JPH01154497A - Lighting device for discharge lamp - Google Patents

Abstract

PURPOSE:To prevent progress in the life of a discharge lamp in the last stage of the life by causing a display lamp provided in an informing circuit to continue lighting at the time the life of the discharge lamp is detected and by turning the discharge lamp off after a specified period of time by means of a timer. CONSTITUTION:A detection coil 5 and a detection circuit 7 detect the life of a discharge lamp 6 by capturing a voltage rise on the secondary side of an oscillation transformer 14 based on half-wave discharge phenomenon of the discharge lamp 6. An informing circuit 14 is actuated by receiving a trigger output issued when the detection circuit 7 detects the life of the discharge lamp 6, and causes a display lamp 42 to light. At the same time, the discharge lamp 6 continues the lighting condition with the half-wave discharge even in the last stage of the life of the lamp 6. A timer 51 detects the lighting of the display lamp 42 of the informing circuit 41 and works, and actuates an oscillation stop circuit 8 after a specified period of time of the detection. This makes it possible to prevent progress in the life of the discharge lamp in the last stage of the life.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a discharge lamp lighting device equipped with an inverter lighting circuit.

[Conventional technology]

Conventionally, in a discharge lamp lighting device provided with an inverter lighting circuit, devices such as those shown in FIGS. 3 and 4 are known as devices that detect and notify the end of the life of the discharge lamp. There is. As schematically shown in Fig. 3, a rectifier circuit 3 is connected to the commercial commercial current m1 via a wall switch 2, an inverter lighting circuit 4 is connected to the rectifier circuit 3, and a detection voltage is connected to the lighting circuit 4. A discharge lamp 6 is connected to the output end of the lighting circuit 4, and a detection winding 5 is provided.
A detection circuit 7 is connected to the detection circuit 7, and an oscillation stop circuit 8 is connected to the detection circuit 7. The inverter lighting circuit 4 includes an inverter oscillation circuit 11 that converts DC voltage into high frequency voltage.
The inverter oscillation circuit 11 includes a starting circuit 12 for starting the oscillation circuit 11, and a feedback circuit 13 for maintaining the oscillation of the inverter oscillation circuit 11.

As shown in FIG. 4, the rectifier circuit 3 used as a DC power source is formed by a diode bridge circuit 9. Further, the inverter oscillation circuit 11 is connected to both ends of a common camera circuit formed by connecting the primary winding 14p of a magnetic leakage type oscillation transformer 14 and a capacitor 15 in parallel.
It is formed by connecting PN type transistors 16 and 17, with the secondary winding 14S of the oscillation transformer 14 serving as an output end. The starting circuit 12 includes a base resistor 18 connected to the base of the transistor 16, a base resistor 19 connected to the base of the transistor 17, and both these resistors 18.
．． 19 and a base starting resistor 20 connected between the positive terminal of the rectifier circuit 3 through a constant current choke coil 10.

The feedback circuit 13 consists of a base winding 21 of an oscillation transformer 14 whose winding ends are connected to the connection point between the base of each transistor 16.17 and a base resistor 18.19, and a base power supply circuit 22. The circuit 22 includes the negative winding 1
A smoothing capacitor 25 is connected in parallel to a feedback winding 23 having the same phase as 4p via a rectifying diode 24 with the polarity shown, and a resistor 26 is connected to the connection point between the diode 24 and the capacitor 25. . The resistor 26 is connected to the connection point between the base resistance 18, 19 and the base startup resistance 20 in the starting circuit 12, and the connection point between the feedback winding 23 and the capacitor 25 is connected to the emitter of the transistor 16.

