JPS6362187A - Discharge lamp lighter - Google Patents

Abstract

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

Description

[Detailed description of the invention]

[Technical Field] The present invention relates to a discharge lamp and a lighting device for lighting a discharge lamp. [Background Art] Conventionally, this type of discharge lamp lighting device is shown in Figs. 5 and 6.
FIG. 5 is a block diagram showing a schematic configuration of the discharge lamp lighting device, and FIG. 6 shows a specific circuit of the circuit shown in FIG. This discharge lamp lighting device is made up of a full-wave rectifier 1 that performs full-wave rectification of commercial power supply VAC, a smoothing capacitor C0 that smoothes the output of this full-wave rectifier 1, and the above-mentioned full-wave rectifier 1 and 1 smoothing capacitor C0. It consists of an inverter 2 that converts a DC voltage into an AC voltage of a predetermined frequency to light the discharge lamp DL, and an igniter 3 as a high-voltage pulse generation circuit that starts the discharge lamp DL. Note that the smoothing capacitor C0 is not necessarily required. In the specific circuit shown in FIG. 6, the full-wave rectifier 1 is composed of a diode bridge DB, and the inverter 2 is a full-wave rectifier composed of transistors Q, -Q, and diodes D, ~D, which are semiconductor switching elements. It is equipped with a control section 4 that controls switching of transistors Q, -Q. In addition, the # control section 4 is a transistor Q 3
- It has a function of detecting the current flowing through the discharge lamp DL with a resistor Rc inserted on the emifuku side of Q4, and controlling the switching of transistors Q1 to Q4 according to this current to keep the inverter 2 output constant. ing. Note that this control unit 4 uses a voltage obtained by stepping down the voltage of the commercial power supply VAC by a transformer T as a power supply. In this discharge lamp lighting i & position, the connection point of transistors Q, , Q, and transistor Q
2. A series circuit of a check 1 coil as a current limiting element that regulates the current flowing to the discharge lamp DL and a capacitor CI is connected to the connection point of the discharge lamp DL, and a discharge lamp DL is connected to both ends of the capacitor C1. It is connected. The capacitor C2 also has the role of a bypass filter, that is, the role of bypassing the high frequency component of the output of the inverter 2 applied to the discharge lamp DL. Igniter 3 is discharge lamp D
a pulse transformer PT that applies a high-voltage pulse to the discharge lamp DL in order to start the discharge lamp; a charging circuit consisting of a resistor R3 and a capacitor C2 that are charged with the voltage applied to both ends of the discharge lamp DL; By discharging the charged charges, the primary s#I of the pulse transformer PT is
A bidirectional thyristor Qs such as a triac that causes a current to flow through the secondary winding 12 to induce a high-voltage pulse that starts the discharge lamp DL, and the element Q@ which controls the conduction of this thyristor Q. Become. Hereinafter, the operation of the above-mentioned conventional example will be schematically explained. When a voltage obtained by rectifying and smoothing the commercial power supply VAC by the diode bridge DB and the smoothing capacitor C0 is applied to the inverter 2, the inverter 2 converts the voltage into an alternating current voltage and applies it to the discharge lamp DL. The operation of this inverter 2 is shown in FIG. Transistors Q, Q, are turned on and off alternately at low frequency as shown in Figure 3 (c) and t (d), transistor Q1 is turned on only when transistor Q is turned on, and transistor Q2 is turned on only when transistor Q is turned on. Turns on and off at high frequency. Therefore, the current shown in FIG. 3(e) flows through the Chittark coil L1! LL flows, and this current ILI flows in a divided manner to the discharge lamp DL and the capacitor C2. As mentioned above, since the capacitor CI acts like a bypass filter, the high frequency component of the lamp current IDL is almost completely removed as shown in FIG. A lamp current IDL having a substantially rectangular waveform determined by the switching frequency flows. The operation of the igniter 3 for starting the discharge lamp DL will be described next. When the above-mentioned inverter 2 operates and a voltage is applied to the discharge lamp DL, the igniter 3 charges the capacitor C2 via the resistor R3 with the voltage across the discharge lamp DL, and charges the capacitor C2 via the resistor R+*Rs. Charge C1. Then, with the capacitor C2 sufficiently charged, the charge charged in the capacitor C5 turns on the tri-element Q, thereby turning on the thyristor Q5.
The charge in the capacitor C2 is discharged through the primary '8 wire n of the pulse transformer PT. This discharge current induces a boosted high voltage pulse in the secondary 8 #i n- of the pulse transformer PT, and this voltage is applied to the discharge lamp DL via the capacitor CI to start the discharge lamp DL. By the way, in the discharge lamp lighting device having the above-mentioned configuration,
