JP2003224970A - Power unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power unit which can embody downsizing of itself at large and the lowering of loss, by lowering commercial AC voltage and improving the general power loss of a key part and enhancing efficiency. <P>SOLUTION: This power unit is of such constitution that a lighting signal S is sent out from outside to a lighting device 5' and a delay circuit 7, that a lighting delay signal S' having passed the delay circuit 7 is sent out to the output voltage varying circuit 4 of a power factor improving circuit 3', and that an input voltage detection signal P outputted from an input voltage detecting circuit 2 for detecting the input of a maximum voltage value EO from a full-wave rectifying circuit 1 is sent out to the output voltage varying circuit 4 of the power factor improving circuit 3'. When the lighting signal S is inputted, an output voltage VL for lighting rises from the lighting device 5' so as to light a discharge lamp 6; then after passage of a specified delay time by the lighting delay signal S' set in the delay circuit 7, the output voltage varying circuit 4 controls an output voltage VO for start to be dropped into a voltage value set by the input voltage detection signal P. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention mainly includes a power factor correction circuit having a step-up chopper circuit (AC-DC converter) and a lighting device having a non-insulated step-down chopper circuit (DC-DC converter). A power supply device having a discharge lamp that is turned on by the output voltage of a lighting device. Specifically, by varying the starting output voltage output from the power factor correction circuit, power loss is reduced (higher power efficiency). Regarding power supply.

[0002]

2. Description of the Related Art Conventionally, as a power supply device of this type, for example, a power supply device having a circuit configuration as shown in FIG.
This power supply device has an AC voltage E obtained from a commercial AC power supply.
Is converted to a direct current (DC) voltage by a full-wave rectifier circuit 1 that outputs a maximum voltage value E0 by inputting a maximum voltage value E0 and a built-in step-up chopper circuit that inputs the maximum voltage value E0. Start-up output voltage V0 with boosted power factor
ON / OFF by inputting the power factor correction circuit 3 for outputting the lighting signal and the lighting signal S generated by the lighting signal generation circuit 8 outside the device.
The output voltage for lighting VL is applied by applying the ignition pulse by the built-in non-insulated step-down / step-down chopper circuit according to the start-up output voltage V0 input from the power factor correction circuit 3 And a discharge lamp 6 such as a high-pressure mercury lamp or a metal halide lamp that keeps arc discharge and is lit by inputting the lighting output voltage VL.

Among these, the AC voltage E used in the commercial AC power source is, for example, AC 100 V in Japan and AC in the United States.
120V, AC240V in Western countries (Europe).
Since the startup output voltage V0 output from the power factor correction circuit 3 to which the maximum voltage value E0 of the AC voltage E is input is obtained by the boosting operation, the maximum voltage value E of the full-wave rectified waveform E
It is necessary to have a voltage with a step-up ratio that is 0 or more and that is high enough to obtain a high power factor.
DC360 for stable operation when C240V is applied
V or more is required.

Further, here, the output voltage V0 for starting is DC
Another reason why 360V is required is that the discharge lamp 6
It is due to the characteristics of. That is, since the lighting device 5 requires a large pulse current after the lamp is started (dielectric breakdown) due to the characteristics of the discharge lamp 6 and before the arc discharge is started, the voltage applied to the lighting device 5 is several hundreds. A high volt potential is required, which requires that the startup output voltage V0 from the power factor correction circuit 3 be maintained at DC360V. For this reason, the output voltage V0 for starting the power factor correction circuit 3 is required to have an output of DC 360 V or higher.

Further, the loss of the power factor correction circuit 3 is generally dominated by the loss of the main switching element constituting the circuit, but this loss is proportional to the starting output voltage V0.
Therefore, in the power factor correction circuit 3, it is known that the efficiency becomes higher as the startup output voltage V0 is lowered, that is, the smaller the boosting ratio.

On the other hand, the loss of the lighting device 5 is generally dominated by the main switching element and the flywheel diode constituting the circuit, but among them, the loss of the flywheel diode operating at turn-off is dominant. And this loss also becomes the input voltage
Is proportional to the starting output voltage V0. Therefore, even in the case of the lighting device 5, it is known that the efficiency is increased by lowering the startup output voltage V0 of the power factor correction circuit 2.