The inverter lighting circuit 4 having such a configuration is activated by being supplied with the output of the rectifier circuit 3 as a DC power source. Then, the primary winding 14 of the oscillation transformer 14
The current flowing through the base winding 21 returns from the base winding 21. Furthermore, since a voltage whose phase and circuit line match the voltage of the negative winding 14P is induced in the feedback winding 23, the voltage is rectified by the diode 24 and smoothed by the capacitor 25.
The DC voltage of the circuit waveform can be obtained, and this is the resistance 26.18
is applied to the base of transistor 16 through resistor 26.19, and to the base of transistor 17 through resistor 26.19. Therefore, transistors 16 and 17 are alternately turned on and off. Thereby, the rectifier circuit 3
The DC voltage supplied from the oscillating transformer 14 is converted into a high-frequency voltage, and the voltage is boosted and discharged to the secondary winding 14s of the oscillation transformer 14, thereby lighting the discharge lamp 6.

The detection winding 5 is provided on the secondary side of the oscillation transformer 14. The detection circuit 7 includes a rectifier circuit 27 formed of a diode bridge circuit that rectifies the detection output of the detection winding 5.
A resistor 28 and a capacitor 29 for smoothing the output are connected in parallel to the output terminal of the circuit, and a time constant circuit consisting of a resistor 30 and a capacitor 31 is connected in parallel to the capacitor 29.
A trigger circuit including a trigger element 32 and a resistor 33 is connected to a capacitor 31. For example, a Zener diode is used as the trigger element, but a two-terminal thyristor may also be used instead.

Further, the oscillation stop circuit 8 is formed of an NPN type transistor. The base and emitter of this transistor 8 are connected through the resistor 33 of the trigger circuit, and the emitter is connected to the feedback winding 23 and the capacitor 2.
It is also connected to the connection point with 5. The collector of this transistor 8 is connected to the connection point between the base resistances 18 and 19 and the base starting resistor 20 in the starting circuit 12.

By the way, it is known that the half-wave discharge phenomenon becomes stronger when the discharge lamp 6 reaches the end of its life. When the discharge lamp 6 is in such a state, the secondary winding 14 of the oscillation transformer 14
As the voltage of S is increased, the induced voltage of the detection winding 5 is also increased in proportion to it. Then, the potential of the capacitor 31 of the time constant circuit becomes high, so when this potential exceeds the Zener voltage of the trigger element 32, the trigger element 32 becomes conductive and sends a trigger output to the base of the transistor forming the oscillation stop circuit 8. give.

This turns on transistor 8, so
No base current flows through the transistors 16 and 17 of the inverter lighting circuit 4, the oscillation of the inverter oscillation circuit 11 stops, and the discharge lamp 6 goes out. at the same time,
By stopping the oscillation as described above, the output voltage of the detection winding 5 disappears. As a result, the potential of the capacitor 31 of the time constant circuit decreases, causing the trigger element 32 to become non-conductive, thereby turning off the transistor 8 as the oscillation stop circuit. Then, the collector potential of this transistor 8 is restored, and the transistor 16.1 of the inverter oscillation circuit 11
A base current flows through the inverter oscillation circuit 11, and the inverter oscillation circuit 11 restarts oscillation, and the discharge lamp 6 is turned on.

Thereafter, by repeating the above operations, the discharge lamp 6 performs a blinking operation, thereby indicating the end of the life of the discharge lamp 6.

[Problem that the invention seeks to solve]

By the way, when using a discharge lamp in a place where it is not easy to replace it immediately, such as a high ceiling in a hall or the ceiling of a moving vehicle, there is no choice but to leave it as is, regardless of the above-mentioned lifespan notification. As described above, in the conventional lighting device, the discharge lamp 6 is blinked at the end of its life to notify the end of its life.
Since the flashing notification is left unattended, there is a problem in that it gives a very unpleasant feeling.

Conventionally, as shown in Japanese Patent Application Laid-Open No. 62-163293, at the end of the life of a discharge lamp, the discharge lamp is made to blink, the number of blinks is detected, and when a predetermined number of blinks is detected, an oscillation stop circuit is A device that continues to stop the oscillation operation by driving the oscillator is also being considered.

