JP2005135645A - Electrodeless discharge lamp lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrodeless discharge lamp lighting device restarting an electrodeless discharge lamp, simultaneously with the restoration of an alternating current power supply, when the interval of power supply break from the alternating current power source at instantaneous outage is short. <P>SOLUTION: When the down time of the alternate current power supply AC is short, the output voltage Vdc of a direct current power supply circuit is kept higher than a drive voltage necessary for operation of a high-frequency power supply circuit 2 by a smoothing capacitor C1, so that the direct current circuit can have the high-frequency power supply circuit 2 operate, as soon as the alternating current power supply AC is restored. So, a signal annihilation circuit 11 is provided as a means against instantaneous outages for invalidating a drive timer circuit 10, when the alternating current power supply AC is restored from the stoppage of the alternating current, till a period where the output voltage Vdc of the direct current power supply circuit is higher than the drive voltage, and if the down time of the alternating current power supply is short, the high-frequency power supply circuit 2 gives an inductance coil 7 a high-frequency output Vcoil, as soon as the alternating current AC is restored to restart the electrodeless discharge lamp 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electrodeless discharge lamp lighting device.

  In general, as shown in FIG. 7, an electrodeless discharge lamp lighting device is known that is supplied with electric power from an AC power supply AC and lights an electrodeless discharge lamp 1. This electrodeless discharge lamp lighting device includes a DC power supply circuit that receives power supply from an AC power supply AC and outputs a DC voltage, and a high-frequency power supply circuit 2 that operates using the DC power supply circuit as a power source and converts the DC voltage into a high-frequency output Vcoil. Is provided.

  The DC power supply circuit includes a rectifier DB such as a diode bridge that rectifies the AC power supply AC, and the boost chopper circuit 3. The step-up chopper circuit 3 is connected between the output terminals of the rectifier DB in such a manner that a series circuit of an inductor L1 and a switching element Q1 composed of an FET connects the inductor L1 to the positive output terminal of the rectifier DB. A series circuit of a smoothing capacitor C1 and a diode D1 is connected between both ends in such a manner that the anode of the diode D1 is connected to the connection point between the switching element Q1 and the inductor L1. Furthermore, the step-up chopper circuit 3 includes an output control unit 4 that turns on and off the switching element Q1 at a high frequency. Both ends of the smoothing capacitor C1 are output ends of the DC power supply circuit, and the smoothing capacitor C1 functions as a smoothing unit that smoothes the output voltage Vdc of the DC power supply circuit.

  The high frequency power supply circuit 2 includes an inverter circuit 5 having a pair of switching elements Q2 and Q3 composed of FETs connected in series between output terminals of the boost chopper circuit 3, and a drive circuit 6 for driving the inverter circuit 5. The

  The inverter circuit 5 includes a series circuit of an inductor L2 and a capacitor C2 connected between both ends of one switching element Q3, and an induction coil constituting the electrodeless discharge lamp 1 via the capacitor C3 between both ends of the capacitor C2. 7 is connected. The drive circuit 6 has a Lout terminal and an L-GND terminal connected to one switching element Q3, and a Hout terminal and an H-GND terminal connected to the other switching element Q2, and each switching element Q2, Q3 On the other hand, the switching elements Q2 and Q3 are alternately turned on and off at a high frequency by outputting drive signals having a phase difference of approximately 180 ° with respect to each other. As a result, the high frequency power supply circuit 2 gives a high frequency output Vcoil to the induction coil 7.

  On the other hand, in the electrodeless discharge lamp 1, a discharge gas such as a metal vapor (for example, mercury) is enclosed together with an inert gas (for example, a rare gas) in a spherical glass bulb 8 having an inner surface coated with a phosphor. The induction coil 7 described above is disposed in the vicinity of. When the inverter circuit 5 causes a high-frequency current of several tens of kHz to several hundreds of MHz (for example, 13.56 MHz) to flow through the induction coil 7, the induction coil 7 causes a high-frequency electromagnetic field to act on the discharge gas in the glass bulb 8. Generates ultraviolet rays. When the phosphor receives ultraviolet rays, visible light is generated, and the electrodeless discharge lamp 1 is turned on. When taking out ultraviolet rays, a glass bulb not coated with a phosphor is employed.

  By the way, in this electrodeless discharge lamp lighting device, when the electrodeless discharge lamp 1 is started for the first time, the electrodeless discharge lamp 1 after the output voltage Vdc of the DC power supply circuit reaches the drive voltage necessary for the operation of the high frequency power supply circuit 2. Is provided with a voltage detection circuit 9 and a start-up timer circuit 10.

