JPH07263166A - Electronic lighting device for discharge lamp and control method thereof - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] The harmonics that cause harmonic interference in the discharge lamp lighting device are removed, the brightness of the discharge lamp is kept uniform, and flicker does not occur. [Structure] Rectifier circuit 11 for converting AC power into DC power
And a step-up chopper circuit 12 that stabilizes the DC voltage from the rectifier circuit 11 and makes the input current sinusoidal.
And connecting a plurality of switching semiconductor elements to the first and second arms so as to form a full bridge circuit configuration 13, converting the DC voltage from the step-up chopper circuit 12 into an AC voltage and supplying the AC voltage to the discharge lamp 15. Full bridge circuit 13
A current detection circuit 16 for detecting an average value of the input current of the full bridge circuit 13, and a first of the pair of switching semiconductor elements located on opposite sides of the full bridge circuit.
And a control circuit 17 for controlling each of the switching semiconductor elements at a low frequency and controlling each of the second switching semiconductor elements at a high frequency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic lighting device suitable for lighting a discharge lamp or a high-intensity discharge lamp such as a metal halide lamp or a high pressure sodium lamp, and a control method thereof.

[0002]

2. Description of the Related Art Most conventional ballasts for discharge lamps use a magnetic leakage transformer, and power control is not performed.
When the input voltage fluctuates, the power consumption of the discharge lamp also fluctuates, and there are problems that the brightness changes and the life of the discharge lamp is affected. Further, as shown in FIG. 6, the power consumption of the discharge lamp also changes according to the voltage change of the commercial AC power, which causes luminance ripples, and when used in a projection device, flicker occurs on the screen, making it difficult to see the image. There was a problem. In addition to the above-mentioned problems, the magnetic leakage transformer method has drawbacks that it is large and heavy, and it is inconvenient to carry. Therefore, in recent years, an electronic lighting device using a high-frequency modulation method using a high-speed switching semiconductor element has been used. Has begun to be used.

A circuit configuration of a general electronic lighting device is shown in FIG.
Shown in. The conventional device will be described below with reference to FIG. The AC / DC conversion circuit 21 includes a full-wave rectification circuit Re and a switch S.
270 is composed of W and capacitors C21 and C21 ', and when the commercial AC input voltage is 100V system, the switch SW1 is closed to perform double voltage rectification, and when the commercial AC input voltage is 200V system, the switch SW1 is opened to perform full-wave rectification.
A DC voltage of about 330 V is obtained. Next, a step-down chopper circuit 22 including a control semiconductor element Q22 such as an FET, a step-down inductor L22, a diode D2, and a capacitor C22 converts into a DC voltage required for the discharge lamp 15. Then, the DC voltage reduced to a predetermined voltage value is applied to the switch semiconductor elements Q2, Q5, Q3 of the full bridge circuit 23.
By alternately switching the conduction of Q4 and Q4, 50 to 3
It is converted into a rectangular wave AC voltage having a frequency of 00 Hz and supplied to the discharge lamp 15 through the filter capacitor C2. Note that CT is a current detector such as a current transformer, D2, D3, D
4 and D5 are diodes anti-parallel to the FETs Q2, Q3, Q4 and Q5, respectively.

[0004]

However, in such a conventional electronic lighting device for a discharge lamp, although a small and lightweight lighting device can be realized by operating the step-down chopper circuit 22 at high frequency, the output Because the current of the discharge lamp is maintained at a constant current, if the terminal voltage of the discharge lamp is different due to variations in manufacturing of the discharge lamp and changes over time, the power consumption also differs, which adversely affects the uniformity of brightness and the service life. There is a problem. Further, the capacitor input type AC-DC converter circuit 21 as shown in FIG. 7 causes a harmonic current to flow in the distribution system, which causes an increase in the receiving / distribution capacity and a harmonic interference. In addition, it will not be possible to satisfy the harmonic regulations that will be implemented soon, making it difficult to sell new products. In order to satisfy the harmonic regulation, it is necessary to add harmonic suppressing means to the rectifier circuit, but then both the harmonic suppressing means and the step-down chopper circuit are required, and there is a problem that the cost becomes large and the size becomes large. .

