JPS58165295A - 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 applies to a discharge lamp lighting device.

Most discharge lamp lighting devices use high-frequency lighting for efficiency reasons, and since lighting using high-frequency waves with a constant amplitude is the most efficient, a three-phase commercial power supply is used, and the sum of the instantaneous power of the three-phase AC is constant. There is a device that takes advantage of this property to obtain a high-frequency voltage with a substantially constant amplitude, thereby lighting a K discharge lamp with high efficiency.

Figure 1 shows the conventional discharge lamp lighting device.
Three sets of constant current flf input each correlated voltage of phase commercial power supply l
l Hudel inverter 2'.

The customer outputs 3' and 4' are combined in series, and the combined output is supplied to the current limiting impedance 5 and the discharge lamp 6. Constant current! The pace terminals ■ and @ of the switching transistors 11 and 12 of the Zuschdel inverter 2' are connected to the drive winding wound on the same core of the oscillation transformer 9, and the other drive winding θ- @ and -6 are drive windings of the switching transistors of the other inverters 3' and 4', and are connected in the same way as the inverter 2'. In addition, in the figure, the interface 1-inter 3'
, 4' are omitted, but are the same as inverter 2' except that they do not have a feedback winding.

In operation, when the conductor 1 is turned on, the full wave rectifier 7
As a result, the UV interphase voltage is made into a full wave 1151e, and an am pulsating current is applied to the collectors of the transistors 11 and 12 via the constant current inverter 8 and the primary winding 19m of the oscillation transformer 90. At the same time, pace current is supplied to the transistors 11 and 12 by the DC power supply 13 through the pace resistors 14 and 15, but one of the transistors is turned on first due to the faults of the transistors, and this leads to the I-order of the oscillation transformer 9. An oscillating voltage is generated by the winding 9a and the oscillating capacitor 10, and this voltage causes the driving circuit 1-@Seki Kml and is positively fed back to the pace of the transistors tt and 12, thereby causing oscillation at t4-. As shown by ma in FIG. 2, a high frequency oscillating voltage is generated depending on the magnitude of the absolute value of the input voltage 'u-v. By the way, other In Eta 3', 4'
obtains a drive signal from the output 01 of the inverter 2' and performs the same operation as the inverter 2', so that the output voltage V of the lighting device is determined. ut does not apply the output voltage of each inverter synchronously in terms of frequency, #t becomes a constant level ^frequency oscillating voltage, and the discharge lamp 6 has no rest period in the lamp current and is highly efficient. It will be lit.

The device shown in Figure 1 operates in this way, but in
Gates 3' and 4' are the only inverter 2' that performs self-sustained oscillation.
Because it is driven by a part of the way the engine is generated, it has some drawbacks as described below. The F% will be explained below with reference to FIG. Time t.

-1, the output of the input signal 2' is at a low level. At this time, the input of other inputs 3' and 4'
1 voltage is relatively high compared to the input voltage of the inverter 2', and therefore a thick 1 voltage signal is required as the drive signal. However, i′ As mentioned above, time t. -11, the drive signal of the transistors 3' and 4' is small due to the invar old 1, υ,
Therefore, the driving of the transistors becomes insufficient, and the inverters 3' and 4' have a drawback that stable nine-high frequency conversion operation cannot be obtained. In such situation 11,
Transistors do not perform full switching operations and operate in an unsaturated region, which generates a large amount of heat, leading to thermal runaway and destruction, and their operation is extremely unstable. In addition, even during a period when the input voltage of input terminals 3' and 4' is low and a large signal is not required as a drive signal for the transistor, a drive signal larger than necessary can be applied due to the phase relationship described above. In this case, there is a drawback that operation becomes unstable due to the O/4 drive.

The present invention was proposed in view of the above points, and the outputs of three sets of inverters that convert each line voltage of a three-phase commercial power source into full-wave 411511 and high-frequency signals are combined in series, and the combined output is used to power a discharge lamp. Reduces the need for large circuitry components to light up, making it more compact.

A self-excited discharge lamp lighting device that uses a transistor inverter and is self-excited to achieve light weight, stable synchronous resonance operation, and stable operation even when the load is empty and there is no load. The aim is to realize this.

Hereinafter, the present invention will be described in detail with reference to the drawings showing examples.

FIG. 3 shows an embodiment of Ill of the present invention. As for the configuration, the voltage between each phase of the 3-phase power supply is full-wave rectified and converted to high frequency.
The set of constant current inverters 2.3.4 are connected in parallel with the power supply IK, and the secondary windings of the oscillation transformers 9 of each inverter 2, 3.4 are connected in series. The open end is connected to a current limiting impedance and a series circuit of the discharge lamp 6 to form a closed circuit. Further, the primary winding of a transformer 16 is connected in parallel with the series circuit of the current limiting impedance 5 and the discharge lamp 6, and the transformer 16 has three sets of secondary □ windings, each of which is connected to the above-mentioned in/9 - 2°3.4 is connected between the bases of both transistors. In the figure, inverter 3
．． Although the internal circuit of No. 4 is omitted, it has the same configuration as No. 2.

