. Further, in the lighting device having the function of resetting the lighting time stored by the specified power-on / off means as described in the conventional example, the lighting device does not stop even when the power is turned off for a predetermined time. Since it is not recognized that the power is turned off, there is a possibility that the lighting time cannot be reset normally.

  In this example, the combination of a single-phase three-wire power supply and a single-cut switch has been described as an example, but not only a single-phase three-wire power supply but also a three-phase four-wire power supply, for example, a single-cut switch If the power supply is configured such that a ground voltage continues to be generated between the power supply line on the side not having the switch and the ground as in the case where the power supply is cut off, a similar problem occurs.

  In order to solve the above problems, the lighting device according to the present invention, as shown in FIGS. 1 to 7, full-wave rectification circuit DB for full-wave rectification of commercial AC power supply AC, and output of the full-wave rectification circuit DB. A lighting circuit that controls lighting of the lamp La in response to a voltage, a capacitor C4 connected between the output terminals of the full-wave rectifier circuit DB, and a low power supply voltage detection that detects a drop in the output voltage of the full-wave rectifier circuit DB The lighting device including the circuit 2 is characterized in that a path to ground is provided from one or both ends of the input-side line of the full-wave rectifier circuit DB through at least one capacitive element C5, C6 (C7). To do.

  According to the present invention, a capacitive element connected between the power source and the ground for noise reduction is connected to the input side from the full-wave rectifier circuit, for example, a single-phase three-wire power source and a one-way switch Even when it is used in a configuration where ground voltage continues to be generated between the power line that does not have a switch and the ground even if the switch is cut off, such as a combination, the path of the current flowing through the full-wave rectifier circuit is cut off In addition, the output voltage of the full-wave rectifier circuit can be immediately reduced. As a result, the operation of the low power supply voltage detection circuit after the power is shut off is not inadvertently delayed when detecting a decrease in the output voltage of the full-wave rectifier circuit when the power is off and performing various controls of the lighting device. Therefore, it is possible to reliably detect the interruption of the power supply in a predetermined time, and various control of the lighting device by the low power supply voltage detection circuit can be reliably performed.

(Embodiment 1)
Embodiment 1 of the present invention is shown in FIG. In this embodiment, a single-phase three-wire power source is used as the power source. In the circuit shown in FIG. 1, the input end of the line filter LF1 is connected between both ends of a single-phase three-wire power source consisting of AC1 and AC2 via a switch SW, and the output end of the line filter LF1 is normal. It is connected to the input terminal of a full-wave rectifier circuit DB for full-wave rectifying the power supply via the filter LF2. A series circuit of a chopper inductor L1, a rectifier diode D1, and an electrolytic capacitor C1 is connected between the output terminals of the full-wave rectifier circuit DB, and a switching element Q3 is connected in parallel with the series circuit of the rectifier diode D1 and the electrolytic capacitor C1. Are connected to form a power supply circuit called a so-called step-up chopper circuit.

  A series circuit of switching elements Q1, Q2 is connected in parallel with the electrolytic capacitor C1, and a series circuit of a coupling capacitor C2, a resonance inductor L2, and a discharge lamp La is connected to a connection point of the switching elements Q1, Q2. A resonance capacitor C3 is connected in parallel with the discharge lamp La, and a so-called half-bridge inverter circuit is constituted by these.

  Here, the switching element Q3 of the power supply circuit and the switching elements Q1 and Q2 of the inverter circuit are separately excited, and are repeatedly turned on and off at a high frequency by a drive signal from the inverter control unit 1 including a high voltage driver IC and the like. . As a result, the power supply voltage is boosted and smoothed by the power supply circuit, the DC voltage is switched at a high frequency, a resonance current is passed through the discharge lamp La, and the discharge lamp La is turned on.

  In addition, a low power supply voltage detection circuit 2 is connected to the inverter control unit 1, and the low power supply voltage detection circuit 2 detects the voltage at the connection point of the resistors R1 and R2 connected in parallel with the capacitor C4. . Here, a threshold value is set in advance in the low power supply voltage detection circuit 2, and when the voltage at the connection point of the resistors R1 and R2 falls below this threshold value, the low power supply voltage detection circuit 2 sends a detection signal to the inverter control unit 1. When the inverter control unit 1 receives this signal, the inverter control unit 1 stops the switching operation of the power supply circuit and the inverter circuit. This prevents component stress at low power supply voltage. Further, when used in an emergency light, contact vapor deposition of the emergency light relay due to residual oscillation of the inverter circuit when the power is off is prevented.