The present invention solves the above drawbacks of the conventional lighting device, and has the same number of parts as the conventional device.
The main purpose is to make the input current sinusoidal and significantly reduce harmonics to eliminate the cause of harmonic interference, while maintaining the brightness uniformity of the discharge lamp, eliminating flicker, and preventing life deterioration. There is.

[0006]

In order to solve the above-mentioned problems, a rectifier circuit for converting AC power into DC power, and a DC voltage from the rectifier circuit are stabilized. , A step-up chopper circuit that makes the input current sinusoidal and a plurality of switching semiconductor elements are connected so as to form a full-bridge circuit configuration, and the direct-current voltage from the step-up chopper circuit is converted into an alternating voltage to generate an alternating voltage in the discharge lamp. A full-bridge circuit for supplying the current, a current detection circuit for detecting an average value of the input current of the full-bridge circuit, and a first switching semiconductor of each pair of the switching semiconductor elements located on opposite sides of the full-bridge circuit. And a control circuit for driving the elements at a low frequency and controlling each of the second switching semiconductor elements at a high frequency. There is provided a lighting device.

In order to solve the above problems, a rectifier circuit for converting AC power into DC power, a DC voltage from the rectifier circuit is stabilized, and an input current is sinusoidal. And a full-bridge circuit that connects a plurality of switching semiconductor elements so as to form a full-bridge circuit configuration, converts a DC voltage from the boost chopper circuit into an AC voltage, and supplies an AC voltage to a discharge lamp. A current detection circuit for detecting an average value of the input current of the full-bridge circuit, and a first switching semiconductor element of each pair of the switching semiconductor elements located on opposite sides of the full-bridge circuit, having the same output frequency The second switching semiconductor elements are driven at a frequency and the duty ratio is adjusted so that the average value of the input current of the full bridge circuit becomes constant. There is provided a discharge lamp electronic ballast apparatus characterized by comprising a control circuit Gosuru.

In order to solve the above-mentioned problems, a third aspect of the present invention is to connect a plurality of switching semiconductor elements so as to form a full bridge circuit structure, convert a DC input voltage into an AC voltage, and release the AC voltage. A full-bridge circuit that supplies an AC voltage to a lamp, a current detection circuit that detects an input current of the full-bridge circuit, and a control that alternately drives each pair of the switching semiconductor elements located on opposite sides of the full-bridge circuit In a discharge lamp electronic lighting device comprising a circuit, the control circuit drives at a low frequency the first switching semiconductor elements of the pair of switching semiconductor elements located on opposite sides of the full bridge circuit, An electronic lighting device for a discharge lamp, characterized in that each of the second switching semiconductor elements is controlled at a high frequency.

In order to solve the above-mentioned problems, a fourth aspect of the present invention comprises a plurality of switching semiconductor elements connected so as to form a full-bridge circuit structure, converting a DC input voltage into an AC voltage and discharging it. A full-bridge circuit that supplies an AC voltage to a lamp, a current detection circuit that detects an input current of the full-bridge circuit, and a control that alternately drives each pair of the switching semiconductor elements located on opposite sides of the full-bridge circuit In the electronic lighting device for a discharge lamp including a circuit, the control circuit controls the first switching semiconductor elements of the switching semiconductor elements of each pair located on opposite sides of the full bridge circuit at the same frequency as the output frequency thereof. While driving, the duty ratio control of each of the second switching semiconductor elements is performed so that the average value of the input current of the full bridge circuit becomes constant. There is provided a discharge lamp electronic lighting device according to claim Rukoto.

According to a fifth aspect of the present invention, in order to solve the above-mentioned problems, when the peak value of the input current of the full bridge circuit reaches a set value, the switching semiconductor elements of each pair are turned on. The electronic lighting device for a discharge lamp according to any one of claims 1 to 4, characterized in that the switching semiconductor element being turned off is turned off.

In order to solve the above-mentioned problems, the invention as set forth in claim 6 is such that the frequency at which the switching semiconductor element under ON control of each pair of switching semiconductor elements is controlled is the output of the full bridge circuit. It is 50 times or more higher than the frequency, and it is characterized in that
An electronic lighting device for a discharge lamp according to any one of items 1 to 3 is provided.