However, even in this conventional example, the flashing of the discharge lamp still signals the end of its lifespan. Therefore, if the flashing period is set for a long time, as already mentioned, it will cause a very unpleasant feeling, and the flashing will cause discomfort. If the period of time is short, there is a problem that there will be fewer notifications of the end of the life of the tli lamp.

Therefore, the present invention provides a discharge lamp lighting device that can notify the end of the discharge lamp's life even after the discharge lamp has been turned off without causing discomfort, and can prevent progression of the discharge lamp's life at the end of the life. It's about doing.

[Means for solving problems]

As shown in FIG. 1, the present invention connects an inverter lighting circuit 4 to a DC power source 3, connects a discharge lamp 6 to a secondary winding 14S of an oscillation transformer 14 included in this lighting circuit 4, and A detection winding 5 is provided on the secondary side of the transformer 14, and a detection circuit 7 for detecting a half-wave discharge phenomenon that occurs at the end of the life of the discharge lamp 6 is connected to the detection winding 5. The present invention is applied to a discharge lamp lighting device in which an oscillation stop circuit 8 for stopping oscillation of the inverter lighting circuit 4 is operated. In order to solve the above-mentioned conventional problems, the present invention turns on an indicator light 42 connected to the output end of the detection circuit 7 and indicating the lifespan of the discharge lamp 6 upon receiving the trigger output of the detection circuit 7. a notification circuit 41 connected to the notification circuit 41, and the indicator light 4 connected to the notification circuit 41.
The timer 51 starts its operation upon detecting the lighting of 2, and has an output terminal connected to the oscillation stop circuit 8. In addition, the present invention is characterized in that the oscillation stop circuit 8 continues to stop the oscillation of the inverter lighting circuit 4 after its operation.

[Effect]

In the present invention, the detection winding 5 and the detection circuit 7 detect the life span of the discharge lamp 6 by detecting the voltage rise on the secondary side of the oscillation transformer 14 based on the half-wave discharge phenomenon of the discharge lamp 6.

Further, the notification circuit 41 is operated in response to a trigger output issued when the detection circuit 7 detects the end of the life of the discharge lamp 6, and lights up the indicator light 42, and the discharge lamp 6 discharges half-wave discharge even at the end of its life. The lighting state is maintained by Therefore, at the end of the life of the discharge lamp 6, it is possible to notify the end of the life of the discharge lamp 6 by lighting the indicator light 6 without blinking the discharge lamp 6, and the indicator light 42 continues until the power is cut off. and lights up. And timer 51
operates by detecting the lighting of the indicator light 42 of the notification circuit 41 as described above, and operates the start/stop north circuit 8 after a certain period of time from the time of this detection. Then, the excavation stop circuit 8 stops the oscillation of the inverter lighting circuit 4 and turns off the discharge lamp 6. Although the output voltage of the detection winding 5 disappears when the discharge lamp 6 is turned off, there is a notification circuit 41 between the detection circuit 7 and the excavation stop circuit 8 which continues the notification operation. A timer 51 is provided,
After these have been operated for -degrees, the operating state is not influenced by the output voltage of the detection winding 5, so the oscillation stop circuit 8 maintains the oscillation stop state of the inverter lighting circuit 4 and resumes excavation. I have nothing to do.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

In the description, the same components as those of the conventional technology described using FIGS. 3 and 4 will be given the same reference numerals, and the description thereof will be omitted, and only the different components will be described.

The notification circuit indicated by 41 in the figure is for receiving a trigger output from the detection circuit 7 and lighting up an indicator lamp 42 to notify the life span of the discharge lamp 6. In other words, this circuit 41 is constructed by connecting a series circuit of a resistor 43, an indicator light 42, and a thyristor 44 to a rectifier circuit 3 as a DC power source, and connects the gate of the thyristor 44 to the trigger circuit in the detection circuit 7. The trigger element 32 is connected to the connection point between the trigger element 32 and the resistor 33. Further, a timer 51 is connected to the rectifier circuit 3 via a base starting resistor 20. This timer 5
1 is formed from a clock circuit 52 and a time constant circuit consisting of a resistor 53 and a capacitor 54. The input end of the timer circuit 52 is connected to the connection point between the indicator light 42 of the alarm' circuit 41 and the thyristor 44 via a diode 55 having the polarity shown. Further, the excavation stop circuit 8 that stops the oscillation of the inverter lighting circuit 4 is formed of a thyristor in order to continue to stop the excavation of the lighting circuit 4 after its operation, and has a gate connected to the output terminal of the clock circuit 52. are connected via a resistor 56. Note that the gate and cathode of the transistor 8 are connected via a resistor 57.