  The voltage detection circuit 9 includes a series circuit of a resistor R1 and a resistor R2 connected between the output terminals of the rectifier DB, and a capacitor C4 connected in parallel to the resistor R2, and a connection between the resistor R1 and the resistor R2. The point is connected to the trigger terminal tr of the activation timer circuit 10. The start-up timer circuit 10 limits a fixed rise time Ts (see FIG. 8B) and outputs a stop signal Vst from the output terminal op within the rise time Ts. The output terminal op of the start timer circuit 10 is connected to a stop terminal st provided in the drive circuit 6, and the drive circuit 6 receives the stop signal Vst and stops outputting the drive signal during the period when the stop terminal st is at the H level. By doing so, the operation of the inverter circuit 5 is stopped.

  That is, when the activation timer circuit 10 rises so that the potential at the connection point between the resistor R1 and the resistor R2 in the voltage detection circuit 9 exceeds the potential (setting potential) that can trigger the activation timer circuit 10 when the power is turned on, The high-frequency power supply circuit 2 is stopped by outputting a stop signal Vst over a certain rise time Ts, and the high-frequency power supply circuit 2 is operated after the rise time Ts has elapsed. Here, the rise time Ts is set to a time required from the start of power supply to the DC power supply circuit until the output voltage Vdc of the DC power supply circuit reaches the drive voltage of the high-frequency power supply circuit 2.

  The operation of the above electrodeless discharge lamp lighting device will be described with reference to FIG. When the voltage Vin between the output terminals of the rectifier DB rises as shown in FIG. 8 (a) at the start of power supply from the AC power supply AC, as shown in FIG. 8 (a), the start timer circuit 10 is shown in FIG. 8 (b). Is triggered to set the stop signal Vst to the H level over the rise time Ts until the time t2. Since the high-frequency power supply circuit 2 stops its operation while the stop terminal st is at the H level, as shown in FIG. 8C, the induction coil 7 is applied to the induction coil 7 from the time t2 after the rise time Ts has elapsed. Start giving high frequency output Vcoil.

As described above, the start timer circuit 10 starts the operation of the high frequency power supply circuit 2 after the output voltage Vdc of the DC power supply circuit reaches the drive voltage of the high frequency power supply circuit 2, and as a result, the start of the electrodeless discharge lamp 1. In this case, it is possible to prevent a starting failure such as the oscillation frequency and amplitude not being stable, and to realize a stable starting. In particular, since the electrodeless discharge lamp 1 is an inductor load at the start of ignition and requires a large amount of power at the start compared with the electrode discharge lamp which is a normal fluorescent lamp, the start timer circuit 10 is provided. The effect by providing is large (for example, refer patent document 1).
Japanese Unexamined Patent Publication No. 2000-100589 (5th page, FIG. 3)

  By the way, as shown in FIG. 8, the AC power supply AC may be subjected to a power failure for a short time (from time t3 to time t4) that is less than several hundred ms. It is desirable that the electrodeless discharge lamp 1 can be restarted early during such an instantaneous power failure. However, in the above-described electrodeless discharge lamp lighting device, the start-up timer circuit 10 operates in the same manner as the initial start time t1 even at the time of recovery of the AC power supply t4. Will only be delayed.

  Further, when the electrodeless discharge lamp 1 is used for illumination such as blinking illumination, the start-up timer circuit 10 is operated every time the electrodeless discharge lamp 1 is restarted, and thus the response of blinking is obtained. There is a possibility of reduction.

  The present invention has been made in view of the above reasons, and in the case where the power supply from the AC power supply such as an instantaneous power failure is short, the electrodeless electrode that restarts the electrodeless discharge lamp simultaneously with the return of the AC power supply. An object is to provide a discharge lamp lighting device.

  According to the first aspect of the present invention, a DC power supply circuit provided with a smoothing section for supplying a DC voltage supplied from an AC power supply and smoothing the output voltage, and converting the output of the DC power supply circuit into a high frequency output and enclosing a discharge gas A high-frequency power supply circuit that turns on the electrodeless discharge lamp by supplying the high-frequency output to the induction coil with respect to the electrodeless discharge lamp in which the induction coil is arranged close to the bulb, and power supply from the AC power supply to the DC power supply circuit is started. A start timer circuit that stops the operation of the high-frequency power supply circuit during the rise time until the output voltage of the DC power supply circuit reaches the drive voltage necessary for the operation of the high-frequency power supply circuit. Instantaneous power failure countermeasure means for disabling the start timer circuit and restarting the electrodeless discharge lamp when the AC power is restored while the voltage is equal to or higher than the drive voltage Characterized by providing.

