Power circuit

Abstract

To improve the working rate of a system having a plurality of electronic circuits.SOLUTION: A power supply circuit comprises a first DC / DC power supply actuated by receiving power supply from a DC power supply, a first relay switch which receives the power supply from the actuated first DC / DC power supply to be transitioned to an ON state, a second DC / DC power supply actuated by receiving the power supply from the DC power supply via the first relay switch in an ON state, and a second relay switch which is provided in parallel with the first relay switch and is transitioned to the ON state by receiving the power supply from the actuated second DC / DC power supply.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a power supply circuit.

Background Art

[0002] In recent years, technologies related to a power supply circuit having a power supply for supplying power to an electronic circuit are known. For example, a control device for controlling power supply from a power supply to an electronic circuit is disclosed (see, for example, Patent Document 1).

[0003] More specifically, such a control device includes a control unit that starts up when receiving power supply from a power supply. Further, the control device includes a first relay switch that turns on the power supply from the power supply to the electronic circuit based on the startup of the control unit, and a second relay switch provided in parallel with the first relay switch and turning on the power supply from the power supply to the electronic circuit based on the ON state of the first relay switch. According to such a configuration, power can be stably supplied from the power supply to the electronic circuit.

[0004] Furthermore, a technique for shifting the timing of turning on a plurality of switching elements is disclosed (see, for example, Patent Document 2). In such a technique, for example, after the power supply from the power supply output circuit to the printer head is started by turning on a certain switching element, after a certain delay time, the power supply from the power supply output circuit to the display is started by turning on another switching element. Thereby, the requirement of making the printer usable before displaying the state of the printer on the display is satisfied.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] Incidentally, in a system with multiple electronic circuits, it can be assumed that each electronic circuit requires a different voltage. Therefore, a converter is required for each electronic circuit to convert the voltage applied from the power supply. In this case, if multiple converters start up simultaneously, the value of the inrush current (hereinafter also referred to as "inrush current") into the converters will become large. And a large inrush current into the converters can cause damage or malfunction of the converters.

[0007] Furthermore, if a relay switch is provided for each converter to turn it ON, if the output from any converter stops, the relay switch and electronic circuit that no longer receive voltage from the converter whose output has stopped will turn OFF. This can cause all subsequent converters and electronic circuits after the converter whose output has stopped to shut down. Therefore, it is necessary to improve the operating rate of systems with multiple electronic circuits.

[0008] Therefore, the present invention has been made in view of the above problems, and the object of the present invention is to provide a novel and improved technology that can improve the operating rate of a system having multiple electronic circuits. [Means for solving the problem]

[0009] To solve the above problems, according to one aspect of the present invention, a power supply circuit is provided comprising: a first DC / DC power supply that is activated by receiving power from a DC power supply; a first relay switch that transitions to an ON state by receiving power from the activated first DC / DC power supply; a second DC / DC power supply that is activated by receiving power from the DC power supply via the ON state first relay switch; and a second relay switch provided in parallel with the first relay switch and transitioning to an ON state by receiving power from the activated second DC / DC power supply.

[0010] The power supply circuit may include a third relay switch that transitions to an ON state by receiving power from the activated second DC / DC power supply, a third DC / DC power supply that is activated by receiving power from the DC power supply via the ON state of the third relay switch, and a fourth relay switch provided in parallel with the third relay switch and transitioning to an ON state by receiving power from the activated third DC / DC power supply.

[0011] The power supply circuit may include a fourth DC / DC power supply that is activated by receiving power from the DC power supply, a fifth relay switch that transitions to an ON state by receiving power from the activated fourth DC / DC power supply, a fifth DC / DC power supply that is activated by receiving power from the DC power supply via the ON state fifth relay switch, and a sixth relay switch provided in parallel with the first relay switch that transitions to an ON state by receiving power from the activated fifth DC / DC power supply.

[0012] The power supply circuit may include a seventh relay switch provided in parallel with the fifth relay switch and transitioning to an ON state when power is supplied from the activated fifth DC / DC power supply, and an eighth relay switch provided in parallel with the fifth relay switch and transitioning to an ON state when power is supplied from the activated first DC / DC power supply.

[0013] The power supply circuit may include a sixth DC / DC power supply connected in parallel with the fourth DC / DC power supply.