  Further, as a means for reducing normal mode noise, the circuit shown in FIG. 1 has a noise prevention capacitor C4 connected between the output terminals of the full-wave rectifier circuit DB. As a means for reducing common mode noise, a series circuit of capacitors C5 and C6 is connected between these lines, and the connection point constitutes a ground circuit connected to the ground via a capacitor C7.

  In the present embodiment, the noise reduction capacitors C5 and C6 connected to one end of the output terminal of the full-wave rectifier circuit DB in the conventional example of FIG. 8 are moved to the input side of the full-wave rectifier circuit DB. As a result, when the cut-off switch SW in the single-phase three-wire power source is cut off, the current is not passed through the capacitor C4 between the output terminals of the full-wave rectifier circuit DB. The point is that no voltage is generated. As a result, as shown in the operation waveform of FIG. 2, when the single-phase three-wire power supply is turned off by the one-way switch, the voltage at the connection point of the resistors R1 and R2 immediately decreases, and the low power supply voltage detection circuit 2 operates. As a result, the oscillation of the inverter circuit can be stopped immediately. Therefore, it is possible to avoid component stress due to continuous oscillation when the power is off and contact vapor deposition of the emergency light relay due to residual oscillation.

  In this example, the combination of a single-phase three-wire power supply and a single-cut switch has been described as an example, but not only a single-phase three-wire power supply but also a three-phase four-wire power supply, for example, a single-cut switch If the power supply has a configuration in which ground voltage continues to be generated between the power supply line on the side having no switch and the ground when the power supply is cut off, the same effect can be obtained by the configuration of the present embodiment.

(Embodiment 2)
A second embodiment of the present invention is shown in FIG. In the present embodiment, as means for reducing common mode noise in the first embodiment, a series circuit of capacitors C5 and C6 is connected between both ends of the power supply line, and the connection point is connected to the ground via the capacitor C7. As shown in FIG. 3, the power supply is changed from one line on one side to the ground via a series circuit of capacitors C5 and C6. Since other circuit configurations and circuit operations are the same as those in the first embodiment, description thereof is omitted here.

  In the first embodiment, when any one of the capacitors C5, C6, and C7 is short-circuited with a component, three capacitors (C5, C5) are used to prevent a short circuit between the power supplies or a short circuit between the power supply line and the ground. C6, C7) is necessary, but since the present embodiment is configured to connect from one power supply line to the ground, two capacitors (C5, C6) may be used. According to the present embodiment, the number of parts can be reduced as compared with the first embodiment by grounding the power supply line on the opposite side to the power supply line where the power switch SW is inserted via the capacitors C5 and C6. The same effect as in the first embodiment can be obtained.

(Embodiment 3)
Embodiment 3 of the present invention is shown in FIG. In the present embodiment, in the lighting device including the initial illuminance correction device 3, capacitors C5 and C6 for reducing common mode noise are connected to one end of the power supply line on the input end side of the full-wave rectifier circuit DB and grounded to the ground. Grounding means is provided.

  The initial illuminance correction device 3 includes a lighting time memory 31, a dimming ratio setting unit 32, a dimming signal generation unit 33, a nonvolatile memory 34, and a reset control unit 35. The lighting time memory 31 reads and stores the previous cumulative lighting time stored in the non-volatile memory 34, receives the power on / off detection signal from the low power supply voltage detection circuit 2, and is supplied with power to the lighting device. Count up as the lighting time. The initial illuminance correction device 3 is operated by the control power supply voltage of the inverter control unit 1. When the power supply to the lighting device is cut off, the cumulative lighting time of the lighting time memory 31 is reduced before the control power supply voltage is lowered. Is saved in the nonvolatile memory 34. The nonvolatile memory 34 stores a dimming ratio table corresponding to the lighting time in addition to the previous cumulative lighting time. In the dimming ratio setting unit 32, the dimming ratio data corresponding to the lighting time is read from the nonvolatile memory 34 in accordance with the lighting time counted in the lighting time memory 31, and inverter control is performed by the dimming signal generation unit 33. The dimming signal of the unit 1 is generated. Thereby, the output of the inverter circuit is controlled so as to suppress the decrease in the luminous flux with the passage of the lighting time.