In order to solve the above-mentioned problems, a rectifier circuit for converting AC power into DC power and a voltage conversion converter for converting a DC voltage from the rectifier circuit into a stable DC voltage are provided. A circuit and a bridge circuit configured to connect a pair of switching semiconductor elements so as to form a bridge circuit configuration, convert the DC voltage from the voltage conversion converter circuit into an AC voltage, and supply the AC voltage to the discharge lamp; In a discharge lamp electronic lighting device, comprising: a current detection circuit that detects an input current of the bridge circuit; and a control circuit that alternately drives each pair of the switching semiconductor elements located on opposite sides of the bridge circuit, An inductor in which a voltage conversion converter circuit is serially connected to the rectifier circuit, and a control semiconductor connected across the inductor and the rectifier circuit An electronic lighting device for a discharge lamp, which is a booster chopper circuit including a child, a diode connected in series to the inductor, and a capacitor connected across the diode and the control semiconductor element. It is provided.

In order to solve the above-mentioned problems, the invention according to claim 8 makes the waveform of the input current from the rectifier circuit for converting AC power into DC power into a sine wave, and the rectified voltage from the rectifier circuit. Is located on the opposite side of the full bridge circuit that controls the voltage conversion converter circuit so as to convert the DC voltage to a stable DC voltage, converts the DC voltage from the voltage conversion converter circuit to an AC voltage, and supplies the AC voltage to the discharge lamp. Driving each of the first switching semiconductor elements of the switching semiconductor elements of each pair at a low frequency, and
The present invention provides a method of controlling an electronic lighting device for a discharge lamp, which comprises controlling each switching semiconductor element at a high frequency.

In order to solve the above-mentioned problems, a ninth aspect of the present invention is to make the waveform of the input current from the rectifier circuit for converting AC power into DC power into a sine wave and to rectify the rectified voltage from the rectifier circuit. The full-bridge circuit for controlling the boost chopper circuit so that the DC voltage is a stable DC voltage, converting the DC voltage from the boost chopper circuit into a low-frequency AC voltage, and supplying the discharge lamp with the low-frequency AC voltage. (EN) A method of controlling an electronic lighting device for a discharge lamp, which is characterized by performing a duty ratio high frequency control so that a current becomes substantially constant.

According to a tenth aspect of the invention, in order to solve the above-mentioned problems, the waveform of the input current from the rectifier circuit for converting AC power into DC power is made sinusoidal, and the rectified voltage from the rectifier circuit is used. Control the step-up chopper circuit to a stable DC voltage, convert the DC voltage from the step-up chopper circuit to AC voltage and supply the AC voltage to the discharge lamp. The present invention provides a method for controlling an electronic lighting device for a discharge lamp, which is characterized by controlling and switching each pair of switching semiconductor elements at a low frequency to operate alternately.

[0016]

According to the present invention, a converter circuit such as a step-up chopper makes the waveform of its input current sinusoidal, and
Since the DC output voltage is stabilized, it is possible to remove the harmonics that are the cause of the harmonic interference, and it is possible to maintain the brightness uniformity of the discharge lamp. Further, according to the present invention, one switching semiconductor element of each arm of the full bridge circuit is switched at a low frequency equal to the normal polarity conversion frequency, and the other switching semiconductor element of each arm is subjected to high frequency control and supplied to the discharge lamp. Since the power to be used is almost constant, it is possible to maintain the uniformity of brightness, remove flicker, and reduce aging deterioration even if there is deterioration of the discharge lamp due to changes in input voltage or aging. .

