JPH01154498A - Lighting device for discharge lamp - Google Patents

Abstract

PURPOSE:To facilitate the discrimination and improve ease of maintenance of a discharge lamp by causing to function an informing circuit, which does not control the oscillation of an inverter circuit when the last stage in the life of the discharge lamp is detected, by means of pover of commercial dc power source and by causing a display lamp provided in the informing circuit to light. CONSTITUTION:A detection coil 5 and a detection circuit 7 detect the life of a discharge lamp 6 by capturing a voltage rise on time secondary side of an oscillation transformer 14 based on half-ware 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. Since the power source of the informing circuit 41 which informs the life by lighting the display lamp 12 comes from a commercial power source 1, the informing circuit 41 continues to inform of the location of the discharge lamp 6 even if a wall switch 2 is turned off after the functioning start of the informing circuit. This improves the ease of maintenance of the discharge lamp.

Description

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

(Prior Art) Conventionally, in a discharge lamp lighting device equipped with an inverter lighting circuit, devices such as those shown in FIGS. 3 and 4 have been used to detect and notify the end of the life of a discharge lamp. As schematically shown in Fig. 3, a rectifier circuit 3 is connected to a commercial AC power source 1 via a wall switch 2, an inverter lighting circuit 4 is connected to this rectifier circuit 3, and this lighting circuit is 4 is provided with a detection winding 5, a discharge lamp 6 is connected to the output end of the lighting circuit 4, and the detection winding 5 is connected to the output terminal of the lighting circuit 4.
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. In addition, the inverter oscillation circuit 11 has N at both ends of a mutual circuit formed by connecting a primary winding 14D 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 first end is 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 voltage circuit 22 includes a rectifier diode 2 in a feedback winding 23 that is in phase with the negative winding 141).
A smoothing capacitor 25 is connected in parallel to the capacitor 24 with the polarity shown, and a resistor 26 is connected to the connection point between the diode 24 and the capacitor 25. resistance 26
is connected to the connection point between the base resistance 18° 19 and the base starting 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 M source. Then, the primary winding 14P 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 up 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 that when this potential exceeds the Zener voltage of the trigger element 32, the trigger element 32 becomes conductive and outputs a trigger 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. Not only that, but if the wall switch 2 is turned off while the wall switch 2 is left unattended, the discharge lamp 6 will naturally go out. It is difficult to easily identify whether a discharge lamp has reached the end of its life, and therefore it is troublesome to replace a discharge lamp whose life has come to an end.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a discharge lamp lighting device that can notify the end of a discharge lamp's life without causing discomfort, and can improve the maintainability of the discharge lamp.

[Means for solving problems]

As shown in FIG. 1, the present invention connects an inverter lighting circuit 4 to a DC power supply 3 that is connected to a commercial AC power supply 1 via a wall switch 2, and While connecting the discharge lamp 6 to the winding 14S,
Applied to a discharge lamp lighting device in which a detection winding 5 is provided on the secondary side of the oscillation 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. A notification circuit 41 is connected to the output terminal of the detection circuit 7, and receives a trigger output from the detection circuit 7 to turn on an indicator light 42 indicating the lifespan of the discharge lamp 6. By connecting to the AC power source 1, the above-mentioned conventional problems are solved.

[Effect]

In the present invention, the detection winding 5 and the detection circuit 7 detect the end of the life 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 is half-filled even at the end of its life. The lighting state is maintained by wave discharge. Therefore, at the end of the life of the discharge lamp 6, the life of the discharge lamp 6 can be notified by lighting the indicator lamp 6 without blinking the discharge lamp 6. Since the power source for the notification circuit 41 that performs such notification is obtained from the commercial electric current H1, even if the wall switch 2 is turned off to start the notification operation, the notification circuit 41 will not be able to connect the discharge lamp 6 whose life has expired. Continue to inform of the whereabouts of.

〔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
A smoothing capacitor 47 is connected in parallel to a rectifier circuit 43 consisting of a diode bridge circuit connected to 1, and a series circuit of a resistor 44, an indicator light 42, and a thyristor 45 is connected in parallel to this. The gate of the thyristor 45 is connected to the trigger element 32 of the trigger circuit in the detection circuit 7.
The resistor 33 is connected to the connection point of the resistor 33. This circuit 41 is provided with a normally closed reset switch 46, although the position is not limited to that shown. Note that the above-mentioned notification circuit 41 is provided in place of the conventional generation/stop circuit described using FIGS. 3 and 4.

According to the discharge lamp lighting device equipped with such a notification circuit 41, the lighting circuit 4 can be started by turning on the wall switch 2 and giving the output of the rectifier circuit 3 to the inverter lighting circuit 4, and the oscillation transformer 14 Feedback from the base winding 21 of the current passing through the primary winding 14P and the base power supply circuit 22
The application of a DC voltage to the transistors 16.17 repeatedly turns them on and off alternately. Thereby, the DC voltage supplied from the rectifier circuit 3 is converted into a high-frequency voltage, and the voltage is boosted and discharged to the secondary winding wA14S of the oscillation transformer 14, so that the discharge lamp 6 can be lit.

When the discharge lamp 6 reaches the end of its life and the half-wave discharge phenomenon becomes strong, the secondary winding '145 of the oscillation transformer 14 becomes
Since the voltage induced in the detection winding 5 is also increased in proportion to the increase in voltage, 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 gives a trigger output to the gate of the thyristor 45 included in the notification circuit 41.

Then, the thyristor 45 becomes conductive, and from then on, the thyristor 45 maintains the conductive state by a self-maintaining function. As described above, when the thyristor 45 becomes conductive, the commercial AC power supply 1 is supplied to the indicator lamp 42 via the rectifier circuit 43, the smoothing capacitor 47, and the resistor 44, so the indicator lamp 42 lights up and the discharge lamp 6 turns on. Notifies that the device has reached the end of its lifespan. Since the power source for the notification by the indicator lamp 42 is obtained from the commercial electric current 81, the notification by the indicator light 42 continues even if the wall switch 2 is turned off. Further, 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, so the wall switch 2 is turned off. Until then, the inverter oscillation circuit 11 continues to oscillate, and the discharge lamp 6 continues to be lit.

That is, the end of the life of the discharge lamp 6 is not notified by blinking the discharge lamp 6 at the end of its life as described above, but the end of the life of the discharge lamp 6 is notified by lighting the indicator light 42 provided in the notification circuit 41, and the end of the life of the discharge lamp 6 is notified. Since the lighting device is configured to continue lighting, 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. Moreover, since the power supply for the notification circuit 41 is determined from the commercial AC power supply 1, even if the wall switch 2 is turned off at the moment the notification operation starts, the notification circuit 41 can continue to notify the whereabouts of the discharge lamp 6 that has reached the end of its service life. can. Therefore, when a large number of discharge lamps are lined up, it is possible to easily identify which discharge lamp is at the end of its service life by lighting the indicator lamp 42, and its replacement can be facilitated.

Furthermore, in order to cancel the notification operation of the notification circuit 41, it is sufficient to open and close the reset switch 46, whereby the thyristor 45 becomes non-conductive, and the notification circuit 41 prepares for the next notification operation.

(Effects of the Invention) As explained above, the present invention provides a notification circuit that does not control the oscillation of the inverter lighting circuit when the detection winding and the detection circuit detect the end of the life of the discharge lamp. It is powered by electricity to light up the indicator light included in the notification circuit, and this lighting is maintained regardless of whether the wall switch is opened or closed, making it ideal for lighting discharge lamps used in locations where replacement cannot be done immediately. The device has the effect of not only being able to notify the end of a discharge lamp's life without causing discomfort due to flashing of the discharge lamp, but also of being able to easily identify discharge lamps that have reached the end of their life, thereby improving maintainability.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the concept of the present invention, and FIG. 2 is an electric circuit diagram showing an embodiment of the present invention. Fig. 3 is a block diagram showing the concept of the conventional example, and Fig. 4 is 1! of the conventional example. It is an air circuit diagram. 1...Commercial AC N source, 2...Sato switch, 3...
DC 1i (rectifier circuit), 4... Inverter lighting circuit,
5... Detection winding, 6... Discharge lamp, 7... Detection circuit, 14... Release transformer, 145... Secondary winding,
41...Notification circuit, 42...Indicator light. Applicant's agent Patent attorney Nihiko Suzue 1. Bakujo, Senwa Ei, 2. Kabe Sui 1. now
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Claims (1)

[Claims] An inverter lighting circuit is connected to a DC power source connected to a commercial AC power source via a wall switch, and a discharge lamp is connected to a secondary winding of an oscillation transformer provided with this lighting circuit,
In a discharge lamp lighting device, a detection winding is provided on the secondary side of the oscillation transformer, and a detection circuit for detecting a half-wave discharge phenomenon that occurs at the end of the life of the discharge lamp is connected to the detection winding, comprising: an output of the detection circuit; A discharge lamp lighting device characterized in that an alarm circuit is connected to one end of the detector circuit for receiving a trigger output from the detection circuit and lighting an indicator light indicating the lifespan of the discharge lamp, and the alarm circuit is connected to the commercial AC power source. Device.