  When the discharge lamp is replaced, the power supply switch SW is turned on / off in a predetermined procedure with the discharge lamp La as a load connected, whereby the power on / off detection signal is detected by the low power supply voltage detection circuit 2. In response, the reset control unit 35 resets the cumulative lighting time of the lamp stored in the nonvolatile memory 34 to the initial value.

  In the present embodiment, the noise reduction capacitors C5 and C6 connected to one end of the output terminal of the full-wave rectifier circuit DB in the conventional example of FIG. 8 are moved to the input side of the full-wave rectifier circuit DB. In this way, no voltage is generated at the connection point of the resistors R1 and R2 because the current does not flow through the capacitor C4 when the cut-off switch SW is cut off in the single-phase three-wire power source. . Thus, for example, even when the single-phase three-wire power source is turned off by the one-way switch, the voltage at the connection point of the resistors R1 and R2 immediately decreases, and the low power source voltage detection circuit 2 operates. Therefore, for example, when the power is turned on after 2 seconds on, 2 seconds off, 2 seconds on, 2 seconds off, it is determined that the resetting of the lighting time has been instructed, and the reset control unit 35 stores in the nonvolatile memory 34. Even in the case of resetting the lighting time, the low power supply voltage detection circuit 2 operates within a specified time, and the lighting time can be reliably reset by a short on / off time.

(Embodiment 4)
Embodiment 4 of the present invention is shown in FIG. In the figure, reference numeral 4 denotes a no-load detection circuit, which gives a no-load detection signal to the reset control unit 35 when the discharge lamp La as a load is not connected. The present embodiment is different from the third embodiment in that when the discharge lamp is replaced, the power switch SW is turned on / off in a predetermined procedure without connecting the discharge lamp as a load, thereby detecting the low power supply voltage. FIG. 5 shows a lighting device having a function of receiving the power on / off detection signal from the circuit 2 and resetting the cumulative lighting time of the lamp stored in the nonvolatile memory 34 to the initial value by the reset control unit 35. Thus, capacitors C5 and C6 for reducing common mode noise are connected to one end of the power supply line on the input end side of the full-wave rectifier circuit DB, and grounding means for grounding to the ground is provided.

  In a no-load state where no discharge lamp is connected, the power consumed by the electrolytic capacitor C1 is very small when the power supply is cut off. Therefore, in the configuration described in the conventional example, the low power supply voltage detection circuit 2 operates. The delay time until is very long. Therefore, as shown in FIG. 5, by connecting capacitors C5 and C6 for reducing common mode noise to one end of the power supply line on the input end side of the full-wave rectifier circuit DB, and providing a grounding means for grounding to the ground, For example, even when a single-phase three-wire power source is turned off by a one-way switch, as shown in the operation waveform diagram of FIG. 6, the capacitor C4 and the resistors R1, R2 are not affected by the residual voltage of the electrolytic capacitor C1. When the voltage at the connection point of the power supply voltage immediately decreases and the low power supply voltage detection circuit 2 operates, for example, when no power is applied, the power is turned on after 2 seconds on, 2 seconds off, 2 seconds on, and 2 seconds off. Even when the reset control unit 35 resets the lighting time stored in the non-volatile memory 34 by determining that the resetting of the time has been instructed, as prescribed. A low power supply voltage detection circuit 2 is operated in time, it is possible to perform resetting of reliably lighting time in a short time on and off.

(Embodiment 5)
Embodiment 5 of the present invention is shown in FIG. In this embodiment, regardless of the presence or absence of a load, the dimming ratio stored in the nonvolatile memory 34 is switched by turning on / off the power switch SW according to a predetermined procedure, and the dimming state of the lamp is changed. In the lighting device that can be set to a desired dimming ratio, as shown in FIG. 7, capacitors C5 and C6 for reducing common mode noise are connected to one end of the power supply line on the input end side of the full-wave rectifier circuit DB. A grounding means for grounding to the ground is provided.

