JP3397218B2 - Power supply device, discharge lamp lighting device and lighting device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device, a discharge lamp lighting device, and a lighting device having switching means having a pair of switching elements.

[0002]

2. Description of the Related Art Conventionally, there is a discharge lamp lighting device using a half-bridge type inverter circuit as shown in FIG.

As shown in FIG. 4, this discharge lamp lighting device includes a coil L1 and a capacitor for a commercial AC power source E.
A full-wave rectifier circuit 2 is connected via a filter circuit 1 composed of C1, a series circuit of a smoothing capacitor C2 and a coil L2 is connected to this full-wave rectifier circuit 2, and this smoothing capacitor C2 is connected in parallel. Is connected to a ripple capacitor C3 having a smaller capacity than the smoothing capacitor C2, and further, the switching elements SW1 and SW2 connected smoothly in series with the smoothing capacitor C2 and these switching elements SW2.
1 and SW2 are connected in parallel with a half-bridge type inverter circuit 3 having freewheeling diodes D1 and D2, and one switching element Q2 is connected in parallel with a capacitor C4,
A series circuit of the fluorescent lamp FL and the ballast choke L3 is connected, and the fluorescent lamp FL has a starting capacitor C5.

Then, the switching elements Q1 and Q2 of the inverter circuit 3 are alternately turned on and off to rectify the commercial AC power source E in a portion where the voltage is low, a ripple capacitor.
Ripple is generated at C3 to improve the power factor.

Further, power is regenerated to the power factor improving capacitor C3 via the ballast choke L3.

[0006]

However, the switching element on the side where the fluorescent lamps FL are not connected in parallel is provided.
When Q1 is turned off, current flows in the closed circuit of ballast choke L3, fluorescent lamp FL, capacitor C4, diode D2 and ballast choke L3, and capacitor C3 for power factor improvement.
There is a problem in that regeneration is not possible in the route via and the peak of the input current cannot be suppressed sufficiently.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a power supply device, a discharge lamp lighting device, and a lighting device capable of making an input current close to a sine wave.

[0008]

According to a first aspect of the present invention, there is provided a power supply device comprising: rectifying means for rectifying an AC voltage from an AC power source; small capacity capacitance means connected between output terminals of the rectifying means; Connected in parallel to the capacity means, for reflux respectively
A switching means having a pair of switching elements connected in series have diode; each between one of one end and the other end of midpoint and capacitor means of switching elements connected in series of the switching means An inductive component connected in series to each of the connected loads, and one of the switching elements is turned on.
When turned off, the other switching element
For freewheeling diode, through load and capacitive means
A path is formed to form a regenerative path including a load .

In the discharge lamp lighting device according to the second aspect, the load of the power supply device according to the first aspect is the discharge lamp.

According to a third aspect of the present invention, there is provided the discharge lamp lighting device according to the second aspect including a fixture main body.

[0011]

According to the power supply device of the present invention, since the inductive component is connected to the load connected between the midpoint of the pair of switching elements of the switching means and the capacitance means, one of the switching elements is turned on. Off from
If it is, the reflux of the other of the switching element
Since the diode of use, the route through the load and capacitor means is formed, since the regenerative path including the load is formed,
The off time of the rectifying means is appropriately maintained , the peak of the input current can be suppressed, and the input current can be made to approach a sine wave.

In the discharge lamp lighting device according to the second aspect, since the load of the power supply device according to the first aspect is the discharge lamp, the discharge lamp can be turned on with a sine wave and flicker is reduced.

Since the lighting device according to a third aspect includes the discharge lamp lighting device according to the second aspect and a fixture body, flicker can be reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the illumination device of the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral 11 denotes an instrument main body, and a load is applied to both ends of the instrument main body 11 and a fluorescent lamp FL as a discharge lamp.
A lamp socket 12 to which 1 and FL2 are attached is connected, and a reflecting plate 13 is provided along the longitudinal direction of the fluorescent lamps FL1 and FL2 between the lamp sockets 12 and 12, and a discharge lamp is lit in the reflecting plate 13. Circuit 14 is stored.

In the discharge lamp lighting circuit 14, as shown in FIG. 1, a commercial AC power source E is connected to a filter circuit 21 composed of a coil L11 and a capacitor C11, and the filter circuit 21 is composed of a diode bridge or the like. The input terminal of a full-wave rectifier 22 as a rectifying means is connected.
Further, the output terminal of the full-wave rectifier 22 is connected to a capacitor C12 of 10 nF as a relatively small capacitance means, a capacitor C13 of 68 μF having a sufficient smoothing capacity, and a smoothing circuit 23 of a coil L12. There is.

Further, in parallel with the smoothing circuit 23,
A half-bridge type inverter circuit 24, which is a switching means composed of a series circuit of two first and second switching elements SW11 and SW12, is connected to the first and second switching elements SW11 and SW12, respectively. The diodes D11 and D12 for are connected.

Further, in parallel with the first switching element SW11, a capacitor C14 of 0.1 μF for cutting DC is provided.
, A fluorescent lamp FL1 and a 2 mH ballast choke L13 as an inductive component are connected in series,
A 10 nF capacitor C15 for starting is connected between both terminals of 1, and in parallel with the second switching element SW12,
A 0.1μF capacitor C16 for DC cut, a fluorescent lamp FL2 and a ballast choke L14 of 2mH as an inductive component are connected in series, and a 10nF capacitor C17 for starting is connected between both terminals of the fluorescent lamp FL2. There is.