In operation, when the power supply 1 is turned on, as in the conventional example, the voltage across both ends of the transformer 16 is made common and the anti-drive signal is used, and the operation is completely synchronized. will be taken. Also, the voltage across the transformer 16 is MA. , and since this is a series combination of the outputs of each inverter 2, 3.4, it becomes an almost smooth constant level high frequency voltage waveform as shown in FIG. The problem of insufficient drive of 3' and 4' is eliminated, and stable self-excited operation can be obtained.

Therefore, problems such as increased power loss and heat generation of the transistor due to operation in an unsaturated state can be solved. In addition, such a transformer 16Fi only flows an excitation W current at most, and since it is very small, transformer 1
There is almost no power loss at 6, so it is possible to drive the inverters 2, 3 and 4 efficiently by self-excitation.
The distance is 4111m.

Furthermore, this inverter device is not limited to single discharge lamps as shown in Figure @3, but can also control multiple discharge lamps as a high-wave power source.This means that when using multiple lamps, it is possible to control multiple discharge lamps. , no load. , is not affected by shadows, so it can perform stable high frequency conversion operations even in such abnormal situations.

Next, FIG. 5 shows a second embodiment of the present invention, in which the primary winding of a transformer 16 that supplies synchronous drive signals to the transistors of each inverter is connected to both ends of the discharge lamp 6. . That is, the run l voltage is approximately constant l,
Moreover, V. Since the inductance of the transformer 16 is smaller than ut, the inductance of the transformer 16 can also be small, and there is an advantage that it can be made much smaller and lighter than the above-mentioned embodiment.

Note that since the configuration and operation are substantially the same as those of the first embodiment described above, the explanation thereof will be omitted to avoid duplication.

Also, in the above implementation, the inverters 2, 3.4:::・ are operated at a constant current! The present invention is not limited to this, and the same effects can be achieved even with inverters of other types. Further, the current limiting impedance 5 does not have to be an inductance, but may be any current limiting element, and it is clear that there is no problem with leakage inductance caused by leakage magnetic flux of the oscillation transformer 9, for example. In addition, if the load is a discharge lamp, it may also be a load such as a motor, and the present transistor inverter is a high frequency power source that supplies a constant level high single wave driving force.

As described above, in the present invention, a full-wave 41 voltage between each phase of a three-phase commercial electrical power source is passed through, and three sets of AC power are output by alternating switching operations of a pair of transistors connected to the rectified output. Equipped with 3 inverters and 3 sets of inverters
In a discharge lamp lighting device that connects the output terminals of the analogue transistor in series to obtain a high-frequency output voltage of approximately constant amplitude and lights the discharge lamp using this high-frequency output voltage, the three strings connected to the pace of the transistor Since the primary winding of the transformer having the feedback winding is connected between both ends of the series connection of the three sets of inverter output ends or between both ends of the discharge lamp, the discharge lamp can be operated with high efficiency. In addition to (a) eliminating the operation in the unsaturated region and reducing stain power loss, it is possible to realize a highly efficient lighting device.

(→ Stable switching operation is obtained and the reliability of the device is increased. c) 3 1111M is simple and costs can be reduced.

2) Reliability can be guaranteed without disrupting drive even when the discharge lamp is at the end of its life or under no load.

It has various effects such as.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing a conventional discharge lamp lighting device, Figure @2 is a diagram explaining its operation, #! FIG. 3 is a circuit diagram showing the first embodiment of the present invention, FIG. 4 is an explanatory diagram of its operation, and FIG. 5 is a circuit diagram showing the second embodiment. l... 3-phase commercial power supply, 2, 3.4... inverter, 5... current reduction impedance, 6... discharge lamp, 7.
... Rectifier, tail, constant current inductor, 9... Oscillation transformer, 9m, 9b, 9e... Winding of oscillation transformer,
10... Vibration capacitor, 11, 12... Transistor, 13... DC 11fi, 14.15... Pace m anti, 16... Transformer.

Claims (2)

[Claims] (1) 41 full-wave voltages between each phase of the 3-phase commercial power supply are applied, and Mukuro 1
Three sets of inverters that output AC power by alternating switching operations of a pair of transistors connected to a 1m output are connected, and the output terminals of the three sets of inverters are connected in series to generate a high frequency output with approximately constant amplitude. In a discharge lamp lighting device that obtains a voltage and lights a discharge lamp with a high-frequency output voltage, the primary winding of a transformer having three sets of feedback windings connected to the pace of the transistor is connected to the in-group of the 31 sets. A discharge lamp lighting device characterized in that the discharge lamp lighting device is connected between both ends of a series connection of output ends of a discharge lamp. (2) The discharge lamp lighting device according to claim 1, wherein a primary winding of a transformer having three sets of feedback windings connected to the base of the transistor is connected to both ends of the discharge lamp.