FIG. 5 is a circuit diagram specifically exemplifying a detailed configuration of the power factor correction circuit 3 provided in the power supply device.
This power factor correction circuit 3 uses a switching element 10, a choke coil 11, a flywheel diode 12, a smoothing coil 13, and an input current / output voltage control circuit 9 as basic elements, and also has a full-wave rectified waveform on the input side. Each part has a circuit configuration such that the maximum voltage value E0 is set and the startup output voltage V0 is set on the output side. However, the basic elements and circuit configuration applied here are well known. The detailed technical description is omitted.

FIG. 6 is a circuit diagram specifically illustrating the configuration of the step-down chopper of the lighting device 5 provided in this power supply device. This lighting device 5 uses a switching element 15, a choke coil 16, a flywheel diode 17, a smoothing coil 18, and a control circuit 14 as basic elements, and has a starting output voltage V0 set on the input side and an output side on the output side. The respective circuits are circuit-configured so that the lighting output voltage VL is set. However, since the basic elements and circuit configurations themselves which are applied here are well known, detailed description of the technical aspects is omitted. .

By the way, as a well-known technique related to such a power supply device, in a discharge lighting device with dimming, when all outputs of a lamp output which is a load are switched to dimming output during dimming, a circuit configuration is provided. In the step-up chopper circuit and the inverter circuit for converting the AC power source inside to the DC voltage, the step-up ratio is selected so that the efficiency of the step-up chopper circuit is maximized when the lamp output with a large load power is selected in all output states. (That is, the power efficiency of the entire device is increased by setting the step-up ratio of the step-up chopper circuit for converting the AC power source to the DC voltage to a higher efficiency).
Japanese Patent Application Laid-Open No. 2001-284073, which discloses that the discharge current output from the lighting device is detected and controlled in order to prevent the damage of the discharge lamp caused by the wrong mounting of the high-pressure discharge lamp or the one disclosed in Japanese Patent Publication No. 273870. And the like disclosed in the publication.

[0010]

In the case of the power supply device shown in FIG. 4 described above, for example, in Europe where commercial AC voltage is high, high efficiency can be maintained under the operating condition of constant operation at DC360V when AC240V is applied. Under the usage conditions such as when applied in Japan where the voltage is low, the total power loss of the power factor correction circuit and the lighting device in the circuit configuration becomes maximum at the time of AC100V input with a large step-up ratio.
It is difficult to maintain high efficiency, and as a result, it is necessary to design the heat radiation of the power supply with the loss at the time of AC100V input and the efficiency is not good, so the overall size of the device is reduced and the loss of power is reduced. There is a problem that it is difficult to realize.

The present invention has been made to solve such a problem, and its technical problem is that the total loss of the power factor correction circuit and the lighting device is improved even when the commercial AC voltage is low, and high efficiency is achieved. It is an object of the present invention to provide a power supply device that can be realized in a compact size and a low loss.

[0012]

According to the present invention, a full-wave rectifier circuit that outputs a maximum voltage value by inputting an AC voltage obtained from a commercial AC power source to form a full-wave rectified waveform, and a maximum voltage value A power factor correction circuit that outputs a startup output voltage that is converted to a DC voltage by a built-in step-up chopper circuit and boosts and improves the power factor to a predetermined level, and a lighting signal generated by a lighting signal generation circuit outside the device. Operation is controlled by inputting,
A lighting device that raises and outputs the lighting output voltage by applying an ignition pulse by the built-in non-insulated step-down chopper circuit according to the starting output voltage input from the power factor correction circuit at the start of operation, and the lighting output In a power supply device having a discharge lamp that maintains a discharge and lights when a voltage is applied, a voltage value of a starting output voltage output from a power factor correction circuit after the lighting device starts a lighting operation of the discharge lamp. A power supply device including a startup output voltage variable control circuit for variably suppressing and setting is obtained.

Further, according to the present invention, in the above power supply device, the startup output voltage variable control circuit is connected and arranged between the full-wave rectification circuit and the power factor correction circuit, and the maximum voltage value is input to detect the startup. The input voltage detection circuit that outputs the input voltage detection signal of the voltage value for which the output voltage for setting and the power factor correction circuit are built-in, and the input voltage detection signal is input to detect the startup output voltage. A power supply device including an output voltage variable circuit that variably suppresses a voltage value that is set by a signal to be lowered can be obtained.

