JPH04200270A - Power converter device - Google Patents

Abstract

PURPOSE:To contrive the miniaturization and the reduction of weight of the title device by a method wherein a power is supplied directly to a plurality of DC-DC converters supply without rectifying an AC current or a pulsating power. CONSTITUTION:When an AC power supply 1 is applied, a full-wave rectifying waveform is impressed on the input side series circuits of respective DC-DC converters 31-3n from a full-wave rectifying diode bridge circuit 2. In this case, the full-wave rectified pulsating voltage is divided into 1/n and the divided voltages are impressed on respective DC-DC converters 31-3n whereby respective DC-DC converters 31-3n start the oscillating operations thereof. Only the pulsating voltage of voltage divided into 1/n is impressed on respective DC-DC converters 31-3n in such a manner whereby the dielectric strengths of the parts of circuits, constituting respective converters, can be 1/n.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power conversion device applied to, for example, a discharge lamp lighting device.

[Prior Art] Conventionally, a power conversion device, for example, a lighting device for controlling the lighting of a low-pressure halogen lamp, uses a step-down transformer to reduce the voltage of the output of a DC-AC conversion circuit, and supplies the output to the halogen lamp.

[Problem to be solved by the invention] However, if one DC-AC converter circuit or step-down transformer is used in this way, each circuit component must have a large withstand voltage, which increases the size of the device. There was a problem with the weight.

By the way, devices that use low-pressure halogen lamps are often used by installing the device on a lighting rail.
Therefore, conventional lighting devices have problems such as the weight of the device, which requires mechanical strength when installing the device on a lighting rail, and the large size of the device, which imposes restrictions on the design of the device.

Therefore, the present invention can be made smaller and lighter, and when applied to a lighting device for a low-pressure halogen lamp, for example, the device can be easily installed on a lighting rail without requiring much mechanical strength. The present invention aims to provide a power conversion device.

[Means for Solving the Problems] The present invention provides a resonant circuit comprising a capacitor and a primary winding of a transformer, a resonant switch for operating this resonant circuit, and a DC-AC conversion circuit for the primary winding of the transformer. A direct current source consisting of an output capacitor connected in parallel to the secondary winding of a transformer electrically isolated via a rectifying element.
A plurality of DC converters are provided, the input terminals of each converter are connected in series, and the series circuit is connected to a power source that rectifies alternating current or a pulsating current power source, and the output terminals of each converter are connected in parallel to each other, and the output terminals of each converter are connected in series. A load is connected to a parallel circuit of terminals.

[Operations] In the present invention having such a configuration, a plurality of direct currents can be directly connected to each other without smoothing a power source that rectifies alternating current or a pulsating current power source.
Since it is input to a DC converter, the input current waveform can be made into a waveform close to a sine wave.

Furthermore, since the power supply voltage is divided by a plurality of DC-DC converters, each converter can be constructed from circuit components with low breakdown voltage.

[Embodiment] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, the present invention will be described in which the present invention is applied to a lighting device for a low-pressure halogen lamp.

In FIG. 1, reference numeral 1 denotes an AC power supply, and an AC input terminal of a full-wave rectifier diode bridge circuit 2 is connected to this power supply 1.

31 + 32 + 33 + ... 3o is a DC-DC converter, and each DC-DC converter 31
,32°33,...3. The input terminals of the series circuit are connected in series with each other, and one end of the series circuit, that is, one end of the input terminal of the DC-DC converter 31 is connected to the positive side of the rectifier output terminal of the aftereffect rectifier diode bridge circuit 2, and the series circuit The other end, that is, the other end of the input terminal of the DC-DC converter 3°, is connected to the negative terminal of the rectified output terminal of the full-wave rectifier diode bridge circuit 2.

Each of the DC-DC converters 31, 3□, 33°...
3. The output terminals of the two are connected in parallel with each other, and a load, for example, a low-pressure halogen lamp 4, is connected between both ends of the parallel circuit.

Each of the DC-DC converters 32, 3□, 3. .

. . 3° connects between the input terminals a resonant circuit consisting of a capacitor 5 and a primary winding 6a of a transformer 6, and a series circuit of a resonant switch 7 for operating this resonant circuit,
A DC-AC conversion circuit is provided in which a diode 8 is connected in parallel to the resonant switch 7. As the resonant switch 7, for example, a MOS type FET (field effect transistor) is used, and this MOS type FET is operated for switching by a well-known self-excited oscillation control circuit.

The transformer 6 includes a primary winding 6a and a secondary winding 6b that is electrically insulated from the primary winding 6a, and outputs an output to the secondary winding 6b via a diode 9, which is a rectifying element. Capacitors 10 are connected in parallel.

and each DC-DC converter 30, 3□.

The output capacitors 10 of 33, .