[0014] The power supply circuit may include a seventh DC / DC power supply connected in parallel with the first DC / DC power supply. [Effects of the Invention]

[0015] According to the present invention described above, it is possible to improve the operating rate of a system having multiple electronic circuits.

Brief Description of the Drawings

[0016] [Figure 1] It is a diagram showing an example of the time change of the inrush current values to a plurality of DC / DC power supplies. [Figure 2] It is a block diagram showing a configuration example of a power supply circuit according to a comparative example. [Figure 3] It is a block diagram showing a configuration example of the power supply circuit 9 according to the comparative example at the time when the startup of all DC / DC power supplies is completed. [Figure 4] It is a diagram for explaining points to be improved in the comparative example. [Figure 5] It is a block diagram showing a configuration example of a power supply circuit according to the first embodiment of the present invention. [Figure 6] It is a block diagram showing a configuration example of the power supply circuit 1 according to the first embodiment of the present invention at the time when the startup of all DC / DC power supplies is completed. [Figure 7] It is a diagram for explaining the effects exhibited by the power supply circuit 1 according to the first embodiment of the present invention. [Figure 8] It is a block diagram showing a configuration example of a power supply circuit according to the second embodiment of the present invention. [Figure 9] It is a diagram for explaining the case where any one of the DC / DC power supplies is faulty before the power supply of the DC power supply A0 is turned ON in the second embodiment of the present invention. [Figure 10] It is a block diagram showing a configuration example of a power supply circuit according to the third embodiment of the present invention. [Figure 11] It is a diagram for explaining the case where the first-stage DC / DC power supply C1 and the first-stage DC / DC power supply F1 are faulty before the power supply of the DC power supply A0 is turned ON in the third embodiment of the present invention.

Modes for Carrying Out the Invention

[0017] Embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

[0018] <0. Overview of the Power Supply Circuit> The overview of the power supply circuit according to the embodiment of the present invention will be described.

[0019] In recent years, systems having a plurality of electronic circuits are known. In such a system, it can be assumed that the voltages required for each electronic circuit are different. Therefore, a converter for converting the voltage applied from the power supply is required for each electronic circuit. As an example, a large electronic device may incorporate a large number of electronic circuits. In such a large electronic device, a large number of converters are required.

[0020] Hereinafter, it is assumed that the voltage applied by the power supply is a direct current (DC) voltage. Therefore, the power supply is also referred to as a "DC power supply". Therefore, the converter may correspond to a DC / DC converter (hereinafter also referred to as a "DC / DC power supply") that converts the voltage output from the DC power supply. Further, in the following description, "voltage is applied" and "voltage having a magnitude equal to or greater than the threshold value is applied" can each be equivalently expressed as "power is supplied".

[0021] (Description of Comparative Example) Here, the time change of the inrush current values to a plurality of DC / DC power supplies will be described with reference to FIG. 1. FIG. 1 is a diagram showing an example of the time change of the inrush current values to a plurality of DC / DC power supplies. Referring to FIG. 1, the time change of the inrush current values to a plurality of DC / DC power supplies when the plurality of DC / DC power supplies are started simultaneously is shown by the graph at "simultaneous startup".

[0022] Referring to the graph for "simultaneous startup," it can be seen that the inrush current values ​​to multiple DC / DC power supplies become large. Large inrush current values ​​to multiple DC / DC power supplies can cause damage or malfunction of the DC / DC power supplies. Therefore, to prevent such large inrush current values, it is envisioned that multiple DC / DC power supplies be started in a chain reaction using a relay switch.

[0023] Referring to Figure 1, the graph for "distributed startup" shows the time variation of the inrush current to multiple DC / DC power supplies when multiple DC / DC power supplies are started up in a chain reaction. Referring to the graph for "distributed startup," it can be seen that the inrush current to multiple DC / DC power supplies is suppressed because the multiple DC / DC power supplies are started up in a time-division manner at different timings.

[0024] Next, referring to Figure 2, we will describe a comparative example in which multiple DC / DC power supplies are started in a chain reaction using a relay switch.

[0025] (Structure of the comparative example) Figure 2 is a block diagram showing an example configuration of a power supply circuit according to a comparative example. As shown in Figure 2, the power supply circuit 9 according to the comparative example includes a DC power supply A0. Furthermore, the power supply circuit 9 according to the comparative example includes a DC / DC power supply C1 and an electronic circuit D1 as the first stage configuration.

