JPS6010598A - 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] [Technical Field of the Invention] This invention provides a high-pressure discharge lamp and a light bulb, and when the high-pressure discharge lamp is started, until the luminous flux of the high-pressure discharge lamp has sufficiently risen.
The present invention relates to a discharge lamp lighting device capable of lighting a light bulb, performing light compensation, and controlling dimming of the high pressure discharge lamp during steady lighting of the high pressure discharge lamp.

[Technical background of the invention and its problems]

Conventionally, as a discharge lamp lighting device having a light compensation function, for example, a high frequency inverter circuit is connected to a DC power source, a metal halide lamp and a starting circuit are connected in parallel to the output terminal of the inverter circuit, and a current is connected to the energizing path to the lamp. A transformer is provided, and the secondary output of the current transformer is rectified into a DC signal, and the DC signal is supplied to a transistor switching circuit to control the switching of the switching circuit to turn on and off light bulbs such as Haloke 97 lamps and incandescent bulbs. Something to control is being considered. In other words, when the lamp current is low, the DC signal level is low and the transistor switching circuit controls the bulb to turn on, and when the lamp is lit and the lamp current increases, the DC signal level increases and the transistor switching circuit controls the bulb to turn off. .

In such a device, the circuit constants are selected so that when the metal halide lamp starts, the bulb is lit to compensate for the light, and when the lamp is lit and the lamp current reaches a steady state, the bulb is turned off.

On the other hand, when attempting to add a new dimming function to such a discharge lamp lighting device with a light compensation function, there is a risk that the light compensation function may be activated during dimming. In other words, since the lamp current decreases during dimming, there is a risk that the bulb may be turned on because it is determined that the metal lamp is in a malfunctioning state or is just starting to start.

[Purpose of the invention]

The present invention has been made to solve such problems, and an object of the present invention is to provide a discharge lamp lighting device in which there is no possibility that the light bulb will light up during dimming of a high-pressure discharge lamp.

[Summary of the invention]

The present invention has means for detecting lamp current or lamp voltage of a high pressure discharge lamp, and has a lower limit set value for the lamp current or lamp voltage, and a lower limit for detecting whether the detected lamp current or lamp voltage is equal to or higher than the lower limit set value. A setting circuit, each having an upper limit setting value for the lamp current or lamp voltage, and an upper limit setting circuit for detecting whether the detected lamp current or lamp tyi pressure is greater than or equal to the upper limit setting value, and the lower limit setting circuit When the lower limit setting value or less is detected or the upper limit setting circuit detects the upper limit setting value or more, the light bulb is controlled to turn on and the lamp current or lamp voltage is between the upper limit setting value and the lower limit setting value during dimming. It is controlled as follows.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, l is a DC' power supply. Above DC power supply 1
The lighting control circuit 2 is connected to. Above lighting control circuit 2
is an inverter transformer, 3.1 pair of transistors 4, 5
and a transistor drive circuit 6 which can alternately turn on and off both transistors 4 and 5 using a rectangular wave signal and control the duty ratio of the rectangular wave signal.
It is composed of a pull-type inverter, and takes out the secondary side output of the inverter transformer 3 via a full-wave rectifier circuit 7 and a choke coil 8.

A starting circuit 9 and a metal halide lamp 10 as a high pressure discharge lamp are connected in parallel to the output terminal of the lighting control circuit 2.

A current transformer 1 for detecting the lamp current of the metal halide lamp 10° is inserted into the full-wave rectifier circuit 7. And the above current transformer 1
The secondary side output of 2 is full-wave rectified through a full-wave rectifier circuit 12, smoothed by a smoothing capacitor 13, and output as a DC voltage.