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram for explaining a most preferred embodiment of the present invention. In the figure, the same symbols as those shown in FIG. 7 indicate members corresponding to the members of FIG. Although the present invention will be described below, although it has a filter circuit, a starting circuit, and the like other than those shown in the drawings, they are omitted because they are irrelevant to the constituent requirements of the present invention. The commercial AC input voltage is rectified by the full-wave rectifier circuit 11 having a normal configuration.
The step-up chopper circuit 12 converts the rectified input current into a sine wave and converts it into a stabilized DC voltage. The boost chopper circuit 12 includes an inductor L1 connected in series to the full-wave rectifier circuit 11, a full-wave rectifier circuit 11 and an inductor L.
A switching semiconductor element Q1 such as a transistor or an IGBT connected across 1, a diode D1 connected in series with an inductor L1, a capacitor C1 connected across the switching semiconductor element Q1 and the diode D1, and It is composed of a control circuit SC.

The DC voltage from the step-up chopper circuit 12 is converted into an AC voltage by the full bridge circuit 13, and a constant power square wave AC power is supplied to the discharge lamp 5 as a load through the output filter circuit 14. The full bridge circuit 13 is a MOSFET connected diagonally, that is, on one of the opposite sides.
Or switching semiconductor devices Q2 and Q such as IGBT
5, MOSFET or IGB connected to the opposite side of the other
It comprises switching semiconductor elements Q3 and Q4 such as T, and diodes D2 to D5 connected in anti-parallel to each of these switching semiconductor elements Q2 to Q5. The switching semiconductor elements Q2 to Q5 are newly controlled by the control circuit 17 described later.

The output filter circuit 14 is composed of an inductor L2 and a capacitor C2, and the output filter circuit 14 removes the high frequency component of the high frequency modulated low frequency voltage output from the full bridge circuit 13 as described later. As a result, a desired low frequency rectangular voltage can be applied to the discharge lamp 15.

The current detection circuit 16 connected between the step-up chopper circuit 12 and the full bridge circuit 13 is a current transformer C.
T, a diode D6, resistors R1, R2, R3, and a capacitor C3, which detects an average value and an instantaneous value proportional to the input current of the full bridge circuit 13 and detects detection voltages V1 and V2 corresponding to those values, respectively. To the control circuit 17. The control circuit 17 will be described while explaining the operation.

Next, the operation of this embodiment will be described with reference to FIGS. The switching semiconductor element Q1 of the boost chopper circuit 12 is controlled by the detection / control circuit SC so that the voltage across the capacitor C1 becomes constant. Although there are various control methods, one typical control method will be described. This control method is characterized in that the switching semiconductor element Q1 is switched at a constant frequency, and the duty ratio of the switching semiconductor element Q1 is changed to the instantaneous value of the input voltage, the detected value V _{1 of the} voltage across the capacitor C1, and the reference value E
It is in control according to the error voltage with ₁ .

More specifically, when the switching semiconductor element Q1 is switched at a frequency significantly higher than the input frequency, the input voltage during one switching cycle period can be regarded as constant. Assuming that the instantaneous value of the input voltage is e _i , the current variation i _ON during the ON period of the switching semiconductor element Q1 is
It looks like this: i _ON = e _i · t / L ₁ (1) Further, the current change amount i _OFF during the off period of the switching semiconductor element Q1 is E ₀ when the voltage across the capacitor C1 is E _0. , Like this: i _OFF = (E ₀ −e _i ) t / L ₁ (2) Here, since the increase / decrease in the current in one switching cycle can be regarded as zero, the ON period of the switching semiconductor element Q1 is When t _ON and one cycle are T, the following is obtained. _{e i · t ON / L 1} = (E 0 -e i) (T-t ON) / L 1 ···· (3) (3) from the equation (4) is obtained. t _ON = (E ₀ −e _i ) T / E ₀ ..... (4) The switching semiconductor element Q1 satisfies the formula (4).
When the duty ratio is controlled, the input current of the boost chopper circuit 12 has a sine wave shape. Therefore, it is possible to remove harmonics that cause harmonic interference.

Control circuit SC for performing such duty ratio control
There is a circuit configuration as shown in FIG. The output voltage of the rectifier circuit 11 is detected by the resistors r1 and r2, and the difference between the detected voltage V _a and the reference voltage value V _r of the reference voltage source E _r is amplified by the error amplifier OA _O to obtain an error signal. This error signal and the detected voltage V _b of the rectified voltage detected by the resistors r3 and r4 are multiplied by the multiplier MP, and then the multiplier MP.
And the triangular wave of the triangular wave oscillator TO are compared by the comparator CO ₀ . Now, here, the output voltage V _C of the multiplier MP is the amplification factor of the error amplifier OA _O is G1, the multiplier M
When the amplification factor of P is G2, the result is as follows. V _C = (V _a −V _r ) V _b · GI · G2 (5) Output of comparator CO ₀ when peak value of triangular wave of triangular wave oscillator TO is V _P width P _W of the _{pulse, P W = {V P -} (V a -V r) V b · GI · G2} T /
When V _P , GI · G2 = G, and (V _a −V _r ) = V _X , formula (6) is obtained. _{P W = (V P -V X} · V b · G) T / V P ········ (6) the ratio of the output voltage a is rectified voltage of the rectifier circuit 11 and the detected voltage V _b, When the peak value of the triangular wave is equal to both the ratio of V _P to the voltage across the capacitor C1, the equation (6) is similar to the equation (4), and the input current is sinusoidal. .

On the other hand, since the difference between the detected value of the voltage across the capacitor C1 and the reference voltage value V _r is amplified by the error amplifier OA _O , even a slight variation in the voltage across the capacitor C1 is amplified, and the input voltage Since it is reflected in the detection voltage V _b , the capacitor C can be controlled by controlling the duty ratio (pulse width).
The voltage between both ends of 1 can be maintained at a constant voltage.

Next, the bridge circuit will be described. The switching semiconductor elements Q3 and Q2 serially connected to the first arm of the full-bridge circuit 13 are driven by the complementary drive signals g and h from the control circuit 17, and the switching semiconductor elements serially connected to the second arm thereof. The elements Q4 and Q5 are driven by the control signals i and j. The drive signals g and h are frequencies determined by the capacity and properties of the discharge lamp, for example 50 to 30.
It is 0 Hz. Further, the control signals i and j have a frequency determined by the circuit conditions, for example, a frequency of 20 to 100 kHz, and the switching semiconductor elements Q4 and Q5 are driven at a much higher frequency than the switching semiconductor elements Q2 and Q3. Therefore, while the switching semiconductor element Q2 is conducting, the switching semiconductor element Q5 and the switching semiconductor element Q4 are repeatedly turned on and off at a high frequency while the switching semiconductor element Q3 is conducting, and the high frequency modulation is applied to the output terminal of the full bridge circuit 13. The generated low frequency voltage appears.

The operational amplifier OA of the control circuit 17 amplifies the error signal between the detection voltage V1 corresponding to the average value proportional to the input current of the full bridge circuit 13 and the current reference value of the reference voltage source E1 to generate the first error signal. To the inverting input terminal of the comparator CO1. As shown in FIG. 2a, the comparator CO1 compares the error amplified signal with the triangular wave signal supplied to the non-inverting input terminal, and as shown in FIG. 2b, the latter logically outputs the output signal only while the latter exceeds the former. Output to the circuit LC. The output signal is an output pulse whose pulse width is controlled, and the switching semiconductor elements Q4 and Q5 are turned on so that the average value of the input current of the full bridge circuit 13 becomes equal to the reference value.
The off time is controlled, that is, the duty is controlled.

The input voltage of the full bridge circuit 13 is maintained at a constant voltage by the boost chopper circuit 12, and the full bridge circuit 1
Since the average value of the input current of 3 is also controlled to be constant, the input power of the full bridge circuit 13 is also constant. Since all the electric power input to the full bridge circuit 13 is supplied to the discharge lamp 15, constant power is supplied to the discharge lamp 15. When the triangular wave signal is obtained by a simple circuit, the output signal from the oscillator OS is obtained by charging and discharging a capacitor (not shown) with a predetermined time constant.

On the other hand, the first comparator CO1 shown in FIG.
The output signal of the duty ratio control as shown in (4) is also input to the counter CN, counted, and divided into 1 / n. Therefore, the counter CN outputs a rectangular signal as shown in FIGS. 2c and 2d to the logic circuit LC. This n is often set to 50 or more. In this case, the switching semiconductor element Q
The frequencies of the control signals i and j of the switching semiconductor elements Q4 and Q5 are 50 times or more higher than the frequencies of the drive signals g and h of Q3 and Q2. The output signal of the oscillator OS is, for example, 2
Since it is a high frequency pulse of 0 to 100 kHz, the control signals i and j supplied to the switching semiconductor elements Q4 and Q5 have a frequency of 20 to 100 kHz in the normal operation, and the driving applied to the switching semiconductor elements Q3 and Q2. The signals g and h have a frequency equal to or lower than 1/50 of the control signals i and j.

In the control circuit 17, the polarity of the output voltage is switched by dividing the output signal of the duty ratio control of the first comparator CO1 as shown in FIG. The second comparator CO2 compares the detection voltage V2 corresponding to the instantaneous value proportional to the input current of the full bridge circuit 13 with the current reference value of the reference voltage source E2, and the detection voltage V2 is the current reference value. Control signal i, j is changed to a low level to turn off the switching semiconductor element. In this way, the peak value of the current flowing through the discharge lamp is limited to a predetermined value or less. This need will be described below.

Generally, the voltage between terminals immediately after lighting of the discharge lamp is very low at 10 to 20 V, and the boost chopper 1
When the constant power control is performed at 2, the output current becomes too large as shown in FIG. 3 and the life of the discharge lamp is shortened. Of course, the current capacity of the lighting device must be increased. The device becomes large and the cost becomes high. Therefore, the above-mentioned problems can be solved by limiting the input current of the full bridge circuit 13 to a predetermined value or less. If the predetermined value for limiting the input current is set to the maximum steady-state current required by the discharge lamp, the current at start-up can be limited most efficiently.

Although the most preferred embodiment of the present invention has been described above, if the voltage conversion converter circuit is a step-up chopper circuit, even if the circuit 13 is the same as the conventional one, the cause of the harmonic interference is eliminated. In addition, a stable DC voltage can be output. Further, the circuit 13 may have a normal half-bridge structure including a capacitor and a switching semiconductor element. In this case, both switching semiconductor elements may be switched at a high frequency and alternately switched at a low frequency to operate. Furthermore, if the circuit 13 is a full-bridge circuit that performs a new operation as described above, even if a conventional voltage conversion converter circuit is used, it is possible to prevent the discharge lamp from flickering and improve the fluctuation in brightness. . In this case, the circuit configuration of the input stage of the full bridge circuit 13 is not limited to that shown in the figure, and any circuit configuration capable of outputting a stable constant voltage will suffice.

Further, in the above embodiment, one pair of switching semiconductor elements of the full bridge circuit were driven at a low frequency and the other pair of switching semiconductor elements were controlled at a high frequency, but all the switching semiconductor elements are driven at a high frequency. It is also possible to perform the switching operation and switch the pair of switching semiconductor elements at a low frequency to alternately operate the switching semiconductor elements in the same manner as in the above embodiment. This operation will be briefly described. The first on the diagonal of the full bridge circuit, that is, on the opposite side,
When the switching semiconductor elements of the second pair are alternately switched at a constant period for a high frequency of a cycle sufficiently shorter than the constant period, one pair of switching semiconductor elements switching at a high frequency are turned off during the off period. The filter circuit 14 is connected through a diode anti-parallel connected to the other pair of switching semiconductor elements which are off for a certain period.
The energy stored in the inductor L2 is returned to the input side. Then, by controlling the duty ratio of the switching semiconductor element, high-frequency constant power having a polarity that can be alternately switched at a low frequency is supplied to the discharge lamp as in the circuit shown in FIG. The current detection circuit 16 needs to have a circuit configuration capable of detecting the current fed back to the input side, and a specific circuit thereof is shown in FIG. In this circuit, the resistor R21 and the resistor R21 are arranged so that bidirectional current flows symmetrically on the secondary winding side of the current transformer CT.
R22 and R23 and a capacitor C21 are connected, and a diode D26 and resistors R24 and R25 connected in series are connected between the secondary windings.

[0033]

As described above, according to the present invention, the following effects can be obtained. (1) Since the step-up chopper circuit is used as the voltage conversion converter and the input current has a sine wave shape, it is possible to remove harmonics that cause harmonic interference. (2) Despite the same number of parts as the conventional electronic ballast, the low-frequency voltage that is high-frequency modulated by the bridge circuit according to the input current is supplied to the discharge lamp, so the response to current fluctuations is extremely high. Fast and therefore flicker-free. (3) Since the voltage and current controlled to have a substantially constant value are supplied to the discharge lamp, it is possible to always supply stable power to the discharge lamp regardless of fluctuations in the input voltage and current, and therefore the brightness of the discharge lamp. Can be held evenly. (4) Since the current flowing through the discharge lamp is limited to a certain value or less, the life of the discharge lamp is not reduced. (5) Since the current is detected on the input side of the full-bridge circuit in which the high-frequency current flows, the current transformer CT can be significantly reduced in size and weight compared to the case where it is detected on the output side. (6) If one pair of switching semiconductor elements of the full bridge circuit is driven at a low frequency and the other pair of switching semiconductor elements is controlled at a high frequency, only a pair of switching semiconductor elements capable of high frequency operation can be used. It is good and economically advantageous.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a preferred embodiment of the present invention.

FIG. 2 is a diagram illustrating a control circuit of a boost chopper circuit according to an embodiment of the present invention.

FIG. 3 is a diagram showing a waveform of each part for explaining an embodiment of the present invention.

FIG. 4 is a waveform chart for explaining one embodiment of the present invention.

FIG. 5 is a diagram for explaining another embodiment of the present invention.

FIG. 6 is a waveform diagram for explaining a conventional example.

FIG. 7 is a circuit diagram for explaining a conventional example.

[Explanation of symbols]

11 ... Rectifier circuit 12 ... Step-up chopper circuit (voltage conversion converter circuit) 13 ... Full bridge circuit (bridge circuit) 14 ... Output filter circuit 15 ... Load (discharge lamp) 16 ... Current detection circuit 17 ... Control circuit Q1, Q2, Q3, Q4, Q5, Q6 ... Switching semiconductor element CO1, CO2 ... First and second comparators OP ... Operational amplifier CT ... Sinks E1, E2 ... Reference voltage source

Claims (10)

[Claims] 1. A rectifier circuit for converting AC power to DC power, a step-up chopper circuit for stabilizing a DC voltage from the rectifier circuit and for making an input current sinusoidal, and a full bridge of a plurality of switching semiconductor elements. A full bridge circuit which is connected to the first and second arms so as to have a circuit configuration, converts a DC voltage from the step-up chopper circuit into an AC voltage and supplies the AC voltage to the discharge lamp, and an input of the full bridge circuit. A current detection circuit that detects an average value of the current and a first switching semiconductor element of each pair of the switching semiconductor elements that are located on opposite sides of the full bridge circuit are driven at a low frequency, and the second switching semiconductor element is driven. An electronic lighting device for a discharge lamp, comprising: a control circuit for controlling a switching semiconductor element at a high frequency. 2. A rectifier circuit for converting AC power to DC power, a boost chopper circuit for stabilizing a DC voltage from the rectifier circuit and for making an input current sinusoidal, and a full bridge of a plurality of switching semiconductor elements. A full bridge circuit that is connected so as to have a circuit configuration, converts a DC voltage from the boost chopper circuit into an AC voltage and supplies an AC voltage to a discharge lamp, and a current that detects an average value of an input current of the full bridge circuit. The detection circuit and the first switching semiconductor element of the pair of switching semiconductor elements located on the opposite side of the full bridge circuit are driven at the same frequency as the output frequency thereof, and the second switching semiconductor element is driven. A discharge lamp comprising a control circuit for controlling a duty ratio so that the average value of the input current of the full bridge circuit becomes constant. Electronic lighting device. 3. A full bridge circuit comprising a plurality of switching semiconductor elements connected in a full bridge circuit configuration to convert a DC input voltage into an AC voltage to supply an AC voltage to a discharge lamp, and the full bridge circuit. An electronic lighting device for a discharge lamp, comprising: a current detection circuit that detects an input current of a circuit; and a control circuit that alternately drives each pair of the switching semiconductor elements located on opposite sides of the full bridge circuit, Driving a first switching semiconductor element of each pair of the switching semiconductor elements whose circuit is located on the opposite side of the full bridge circuit at a low frequency, and controlling a second switching semiconductor element of the same at a high frequency. An electronic lighting device for a discharge lamp, comprising: 4. A full bridge circuit comprising a plurality of switching semiconductor elements connected in a full bridge circuit configuration to convert a DC input voltage into an AC voltage to supply an AC voltage to a discharge lamp, and the full bridge circuit. An electronic lighting device for a discharge lamp, comprising: a current detection circuit that detects an input current of a circuit; and a control circuit that alternately drives each pair of the switching semiconductor elements located on opposite sides of the full bridge circuit, A circuit drives the first switching semiconductor elements of the pair of switching semiconductor elements located on opposite sides of the full-bridge circuit at the same frequency as the output frequency thereof, and drives the second switching semiconductor elements at the full frequency. An electronic lighting device for a discharge lamp, characterized in that the duty ratio is controlled so that the average value of the input current of the bridge circuit becomes constant. 5. A switching semiconductor element that is on-controlled for each pair of switching semiconductor elements is turned off when the peak value of the input current of the full bridge circuit reaches a set value. The electronic lighting device for a discharge lamp according to any one of claims 1 to 4. 6. The frequency at which the on-controlled switching semiconductor element of each pair of switching semiconductor elements is controlled is 50 times or more higher than the output frequency of the full bridge circuit. The electronic lighting device for a discharge lamp according to any one of claims 1 to 5. 7. A rectifier circuit for converting AC power into DC power, a voltage conversion converter circuit for converting DC voltage from the rectifier circuit into stable DC voltage, and a pair of switching semiconductor elements in a bridge circuit configuration. A bridge circuit for connecting a DC voltage from the voltage conversion converter circuit to an AC voltage to supply an AC voltage to the discharge lamp; a current detection circuit for detecting an input current of the bridge circuit; In an electronic lighting device for a discharge lamp, comprising: a control circuit for alternately driving each pair of switching semiconductor elements located on opposite sides of a bridge circuit, wherein the converter circuit is an inductor connected in series to the rectifying circuit; A control semiconductor element connected across the inductor and the rectifier circuit, a diode connected in series to the inductor, and the diode. An electronic lighting device for a discharge lamp, which is a step-up chopper circuit including an capacitor and a capacitor connected across the control semiconductor element. 8. The voltage conversion converter circuit is controlled so that the waveform of the input current from the rectifier circuit for converting AC power into DC power is made sinusoidal and the rectified voltage from the rectifier circuit is converted into a stable DC voltage. Then, the first switching semiconductor element of each pair of the switching semiconductor elements located on the opposite side of the full bridge circuit for converting the DC voltage from the voltage conversion converter circuit into the AC voltage and supplying the AC voltage to the discharge lamp. Is driven at a low frequency, and each of the second switching semiconductor elements is controlled at a high frequency. A method for controlling an electronic lighting device for a discharge lamp, comprising: 9. The step-up chopper circuit is controlled so that the waveform of the input current from the rectifier circuit for converting AC power into DC power is sinusoidal, and the rectified voltage from the rectifier circuit is a stable DC voltage. The full bridge circuit for converting the DC voltage from the step-up chopper circuit into an AC voltage of low frequency and supplying the AC voltage of low frequency to the discharge lamp is controlled by a duty ratio high frequency control so that its input current becomes substantially constant. A method for controlling an electronic lighting device for a discharge lamp. 10. A step-up chopper circuit is controlled so that a waveform of an input current from a rectifying circuit for converting AC power into DC power is sinusoidal, and a rectified voltage from the rectifier circuit is a stable DC voltage. Each switching semiconductor element of the full bridge circuit that converts the DC voltage from the boost chopper circuit into an AC voltage and supplies the AC voltage to the discharge lamp is controlled at a high frequency, and each pair of switching semiconductor elements is controlled at a low frequency. A method of controlling an electronic lighting device for a discharge lamp, which is switched and operated alternately.