Further, according to the present invention, in the above power supply device, the startup output voltage variable control circuit includes a delay circuit which inputs a lighting signal and outputs a lighting delay signal delayed by a predetermined amount, and the output voltage variable control circuit. The circuit is a power supply device that operates to reduce the startup output voltage to the voltage value set by the input voltage detection signal after the elapse of a predetermined delay time set by inputting the lighting delay signal from the delay circuit. To be

In addition, according to the present invention, in the above power supply device, the lighting device is initially supplied with a lighting signal and is turned on.
When the FF operation is shown, lighting is performed according to a predetermined maximum value of the output voltage for start-up obtained from the output voltage variable circuit of the power factor correction circuit regardless of the instruction setting by the input voltage detection signal from the input voltage detection circuit. From the output voltage variable circuit of the power factor correction circuit to which the lighting delay signal from the delay circuit is input when the lighting signal is switched from the OFF operation to the one indicating the ON operation after the output voltage for output is raised and output. A power supply device can be obtained that outputs the lighting output voltage in accordance with the maximum value of the startup output voltage that is set to the minimum value after the elapse of the obtained predetermined delay time.

On the other hand, according to the present invention, in any one of the power supply devices described above, the voltage value of the input voltage detection signal output from the input voltage detection circuit is proportional to the maximum voltage value output from the full-wave rectification circuit. A power supply device having the characteristics that

On the other hand, according to the present invention, in any one of the power supply devices described above, the voltage value set by variably suppressing the starting output voltage output from the power factor correction circuit including the output voltage variable circuit is: The input voltage detection is performed in the first section in each of the predetermined first to third sections which are divided according to the increase of the voltage value of the input voltage detection signal output from the input voltage detection circuit. A constant minimum value is maintained regardless of an increase in the voltage value of the signal, the voltage is proportionally increased according to the increase of the voltage value of the input voltage detection signal in the second section, and the input voltage detection is performed in the third section. It is possible to obtain a power supply device having a characteristic of maintaining a constant maximum value regardless of an increase in the voltage value of a signal.

Further, according to the present invention, in the above power supply device, the voltage value set by variably suppressing the startup output voltage is such that the minimum value maintained in the first section is the voltage value of the input voltage detection signal. Is larger than the change value of the maximum voltage value of the full-wave rectified waveform corresponding to the maximum value that defines the first section in the change of, and is larger than the lighting output voltage, and is maintained in the third section. The maximum value is larger than the change value of the maximum voltage value of the full-wave rectified waveform corresponding to the maximum value that defines the third section when the voltage value of the input voltage detection signal changes, and The step-up chopper circuit has a step-up chopper ratio sufficient to obtain a high power factor, and the step-down chopper circuit has a step-down ratio necessary for the step-down chopper operation to obtain a power supply device.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a circuit block diagram showing a basic configuration of a power supply device according to one embodiment of the present invention. In the case of this power supply device, compared with the conventional device shown in FIG. 4, a full-wave rectification circuit 1 that outputs the maximum voltage value E0 by inputting an AC voltage E obtained from a commercial AC power supply and performing a full-wave rectification waveform
And a power factor correction circuit 3'which outputs a starting output voltage V0 which is converted to a DC voltage by a built-in boost chopper circuit based on the maximum voltage value E0 and has a predetermined power factor boosted and improved.
The lighting signal S generated by the lighting signal generation circuit outside the device is input to control the operation, and at the start of the operation, the power factor correction circuit 3 '
The lighting device 5'which raises and outputs the lighting output voltage VL by applying the ignition pulse by the built-in non-insulated step-down chopper circuit according to the starting output voltage V0 input from Although the basic configuration and function including the discharge lamp 6 that maintains the discharge and lights by applying an input are generally common, here, the power is supplied after the lighting device 5'starts the lighting operation of the discharge lamp 6. The difference is that a startup output voltage variable control circuit for variably suppressing and setting the voltage value of the startup output voltage V0 output from the rate improvement circuit 3'is provided.

