JPH07241031A - Multi-output power supply circuit - Google Patents

Abstract

PURPOSE:To provide a multi-output power supply circuit for feeding desired power from an existing multi-output power supply to various apparatus requiring more than one different DC power supply. CONSTITUTION:When a plurality of voltages, including a desired voltage different from any one of a plurality of different DC output voltages, are obtained from a multi-output power supply producing the plurality of different DC output voltages, a multi-output power supply circuit connects the plurality of power supplies in series to obtain the desired voltages. Diodes 6, 7 are connected, as required, with the output terminals of the plurality of power supplies.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-output power supply circuit for supplying power to various devices which require two or more different DC power supplies.

[0002]

2. Description of the Related Art When two or more different DC power supplies are required, a multi-output power supply device, which is a standard product of a power supply manufacturer, may be used in the past, but the output voltage of this standard product is usually ± 5V. , ± 12V, ± 15V, ± 24V, most of them have 2 outputs or 3 outputs. Therefore, if the required multiple voltages correspond to any of the multiple output voltages of the standard product, the standard product can be used, but even one of the required multiple voltages will become the standard product. If not, another power supply had to be installed.

Therefore, when the conventional multi-output power supply device cannot be used, a plurality of power supply devices must be used as shown in FIGS. 4 (a) and 4 (b). That is, FIG. 4A uses the respective voltages V1 and V2 of the two power supply devices of the DC power supply devices 1 and 2. Further, FIG. 4B shows the voltage V1 of the DC power supply device 1.
And DC / DC connected to the output of the DC power supply device 1.
The output voltage V2 of the converter 3 is used for supply.

[0004]

However, the power supply method shown in FIG. 4 has the following problems as compared with the case where power is supplied by one power supply device. Since the number of power supply devices increases, the cost is high. The mounting area of the power supply device for the equipment used increases,
The miniaturization of the device is hindered. In the conventional example as shown in FIG. 4B, power consumption is large and uneconomical. That is, a specific example in the case of using the two power supply devices shown in FIG. 4B is shown in FIG. The DC power supply device 1 having an output voltage of 30 V and the DC / DC converter 3 having an output voltage of 5 V are connected to the power supply device 4, and the power consumption of the load circuits 41 and 42 of the power supply device 4 is 30 W, respectively, and a total of 6 units.
It is assumed that power consumption of 0 W is required. And DC / D
When the conversion efficiency of the C converter 3 is 80%, the output current of the DC power supply device 1 is 2.25 A, and the output power is 6
It becomes 7.5W. Therefore, 7.5 W is required more than the power consumption actually required, and power is wasted. The present invention improves on the problems of conventional power supply circuits when multiple different power supply voltages are required.

[0005]

A multi-output power supply circuit according to a first aspect of the present invention provides a multi-output power supply device capable of obtaining a plurality of different output DC voltages from at least one of the plurality of different output DC voltages. When a plurality of voltages including a desired voltage that does not apply are obtained, the desired voltage is obtained by connecting the plurality of power sources in series, and a plurality of voltage outputs are obtained from the multi-output power supply device. .
Also, a multi-output power supply circuit of a second invention of the present invention is one of the plurality of power supplies connected in series for obtaining the desired voltage of the first invention and the plurality of different output DC voltages. When the power source corresponding to the voltage of 1 is shared, a diode is provided at the output terminal of each power source. Also, in the multi-output power supply circuit of the third invention of the present invention, the plurality of the desired voltages of the first invention are provided, and the plurality of series-connected plurality are provided to obtain the plurality of desired voltages. When any one of the power supplies is used in common, a diode is provided at the output end of each power supply. Also, in the multi-output power supply circuit of the fourth invention of the present invention, among the diodes connected to the output terminals of the respective power supplies of the second or third invention, a diode connected to a power supply having a low output voltage is zenered. It is a diode.

[0006]

The present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, 5 is the output voltage V2 (DC5V) and the output voltage V3.
In a multi-output power supply device that outputs (DC24V), each power supply output on the secondary side is insulated from each other. And
This multi-output power supply device 5 is intended to obtain a power supply output of 5V and 30V ± 2V. The power supply output + terminal of DC5V and the power supply output-terminal of DC24V are connected to each other to connect the DC5
At the output terminals of V and DC24V, diode 7,
6 is connected. Therefore, with this power supply circuit, D
An output voltage V2 of C5V and an output voltage V1 of DC29V can be obtained, and an output voltage not prepared for the multi-output power supply device 5 can be obtained. Next, the operation of the diodes 6 and 7 described above will be described with reference to FIGS. The diodes 6 and 7 are for protecting the power supply device 4 or the multi-output power supply device 5 when there is a time lag between rising and falling of the output voltage when the power is momentarily cut off or when the power is turned on. is there.