  By the way, when the power supply from the AC power supply such as an instantaneous power failure is short, the output voltage of the DC power supply circuit is maintained at the driving voltage or higher by the smoothing unit. A high-frequency power supply circuit can be operated. Therefore, by adopting the configuration of claim 1, when the AC power supply is restored while the output voltage of the DC power supply circuit is equal to or higher than the drive voltage even when the AC power supply is stopped, the high-frequency power supply circuit is simultaneously with the restoration of the AC power supply. By starting this operation, the electrodeless discharge lamp can be restarted early. For example, when an electrodeless discharge lamp is used for illumination such as flashing illumination, the response of flashing is higher than that of the conventional configuration.

  According to a second aspect of the present invention, in the first aspect of the invention, the start timer circuit outputs a stop signal over the rise time, and the high frequency power supply circuit stops the high frequency output during a period in which the stop signal is received. And the instantaneous power failure countermeasure means comprises a signal invalid circuit for invalidating a stop signal.

  According to this configuration, since the signal invalidation circuit only needs to invalidate the stop signal between the start timer circuit and the high frequency power supply circuit, there is no need to make a major change to the conventional configuration when providing the signal invalidation circuit. Instantaneous power failure countermeasures can be realized with easy changes to the configuration.

  According to a third aspect of the present invention, in the second aspect of the present invention, the signal invalid circuit operates at least during the rise time after the AC power supply is restored.

  According to this configuration, since the signal invalid circuit only needs to operate during the rise time, an increase in power consumption due to provision of the instantaneous power failure countermeasure means can be suppressed.

  According to a fourth aspect of the invention, there is provided a voltage detection circuit for detecting a voltage proportional to an absolute value of the AC power supply according to the first aspect of the invention, and the start-up timer circuit applies a voltage detected by the voltage detection circuit. The high frequency power supply circuit is stopped by rising so that the potential of the trigger terminal exceeds a predetermined set potential, and the instantaneous power failure countermeasure means sets the potential of the trigger terminal to a value larger than the set potential. It is characterized by comprising a potential maintaining circuit that maintains the above.

  According to this configuration, since the potential maintaining circuit only needs to operate by being connected to the trigger terminal, it is not necessary to make a major change to the conventional configuration when providing the potential maintaining circuit, and an instantaneous power failure countermeasure can be made by an easy change to the conventional configuration. Means can be realized.

  According to a fifth aspect of the present invention, in the fourth aspect of the invention, the potential maintaining circuit operates during at least the output voltage of the DC power supply circuit being equal to or higher than the driving voltage after the AC power supply is stopped. .

  According to this configuration, since the potential maintaining circuit only needs to operate while the output voltage of the DC power supply circuit is equal to or higher than the drive voltage after the AC power supply is stopped, the increase in power consumption due to the provision of an instantaneous power failure countermeasure is suppressed. Can do.

  The invention of claim 6 is the output of the high frequency power supply circuit according to any one of claims 1 to 5, wherein at least the output voltage of the DC power supply circuit is equal to or higher than the drive voltage after the AC power supply is stopped. It is characterized by comprising lighting maintaining means for continuing the lighting of the electrodeless discharge lamp by reducing the voltage.

  According to this configuration, the flicker of the electrodeless discharge lamp can be prevented when the power supply from the AC power source such as an instantaneous power failure is short.

  According to the seventh aspect of the present invention, a DC power supply circuit provided with a smoothing section for supplying a DC voltage supplied from an AC power supply and smoothing the output voltage, and converting the output of the DC power supply circuit into a high frequency output and enclosing a discharge gas A high-frequency power supply circuit for lighting the electrodeless discharge lamp by supplying the high-frequency output to the induction coil with respect to the electrodeless discharge lamp in which the induction coil is arranged close to the bulb, and a voltage detection circuit for detecting a voltage proportional to the absolute value of the AC power supply And a trigger terminal to which the voltage detected by the voltage detection circuit is applied, and the trigger terminal is triggered by rising so that the potential of the trigger terminal exceeds a predetermined set potential. The output voltage of the DC power supply circuit is necessary for the operation of the high-frequency power supply circuit. A start timer circuit that outputs a stop signal during the rise time until the drive voltage is reached, and a high-frequency output during the period when the high-frequency power supply circuit receives the stop signal Provided with a drive circuit for stopping, and interposed between the start timer circuit and the drive circuit, the stop signal is invalidated when the AC power supply recovers while the output voltage of the DC power supply circuit is equal to or higher than the drive voltage after the AC power supply stops The signal invalid circuit is provided, and the signal invalid circuit operates at least for a rise time after the AC power supply is restored.