According to the discharge lamp lighting device in which such a notification circuit 41 and a timer 51 are provided between the detection circuit 7 and the oscillation stop circuit (thyristor) 8, when the wall switch 2 is turned on, the inverter lighting circuit 4 receives rectification. By supplying the output of the circuit 3, this lighting circuit 4 can be activated, and the primary winding 14 of the oscillation transformer 14? By feeding back current from the base winding 21 through the base power supply circuit 22 and applying a DC voltage obtained from the base power supply circuit 22 to the transistors 16.17, these transistors 16.
17 are repeatedly turned on and off alternately.

Thereby, the DC voltage supplied from the rectifier circuit 3 is converted into a high frequency voltage, and the secondary winding 14 of the excavation transformer 14 is
The discharge lamp 6 can be turned on by increasing the pressure to S and discharging it.

When the discharge lamp 6 reaches the end of its life and the half-wave discharge phenomenon becomes stronger, the voltage of the secondary winding 145 of the oscillation transformer 14 is increased, and the voltage of the detection winding 5 is increased proportionally.
Since the induced voltage of is also increased, this is detected by the detection circuit 7. In other words, the potential of the capacitor 31 of the time constant circuit included in the detection circuit 7 becomes high. Then, when this potential exceeds the Zener voltage of the trigger element 32, the trigger element 32 becomes conductive at that point, so the detection circuit 7 provides an output to the gate of the thyristor 44 included in the notification circuit 41.

Then, the thyristor 44 becomes conductive, and after that, the thyristor 44 maintains the conductive state by its self-holding function. As described above, when the thyristor 44 becomes conductive, the DC output from the rectifier circuit 3 is supplied to the indicator lamp 42 via the resistor 43, so the indicator lamp 42 lights up and the discharge lamp 6 is in the initial state at the end of its life. Notify that this has been reached.

The predictive notification of the life of the discharge lamp 6 by the indicator lamp 42 is continued until the wall switch 2 is turned off by the self-holding function of the thyristor 44. In addition, since the trigger output of the detection circuit 7 only starts the operation of the notification circuit 41 as described above, and does not control the oscillation operation of the inverter lighting circuit 4, the inverter oscillation circuit 11 cannot be detected as before. continues, and the discharge lamp 6 continues to be lit.

That is, instead of letting the discharge lamp 6 blink at the end of its lifespan as described above to notify the end of its lifespan, the lifespan of the discharge lamp 6 is predicted and notified by lighting the indicator light 42 included in the notification circuit 41. Since the device is configured to continue lighting the discharge lamp 6, it is possible to notify the end of the life of the discharge lamp 6 without causing discomfort as a lighting device for the discharge lamp 6 used in a place where replacement cannot be performed immediately.

When the thyristor 44 is turned on to start the notification operation of the notification circuit 41 as described above, the potential on the cathode side of the diode 55 decreases accordingly. Due to this change, the diode 55 detects the lighting of the indicator lamp 42, so the timer circuit 52 of the timer 51 is triggered and the timer 51 starts operating. Therefore, the clock circuit 52 outputs the signal with a delay of a time determined by a time constant circuit including a resistor 53 and a capacitor 54.

Then, the timer 51 provides an output via the resistor 56 to the gate of the thyristor 8 as an oscillation stop circuit, so the thyristor 8 becomes conductive and from then on,
Thyristor 8 maintains a conductive state by a self-holding function. Due to this conduction, the base electric current no longer flows to the transistors 16 and 17 of the inverter lighting circuit 4, and the oscillation of the inverter oscillation circuit 11 is stopped, and the discharge lamp 6
goes out.

