JP2003264981A - Dc power supply apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate a waste by obviating necessary or larger value of a capacitance of an electrolytic capacitor even when a load is reduced. <P>SOLUTION: A DC power supply apparatus has a DC power generator 2 for obtaining a DC voltage from an AC power source 1, a plurality of loads 26 connected to an output side of the generator 2 to supply the power from the generator 2 to the plurality of the loads 26. The power source comprises an electrolytic capacitor 18 provided at the output side of the generator 2 to smooth a valley of the power source voltage, and another electrolytic capacitor 27 from the capacitor 18, connected in parallel with at least partial load 26 of the plurality of the loads 26. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC power supply device having a DC power supply generator that obtains a DC voltage from an AC power supply.

[0002]

2. Description of the Related Art As shown in FIG. 4, a DC power supply device adapted to obtain a DC voltage from an AC power supply to supply power to a plurality of loads is provided with a DC power supply generation unit 53 and a DC power supply generation unit 53. And a rectifier circuit 55 for rectifying the AC power supply 51 and 1
A transformer 60 having a secondary winding 58 and a secondary winding 59,
A switch circuit 62 and a rectifying / smoothing circuit 64 having a small-capacity electrolytic capacitor or the like are provided, and the DC power supply generation unit 53
A plurality of loads 52 are connected to the output side of the
There is one in which power is supplied from the DC power supply generation unit 53.

In this type of conventional DC power supply device, for example, when a plurality of LED modules are lit by an AC input from an AC power supply 51, a large number of LED modules which are loads 52 are arranged apart from the power supply side, The necessary modules are constructed according to the lighting conditions to obtain the required brightness. In such a DC power supply device, it is necessary to store energy in order to smooth the valley portion of the AC output of the AC power supply 51, and the rectification circuit 55 and the switch circuit 62 inside the DC power supply generation unit 53 The electrolytic capacitor 56 was provided between them.

However, in order to output a continuous DC voltage from the DC power supply generation unit 53 in accordance with the number of the plurality of loads (LED modules) 52, the load 52 can be supplied with good power even during a low power supply voltage period. It is necessary to store energy in the electrolytic capacitor 56 so that the electrolytic capacitor 56 can be supplied. Therefore, it is necessary to provide the electrolytic capacitor 56 corresponding to the maximum load. The capacity of the electrolytic capacitor 56 becomes too large with respect to the capacity of the load 52, resulting in waste.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, the present invention is designed to prevent the capacity of the electrolytic capacitor from becoming larger than necessary even when the load is reduced, thereby eliminating waste. Is.

[0006]

The technical means of the present invention for solving this technical problem comprises a DC power supply generation unit 2 for obtaining a DC voltage from an AC power supply 1, and a plurality of DC power supply generation units 2 are provided on the output side. In the DC power supply device, which is connected to the load 26 of FIG. 1 and supplies electric power from the DC power supply generation unit 2 to the plurality of loads 26, the electrolytic side for smoothing the valley of the power supply voltage is provided on the output side of the DC power supply generation unit 2. A capacitor 18 is provided, and at least some of the loads 26 of the plurality of loads 26 are
The electrolytic capacitor 27 different from the electrolytic capacitor 18 is connected in parallel.

Another technical means of the present invention is that the electrolytic capacitor 18 is set to have a capacity corresponding to the minimum load connected to the output side of the DC power supply generating section 2. Another technical means of the present invention includes a DC power supply generation unit 2 that obtains a DC voltage from an AC power supply 1, a plurality of loads 26 are connected to the output side of the DC power supply generation unit 2, and a plurality of DC power generation units 2 are connected. In the DC power supply device configured to supply power to the load 26, the electrolytic capacitor 27 for smoothing the valley of the power supply voltage is provided only on the output side of the DC power supply generation unit 2.