[0026] Furthermore, the power supply circuit 9 comprises a relay switch Bk, a DC / DC power supply Ck, and an electronic circuit Dk as the configuration of the k-th stage (where k is any integer satisfying 2 ≤ k ≤ n). Here, n is an integer greater than or equal to 2. Figure 2 shows the configuration of the second stage as a relay switch B2, a DC / DC power supply C2, and an electronic circuit D2, the configuration of the third stage as a relay switch B3, a DC / DC power supply C3, and an electronic circuit D3, and the configuration of the n-th stage as a relay switch Bn, a DC / DC power supply Cn, and an electronic circuit Dn.

[0027] For example, each of the electronic circuits D1 to Dn can be an input device or an output device. An input device can be a sensor (e.g., an acoustic sensor). An output device can be a printer, a display, or other output device. Electronic circuits D2 to Dn can also be input devices or output devices similar to electronic circuit D1. Note that electronic circuits D1 to Dn constitute a single system (e.g., an electronic device).

[0028] DC power supply A0 is connected to the first stage DC / DC power supply C1, as well as to each of the relay switches from the second stage B2 to the nth stage relay switch Bn. DC / DC power supply C1 is connected to the first stage electronic circuit D1.

[0029] Relay switch Bk is connected to the DC / DC power supply Ck on the same stage as itself. In the example shown in Figure 2, relay switch B2 is connected to DC / DC power supply C2, relay switch B3 is connected to DC / DC power supply C3, and relay switch Bn is connected to DC / DC power supply Cn.

[0030] DC / DC power supply Ck is connected to the electronic circuit Dk of the same stage. In the example shown in Figure 2, DC / DC power supply C2 is connected to electronic circuit D2, DC / DC power supply C3 is connected to electronic circuit D3, and DC / DC power supply Cn is connected to electronic circuit Dn.

[0031] Furthermore, the DC / DC power supply C(k-1) is connected to the next stage relay switch Bk by a connecting line N(k-1). In the example shown in Figure 2, DC / DC power supply C1 is connected to relay switch B2 by a connecting line N1, DC / DC power supply C2 is connected to relay switch B3 by a connecting line N2, and DC / DC power supply C(n-1) (not shown) is connected to relay switch Bn by a connecting line N(n-1).

[0032] (Action of the comparative example) In this power supply circuit 9, when the DC power supply A0 is turned ON, the first stage DC / DC power supply C1 (first DC / DC power supply) connected to the DC power supply A0 is activated. As a result, a voltage is applied by the first stage DC / DC power supply C1 to the electronic circuit D1 connected to the output of the first stage DC / DC power supply C1, and then the first stage DC / DC power supply C1 applies a voltage greater than or equal to a threshold value to the second stage relay switch B2 (first relay switch) via the connecting line N1.

[0033] When a voltage greater than or equal to the threshold is applied to the second-stage relay switch B2, the second-stage relay switch B2 transitions to the ON state. As a result, the DC power supply A0 applies voltage to the second-stage DC / DC power supply C2 (the second DC / DC power supply) via the second-stage relay switch B2, thereby activating the second-stage DC / DC power supply C2. As a result, the second-stage DC / DC power supply C2 applies voltage greater than or equal to the threshold to the third-stage relay switch B3 (the third relay switch) via the connecting line N2.

[0034] Next, relay switch B3, to which a voltage greater than the threshold is applied by DC / DC power supply C2, transitions to the ON state. Through relay switch B3, which has transitioned to the ON state, DC power supply A0 applies voltage to DC / DC power supply C3 (the third DC / DC power supply), thereby activating DC / DC power supply C3. DC / DC power supply C3 then applies voltage to electronic circuit D3, and DC / DC power supply C3 applies a voltage greater than the threshold to the next relay switch B4.

[0035] In the following steps, for k=3,...,n-2, relay switch B(k+1), to which a voltage greater than or equal to the threshold is applied by the preceding DC / DC power supply Ck, transitions to the ON state. The DC / DC power supply C(k+1) in the same stage as the ON-state relay switch B(k+1) is activated, and a voltage is applied to the electronic circuit D(k+1) by the DC / DC power supply C(k+1). This process is repeated, with the DC / DC power supply C(k+1) then applying a voltage greater than or equal to the threshold to the next-stage relay switch B(k+2).