  According to this configuration, when the AC power supply is restored while the output voltage of the DC power supply circuit is equal to or higher than the drive voltage even when the AC power supply is stopped, the operation of the high-frequency power supply circuit is started simultaneously with the restoration of the AC power supply. The electrodeless discharge lamp can be restarted early. For example, when an electrodeless discharge lamp is used for illumination such as flashing illumination, the response of flashing is higher than that of the conventional configuration.

  In the case where the power supply from the AC power supply is interrupted so that the AC power supply recovers while the output voltage of the DC power supply circuit is equal to or higher than the drive voltage even when the AC power supply is stopped, the AC power supply There is an advantage that the electrodeless discharge lamp can be restarted early by starting the operation of the high-frequency power supply circuit simultaneously with the return. For example, when an electrodeless discharge lamp is used for illumination such as flashing illumination, the response of flashing is higher than that of the conventional configuration.

  In the following embodiments, the same functions and configurations as those of the conventional configuration are denoted by the same reference numerals as those of the conventional configuration, and description thereof is omitted.

(Embodiment 1)
As shown in FIG. 1, the electrodeless discharge lamp lighting device of the present embodiment is obtained by adding a signal invalid circuit 11 as an instantaneous power failure countermeasure means to the conventional configuration shown in FIG.

  In the present embodiment, the start timer circuit 10 outputs a stop signal Vst from the output terminal op to the stop terminal st of the drive circuit 6 at the start and restart of power supply from the AC power supply AC, and the stop terminal The stop signal output from the start timer circuit 10 is used when the operation of the high frequency power supply circuit 2 is stopped by setting st to H level and the power supply from the AC power supply AC such as an instantaneous power failure is short. By disabling Vst with respect to the stop terminal st, the high-frequency power supply circuit 2 is operated regardless of the start timer circuit 10.

  The signal invalidation circuit 11 of the present embodiment uses a stop signal in order to invalidate the stop signal Vst for the stop terminal st by setting the stop terminal st of the drive circuit 6 to the same potential as the output terminal of the cathode of the rectifier DB. A switching element Q4 is provided between the terminal st and the cathode output terminal of the rectifier DB. The switching element Q4 is composed of an FET. During the period when the switching element Q4 is on, all the stop signals Vst for the stop terminal st are invalid because the stop terminal st is at the same potential as the cathode output terminal of the rectifier DB. .

  The signal invalid circuit 11 is inserted between the reference power supply circuit 12 that is supplied with power from the smoothing capacitor C1 and generates a reference potential at the output end, and between the output end of the reference power supply circuit 12 and the output end of the cathode of the rectifier DB. A resistor R3 and a capacitor C5, and a switching element Q5 inserted between the output terminal of the reference power supply circuit 12 and the resistor R3. During the period when the switching element Q5 is on, the reference power supply circuit 12 Capacitor C5 is charged. The switching element Q5 is composed of a pnp type transistor, and the base is connected to the connection point between the resistor R1 and the resistor R2 in the voltage detection circuit 9, so that the potential at the connection point between the resistor R1 and the resistor R2 is higher than the reference potential. Turns on when smaller. The connection point between the capacitor C5 and the resistor R3 is connected to the gate of the switching element Q4. When the voltage Vc across the capacitor C5 becomes equal to or higher than the threshold voltage of the switching element Q4, the switching element Q4 is turned on.

  Further, a resistor R4 is inserted between the connection point between the switching element Q5 and the resistor R3 and the cathode output terminal of the rectifier DB so that the charge charged in the capacitor C5 can be discharged by turning off the switching element Q5. The

  The operation of the present embodiment will be described with reference to FIG. 2 showing the operation in the case of a momentary power failure in which the time from the stop of the AC power supply AC to the return of the AC power supply AC is less than several hundred ms. explain. In such an instantaneous power failure, the output voltage Vdc of the DC power supply circuit is maintained to be equal to or higher than the drive voltage of the high-frequency power supply circuit 2 by the smoothing capacitor C1.

  In the lighting period of the electrodeless discharge lamp 1 from the time t2 to the time t3 when the AC power supply AC is stopped, the reference power supply circuit 12 is set so that the potential at the connection point between the resistor R1 and the resistor R2 in the voltage detection circuit 9 becomes larger than the reference potential. And constants for each component of the voltage detection circuit 9 are set. Accordingly, since the switching element Q5 is off and the switching element Q4 is also off during this period, the stop signal Vst output from the start timer circuit 10 is valid for the stop terminal st. On the other hand, at the time t3 when the AC power supply AC is stopped, as shown in FIG. 2A, the voltage Vin between the output terminals of the rectifier DB falls, so that the connection point between the resistor R1 and the resistor R2 in the voltage detection circuit 9 Is reduced, the switching element Q5 is turned on, and the reference power supply circuit 12 starts charging the capacitor C5. As shown in FIG. 2C, when the voltage Vc across the capacitor C5 reaches the threshold voltage Vth1 of the switching element Q4, the switching element Q4 is turned on.

