JPS59175597A - 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 compact and lightweight discharge lamp lighting device.

High-pressure mercury lamp, commonly known as HI
Even if a high-intensity discharge lamp called a D-lamp is tried to be turned on again after it has been turned off by a stone, it will continue to be turned on again for several minutes to ten-odd minutes until the lamp cools down.

This is because the gas pressure inside the arc tube is high, so that no discharge occurs between the 8 poles of the main cylinder. In order to be able to relight the lamp at any time after it has been turned off, a common method is so-called instantaneous relighting, in which a high pulse voltage is applied between the main electrodes to force a main discharge.

FIG. 1 shows a conventional example of a discharge lamp lighting device using such a method. For example, in order to instantaneously relight a 100 W metal halide lamp, it is necessary to apply a high voltage pulse of about 3° KV to the lamp. For this purpose, the Kid step-up transformer 1 steps up the commercial power supply by, for example, 5000 VK to charge the capacitor 2. Dielectric breakdown voltage of discharge gap 3 is 5
000V.

When the step-up ratio of the pulse transformer 4 is increased to 6 times, a voltage of 30 KV is generated on the secondary side of the pulse transformer 40 and is applied to the lamp 6 through the bypass capacitor 5, causing a breakdown between the main electrodes of the lamp and lighting the lamp. .

However, since these devices boost the voltage using the step-up transformer lIr1 commercial frequency, they have the drawbacks of being very large, heavy, and expensive.

In addition, as shown in Figure 2, if a voltage doubler rectifier circuit is used to boost the voltage, the step-up ratio of the step-up transformer 4 can be reduced to half, but the capacitor 7 is large because it reverses charging and discharging at the bending frequency. (For example, 02μF, about 4KV) and is expensive.

Since the circuits that generate high-voltage pulses using commercial frequencies are extremely large, heavy, and expensive, these instant lighting devices are currently only used for specific purposes. Ta.

Furthermore, it is common to use a choke coil in the case of a commercial frequency power supply as the current limiting element 8 that limits the lamp current to an appropriate level, but this choke coil is very large and difficult to use. There were also drawbacks.

The present invention has been devised in view of these points, and focuses on the fact that transformers and current limiting elements can be made smaller and lighter in proportion to their operating frequency Vi, and in order to eliminate the above-mentioned drawbacks, it is possible to reduce the size and weight of transformers and current limiting elements. After converting the voltage into a high-frequency voltage, power is supplied to the pulse generator circuit and the lamp.This makes it possible to significantly reduce the size and weight of step-up transistors and capacitor current-limiting elements, and to reduce costs. can.

FIG. 3 shows an embodiment of the present invention. In the figure, reference numeral 1 is a commercial frequency AC power supply, and the inverter 2 is supplied with power from this power supply, which generates high-frequency electricity of several tens of KH2 to several hundred KH2.
Generates pressure. The high frequency output of inverter 2 is switched to switch 3.
The signal is input to the pulse generating circuit 4 via the pulse generating circuit 4. As will be described later, while the switch 3 is on, a high voltage A/S is generated on the secondary side n and VC of the pulse transformer 5, and this voltage e is applied to the lamp 7 via the bypass capacitor 6'.

At the same time, the high frequency output of the inverter 2 is being supplied to the lamp via the current limiting element 8. A suitable value r (limited main current is supplied to the lamp, and the lamp 7 is turned on. After the lamp is turned on, when the switch 3 is turned off, the generation of high voltage pulses is stopped.

The operation of the pulse generating circuit 4 is as follows.

When the switch 3 is in the on state, the primary IQ Vc of the step-up transformer 9 is applied to the output voltage of the inverter 2, and the voltage is stepped up and output to the secondary side. When the anode side of the diode 10 is positive, the capacitor 11 is charged with the peak value 1 of the secondary side voltage of the step-up transformer 9 through the diode 10. ◇ Next, when the anode IT1+1 of the diode 10 is negative, the capacitor 11 is charged through the diode 12. capacitor] is charged to 3,
The value reaches twice the peak normal pressure value generated on the secondary side of the step-up transformer 9 at the lifting height [2].

If the breakover voltage of the discharge gap 14 is set below this value, the capacitor pressure will be lower than the discharge gap 14.
When the breakover voltage is reached, the discharge gear 1r knob 1
4ir1 breaks over, and the charge of the near tensor 13 is discharged into the discharge gap 14, the primary side n of the pulse transformer 5,
The primary InnI of the pulse transformer 5 is discharged through the
K pulse-shaped snow pressure is induced, and this voltage is stepped up to generate n*Vc on the secondary side of the pulse transformer 5.