An upper limit setting circuit 14, a lower limit setting circuit J5, and a circuit 16 are connected in parallel to the smoothing capacitor J3. The upper limit setting circuit No. 4 has a resistor 17.
18 connected in series is provided, and the connection point A of the resistor 17° and 8 is connected to the first voltage regulator diode 19.
is connected to the first transistor 20 of the NPN type through the gate, and the voltage at the connection point A is equal to the *! The voltage is applied between the pace emitter of the first transistor 2o through the constant voltage diode 19 of the first transistor 2o. This upper limit setting circuit 14 sets the lamp current immediately after the metal halide lung 10 arc discharges as the upper limit setting value, and connects point A when this upper limit lamp current is detected by the current transformer 11.
The first transistor 20 is not turned on below the voltage of
Circuit constants are set so that the first transistor 20 is turned on via the first constant voltage diode 19 when a voltage exceeding that voltage is applied. The lower limit setting circuit 15 is provided with a series circuit of a second voltage regulator diode 2 and a resistor 22, and the voltage at a connection point B between the anode of the second voltage regulator diode 2 and the resistor 22 is connected to the resistor 23. It is output via. This lower limit setting circuit 15 has a lamp current immediately before the metal halide transition θ changes from glow discharge to arc discharge as the lower limit setting value, and when this lower limit lamp current is detected by the current transformer 11, both ends of the smoothing capacitor 13 The circuit constants are set so that the second constant voltage diode 2 is conductive when the voltage is higher than that voltage, and the second constant voltage diode 2 is not conductive when the voltage is lower than that voltage. The above-mentioned circuit 16 is a well-known circuit consisting of an NPN type second transistor 24 constituting the front stage and an NPN type third transistor 25 constituting the rear stage, and is the first transistor in the upper limit setting circuit 14. 20 and the opposite side of the connection point B of the resistor 23 in the lower limit setting circuit 15 are connected to the pace of the second transistor 24.

Further, a delay circuit 29 formed by connecting a resistor 27 and a capacitor 28 in series is connected in parallel to the smoothing capacitor 13 via a fourth transistor 26 of NPN type. The pace of the fourth transistor 26 is connected to the collector of the third transistor 25.

Further, a light bulb control circuit 30 is connected to the DC power supply 1. The light bulb control circuit 30 includes a series circuit of an NPN type fifth transistor 3 and a collector resistor 32, and an NPN type sixth transistor.
It consists of a parallel circuit of a series circuit of a transistor 33 and a relay 34 inserted on its collector side, and the pace of the sixth transistor 33 is connected to the collector of the fifth transistor 3. are doing. A resistor 35 is connected between the pace emitter of the fifth transistor 31,
The pace is connected to the connection point between the resistor 27 and the capacitor 28 of the delay circuit 29. Furthermore, a light bulb, for example, a Halodanlan f36, is connected to the DC power supply 1 via the normally open contact 34m of the relay 34.

Next, the operation of the embodiment of the present invention configured as described above will be described.

When the DC power supply was first turned on, it was a metal halide run f1o.
Since the lamp is in a glow discharge state, the lamp's current is approximately zero, the first transistor, z, and 20 are turned off, and the voltage at the connection point B is at a low level. Therefore, the second transistor 24 in the circuit failure is turned off, and the third transistor 24 is turned off.
The fourth transistor 25 is turned on, and the fourth transistor 26 is turned off. However, the fifth transistor 3
is turned off, the sixth transistor 33 is turned on, the relay 34 is operated, its normally open contact 34m is turned on, and the halogen lamp 36 is lit. Then metal halide lamp 1
o gradually transitions from glow discharge to arc discharge and starts lighting. When the metal halide lamp 10 shifts to arc discharge, the lamp current rapidly increases rlk Ic, but at this time, the light voltage across the smoothing capacitor 13 increases, and the voltage at the connection point A causes the first voltage regulator diode 19 to The second transistor 2o of the Schmitt trigger circuit J6 becomes conductive and the first transistor 2o is turned on. The pace voltage of the transistor 24 does not change to the low level, and the halogen lamp 36 remains lit. Thereafter, when the metal halide lung 10 shifts to arc discharge and the lamp current approaches a substantially steady state, the first transistor 20 is turned off. At this time, the second constant voltage diode 2 is conductive. Thus, the second transistor 24 is turned on, the third transistor 25 is turned off, and thereby the fourth transistor 26 is turned on, and charging of the capacitors 2 to 8 of the delay circuit 29 is started. After a predetermined period of time has elapsed, the fifth transistor 3 is turned on by the charging voltage of the capacitor 28, the sixth transistor 33 is turned off, the relay 34 is put into a non-operating state, and the dihalogen lamp 36 is turned off. After the metal halide lamp 10 shifts to arc discharge in this manner, that is, when the rung current becomes less than the upper limit setting value, the halogen lamp 36 is turned off. Furthermore, when the metal halide lamp 10 is glow discharging, the lamp current is 10, and even if the state is the same as the state after arc discharge, the fifth transistor 3 is activated due to the circuit slag and the action of the delay circuit 29. It is never turned on. Therefore, the halogen lamp 36 is kept lit and does not malfunction.

Further, when the metal halide lamp 10 is lit steadily, if the duty ratio of the rectangular wave from the transistor drive circuit 6 is reduced to dim the metal halide lamp 10, the lamp current of the metal halide lamp 10 is reduced. However, the lamp current at this time is larger than the lamp current before the metal halide lamp 10 transitions from glow discharge to arc discharge, that is, compared to the lower limit setting value, so the second constant voltage diode 2 maintains a conductive state, and the second The on state of the transistor 24 does not change. Therefore, Halodan run';f'36 will not be turned on by mistake.