The inverter circuit 24 oscillates at 45 kHz, and the capacitor C12 and the ballast choke L14.
Resonance frequency of the inverter circuit 24 is higher than that of the inverter circuit 24.
The resonance frequency of L13 is also set higher than the oscillation operating frequency of the inverter circuit 24.

Next, the operation of the above embodiment will be described.

First, the voltage of the commercial AC power source E is noise-removed by the filter circuit 21, full-wave rectified by the full-wave rectifier 22, and smoothed by the smoothing circuit 23.

Then, the first and second switching elements SW11 and SW12 are alternately turned on and off. First, the first
When switching element SW11 of is turned on, full-wave rectifier 22,
1st switching element SW11, ballast choke L14,
A current flows in the path of the fluorescent lamp FL2, the capacitor C16, and the full-wave rectifier 22. Then, the first switching element SW
When 11 is off, ballast choke L13, fluorescent lamp FL
1 , the reactive power is regenerated in the capacitor C12 through the path of the capacitor C14, the capacitor C12, the diode D12 and the ballast choke L13.

On the contrary, when the second switching element SW12 is turned on, the full-wave rectifier 22 and the second switching element SW1 are turned on.
2, capacitor C14, fluorescent lamp FL1, ballast choke L13, second switching element SW12 and full-wave rectifier 2
The current flows through the route of 2. Then, when the second switching element SW12 is off, the ballast choke L14, the diode D11, the capacitor C12, the capacitor C16, the fluorescent lamp FL2 and the ballast choke L14 are used as the capacitors.
Reactive power is regenerated to C12.

When the voltage full-wave rectified by the full-wave rectifier 22 is low, the high-frequency ripple voltage from the capacitor C12 is superposed and becomes a substantially constant voltage. That is, since the capacitance of the capacitor C12 is relatively small, the discharge is immediately terminated even if the current from the full-wave rectifier 22 drops, and the ballast choke L13 or the ballast choke
It resonates at L14 and is charged again, and discharging and charging are repeated to superimpose the ripple current on the voltage rectified by the full-wave rectifier 22.

As described above, in both cases where the first and second switching elements SW11 and SW12 are turned off, a path for flowing the regenerative current to the capacitor C12 is always formed, so that the peak of the input current is reduced. Can be suppressed,
The on-time of the full-wave rectifier 22 can be shortened, the off-time can be appropriately maintained, and the input current can be approximated to a sine wave.

Not only the above circuit constants but also the circuit constants can be used to obtain the same effect as long as a predetermined condition is satisfied.

Next, another embodiment will be described with reference to FIG.

The embodiment shown in FIG. 3 is different from the embodiment shown in FIG. 1 in that instead of the ballast chokes L13 and L14, choke coils L15 and L16 which are merely inductive components are connected, and these choke coils L15 and L16 are connected. The ballast choke L17 is connected to the connection point of.

The embodiment shown in FIG. 3 has the same effect as the embodiment shown in FIG.

[0030]

According to the power supply device of the first aspect, since the inductive component is connected to the midpoint of the pair of switching elements of the switching means and the load connected between the capacitive means, respectively, either one of them is connected. the switching element tail
Switch off the other switch
Wheeling diodes grayed element, since the path through the load and capacitor means is formed, since the regenerative path including the load is formed <br/>, off-time of the rectifier means is properly held, the input The current peak can be suppressed, and the input current can be made close to a sine wave.

According to the discharge lamp lighting device of the second aspect,
Since the load of the power supply device according to the first aspect is the discharge lamp, the sine wave can light the discharge lamp and flicker can be reduced.

According to the lighting device of the third aspect, since the discharge lamp lighting device according to the second aspect includes the instrument main body, flicker can be reduced.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a discharge lamp lighting device of the present invention.

FIG. 2 is a perspective view showing the same illumination device.

FIG. 3 is a circuit diagram showing a discharge lamp lighting device according to another embodiment.

FIG. 4 is a circuit diagram showing a conventional discharge lamp lighting device.

[Explanation of symbols]

11 Instrument body 22 Full-wave rectifier as rectifying means 24 Inverter circuit as switching means C12 Capacitor as capacitance means E Commercial AC power supply FL1, FL2 load, fluorescent lamp as discharge lamp L13, L14 Ballast choke as inductive component L15, L16 Choke coil as inductive component SW11, SW12 switching element

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-260753 (JP, A) JP-A-3-3675 (JP, A) JP-A-5-49267 (JP, A) Actually open flat 2- 30293 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H02M 7/5387 H05B 41/24

Claims (3)

(57) [Claims] 1. Rectifying means for rectifying an AC voltage from an AC power source; small capacity capacitance means connected between output terminals of the rectifying means; and parallel connection to the capacitance means, each for return current. Da
A switching means having a pair of switching elements having an iodine and connected in series; either the midpoint of the switching elements connected in series of the switching means and one end or the other end of the capacitive means
And an inductive component connected in series to each of the loads connected between, and one of the switching elements is switched from ON to OFF.
If either of the other switching elements
Forms a path through the diode, load and capacitive means
The power supply device is characterized in that a regeneration path including a load is formed . 2. A discharge lamp lighting device, wherein the load of the power supply device according to claim 1 is a discharge lamp. 3. A lighting device comprising the discharge lamp lighting device according to claim 2 and a fixture main body.