This startup output voltage variable control circuit is connected and arranged between the full-wave rectifier circuit 1 and the power factor correction circuit 3 ',
The input voltage detection circuit 2 that detects the maximum voltage value E0 by input and outputs the input voltage detection signal P having the voltage value at which the startup output voltage V0 should be set, and the power factor correction circuit 3'are installed in the input voltage detection circuit 2. The detection signal P is input to start the output voltage V0.
Output voltage variable circuit 4 that variably suppresses the voltage to a voltage value set by the input voltage detection signal P, and a lighting delay signal S ′ that is a predetermined delay by inputting the lighting signal S.
And a delay (DELAY) circuit 7 for outputting the start voltage, and the output voltage variable circuit 4 inputs the lighting delay signal S'from the delay circuit 7 and a start output after a predetermined delay time set and instructed. The operation of lowering the voltage V0 to the voltage value set by the input voltage detection signal P is performed.

Therefore, the lighting device 5'improves the power factor regardless of the instruction setting by the input voltage detection signal P from the input voltage detection circuit 2 when the lighting signal S is initially input to indicate the OFF operation. The maximum value V0m of the predetermined starting output voltage V0 obtained from the output voltage variable circuit 4 of the circuit 3 '
After the lighting output voltage VL is raised according to ax and output, the lighting delay signal S ′ from the delay circuit 7 is changed when the lighting signal S is switched from OFF operation to ON operation.
The output voltage for lighting according to what is set by switching the maximum value V0max of the startup output voltage V0 after the elapse of a predetermined delay time obtained from the output voltage variable circuit 4 of the power factor correction circuit 3'which has been input to the minimum value V0min. Output VL.

That is, in the case of this power supply device, the lighting signal S is sent from the outside to the lighting device 5'and the delay circuit 7, and the lighting delay signal S'through the delay circuit 7 is supplied to the power factor improving circuit 3 '. The input voltage detection signal P output from the input voltage detection circuit 2 that outputs the maximum voltage value E0 from the full-wave rectifier circuit 1 to the output voltage variable circuit 4 is detected by the output voltage variable circuit of the power factor correction circuit 3 '. Since the lighting signal S is sent to the outside, the lighting output voltage VL of the lighting device 5 ′ rises to light the discharge lamp 6 and then set by the delay circuit 7. After the elapse of a predetermined delay time due to the lighting delay signal S ', the power factor correction circuit 3'
Since the output voltage varying circuit 4 can variably reduce and suppress the starting output voltage V0 to the voltage value set by the input voltage detection signal P, even when the commercial AC voltage is as low as AC100V. The overall power loss of the power factor correction circuit 3'and the lighting device 5'is reduced and improved to improve efficiency, and the entire device can be downsized and reduced in loss.

FIG. 2 shows the relationship between the voltage values of the input voltage detection signal P output from the input voltage detection circuit 2 in response to changes in the maximum voltage value E0 output from the full-wave rectification circuit 1 of this power supply device. It is the shown maximum voltage value E0-input voltage detection signal P characteristic waveform (variable output characteristic of the input voltage detection signal P in the input voltage detection circuit 2) figure.

Here, the voltage value of the input voltage detection signal P output from the input voltage detection circuit 2 has a characteristic proportional to the maximum voltage value E0 output from the full-wave rectification circuit 1, and the input voltage detection signal P is detected. Circuit 2 shows the maximum voltage value E of the full-wave rectified waveform
The input voltage detection signal P having a voltage value proportional to 0 is output to the output voltage variable circuit 4. That is, the input voltage detection circuit 2 increases the maximum voltage value E0 in this order by increasing E1, E2, E.
When 3 and E4 are input, P1 is output as the input voltage detection signal P when E1 is input, and
When it is 2, it outputs P2, when it is E3, it outputs P3, and when it is E4, it outputs P4.

FIG. 3 shows a power factor correction circuit 3'when the input voltage detection signal P output from the input voltage detection circuit 2 provided in this power supply device follows the characteristics (P1, P2, P3, P4) shown in FIG. Input voltage detection signal P-representing the relationship between the voltage values of the output voltage V0 for startup output from the output voltage V for startup
It is a 0 characteristic waveform (variable output characteristic waveform of the starting output voltage V0 in the power factor correction circuit 3 ').

Here, the variable voltage value of the startup output voltage V0 output from the power factor correction circuit 3 including the output voltage variable circuit 4 is the input voltage detection signal P output from the input voltage detection circuit 2. Increase in voltage value (P1, P2, P3, P
4) The first section (P1 to P) in the predetermined first section to the third section, which are respectively continuous, are distinguished.
In 2), the constant minimum value V0min is maintained regardless of the increase in the voltage value of the input voltage detection signal P, and the second interval (P2 to P2
In 3), the voltage value of the input voltage detection signal P is proportionally increased according to the increase, and in the third section (P3 to P4), the maximum value V0ma is constant regardless of the increase of the voltage value of the input voltage detection signal P.
It has a characteristic of maintaining x, and the output voltage variable circuit 4 has a minimum value as the startup output voltage V0 when the voltage value of the input voltage detection signal P corresponding to the first section (P1 to P2) is input. V0min is output and the second section (P2-P
The voltage value between V0min and V0max, which increases proportionally when the voltage value of the input voltage detection signal P corresponding to 3) is input, is output, and the input voltage detection signal P corresponding to the third section (P3 to P4) is output. Maximum value V0 when the voltage value of
Output max.

However, when the lighting signal S or the lighting delay signal S'which is delayed by the delay circuit 7 initially indicates the OFF operation, the output voltage variable circuit 4 changes the voltage value of the input voltage detection signal P. Regardless, the maximum value V0max is fixed and output as the starting output voltage V0.

In the case of this power supply device, the maximum voltage value E0 of the full-wave rectified waveform input to the input voltage detection circuit 2 is E
The relationship 1 <E2 <E3 <E4 needs to be established, and the variable starting output voltage V0 from the power factor correction circuit 3'is V0mi between the change value of the maximum voltage value E0.
n> E2 and V0max> E4 are established, and the power factor correction circuit 3'needs to have a sufficient boost chopper ratio as a boost chopper circuit to obtain a high power factor. The output voltage V0 for starting the rate improving circuit 3'and the output voltage VL for lighting from the lighting device 5'have a relationship of V0min> VL, and the lighting device 5'operates as a step-down chopper circuit as a step-down chopper circuit. It should have the required step-down ratio.
It should be noted that the basic components of the main body of the power factor correction circuit 3'and the lighting device 5'herein can have the circuit configurations shown in FIGS. 5 and 6 as they are.

The basic operation of this power supply device will be specifically described below with reference to the characteristic diagrams shown in FIG. 2 and FIG.

First, in this power supply device, the maximum voltage value E0 of the full-wave rectified waveform output from the full-wave rectifier circuit 1 is E.
When it is 1 and the lighting signal S indicates an OFF operation, the input voltage detection signal P output from the input voltage detection circuit 2 becomes P1 according to the correspondence shown in FIG. At this time, the starting output voltage V output from the power factor correction circuit 3 '
As described above, regardless of the input voltage detection signal P, 0 becomes V0max due to the setting of the output voltage variable circuit 4.

Next, when the external lighting signal S is switched from OFF operation to ON operation, the lighting device 5'starts operation and the discharge lamp 6 is turned on.

Further, the output voltage variable circuit 4 has a lighting signal S
Has turned on, the start output voltage V0 of the power factor correction circuit 3'has elapsed after the elapse of a predetermined delay time set by the lighting delay signal S'through the delay circuit 7.
From the maximum value V0max shown in FIG. 3 to the minimum value V0mi
Switch to n and set.

Similarly, even when the maximum voltage value E0 of the full-wave rectified waveform output from the full-wave rectification circuit 1 is E2, the starting output voltage V0 of the power factor correction circuit 3'is changed from the maximum value V0max to the minimum value V0min. Switch to and set.

On the other hand, when the maximum voltage value E0 of the full-wave rectified waveform output from the full-wave rectifier circuit 1 is between E2 and E3, the input voltage detection signal P becomes P2-P3, and the power factor correction circuit 3 '. The output voltage V0 for starting from is the minimum value V0mi
A voltage value proportional to the change of the maximum voltage value E0 is set and output between n and the maximum value V0max.

On the other hand, when the maximum voltage value E0 of the full-wave rectified waveform output from the full-wave rectifier circuit 1 is between E3 and E4, the input voltage detection signal P becomes P3 to P4, and the power factor correction circuit 3 '. The output voltage V0 for startup from is the maximum value V0ma
Fixedly set to x.

On the other hand, when the maximum voltage value E0 of the full-wave rectified waveform output from the full-wave rectifier circuit 1 exceeds E4,
That is, when the maximum value V0max <E4, the power factor correction circuit 3'is constituted by the step-up chopper circuit, so the operation is stopped and the maximum voltage value E0 of the full-wave rectified waveform is the lighting device 5 '.
Becomes the input voltage value.

As a result, the step-up ratio of the step-up chopper circuit of the power factor correction circuit 3'is set and maintained at a specific constant value at the start of the lighting operation of the discharge lamp 6 by the lighting device 5 ', and is suppressed more than that after the lighting operation. When the boosted voltage reaches a certain constant value within the range of the condition where the AC power source is used, the function of operating the booster ratio to 1 without boosting is obtained. It can be applied as a worldwide power supply corresponding to a voltage of 100V to 240V.

Incidentally, the starting output voltage V0 from the power factor correction circuit 3 ', even if the maximum voltage value E0 of the full-wave rectification waveform output from the full-wave rectification circuit 1 changes from E1 to E4,
It is general to always output at a maximum value V0max which is a constant voltage, but in the case of the power supply device of the present invention, the startup output voltage V0 is variably suppressed and set to a constant boosting ratio with respect to the AC voltage E. By maintaining the above, it becomes possible to reduce the power loss of the power factor correction circuit 3 ', and also for the lighting device 5', when the AC voltage E is low, the starting output voltage V0 is lowered to lower the step-down ratio. This makes it possible to reduce power loss. Therefore, Japanese Patent Laid-Open No. 8-273
In contrast to the technique disclosed in Japanese Patent Publication No. 870, the known technique sets the boosting ratio of the boosting chopper circuit corresponding to the power factor correction circuit 3'to a specific region having the highest efficiency. On the other hand, in the present invention, the power factor correction circuit 3 '
In the step-up chopper circuit of step-up chopper circuit (DC-D)
Since the efficiency of the C converter) is set to a value that can be most improved, both have different technical gist regarding the improvement of power efficiency.

The relationship between the power loss of the power factor correction circuit 3'and the lighting device 5'and the starting output voltage V0 will be described below.

First, referring to FIG. 5, considering the general circuit configuration of the power factor correction circuit 3'having a boost chopper circuit, here, the switching element 10 occupies most of the loss in the circuit. Can be easily imagined. The loss of the switching element 10 may be loss at turn-on, turn-off, ON resistance, etc.
Assuming that the circuit is configured by the ero volt switching method, the loss at the time of turn-on is zero among the losses of the switching element 10.

Since the loss due to the ON resistance is much smaller than the loss at the time of turn-off, the loss of the switching element 10 is dominated by the loss at the time of turn-off. Here, assuming that the switching element 10 is an FET, the relationship between the loss at turn-off and the output voltage V0 for start-up can be interpreted as follows.

That is, the loss Poff at turn-off is Poff = {E0 × Tf / (12 ×), assuming that the switching element 10 is an FET and the duty ratio is 50%.
L)} × Vds, where E0 is the voltage input to the power factor correction circuit 3 '(maximum voltage value of full-wave rectified waveform),
Tf is the turn-off time of the switching element 10, L is the inductance value of the choke coil, and Vds is the drain-source voltage of the switching element 10, where {E0 ×
Since Tf / (12 × L)} is a constant that does not change, substituting this with a coefficient K results in Poff described above.
The relational expression of is Poff = K × Vds.

From this equation, the loss Pof at turn-off
It can be seen that in order to reduce f, the loss can be reduced by lowering Vds, that is, lowering the startup output voltage V0. Therefore, if the starting output voltage V0 of the power factor correction circuit 3'is lowered, the loss of the switching element 10 can be suppressed, and the efficiency of the power factor correction circuit 3'is increased.

Next, referring to FIG. 6, taking note of the general circuit configuration of the lighting device 5'having a step-down chopper circuit, here, the switching element 15 and the flywheel diode 17 cause much loss in the circuit. It's easy to imagine what they're occupying. The loss of the switching element 15 and the flywheel diode 17 can be divided into a loss due to duty and a loss due to switching.

Here, assuming that the switching element 15 is an FET, the loss due to duty is mainly due to the loss Pq due to the on-resistance Ron and the loss Pd due to the forward voltage Vf of the flywheel diode 17, and the respective losses are: Pq = Ron × I2 × {Ton / (Ton + To
ff)}, Pd = Vf × I × {Toff / (Ton + T
off)}, where Ton is the ON period of the switching element 15, Toff is the OFF period of the switching element 15, and I is the output current.