Another technical means of the present invention is that the electrolytic capacitor 27 generates DC power so that the capacity of the electrolytic capacitor 27 can be changed according to the load 26 connected to the output side of the DC power generator 2. It is connected to the output side of the section 2 in a freely replaceable manner.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a commercial AC power supply,
Reference numeral 2 is a DC power supply generation unit, which is a rectifier circuit 4 including a diode bridge, a transformer 9 having a primary winding 5, a secondary winding 6, and a tertiary winding 7, and a switching element 10.
A PWM control circuit 11, an auxiliary power supply circuit 15 having an electrolytic capacitor 13 and a diode 14, and a transformer 9
17 connected to the secondary winding 6 side of the transformer 9 and the electrolytic capacitor 18 connected to the secondary winding 6 side of the transformer 9
And a feedback circuit 20, and a secondary side rectifying / smoothing circuit 21 is configured by the diode 17 and the electrolytic capacitor 18, and the electrolytic capacitor 18 has a valley portion of the power source voltage which is an output of the DC power source generating section 2. It is designed to be smooth. The feedback circuit 20 includes the DC power supply generation unit 2
Is monitored and the feedback is applied to the PWM control circuit 11 so that the fluctuation of the output voltage of the DC power supply generation unit 2 is reduced.

The electrolytic capacitor 18 for smoothing the valley of the power source voltage is provided only on the output side of the DC power source generating unit 2, and is provided on the input side of the DC power source generating unit 2 and inside the DC power source generating unit 2. Not not. The electrolytic capacitor 18 provided on the output side of the DC power supply generation unit 2 is set to have a capacity corresponding to the minimum load connected to the output side of the DC power supply generation unit 2. Here, the minimum load refers to the following case. That is, in a power supply device that monitors the output voltage of the DC power supply generation unit 2 and provides feedback, even if the load is less than or equal to the rated load, the output voltage fluctuation is small, but generally the efficiency is poor. In this case, for example, the efficiency at rated load is 85%
When the minimum efficiency is 75%, the minimum load is obtained as the load corresponding to the minimum efficiency. If the output voltage fluctuation at the minimum load is within 1%, for example, it means that the capacity of the electrolytic capacitor 18 corresponding to the fluctuation is required (the smaller the capacity, the larger the ripple and the lower the fluctuation rate). ). Further, in the case of a power supply device that monitors the secondary winding 6 of the transformer 9 and provides feedback, the output voltage tends to increase when the load is below the rated load.
Therefore, the minimum load is the upper limit value of the fluctuation range of the rated output.

An LED is provided on the output side of the DC power supply generator 2.
A plurality of modules 23 are connected in parallel. Each LE
The D module 23 includes a plurality of light emitting diodes (LEDs).
24 and a constant current circuit 25 are connected in series, and a substantial load 26 is provided.
7 are connected in parallel. Therefore, each of the plurality of LED modules 23 has a built-in electrolytic capacitor 27. According to the above-described embodiment, the AC voltage of the AC power supply 1 is rectified by the rectifier circuit 4 into a DC voltage, and the DC voltage rectified by the rectifier circuit 4 is supplied to the switching element 10 and simultaneously supplied to the auxiliary power supply circuit 15. Supplied. As a result, the potential of the electrolytic capacitor 18 in the auxiliary power supply circuit 15 gradually rises, and the PWM control circuit 11 starts its operation when it reaches the operation start voltage of the PWM control circuit 11. PW
When the M control circuit 11 starts operating, the switching element 10 is turned on and off, and the secondary windings 6 and 3 of the transformer 9 are turned on and off.
AC voltage is output to the secondary winding 7, and the secondary side rectifying and smoothing circuit 2
Power is supplied to the load 26 side via 1 and voltage is supplied to the auxiliary power supply circuit 21 to keep the PWM control circuit 11 in an operating state.

In the case of this embodiment, the capacity of the electrolytic capacitor 18 is set to the capacity corresponding to the minimum load, and the LED module 2 is provided on the output side of the DC power supply generating section 2.
When 3 is additionally connected and the load 26 is increased, the capacitance of the electrolytic capacitor corresponding to the additional load 26 can be supplemented by the electrolytic capacitor 27. Therefore, when the load is small, the minimum capacity of the electrolytic capacitor 18 corresponding to the small load can be used, and the capacity of the electrolytic capacitor 18 is prevented from becoming larger than necessary.
Waste can be eliminated. Moreover, if the load 26 is increased, the capacity of the electrolytic capacitor can be increased in response to the increase, and there is no inconvenience that the capacity of the electrolytic capacitor becomes insufficient even if the load is increased.