2nd νj (a) is a graph showing the temporal change in the pressure of 100 metal halide lamps in this example;
2(b) is a graph similarly showing the temporal change in the rung current of the metal halide lamp 10, and FIG. 2(c) is a graph similarly showing the temporal change in the luminous flux of the metal halide lamp 10. Figure 3 shows metal halide lamp 10.
In this embodiment, when the rung current is in the range A in the figure, the location lamp 36 is controlled to be turned off. In addition, the load % characteristic during constant lighting, curve C
The upper point 0 indicates the position during steady lighting, and the d point on the load characteristic curve during dimming indicates the position during dimming.

Although the metal halide lamp is used in the above embodiment, it is not necessarily limited to this, and it may be a device that detects the lamp pressure.

When detecting the lamp voltage, a resistive voltage divider circuit may be connected between the output terminals of the lighting control circuit 2, and the divided voltage from the voltage divider circuit may be input to the capacitor 13. In this case, the upper limit setting circuit 14 has a circuit constant so that the first transistor 20 does not turn on below the voltage at the connection point A when detecting the lamp voltage immediately before the transition from glow discharge to arc discharge of the metal halide lamp 1θ. , and the lower limit setting circuit 15 controls the smoothing capacitor 1 when detecting the lamp voltage immediately after the metal halide lamp transitions to arc discharge.
It is preferable to set the circuit constants so that the second constant voltage diode 2) becomes conductive when the voltage between both ends exceeds 30, but if the run f voltage or lamp current exceeds the upper limit set value during dimming, the lower limit You can freely choose as long as it does not fall below the set value.

In the above embodiment, a metal halide lamp was used as a high-voltage lamp, but it is needless to say that the present invention is not limited to this. Furthermore, in the above embodiments, a halodan lamp was used as the light bulb, but the present invention is not limited to this, and an incandescent light bulb may also be used.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to provide a discharge lamp lighting device that has a light function that eliminates the risk of the bulb lighting up even if the lamp current decreases due to dimming of the high-pressure discharge lamp. be.

[Brief explanation of the drawing]

The figures show an embodiment of the invention, and Figure 1 is a circuit diagram;
Figures 2 (a), (b), and (e) are graphs showing the temporal changes in the lamp voltage, lamp current, and luminous flux of a metal halide lamp, respectively, and Figure 3 is a graph showing the irregular characteristics of a metal halide lamp. . 2... Lighting control circuit, 10... Metal halide lamp, 1... Current transformer, 14... Upper limit setting circuit, 15... Lower limit setting circuit, 29... Delay circuit,
30... Bulb control circuit, 36... Halodan lamp.

Claims (3)

[Claims] (1) A high-pressure discharge lamp and a light bulb are provided, and when the high-pressure discharge lamp is started, the above-mentioned light bulb is lit until the luminous flux of the high-pressure discharge lamp has sufficiently risen to provide light compensation, and the high-pressure discharge lamp is A discharge lamp lighting device capable of controlling dimming of the high-pressure discharge lamp during steady lighting, comprising a detection means for detecting the lamp current or lamp voltage of the high-pressure discharge lamp, and a lower limit setting value for the lamp current or lamp voltage. and a lower limit setting circuit for detecting whether the output of the detection means is equal to or higher than the lower limit set value, and an upper limit set value of the lamp current or lamp voltage, and has a lower limit setting circuit for detecting whether the output of the detection means is equal to or lower than the set value. and a light bulb control circuit that controls lighting of the light bulb when the lower limit setting circuit detects a value below the lower limit set value or the upper limit setting circuit detects a value equal to or higher than the upper limit set value, A discharge lamp lighting device characterized in that the lamp current or lamp voltage is controlled to be between the upper limit setting value and the lower limit setting value during the dimming control. (2) The detection means detects the lamp current, the upper limit setting value is the lamp current value immediately after arc discharge of the discharge lamp, and the lower limit setting value is the lamp current value immediately before the discharge lamp transitions from glow discharge to arc discharge. The discharge lamp lighting device according to claim (1), wherein the discharge lamp lighting device is a value. (3) The detection means detects the lamp voltage, and the upper limit setting value is the lamp voltage value immediately before the discharge lamp transitions from glow discharge to arc discharge, and the lower limit setting value is the rung voltage value immediately after arc discharge of the discharge lamp. A discharge lamp lighting device according to claim (1), characterized in that: