JPS58192289A - Device for firing discharge lamp - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-frequency superimposed type lamp lighting device using a high-pressure discharge lamp as a load.
To reduce the current and prevent damage to the electrodes of the discharge lamp, and to provide a vertical configuration.

FIG. 1 shows an example of a conventional high-frequency superimposition type discharge lamp lighting device, in which a discharge lamp 3 is connected via a coil 2 to both ends of a low-pitched wave source 1 composed of a commercial power source, etc. High frequency type consisting of inverter, etc.! The same discharge lamp 3 described above is connected to both ends of the lamp 4 via a capacitor 5.

Such a lighting device is, as is well known, a discharge lamp 3.
By supplying lighting maintenance power or restriking power from both the low frequency power source 1 and the high frequency type #4, the entire device can be miniaturized while maintaining rated lighting.

However, when such a lighting device is applied to a high-pressure discharge lamp such as a mercury lamp, as is well known, the high-pressure discharge lamp exhibits an extremely low impedance immediately after starting, so the discharge lamp is almost in a short-circuit state, and the low-frequency power supply 1 and the high-frequency power supply Each input current from 4 is very large (and there is a risk of damaging the electrodes of the high-pressure discharge lamp.

In addition, the wholesale power supply 1[&4 is configured with an inverter etc. supplied with power from the low frequency type #1, and the high frequency power supply 4, coil 2, capacitor 5, etc. are collectively housed in a case and the ballast is installed. If 6 is formed, low frequency 1! At startup, a large current flows through the output line 7.7 from iv1 and the output line 8.8 from the ballast 6 to the discharge lamp 3. When is long, the electrical wiring capacitance becomes g-.

The present invention has been made in view of these drawbacks, and will be described below based on embodiments shown in the drawings.

Figure 2 is a block circuit diagram showing the principle of this @Ming.
A high-pressure discharge lamp 3 is connected via a coil 2 serving as an impedance, and a capacitor 5 serving as a current-limiting impedance is connected to both ends of an insect-frequency electric current 4 formed by an inverter or the like supplied with power from a low frequency of 1 m-1. The same high pressure discharge lamps 3 are connected. Then, connect the voltage detector #1lii [89] in parallel with the high pressure discharge lamp 3, and
The output signal of is the ionization control circuit i which controls the output of the frequency control circuit 4.

sent to.

In such a device, the voltage detection circuit 9 is the voltage detection circuit Va.
The detection voltage (i.e. the voltage across the lamp) is -
When the value is lower than the value Va, an output signal is sent to the power supply control circuit 1°, and the power supply control circuit 10 uses the output signal to control the frequency power supply 4.
The output stop signal is sent to the high frequency signal 11111, and the output signal 4 is stopped.

Here, the threshold value V must be set lower than the rated lamp voltage VL of the discharge lamp 3.

Therefore, according to the circuit shown in FIG. 2, as shown in FIG. 3, before the discharge lamp 3 starts, a no-load secondary voltage or a low frequency voltage V appears at both ends of the discharge lamp 3. Since the ionization voltage V- is naturally larger than the threshold value va, the true frequency electric current g4 emits a high frequency wave, and in addition to the low wave voltage VmK, a high frequency power supply voltage is also applied to the high pressure discharge lamp 3. starts at time t1. When the high voltage illumination 3 starts, the lamp voltage v6 decreases by +1 after starting 1 and becomes smaller than the value Va, so the voltage detection circuit 9 sends the power supply control circuit to the power supply @III. (b) Route W is a high frequency power source 4
Send an output stop signal to 6 to stop the output of the high frequency power source 4.
° [For this reason, from time t onwards, when the lamp voltage vt reaches the threshold value Va, 1iJ
Between 4t and t, high-pressure discharge lamp No. 3 is supplied with only the low-level wave from the low-shoulder wave I11, and the incoming electric current to high-pressure discharge lamp 3 is reduced by the garden frequency electric machine. Damage to the electrodes is prevented.

Also, a power line 8. from the high frequency power source 4 to the high pressure discharge lamp 8.
In addition to being able to reduce the size of the current capacitor, if all components from the low-frequency electric cape 1 to the high-pressure discharge lamp 3 are collectively configured as a ballast 6, the current of 116117.7 from the low-frequency electric cape 1 can be reduced. FIG. 4 is a circuit diagram showing a specific example, in which the voltage detection circuit 9 includes a detection transformer 90 and a rectifying and smoothing circuit s9 connected to both ends of the secondary winding of the transformer 90.
1 and a Zener diode 92 for direct setting of the hook connected to the output end of the rectifying and smoothing circuit section 91 and voltage dividing resistors 93 and 94.
The power supply control circuit 10 is composed of a series circuit including a relay 100 controlled by the transistor 95, and a transistor 95 for generating an output signal, which is controlled on and off by its divided voltage output. 4 is constituted by an inverter 40 supplied with power from the low frequency 1F[, 1 via a relay switch S. Note that 101 in the figure is a control power supply section for driving the relay.

In this embodiment, the operation at time t1cD when the lamp voltage η exceeds the threshold value Va is as follows: the output voltage of the am smoothing circuit 91 reaches the Zener voltage and the Zener diode 9
Current flows through the transistor 2, turning on the transistor 95. In response to this, the relay 100 is turned off, the relay thickness switch S formed between the regular contacts is closed, the inverter 4o is activated, and high frequency output is generated.

Of course, after the starting time t1, a high frequency output is generated in the same manner as above, and at time 1.1 when the lamp voltage vt is lower than the threshold value Va. ．． 1. During this period, no current flows through the Zener diode 92, so the relay switch S is open and the inverter 4o does not operate.

As described above, in the high-frequency superimposition type discharge lamp lighting device of the present invention, the lamp voltage threshold for stopping the output of high-frequency power is set lower than the rated lamp voltage, and this is used for the high-pressure discharge lamp Kji. While fully utilizing the advantages of the high-frequency superimposition method during rated lighting, it is possible to automatically stop the output of the high-pressure discharge lamp for a predetermined period after starting, suppressing the input power of the high-pressure discharge lamp and protecting the electrodes. In addition, the wiring space can be reduced, and the circuit configuration is simple, making it possible to obtain a highly practical discharge lamp lighting device.

It should be noted that the present invention is of course not limited to the above-described embodiments, and there is no need to collectively accommodate each component to form a single part called the ballast 6, and it is not necessary to construct a single part called the ballast 6, such as in a street light, etc., which has a long wiring distance. There is no requirement to apply it to anything.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a conventional example, FIGS. 2 and 94 are block circuit diagrams and specific circuit diagrams showing an embodiment of the present invention, respectively, and FIG. 3 is a graph for explaining the operation of the embodiment. 1...Low frequency ionization, 3...High pressure discharge lamp, 4...High frequency 111111.9...Voltage detection circuit, 10...
・Power supply control circuit.

Claims (1)

[Claims] (1) A low-frequency power supply, a high-frequency power supply, a high-pressure discharge lamp that serves as a common load for the low-frequency power supply and the noodle frequency power supply, and a rated lamp that detects the voltage across the pressure discharge lamp and that voltage is a high-pressure discharge illusion. A discharge lamp lighting device comprising: a voltage detection circuit that generates an output signal when the voltage is lower than a threshold value; and an electric control circuit that receives the output signal and sends an output stop signal to a high-frequency power source. Device.