FIG. 2 shows another embodiment, in which a plurality of LED modules 23 are connected in parallel on the output side of the DC power supply generator 2. The LED module 23 includes a plurality of light emitting diodes (LEDs) 24 and a constant current circuit 25 connected in series, and each LED module 23 constitutes a load 26. The electrolytic capacitor 18 that smoothes the valley of the power supply voltage is replaceably connected to the output side of the DC power supply generation unit 2 (in the chain line A portion), and thus connected to the output side of the DC power supply generation unit 2. The capacitance of the electrolytic capacitor 18 can be changed or added according to the load applied.

The other points are the same as in the case of the above-mentioned embodiment, and like the case of the above-mentioned embodiment, the capacity of the electrolytic capacitor 18 is prevented from becoming unnecessarily large and waste is eliminated. You can Moreover, the load 26
The capacitance of the electrolytic capacitor 18 can be increased in response to the increase, and there is no inconvenience that the capacitance of the electrolytic capacitor becomes insufficient. FIG. 3 shows another embodiment, in which the electrolytic capacitor 18 is set to a capacity corresponding to the minimum load 26 (26a) which is always connected to the output side of the DC power supply generation unit 2, Load 26 (26b) other than the minimum load 26a that is detachably connected
On the other hand, the electrolytic capacitors 27 having the capacities corresponding to the respective loads 26b are connected in parallel. Further, the switch circuit 29 having switching elements and the like is turned on and off by a control unit (not shown), and the feedback circuit 20, the auxiliary power supply circuit 15, the tertiary winding 7 of the transformer 9 and the like in the above-described embodiment are omitted. . The other points are the same as those in the above-described embodiment.

In the above-described embodiment, the DC power supply generation unit 2 that obtains a DC voltage from the AC power supply 1 includes the rectifier circuit 4, the switching element 10, the transformer 9 and the like.
The DC power supply generation unit 2 is not limited to this, and may be any unit that obtains a DC voltage from the AC power supply 1, and may include, for example, a rectifier circuit and a chopper circuit.

[0016]

According to the present invention, even when the load is reduced, it is possible to prevent the capacity of the electrolytic capacitor from becoming unnecessarily large and to eliminate waste.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a circuit diagram showing another embodiment.

FIG. 3 is a circuit diagram showing another embodiment.

FIG. 4 is a circuit diagram showing a conventional example.

[Explanation of symbols]

1 Commercial AC power supply 2 DC power generator 4 Rectifier circuit 18 Electrolytic capacitor 26 load

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takahiro Hara             404-1 Nishinosue, Himeji City, Hyogo Prefecture Ikeda Electric Co., Ltd.             Inside the company F term (reference) 5H006 AA07 CA07 CB03 CC08 HA83                 5H730 AA16 AS01 AS11 BB43 BB57                       CC01 EE02 EE07 EE42 FG05

Claims (4)

[Claims] 1. A DC power supply generation unit (2) for obtaining a DC voltage from an AC power supply (1), wherein a plurality of loads (26) are connected to the output side of the DC power supply generation unit (2), and a DC power supply generation unit. In the DC power supply device configured to supply power from (2) to the plurality of loads (26), an electrolytic capacitor (18) for smoothing a valley of the power supply voltage is provided on the output side of the DC power supply generation unit (2). A load (2) is provided for at least a part of the plurality of loads (26).
6), a DC power supply device characterized in that an electrolytic capacitor (27) different from the electrolytic capacitor (18) is connected in parallel. 2. The DC capacitor according to claim 1, wherein the electrolytic capacitor (18) is set to have a capacity corresponding to a minimum load connected to an output side of the DC power supply generation unit (2). Power supply. 3. A DC power supply generation unit (2) for obtaining a DC voltage from an AC power supply (1), a plurality of loads (26) being connected to the output side of the DC power supply generation unit (2), and a DC power supply generation unit. In a DC power supply device configured to supply power from (2) to a plurality of loads (26), an electrolytic capacitor (27) for smoothing a valley of a power supply voltage only on the output side of the DC power supply generation unit (2). A DC power supply device characterized by being provided. 4. The electrolytic capacitor (27) so that the capacity of the electrolytic capacitor (27) can be changed according to the load (26) connected to the output side of the DC power supply generation unit (2).
The DC power supply device according to claim 3, wherein the DC power supply device is connected to the output side of the DC power supply generation unit (2) in a replaceable manner.