In these relational expressions, assuming that the duty ratio is 50%, Ron is 0.5 ohms, and Vf is 3V, the ratio of the loss to the flywheel diode 17 is.
Is bigger. In order to reduce the loss Pd of the flywheel diode 17 here, Ton is set to be long T
It can be seen that the loss can be reduced by shortening off, that is, by lowering the input output voltage V0 for activation.

On the other hand, the switching loss is
Loss Pt when the switching element 15 is turned on
r, a loss Ptf due to turn-off, and each loss is Ptr = (I × Vds × Tr × F) / 6, Pt
f = (I × Vds × Tf × F) / 6, where Vds is the drain-source voltage of the switching element 15, Tr is the turn-on period of the switching element 15, and Tf is the switching element 15. Is the turn-off period, and F is the oscillation frequency. In these relational expressions, since I, Tr, and Tf are constant, the loss depends on Vds. Therefore, in order to reduce the switching loss Ptr + Ptf, Vds
Lowering, that is, the starting output voltage V applied to the input
It can be seen that the loss can be reduced by decreasing 0. Therefore, if the starting output voltage V0 of the power factor correction circuit 3'is reduced, the switching element 15 and the flywheel diode 17 are reduced.
Can be reduced, and the loss of the lighting device 5'can be reduced.

For the above reasons, if the basic configuration of the power supply device of the present invention described above is applied, the total loss of the power factor correction circuit 3'and the lighting device 5'is improved even when the commercial AC voltage is low. High efficiency is achieved, and miniaturization and low loss of the entire device are realized.

[0050]

As described above, according to the power supply device of the present invention, the starting output voltage variable control circuit for changing the starting output voltage output from the power factor correction circuit is provided,
This startup output voltage variable control circuit lowers the startup output voltage applied to the lighting device after the lighting of the discharge lamp by the lighting device is stabilized, that is, by reducing the boosting ratio, the power factor correction circuit Since it is possible to reduce the loss and also reduce the loss of the lighting device at the same time, the power factor correction circuit and the lighting are stabilized after the lighting of the discharge lamp is stable even when the commercial AC voltage is low such as when the AC100V is input. The overall loss of the device is improved, the efficiency is increased, and the size and loss of the entire device can be reduced.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing a basic configuration of a power supply device according to an embodiment of the present invention.

FIG. 2 is a maximum voltage showing a relationship between voltage values of an input voltage detection signal output from an input voltage detection circuit according to a change in a maximum voltage value output from a full-wave rectification circuit included in the power supply device shown in FIG. Value-Input voltage detection signal characteristic waveform (variable output characteristic waveform of input voltage detection signal in input voltage detection circuit)
It is a figure.

3 is a relationship between voltage values of start-up output voltages output from the power factor correction circuit when the input voltage detection signal output from the input voltage detection circuit included in the power supply device shown in FIG. 1 follows the characteristics shown in FIG. 2; Is a diagram showing the input voltage detection signal-starting output voltage characteristic waveform (variable output characteristic waveform of starting output voltage in the power factor correction circuit).

FIG. 4 is a circuit block diagram showing a basic configuration of a conventional power supply device.

5 is a circuit diagram specifically exemplifying a detailed configuration of a power factor correction circuit provided in the power supply device shown in FIG.

6 is a circuit diagram specifically exemplifying a configuration of a step-down chopper of a lighting device provided in the power supply device shown in FIG.

[Explanation of symbols]

1 Full wave rectifier circuit 2 Input voltage detection circuit 3,3 'Power factor correction circuit 4 Output voltage variable circuit 5,5 'lighting device 6 discharge lamp 7 Delay (DELAY) circuit 8 Lighting signal generation circuit 9 Input current / output voltage control circuit 10,15 Switching element 11,16 choke coil 12,17 Diode 13,18 Smoothing coil 14 Control circuit

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshihisa Kudo             Enshi, 5-8-3 Shiba, Minato-ku, Tokyo             View Technology Co., Ltd. (72) Inventor Yoshiyuki Kasuga             1938 Nishi Minowa, Ina City, Nagano Prefecture             Within Con Co., Ltd. F term (reference) 3K072 AA12 AA13 AC20 BA03 BB01                       BB10 CA11 CB03 CB08 DD03                       DD06 DE05 DE06 GA01 GB03                       HA10                 3K083 AA77 AA81 AA92 BA02 BA26                       BA33 BC13 BC33 BD03 BD10                       BD18 BE10 CA33                 5H006 AA02 CA01 CA07 CB01 CB08                       DA04                 5H730 AA18 AS04 AS11 BB14 BB57                       CC01 CC04 DD02 FD01 FD11                       FD41