In this embodiment with such a configuration, when the AC power supply 1 is turned on, the full-wave rectified waveform from the aftermath rectifier diode bridge circuit 2 is input to the input series circuit of each DC-DC converter 3, to 3□. applied. The full-wave rectified pulsating current voltage is divided into 1/n and applied to each DC-DC converter 31 to 3fi.

In this way, each of the DC-DC converters 31 to 3° begins to oscillate.

In this way, only the voltage obtained by dividing the pulsating current voltage by 1/n is applied to each DC-DC converter 3, ~3°, so the withstand voltage of the circuit components constituting each converter is reduced to 1/n.
Can be n.

Further, the output terminals of each of the DC-DC converters 31 to 3fi are connected in parallel to each other and connected to the low voltage 10-gen lamp 4. ．．
need only supply 1/n of the current supplied to the low-pressure halogen lamp 4, and the current capacity of the circuit components constituting each converter can be reduced to 1/n.

In this way, it is possible to use low voltage and low current capacity circuit components that make up each converter, making it possible to use chip components and achieve high integration. This allows the device to be made smaller and lighter.

For example, each part can be made thinner than a few inches, and the entire device can be made thinner.

In addition, n converters 3, to 3. Since the output currents from the lamps are summed, even if a plurality of low-pressure halogen lamps 4 are connected in parallel, it can be handled satisfactorily.

Furthermore, since full-wave rectified pulsating voltage is directly applied to the input terminals of each DC-DC converter 31 to 3o, the input current waveform can be made into a waveform close to a sine wave, and a high power factor can be achieved. can get. Furthermore, there is no need to use a large-capacity electrolytic capacitor for smoothing, and a longer life can be achieved.

Furthermore, since the entire device can be made smaller and lighter, for example, as shown in FIG.
In this case, a lighting rail B is attached to the lighting rail B, and a lighting fixture equipped with a low-pressure halogen lamp 4 is suspended from the lighting rail B via an electronic ballast C incorporating the device of this embodiment, as shown in FIG. In the case where an electronic ballast C' is installed above the ceiling A and multiple lights D2 are hung from the lighting rail B attached to the ceiling A, it is easy to do so without requiring much mechanical strength. It can be installed to improve practicality.

In the above embodiment, the DC-DC converter is described in which the output capacitor 1o is connected to the secondary winding 6b of the transformer 6 via the rectifying diode 9, but the invention is not limited to this. 4, each end of the secondary winding 6b of the transformer 6 is connected to an output capacitor 10 via rectifying diodes 11 and 12, respectively.
Even if a full-wave rectifier circuit is used, in which the center tap of the secondary winding 6b is connected to the other end of the output capacitor 10, as shown in FIG. The next winding 6b is connected to the AC input terminal of the full-wave rectifier diode bridge circuit 13, and the diode bridge circuit 1
Alternatively, an output capacitor 10 may be connected between the rectified output terminals of No. 3.

In the above embodiment, a pulsating current obtained by full-wave rectification of alternating current is applied to each DC-DC converter, but the invention is not necessarily limited to this, and any DC power source containing a pulsating current component can be used. It may be a power source.

Further, although the above embodiments have been described in which the present invention is applied to a lighting device for a low-pressure halogen lamp, it is needless to say that the present invention is not necessarily limited to this.

[Effects of the Invention] As detailed above, according to the present invention, the present invention can be made smaller and lighter, and when applied to a lighting device for a low-pressure halogen lamp, for example, the installation of the fixture on the lighting rail is easy. It is possible to provide a power converter that can be easily manufactured without requiring much mechanical strength.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing one embodiment of the present invention, FIGS. 2 and 3 are diagrams showing an installation example of the same embodiment, and FIGS. 4 and 5 are diagrams showing other embodiments of the present invention. It is a partial circuit diagram. 1... AC power supply, 2... Full wave rectifier diode bridge circuit, 3, ~3°... DC-DC converter, 4... Low pressure halogen lamp. Applicant's agent Patent attorney Takehiko Suzue Figure 2 C'

Claims (2)

[Claims] (1) A resonant circuit consisting of a capacitor and the primary winding of a transformer, a DC-AC conversion circuit having a resonant switch for operating this resonant circuit, and a transformer electrically insulated from the primary winding of the transformer. Direct current consisting of an output capacitor connected in parallel to the secondary winding via a rectifier.
A plurality of DC converters are provided, the input terminals of each converter are connected in series, the series circuit is connected to a power source for rectifying alternating current or a pulsating current power source, and the output terminals of each of the converters are connected in parallel to each other. A power conversion device characterized in that a load is connected to a parallel circuit of output terminals. (2) The power conversion device according to claim (1), wherein the load is a low-pressure halogen lamp.