That is, as shown in the timing chart of FIG. 2 (b), the diode 6 has the multi-output power supply shown in FIG. 2 (a) when V1 <V2 at the rising time t1 of the output voltage. Since the voltage at the output end c of the device 5 becomes lower than that at the output end c, the reverse bias occurs on the V1 side, and this is prevented by the diode 6. In addition, the diode 7 may have a load Z shown in FIG.
When 1 is short-circuited, the voltage at the output end b of the multi-output power supply device 5 becomes lower than that at the output end a, so that a reverse bias occurs on the V2 side, and this is prevented by the diode 7.

Further, as in this embodiment, in the steady state V1> V
In the case of the output voltage having the relationship of 2, it is possible to protect the parts on the power supply device 4 side by using the zener diode as the diode 7. This is at the falling time t2 of the output voltage shown in FIG.
When the voltage charged by the capacitor C1 of the load Z1 shown in FIG. 6 returns to the multi-output power supply device 5 side, the potential of the output terminal b becomes larger than V2, and this voltage causes the load Z2
You can protect this as you join. In the present invention, even if the voltage conversion efficiency of each power supply unit of the multi-output power supply device 5 is 80%, it is not affected by the output voltage.

A connection example for converting each output voltage of the multi-output power supply device according to the present invention into various voltages will be described with reference to FIG. FIG. 3 (a) shows a multi-output power supply device with output voltages of 5V, 15V and 24V from 5V and 20V.
The output voltage of V is obtained. In this case, diodes are connected to the output terminals of 5V and 15V, respectively. Figure 3 (b) shows a similar multi-output power supply with 15V and 2
An output voltage of 9V is obtained, and in this case, it is not necessary to connect a diode to each output terminal. FIG. 3 (c) obtains output voltages of 15V and 20V from the same multi-output power supply device, and diodes are connected to the output terminals of 5V and 15V, respectively. FIG. 3 (d) shows output voltages of 20V and 39V from the same multi-output power supply device.
Diodes are connected to the respective output terminals of V, 15V and 24V. In this way, it is possible to obtain desired plural power supply outputs by combining the output voltages of the existing standard multi-output power supply devices. In the above embodiment, an example in which two power source outputs are obtained has been described, but the same circuit can be used to obtain three power source outputs.

[0010]

As described above in detail, in the multi-output power supply circuit of the present invention, when a plurality of desired power supply outputs are to be obtained, conventionally, a plurality of power supply devices must be used. Since this can be achieved by one multi-output power supply device, the cost can be reduced, the mounting space for mounting the power supply device can be reduced, and the housing can be downsized. .

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a multi-output power supply circuit of the present invention.

FIG. 2 is an operation explanatory diagram when the multi-output power supply circuit of the present invention is used.

FIG. 3 is a connection example of the multi-output power supply circuit of the present invention.

FIG. 4 is a block diagram of a conventional power supply circuit for obtaining a plurality of power supplies.

FIG. 5 is a block diagram illustrating a usage state of a conventional multiple power supply circuit.

[Explanation of symbols]

 1, 2 DC power supply device 3 DC / DC converter 4 Power supply device 41, 42 Load circuit 5 Multi-output power supply device 6, 7 Diode

Claims (4)

[Claims] 1. When a plurality of voltages including at least a desired voltage that does not correspond to any of the plurality of different output DC voltages are obtained from a multi-output power supply device that obtains a plurality of different output DC voltages, the desired voltage is obtained. Is a multi-output power supply circuit configured to obtain a plurality of voltage outputs from a multi-output power supply device by connecting the plurality of power supplies in series. 2. When the plurality of power supplies connected in series to obtain the desired voltage and the power supply corresponding to any of the plurality of different output DC voltages are shared, The multi-output power supply circuit according to claim 1, wherein each output terminal is provided with a diode. 3. The output terminal of each power supply when the desired voltage is plural and any one of the plurality of power supplies connected in series is shared in order to obtain the plurality of desired voltages. The multi-output power supply circuit according to claim 1, wherein each of the diodes has a diode. 4. The multi-output power supply circuit according to claim 2, wherein among the diodes connected to the output terminals of the respective power supplies, a diode connected to a power supply having a low output voltage is a Zener diode.