Therefore, since the discharge lamp 6 does not continue lighting indefinitely at the end of its life, problems caused by continuous lighting at the end of its life, such as unstable lighting of the discharge lamp 6, intermittent lighting, abnormal light emission, blackening of the tube end, etc. i! ! There is no possibility of extreme drop, excessive temperature rise of the inverter lighting circuit 4, etc.

Moreover, even after the discharge lamp 6 is turned off as described above, as long as the wall switch 2 is turned on, the notification circuit 4
Since the lamp 1 continues the notification operation, the location of the discharge lamp 6 that has reached the end of its life can be easily identified by the notification, and its replacement can be facilitated.

Further, in order to cancel the notification state and the oscillation stop state of the notification circuit 41, it is sufficient to open and close the wall switch 2, thereby causing the thyristors 44 and 8 to become non-conductive, respectively.
The notification circuit 41 and the oscillation stop circuit 8 prepare for the next operation.

〔Effect of the invention〕

As explained above, the present invention allows the indicator lamp included in the notification circuit to continue to be lit when the detection winding and the detection circuit detect the lifespan of the discharge lamp, and to emit light regardless of whether the indicator lamp provided in the notification circuit is turned on to notify the discharge lamp lifespan. Since the electric lamp is turned on and the discharge lamp is turned off after a certain period of time from the above-mentioned notification using a timer, it can be used as a lighting device for a discharge lamp used in a place where replacement cannot be performed immediately. It is possible to notify the lifespan of a discharge lamp without giving a pleasant sensation, and this notification can be maintained even after the discharge lamp is turned off, making it easier to identify discharge lamps that have reached the end of their lifespan and improving maintainability.
Moreover, since the discharge lamp is not lit continuously at the end of its life, it is possible to prevent the life of the discharge lamp from progressing at the end of its life.

[Brief explanation of the drawing]

1F is a block diagram showing the concept of the present invention, and FIG. 2 is an electric circuit diagram showing one embodiment of the present invention. FIG. 3 is a block diagram showing the concept of the conventional example, and FIG. 4 is an electric circuit diagram of the conventional example. 3... DC power supply (rectifier circuit), 4... Inverter lighting circuit, 5... Detection winding, 6... Discharge lamp, 7...
Detection circuit, 8... Oscillation stop circuit (thyristor), 14
...Oscillation transformer, 14 ...Secondary winding, 41...
- Notification circuit, 42... Indicator light, 51... Timer. Applicant's representative Patent attorney Takehiko Suzue 6, marriage (denzucho, 7 Separate reprimand [0 approval, 8
Shoulder 57 kHz times M Irisda), 14-t tsubo ← Lance 14S 2 end? , 41 Ienaka Kaisei , 42
Long hit, light, 51 Daima Figure 3

Claims (1)

[Claims] An inverter lighting circuit is connected to a DC power source, a discharge lamp is connected to a secondary winding of an oscillation transformer included in the lighting circuit, and a detection winding is provided on the secondary side of the oscillation transformer. ,
A detection circuit that detects a half-wave discharge phenomenon that occurs at the end of the life of the discharge lamp is connected to the detection winding, and an oscillation stop circuit that stops the oscillation of the inverter lighting circuit based on the detection of this detection circuit is operated. In the discharge lamp lighting device, the discharge lamp lighting device is connected to the output end of the detection circuit, and receives a trigger output from the detection circuit to continue lighting an indicator lamp indicating the lifespan of the discharge lamp; and a timer that detects lighting of the indicator light and starts operation, and has its output terminal connected to the oscillation stop circuit, and after the oscillation stop circuit is operated, the timer starts the operation by detecting the lighting of the indicator light. A discharge lamp lighting device characterized in that the discharge lamp lighting device continues to stop the discharge lamp.