The high-frequency, high-voltage pulses generated in the pulse transformer PT enter the control unit 4 of the impark 2 as noise, causing malfunctions such as transistor Q and F transistor Q < or transistor Q2 and transistor Q being turned on simultaneously. There was fear.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a discharge lamp lighting device that can prevent the inverter control l1lvlS from malfunctioning due to high voltage pulses generated by the igniter. be. [Disclosure of the Invention] (Structure) The present invention includes an inverter having a control section that applies an AC voltage obtained by switching a DC power supply output to a semiconductor switching element to a discharge lamp and controls switching of the semiconductor switching element. , a discharge lamp comprising a high-voltage pulse generation circuit that applies a high-voltage pulse to the discharge lamp to start the discharge lamp, and a choke coil that is connected in series to the discharge lamp and regulates the current flowing through the discharge lamp, and a σ lamp holder. At least the semiconductor switching elements and control section of the inverter, the high-voltage pulse generation circuit, and the choke coil are housed separately in separate metal cases, so that electromagnetic noise caused by high-voltage pulses generated in the high-voltage pulse generation circuit can be removed from the inverter. The shielding effect of the metal case prevents the circuit from reaching the switching element or control unit, and the current limiting effect of the choke coil generates high voltage pulses to the switching element or control unit via the +7- wire that connects the above circuits. This prevents the high-voltage pulses from going around the circuit. (Example) FIGS. 1 to 4 are diagrams showing an example of the present invention,
In this embodiment, as shown in FIGS. 1 and 2, the circuits within the broken lines are housed separately in a separate case. Note that Fig. 1 corresponds to Fig. 5, and Fig. 2 corresponds to Fig. 5.
The figure corresponds to FIG. This will be explained below with reference to FIG. Note that the configuration of each part is the same as that explained in the conventional example, so e
I will explain the characteristics. In this embodiment, basically at least a pulse transformer PT, a transistor Q,
~Q and the control section 4 are housed in separate metal cases A and B, and a choke coil is housed in the metal case B in which the pulse transformer PT is housed. In this way, at least the pulse transformer PT, the transistors Q, ~Q4, and the control section 4 are housed in separate metal cases A.
, B, the pulse transformer PT is electromagnetically shielded by the metal case B, and the pulse transformer PT
Electromagnetic noise caused by high voltage pulses generated in The high voltage pulse generated in the pulse transformer PT due to the current limiting action of the lead #I6 connects the inverter 2 and the high voltage pulse generation circuit 3.
It is possible to reduce the possibility of the metal case AI going around through the metal case AI. Therefore, the high voltage pulses generated in the pulse transformer PT do not affect the transistors Q and -Q of the inverter 2 or the control section 4, and therefore the control section 4 does not affect the transistors Q1 and -Q, or the transistors Q2 and Q, There is no possibility of malfunctions such as turning on at the same time. Note that in this embodiment, the transistor Q
, ~Q4, which are not directly related to the malfunction of the control unit 4, are housed in the metal case B on the pulse transformer PT side, and the dimensional expansion of the metal cases A and B is taken care of. In other words, the guide bridge D B +, the smoothing capacitor C0, and the inverter 2 in the circuit of Fig. 2 are housed in the metal case A, and the choke coil-like capacitor C
I, the igniter 3, and the transformer T of the control unit 4 are housed in a metal case B@. Also, metal case A. B has a U-shaped cross section with an upward opening as shown in Figure 3.
It consists of a base 7 to which a printed circuit board 5 with circuit components mounted as described above is mounted, and a cover 8 that covers the opening of the base 7. The attached printed circuit board 5 is connected by a lead wire 6. This separate metal case A,
For example, in the case of the downlight shown in FIG. 4, the discharge lamp lighting device housed in B is housed in the housing 10 together with the discharge lamp DL as follows. In other words, fiil[