  The dimming ratio is set according to the number of times the power switch SW is turned on / off within the specified time. For example, the dimming ratio is 80% when the number of on / off times is once, 70% when twice, 60% when three times, and 4 times. Thus, the dimming ratio setting unit 32 may perform processing so as to change the dimming ratio stored in the nonvolatile memory 34 in accordance with the number of times of detection of the low power supply voltage by on / off, such as 100%.

  According to this embodiment, capacitors C5 and C6 for reducing common mode noise are connected to one end of the power supply line on the input end side of the full-wave rectifier circuit DB, and grounding means for grounding to the ground is provided. Even when the three-wire power source is turned off by the one-way switch, the voltage at the connection point of the capacitor C4 and the resistors R1 and R2 immediately decreases, and the low power source voltage detection circuit 2 operates, for example, at intervals of several seconds. By operating the low power supply voltage detection circuit 2 within a specified time depending on the number of times the power switch SW is turned on / off, the dimming ratio can be reliably changed.

It is a circuit diagram of Embodiment 1 of the present invention. It is an operation | movement waveform diagram of Embodiment 1 of this invention. It is a circuit diagram of Embodiment 2 of the present invention. It is a circuit diagram of Embodiment 3 of the present invention. It is a circuit diagram of Embodiment 4 of the present invention. It is an operation | movement waveform diagram of Embodiment 4 of this invention. It is a circuit diagram of Embodiment 5 of the present invention. It is a circuit diagram of the conventional lighting device. It is a circuit diagram of the transformer used for a prior art example. It is a circuit diagram for operation | movement description of the conventional lighting device. It is an operation | movement waveform diagram of the conventional lighting device.

Explanation of symbols

1 Inverter control unit 2 Low power supply voltage detection circuit

Claims (10)

A full-wave rectification circuit for full-wave rectification of a commercial AC power supply, a lighting circuit for controlling lighting of the lamp in response to an output voltage of the full-wave rectification circuit, a capacitor connected between output terminals of the full-wave rectification circuit, In a lighting device including a low power supply voltage detection circuit that detects a decrease in the output voltage of the full-wave rectifier circuit, the ground is grounded from one or both ends of the input-side line of the full-wave rectifier circuit through at least one capacitive element. A lighting device characterized in that a route is provided. The commercial AC power supply has one end connected to the lighting circuit via a switching element for turning on / off the power supply, and the other end connected directly to the lighting circuit without going through the switching element. 2. The lighting device according to claim 1, wherein the other end of the AC power supply not through the switch element is not grounded. 3. The low power supply voltage detection circuit detects that the power switch has shifted from an on state to an off state by detecting a decrease in the output voltage of the full-wave rectifier circuit. The lighting device described. The lighting device according to claim 3, wherein the lighting circuit includes a lighting state control unit that receives an output of the low power supply voltage detection circuit and switches a lighting state of the lamp. The lighting circuit further includes a no-load detection circuit that detects a no-load state of the lamp, and switches the lighting state of the lamp in response to both the output of the low power supply voltage detection circuit and the output of the no-load detection circuit. The lighting device according to claim 4, further comprising a lighting state control unit. 6. The lighting device according to claim 4, wherein the lighting state control means is control means for stopping supply of electric power to the lamp. 6. The lighting device according to claim 4, wherein the lighting state control means is control means for changing a set value of a power level supplied to the lamp. The lighting state control unit includes a lighting state storage unit that stores a lighting state of the lamp in a memory, and outputs the low power supply voltage detection circuit or outputs of the low power supply voltage detection circuit and the no-load detection circuit. 6. The lighting device according to claim 4, further comprising reset means for receiving both outputs and resetting a stored lighting state to a predetermined value. 9. The lighting state stored in the memory is a cumulative lighting time of the lamp, and the reset means is a means for resetting the cumulative lighting time stored in the memory to an initial value. Lighting device. A lighting apparatus comprising the lighting device according to claim 1 and a lamp.

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