  On the other hand, at the time t4 when the AC power supply AC is restored, the switching element Q5 is turned off by increasing the potential at the connection point between the resistor R1 and the resistor R2 in the voltage detection circuit 9. Therefore, the electric charge charged in the capacitor C5 starts to be discharged slowly through the resistors R3 and R4 as compared with the time of charging, and as shown in FIG. 2C, the voltage Vc across the capacitor C5 is reduced. Start descent. Here, the constants of the respective components of the signal invalid circuit 11 are set so that the switching element Q4 remains on for a certain mask time Tm, and the mask time Tm after the switching element Q4 is turned on. It turns off at time t6 after the lapse.

  For the mask time Tm, at least the rise time Ts is added to the instantaneous power failure time of, for example, several hundred ms so that the switching element Q4 is turned on for at least the rise time Ts from the return time t4 of the AC power supply AC. Set to time. Therefore, as shown in FIG. 2B, the start timer circuit 10 outputs the stop signal Vst over the rise time Ts from the time t4 when the AC power supply AC is restored to the time t5, but the switching element Q4 By being on, the stop signal Vst for the stop terminal st of the drive circuit 6 becomes invalid as shown by the broken line in the figure.

  That is, since the electrodeless discharge lamp lighting device described above disables the activation timer circuit 10 when the time during which the power supply from the AC power supply AC is interrupted, such as an instantaneous power failure, is short, as shown in FIG. At the same time, the high frequency power supply circuit 2 starts to give a high frequency output Vcoil to the induction coil 7 simultaneously with the return of the AC power supply AC, and restarts the electrodeless discharge lamp 1.

  In addition, when the power supply from the AC power supply AC is interrupted for a long time, the charge charged in the smoothing capacitor C1 is reduced, and the output voltage Vdc of the DC power supply circuit is lower than the drive voltage of the high frequency power supply circuit 2. When the potential of the output terminal of the reference power supply circuit 12 supplied with power from the smoothing capacitor C1 is lowered and the switching element Q5 is turned off, the switching element Q4 is also turned off later. In this case, when the AC power supply AC is restored, the switching element Q4 is off, so that the stop signal Vst output from the start timer circuit 10 is effective for the stop terminal st of the drive circuit 6. Therefore, the start-up timer circuit 10 restarts the electrodeless discharge lamp 1 after the rise time Ts elapses as in the conventional configuration, and prevents starting failure such as oscillation frequency and amplitude not being stable when the electrodeless discharge lamp 1 is started. And stable starting.

  By the way, the electrodeless discharge lamp 1 has an advantage that it has a long life and saves maintenance, and has a great merit in adopting the electrodeless discharge lamp 1 as tunnel lamp illumination that is troublesome to maintain. When the electrodeless discharge lamp 1 is employed as tunnel lamp illumination, an emergency battery is provided to prevent the tunnel from being extinguished due to a power failure, and the power supply source is changed from the AC power source AC to the emergency battery during a power failure of the AC power source AC. It is preferable to employ an electrodeless discharge lamp lighting device that corresponds to an emergency lamp function that operates by switching. Here, if the countermeasure for the instantaneous power failure is added to the electrodeless discharge lamp lighting device corresponding to the emergency light function, the electrodeless discharge lamp 1 can be restarted simultaneously with the switching of the power supply source. The turn-off time is shortened, and as a result, safety in the tunnel is improved.

  The electrodeless discharge lamp 1 can be lit if the absolute value of the high frequency output Vcoil of the high frequency power supply circuit 2 is equal to or higher than a constant lighting output Vth2 (see FIG. 3D). Since the smoothing capacitor C1 becomes the power supply source of the high frequency power supply circuit 2 while the AC power supply AC is stopped, the high frequency power supply circuit 2 is operated in a state where consumption of the electric charge charged in the smoothing capacitor C1 is suppressed. Then, when the time during which the power supply from the AC power source AC is interrupted, such as an instantaneous power failure, is short, the electrodeless discharge lamp 1 can be kept on. Therefore, when the AC power supply AC is stopped, the absolute value of the high-frequency output Vcoil of the high-frequency power supply circuit 2 is reduced from the other lighting periods within the range of the lighting output Vth2 or more so as to keep the electrodeless discharge lamp 1 turned on. Provide sustaining means.

  As the lighting sustaining means, a configuration in which the frequency f (see FIG. 3C) of the drive signal generated by the drive circuit 6 of the high-frequency power supply circuit 2 is increased and a configuration in which the output voltage Vdc of the DC power supply circuit is reduced are conceivable. .