The TDL was attached to one side of the housing 10, the metal case B containing the igniter 3 including the Chirok coil L was housed next to the discharge lamp DL, and the inverter 2 was housed on the other side. Store metal case A. Note that the igniter 3 housed in the metal case B operates only at the time of starting, and does not operate when the discharge lamp DL is lit due to a decrease in the voltage across the discharge lamp DL, so that self-heating of the component parts is small, and The parts housed in the metal case B have good heat resistance because their main components include a transformer. In addition, the components housed in the metal case A operate when turned on, generate a large amount of self-heating, and many components such as semiconductors are susceptible to thermal stress. Therefore, if the discharge lamp DL is housed in the housing 10 as described above, the heat generated by the discharge lamp DL remains in the metal case B and is unlikely to reach the metal case A, resulting in the best arrangement in terms of heat setting. Furthermore, by arranging the metal case B housing the igniter 3 that applies a starting pulse to the discharge lamp DL close to the discharge lamp DL, the lead wire 6 connecting the discharge lamp DL and the metal case B
The length of the lead wire 6 can be shortened, the drop between the lines due to the lead wire 6 can be reduced, the starting efficiency can be improved, and the radiation of electromagnetic noise due to lamp current, starting pulses, etc. can be reduced. Also, the discharge lamp lights up like this! ! By storing the discharge lamp lighting device separately in the metal cases A and B, the degree of freedom in arranging the discharge lamp lighting device increases, and it becomes easy to incorporate the discharge lamp lighting device into the illuminator. In the above description, the case where the discharge lamp lighting device is divided into two parts has been explained, but if at least the pulse transformer PT, the transistors Q, to Q4, and the control section 4 are housed in separate metal cases, it is possible to , 3 blocks, locks or more. [Effects of the Invention] As described above, the present invention provides an inverter having a control section that applies an AC voltage obtained by switching a DC power supply output to a semiconductor switching element to a discharge lamp and controls the switching of the semiconductor switching element. and a discharge lamp lighting device comprising: a high-voltage pulse generating circuit that applies a high-voltage pulse to the discharge lamp to start the discharge lamp; and a choke coil that is connected in series to the discharge lamp and regulates the current flowing through the discharge lamp. At least the semiconductor switching elements and control section of the inverter, the high voltage pulse generation circuit and the Chirok twill are housed separately in separate metal cases, so the high voltage pulse generation circuit is electromagnetically shielded by the metal case. It is possible to prevent electromagnetic noise caused by the high voltage pulses generated in the high voltage pulse generating circuit from jumping to the switching elements or control section of the inverter via the wire, and in addition, a choke coil is installed on the side of the metal case where the high voltage pulse generating circuit is housed. Since the high-voltage pulse voltage generated in the high-voltage pulse generation circuit due to the current limiting action of the Chirok coil is stored in the inverter switching element or control unit through the lead wire connecting the inverter and the high-voltage pulse generation circuit, This prevents the inverter's switching elements and control unit from being affected by the high-voltage pulses generated by the high-voltage pulse generation circuit, preventing malfunctions such as malfunctions in the inverter's switching operation. It produces an effect that does not have to be. Moreover, by separately housing the discharge lamp lighting device in a metal case, the degree of freedom in arranging the discharge lamp lighting device increases, and there is also an effect that it is easy to incorporate the discharge lamp lighting device into the illuminator.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an embodiment of the present invention, FIG. 2 is a specific circuit diagram of the same, and FIG. 3 is a perspective view of the same.
FIG. 4 is an explanatory diagram showing the arrangement of the illuminators as above.
Figure #5 is a block diagram showing a schematic configuration of the conventional example, Figure 6 is a specific circuit diagram of the same, and Figure 7 is an explanatory diagram of the operation of the same. 2 is an inverter, 3 is an igniter, 4 is a control unit, Q, ~
Q is a transistor, DL is a discharge lamp, LI is a choke coil, and A and B are metal cases. Agent Patent Attorney Ishi 1) Chief Shichiki + r″′1 Figure 4 Figure 5

Claims (1)

[Claims] (1) An inverter having a control unit that applies an AC voltage obtained by switching a DC power output to a semiconductor switching element to the discharge lamp and controls switching of the semiconductor switching element; and a high-voltage pulse that is applied to the discharge lamp. a high-voltage pulse generation circuit that starts the discharge lamp by
In a discharge lamp lighting device comprising a choke coil connected in series with the discharge lamp to regulate the current flowing through the discharge lamp, at least the semiconductor switching element and control section of the inverter, the high voltage pulse generation circuit and the choke coil are made of metal. A discharge lamp lighting device characterized in that it is separately housed in a separate case.