As described above, since it operates with the high frequency output of the step-up transformer 9, the capacitor 11, and the current limiting element 811-1t inverter 2, its size and weight can be significantly reduced.

FIG. 4 σ is another embodiment of the present invention. Components having the same functions as those in FIG. 3 are given the same reference numerals.

A full wave rectifier 15 is added after the current limiting element 8 and the inverter 2
The output of the converter is converted into DC and supplied to the lamp 7. The bypass capacitor 6 also functions as a smoothing capacitor and can light the lamp with smoothed direct current. Since it is placed in front of the eight current limiting elements full-wave rectifier 15, it operates at a high frequency, making it much smaller and lighter than a commercial frequency device.

Since the pulse generating port @4 also operates with high frequency voltage, it can also be made smaller and lighter.

If the input of the pulse generating circuit is obtained after the current limiting element 8, the input voltage of the pulse generating circuit 4 will be reduced by the voltage drop across the current limiting element 8 when the lamp 7 is lit. At this time, a lamp 7 whose constants are set so that the voltage of the capacitor 13 is equal to or less than the breakover voltage of the discharge gap 14 is turned on, and the pulse generation is automatically stopped.

In other words, a pulse generation automatic stop function can be provided.

This automatic stop function of pulse generation can prevent unnecessary generation of high-voltage pulses and is useful for increasing the reliability of the hazard prevention device. In addition, this DC lighting method
This is preferable because even if a lamp that is likely to cause acoustic resonance (acoustic resonance phenomenon) is lit due to high-frequency lighting, such a phenomenon will not occur.

;! Figure g5 is a specific example of an inverter. The operation of this inverter is well known, so I will not explain TiI's own work, but if a capacitor is used as the eye element 8 in such a sine wave inverter, it will work better when the lamp is out than when the lamp is on. The frequency is high. This is because the current limiting element 8 (capacitor) is connected in parallel to the oscillation capacitor 16 when the lamp is lit, and the resonance frequency is lowered.

In this way, by using an inverter whose operating frequency under no load is higher than when under load, the pulse generation circuit can be operated at a higher frequency and further miniaturized. - Increasing the operating frequency of an inverter generally increases loss, so it cannot be increased unnecessarily. However, when there is no load, even if the loss is somewhat large, the main current is not flowing through the circuit, so there is some thermal margin, so the frequency can be increased. In addition, since the pulse generation circuit is used temporarily during #3 operation, it is not a big problem even if there is a large amount of loss, and there is no problem even if the frequency is increased.

In this way, even if the operating frequency during no-load is increased, there will be no major problem and it will be advantageous in terms of size and weight reduction.

If inverter 2 has current limiting function, current limiting element 8t
fi is unnecessary.

In this embodiment, an AC type power source is used, but the power source may be an 11 current power source such as a battery.
In that case, a circuit for rectifying and smoothing the commercial power supply becomes unnecessary.

The output waveform of the inverter may be a sine wave or, for example, a square wave to obtain the same effect.

Figure 6 shows a step-up winding 18 in the transformer 17 of the inverter 2.
is separately wound and the output voltage is used to obtain a high voltage pulse.In this way, the step-up transformer 9d as shown in FIG. 3 is not required.

As explained above, the present invention is configured to convert a commercial frequency power supply to a high frequency and then supply this output to a pulse generation circuit and a lamp. It can be quantified and the cost can be reduced. Moreover, HID lamps, especially 10
Low-wattage lamps of 0W or less can now be used indoors for photography and general illumination.

Furthermore, if a battery is used, a light source device such as a video light, which can be used outdoors, can be obtained.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of a conventional discharge lamp lighting device, Fig. 2 is a circuit diagram of a high-voltage pulse generation circuit used in the same device, and Figs. 3 to 6 are circuit diagrams of a discharge lamp lighting device according to the present invention. be. 3 to 6, 2...inverter, 4-...high voltage pulse generation circuit, 7
...Discharge lamp, 8...Current limiting element.

Claims (3)

[Claims] (1) An inverter, a discharge lamp energized by the output of the inverter, a current limiting element that limits the current of the discharge lamp, and a current-limiting element that converts the high-frequency output of the inverter to generate high-voltage pulses and generates high-voltage pulses. A lightning discharge and lamp lighting device characterized by comprising a pulse generating circuit for applying voltage to the discharge lamp. (2) The discharge lamp lighting device according to claim 1, wherein the operating frequency of the inverter is higher when the discharge lamp is not lit than when it is lit. (3) The discharge lamp lighting device according to claim 1, wherein the input to the pulse generating circuit is obtained from the output side of the current limiting element.