  The former lighting continuation means has a function of outputting an increase signal while the AC power supply AC is stopped in the start timer circuit 10 and a function of increasing the frequency of the drive signal during the period of receiving the increase signal in the drive circuit 6. It is realized by providing. In short, as shown in FIG. 3, the high frequency power supply circuit 2 increases the frequency f of the drive signal by receiving the increase signal from the start timer circuit 10 during the period from t3 to t4 when the AC power supply AC is stopped, and the absolute value of the high frequency output Vcoil. Reduce.

  On the other hand, the latter lighting continuation means is provided with a function for outputting a reduction signal while the AC power supply AC is stopped in the start-up timer circuit 10, and the step-up chopper during the period in which the output control unit 4 in the DC power supply circuit receives the reduction signal. This is realized by providing a function of reducing the output voltage Vdc of the circuit 3. In short, as shown in FIG. 4, during the period from t3 to t4 when the AC power supply AC is stopped, the DC power supply circuit receives the reduction signal from the start timer circuit 10 to reduce the output voltage Vdc, and as a result, the high frequency power supply circuit 2 The absolute value of the high frequency output Vcoil is reduced.

  By providing the lighting continuous means as described above, an effect of preventing the flicker of the electrodeless discharge lamp 1 can be expected when the power supply from the AC power supply AC such as an instantaneous power failure is short.

  When the power supply from the AC power supply AC is interrupted, such as an instantaneous power failure, the output voltage Vdc of the DC power supply circuit is held above the drive voltage necessary for the operation of the high frequency power supply circuit 2 by the smoothing capacitor C1. Therefore, even if the high frequency power supply circuit 2 is operated simultaneously with the return of the AC power supply AC as in the present embodiment, a starting failure such as an unstable oscillation frequency or amplitude does not occur when the electrodeless discharge lamp 1 is restarted. .

(Embodiment 2)
As shown in FIG. 5, the electrodeless discharge lamp lighting device of the present embodiment is characterized in that a potential maintaining circuit 13 is adopted as an instantaneous power failure countermeasure means in place of the signal invalid circuit 11 in the first embodiment.

  By the way, the activation timer circuit 10 is triggered by rising so that the potential Vtr of the trigger terminal tr exceeds a set potential Vth3 (see FIG. 6C), and starts the time limit of the rising time Ts and the drive circuit 6 The operation of the high frequency power supply circuit 2 is stopped by outputting a stop signal Vst to the stop terminal st. The potential Vtr of the trigger terminal tr is equal to the potential at the connection point between the resistor R1 and the resistor R2 in the voltage detection circuit 9, and is kept higher than the set potential Vth3 during a period when power is supplied from the AC power supply AC. However, as soon as the power supply from the AC power supply AC is cut off, it becomes lower than the set potential Vth3. In the present embodiment, the activation timer circuit 10 is not triggered unless the potential Vtr of the trigger terminal tr of the activation timer circuit 10 rises above the set potential Vth3. When the power supply is interrupted for a short time, the activation timer circuit 10 is prevented from operating after the AC power supply AC is restored by maintaining the potential Vtr of the trigger terminal tr at a value higher than the set potential Vth3.

  The potential maintaining circuit 13 of the present embodiment includes a reference power supply circuit 12 that is supplied with power from the smoothing capacitor C1 and maintains the potential of the output terminal at the reference potential, the output terminal of the reference power supply circuit 12, and the output terminal of the cathode of the rectifier DB. The resistor R5 and the resistor R6 are connected in series, and the connection point between the resistor R5 and the resistor R6 is connected to the trigger terminal tr of the start timer circuit 10 via the voltage follower including the operational amplifier OP1 and the diode D2. It has a connected configuration. Furthermore, the potential maintaining circuit 13 includes a switching element Q6 inserted between the output terminal of the reference power supply circuit 12 and the resistor R5. The switching element Q6 is composed of a pnp transistor, and the base is connected to the connection point between the resistor R1 and the resistor R2 in the voltage detection circuit 9, so that the potential at the connection point between the resistor R1 and the resistor R2 is higher than the reference potential. Turns on when smaller.

  Due to the connection relationship described above, the potential maintaining circuit 13 starts up the voltage at the output terminal of the reference power supply circuit 12 by using both resistors R5 and R6 during the period when the switching element Q6 is ON, and is activated via the operational amplifier OP1 and the diode D2. The voltage is applied to the trigger terminal tr of the timer circuit 10. Here, the constants of the components of the potential maintaining circuit 13 are set so that the potential Vtr of the trigger terminal tr becomes larger than the set potential Vth3 when the potential at the output terminal of the reference power supply circuit 12 is the reference potential.

  The operation of the present embodiment will be described with reference to FIG. 6 showing the operation in the case of a momentary power failure in which the time from the stop of the AC power supply AC to the return of the AC power supply AC is less than several hundred ms. explain. In such an instantaneous power failure, the output voltage Vdc of the DC power supply circuit is maintained to be equal to or higher than the drive voltage of the high-frequency power supply circuit 2 by the smoothing capacitor C1, and the potential at the output terminal of the reference power supply circuit 12 is maintained by the smoothing capacitor C1. The reference potential is maintained.

  In the lighting period of the electrodeless discharge lamp 1 from the time t2 to the time t3 when the AC power supply is stopped, the reference power supply circuit 12 and the reference power supply circuit 12 are set so that the potential at the connection point between the resistor R1 and the resistor R2 in the voltage detection circuit 9 becomes larger than the reference potential. Constants for each component of the voltage detection circuit 9 are set. Accordingly, since the switching element Q6 is OFF during this period, the potential Vtr of the trigger terminal tr of the activation timer circuit 10 is equal to the potential of the connection point between the resistor R1 and the resistor R2 in the voltage detection circuit 9. As shown in (c), it is maintained at a value greater than the set potential Vth3.

  At the time t3 when the AC power supply AC is stopped, as shown in FIG. 6A, the voltage Vin between the output terminals of the rectifier DB falls, so the potential at the connection point between the resistor R1 and the resistor R2 in the voltage detection circuit 9 Decreases the switching element Q6. When the switching element Q6 is turned on, as described above, the output of the reference power supply circuit 12 is divided by both resistors R5 and R6 and fed back to the trigger terminal tr of the activation timer circuit 10 via the operational amplifier OP1 and the diode D2. . Since the potential of the output terminal of the reference power supply circuit 12 is maintained at the reference potential by the smoothing capacitor C1 during the period from t3 to t4 when the AC power supply is stopped, as shown in FIG. 6C, the potential Vtr of the trigger terminal tr Is maintained at a value greater than the set potential Vth3.

  At the time t4 when the AC power supply AC is restored, the switching element Q6 is turned off by increasing the potential at the connection point between the resistor R1 and the resistor R2 in the voltage detection circuit 9. Therefore, the potential Vtr of the trigger terminal tr of the activation timer circuit 10 is equal to the potential of the connection point between the resistors R1 and R2, and is maintained at a value higher than the set potential Vth3 as shown in FIG.

  That is, when the time during which the power supply from the AC power supply AC is interrupted, such as an instantaneous power failure, is short, the potential maintaining circuit 13 receives the power supply from the smoothing capacitor C1 and sets the potential Vtr at the trigger terminal tr of the start timer circuit 10. By maintaining the value higher than the set potential Vth3, the activation timer circuit 10 is invalidated as shown in FIG. 6B. As a result, as shown in FIG. 6D, the high frequency power supply circuit 2 starts to give a high frequency output Vcoil to the induction coil 7 simultaneously with the return of the AC power supply AC, and restarts the electrodeless discharge lamp 1.

  In addition, when the power supply from the AC power supply AC is interrupted for a long time, the charge charged in the smoothing capacitor C1 is reduced, and the output voltage Vdc of the DC power supply circuit is lower than the drive voltage of the high frequency power supply circuit 2. The potential at the output terminal of the reference power supply circuit 12 supplied with power from the smoothing capacitor C1 is lowered, and the switching element Q6 is turned off. Therefore, since the potential Vtr of the trigger terminal tr becomes equal to the potential of the connection point between the resistor R1 and the resistor R2 in the voltage detection circuit 9 while the AC power supply AC is stopped, the potential Vtr is lower than the set potential Vth3. In this case, when the AC power supply AC is restored, the potential Vtr of the trigger terminal tr of the activation timer circuit 10 rises so as to exceed the set potential Vth3. Therefore, when the activation timer circuit 10 is triggered, the rise time is the same as in the conventional configuration. The electrodeless discharge lamp 1 is restarted after a lapse of Ts, and as a result, starting failure such as oscillation frequency and amplitude being unstable at the time of starting the electrodeless discharge lamp 1 is prevented and stable starting is realized.

  In addition, a configuration in which power factor correction control is employed by using, for example, a Motorola MC33262 for the output control unit 4 in the DC power supply circuit is also conceivable. In that case, the voltage detected by the voltage detection circuit provided for the multiplier input (No. 3 pin) for detecting the waveform of the AC power supply AC for power factor improvement is diverted. There is no need to provide such a voltage detection circuit 9 separately, and the number of parts can be reduced, and cost reduction can be expected. Other configurations and functions are the same as those of the first embodiment.

It is a circuit diagram which shows Embodiment 1 of this invention. It is a time chart which shows operation | movement same as the above. It is a time chart which shows operation | movement at the time of providing a lighting continuous means on the same as the above. It is a time chart which shows operation | movement at the time of providing a lighting continuous means on the same as the above. It is a circuit diagram which shows Embodiment 2 of this invention. It is a time chart which shows operation | movement same as the above. It is a circuit diagram which shows a conventional structure. It is a time chart which shows operation | movement same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrodeless discharge lamp 2 High frequency power supply circuit 6 Drive circuit 7 Induction coil 8 Valve 9 Voltage detection circuit 10 Start-up timer circuit 11 Signal invalidity circuit 13 Potential maintenance circuit AC AC power supply C1 Smoothing capacitor (smoothing part)
tr Trigger terminal Ts Rise time Vcoil High frequency output Vst Stop signal Vth3 Setting potential

Claims (7)

  An induction coil is placed in close proximity to a DC power supply circuit equipped with a smoothing unit that outputs DC voltage supplied from an AC power supply and smoothes the output voltage, and a valve that converts the output of the DC power supply circuit into a high-frequency output and encloses a discharge gas. The high frequency power supply circuit that applies the high frequency output to the induction coil to the electrodeless discharge lamp to light the electrodeless discharge lamp, and the output voltage of the DC power supply circuit after the supply of power from the AC power supply to the DC power supply circuit is started. A start-up timer circuit that stops the operation of the high-frequency power supply circuit during the rise time until the drive voltage required for the operation of the high-frequency power supply circuit is reached, Provided with an instantaneous power failure countermeasure means that disables the start-up timer circuit and restarts the electrodeless discharge lamp when the AC power supply is restored for a while An electrodeless discharge lamp lighting apparatus.   The start-up timer circuit outputs a stop signal over the rise time, the high-frequency power supply circuit includes a drive circuit that stops high-frequency output during a period of receiving the stop signal, and the instantaneous power failure countermeasure means includes a stop signal 2. The electrodeless discharge lamp lighting device according to claim 1, further comprising a signal invalidation circuit for invalidation.   3. The electrodeless discharge lamp lighting device according to claim 2, wherein the signal invalidation circuit operates at least during the start-up time after the AC power supply is restored.   A voltage detection circuit for detecting a voltage proportional to an absolute value of the AC power supply; and the activation timer circuit includes a trigger terminal to which a voltage detected by the voltage detection circuit is applied, and the potential of the trigger terminal is a predetermined set potential. 2. The operation of the high frequency power supply circuit is stopped by rising so as to exceed, and the instantaneous power failure countermeasure means comprises a potential maintaining circuit for maintaining the potential of the trigger terminal at a value larger than the set potential. The electrodeless discharge lamp lighting device described.   5. The electrodeless discharge lamp lighting device according to claim 4, wherein the potential maintaining circuit operates during at least an output voltage of the DC power supply circuit being equal to or higher than the driving voltage after the AC power supply is stopped.   There is provided a lighting maintaining means for continuing the lighting of the electrodeless discharge lamp by reducing the output voltage of the high-frequency power supply circuit at least while the output voltage of the DC power supply circuit is equal to or higher than the driving voltage after the AC power supply is stopped. The electrodeless discharge lamp lighting device according to any one of claims 1 to 5, characterized in that: An induction coil is placed in close proximity to a DC power supply circuit equipped with a smoothing unit that outputs DC voltage supplied from an AC power supply and smoothes the output voltage, and a valve that converts the output of the DC power supply circuit into a high-frequency output and encloses a discharge gas. A high frequency power supply circuit that turns on the electrodeless discharge lamp by supplying the high frequency output to the induction coil with respect to the electrodeless discharge lamp, a voltage detection circuit that detects a voltage proportional to the absolute value of the AC power supply, and a detection of the voltage detection circuit A trigger terminal to which a voltage to be applied is applied, and is triggered until the output voltage of the DC power supply circuit reaches the drive voltage required for the operation of the high-frequency power supply circuit, triggered by rising so that the potential of the trigger terminal exceeds a predetermined set potential. A start timer circuit that outputs a stop signal at an upper time, and the high frequency power supply circuit is a driver that stops the high frequency output during a period of receiving the stop signal. A circuit that is connected between the start timer circuit and the drive circuit and disables the stop signal when the AC power is restored while the output voltage of the DC power circuit is equal to or higher than the drive voltage from the stop of the AC power supply An electrodeless discharge lamp lighting device, characterized in that a circuit is provided and the signal invalid circuit operates at least for a rise time after the AC power supply is restored.

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