Claims (7)

[Claims] 1. A full-wave rectifier circuit that outputs a maximum voltage value by inputting an AC voltage obtained from a commercial AC power source to form a full-wave rectified waveform, and a boost chopper circuit incorporated based on the maximum voltage value. The power factor correction circuit that converts to DC voltage and outputs the startup output voltage that boosts and improves the power factor to a predetermined level, and the lighting signal generated by the lighting signal generation circuit outside the device are input to control the operation and start the operation. A lighting device that raises and outputs a lighting output voltage by applying an ignition pulse by a built-in non-insulated step-down chopper circuit according to the start-up output voltage which is sometimes input from the power factor correction circuit, and the lighting device. In a power supply device provided with a discharge lamp that maintains a discharge and lights up when an output voltage is applied, the power is supplied to the discharge lamp after the lighting device starts a lighting operation. A power supply device comprising a startup output voltage variable control circuit for variably suppressing and setting the voltage value of the startup output voltage output from the rate improvement circuit. 2. The power supply device according to claim 1, wherein the startup output voltage variable control circuit is connected and arranged between the full-wave rectification circuit and the power factor correction circuit, and detects the maximum voltage value. And an input voltage detection circuit for outputting an input voltage detection signal of a voltage value to which the startup output voltage is to be set, and a power factor correction circuit that is internally provided and receives the input voltage detection signal and outputs the startup output. An output voltage variable circuit that variably suppresses the voltage so that the voltage is lowered to a voltage value set by the input voltage detection signal. 3. The power supply device according to claim 2, wherein the startup output voltage variable control circuit includes a delay circuit which inputs the lighting signal and outputs a lighting delay signal delayed by a predetermined amount, and the output voltage. The variable circuit receives the lighting delay signal from the delay circuit and, after the elapse of the predetermined delay time instructed and set, lowers the startup output voltage to a voltage value set by the input voltage detection signal. A power supply device characterized by performing. 4. The power supply device according to claim 3, wherein the lighting device is initially turned off when the lighting signal is input.
When the operation is indicated, the predetermined maximum value of the starting output voltage obtained from the output voltage variable circuit of the power factor correction circuit regardless of the instruction setting by the input voltage detection signal from the input voltage detection circuit. The power factor correction circuit which inputs the lighting delay signal from the delay circuit when the lighting signal is switched from the OFF operation to the one indicating the ON operation after the lighting output voltage is raised and output according to A power source for outputting the lighting output voltage in accordance with the maximum value of the startup output voltage after the lapse of the predetermined delay time obtained from the output voltage variable circuit is set to the minimum value. apparatus. 5. The power supply device according to claim 2, wherein the voltage value of the input voltage detection signal output from the input voltage detection circuit is output from the full-wave rectification circuit. A power supply device having a characteristic proportional to the maximum voltage value. 6. The power supply device according to claim 5, wherein the voltage value set by variably suppressing the startup output voltage output from the power factor correction circuit including the output voltage variable circuit is the input voltage. The input voltage detection signal is detected in the first section in each of the predetermined first to third sections which are divided according to the increase of the voltage value of the input voltage detection signal output from the detection circuit. Maintains a constant minimum value regardless of the increase of the voltage value of the input voltage detection signal, and increases proportionally in accordance with the increase of the voltage value of the input voltage detection signal in the second section.
A power supply device having a characteristic of maintaining a constant maximum value regardless of an increase in the voltage value of the input voltage detection signal in the section. 7. The power supply device according to claim 6, wherein the voltage value set by variably suppressing the startup output voltage is the minimum value maintained in the first section of the input voltage detection signal. The change is larger than the change value of the maximum voltage value of the full-wave rectified waveform corresponding to the maximum value defining the first section in the change of the voltage value, and is larger than the lighting output voltage, Change in the maximum voltage value of the full-wave rectified waveform corresponding to the maximum value defining the third section when the maximum value maintained in section 3 corresponds to the change in the voltage value of the input voltage detection signal. The step-up chopper circuit has a step-up chopper ratio sufficient to obtain a high power factor, and the step-down chopper circuit has a step-down ratio necessary for the step-down chopper operation. Power supply device characterized by Place