[0036] Finally, the relay switch Bn transitions to the ON state, the nth stage DC / DC power supply Cn is activated, and a voltage is applied to the nth stage electronic circuit Dn.

[0037] Figure 3 is a block diagram showing an example configuration of the power supply circuit 9 in the comparative example at the point when all DC / DC power supplies have finished starting up. Referring to Figure 3, all relay switches B2 to Bn have transitioned to the ON state, and the DC / DC power supplies C1 to Cn have finished starting up. In this way, by starting up the DC / DC power supplies C1 to Cn at different timings, the inrush current value to the DC / DC power supplies C1 to Cn is suppressed.

[0038] (Areas for improvement in the comparative example) However, the comparative example has areas that need improvement. These areas for improvement will be explained with reference to Figure 4.

[0039] Figure 4 is a diagram illustrating the areas for improvement in the comparative example. It assumes that when all relay switches B2 to Bn are switched to the ON state and the DC / DC power supplies C1 to Cn have started up, the output section Ex of the DC / DC power supply C2 stops for some reason (for example, due to poor contact in the output section Ex), as shown in Figure 4.

[0040] In this case, the DC / DC power supply C2 prevents a voltage greater than the threshold from being applied to the relay switch B3, which is the next stage of the DC / DC power supply C2. As a result, the relay switch B3 transitions to the OFF state, as shown in Figure 4 (S91). Consequently, the DC power supply A0 no longer applies voltage to the DC / DC power supply C3 via the relay switch B3, causing the DC / DC power supply C3 to stop. The electronic circuit D3, which no longer receives voltage from the DC / DC power supply C3, also transitions to the stopped state (S92).

[0041] In the fourth stage and beyond, the relay switch transitions to the OFF state, and the DC / DC power supply stops. Finally, the relay switch Bn of the final stage transitions to the OFF state (S93), the DC / DC power supply Cn of the final stage transitions to the stopped state, and the electronic circuit Dn of the final stage also transitions to the stopped state (S94). In other words, the point that needs improvement is that if the output section of any DC / DC power supply stops, all DC / DC power supplies in the stages following the DC / DC power supply whose output section has stopped will also stop.

[0042] Therefore, embodiments of the present invention will primarily describe how to improve upon the shortcomings of the comparative examples.

[0043] The outline of the power supply circuit according to an embodiment of the present invention has been described above.

[0044] <1. First Embodiment> Next, a first embodiment of the present invention will be described.

[0045] (composition) First, with reference to Figure 5, an example of the configuration of a power supply circuit according to the first embodiment of the present invention will be described.

[0046] Figure 5 is a block diagram showing an example configuration of a power supply circuit according to the first embodiment of the present invention. Referring to Figure 5, the power supply circuit 1 according to the first embodiment of the present invention is shown. Furthermore, referring to Figure 5, the configuration of the power supply circuit 1 according to the first embodiment of the present invention that is particularly different from the power supply circuit 9 (Figure 2) according to the comparative example is highlighted with a thick line.

[0047] As can be seen from this thick line, the power supply circuit 1 according to the first embodiment of the present invention mainly differs from the power supply circuit 9 (Figure 2) according to the comparative example in that it includes relay switches B2-α to Bn-α. Therefore, the following will mainly describe the relay switches B2-α to Bn-α, and a detailed explanation of the components of the power supply circuit 1 according to the first embodiment of the present invention that are common with the power supply circuit 9 (Figure 2) according to the comparative example will be omitted.

[0048] Power supply circuit 1 includes a relay switch Bk-α as the kth stage (where k is any integer satisfying 2 ≤ k ≤ n), where n is an integer greater than or equal to 2. Figure 5 shows the relay switch B2-α as the second stage, the relay switch B3-α as the third stage, and the relay switch Bn-α as the nth stage. Relay switch Bk-α is installed in parallel with relay switch Bk.

[0049] Therefore, each of the relay switches from the second stage B2-α to the nth stage Bn-α is connected to the DC power supply A0.

[0050] Relay switch Bk-α (where k is any integer satisfying 2 ≤ k ≤ n) is connected to the DC / DC power supply Ck of the same stage. In the example shown in Figure 5, relay switch B2-α is connected to DC / DC power supply C2, relay switch B3-α is connected to DC / DC power supply C3, and relay switch Bn-α is connected to DC / DC power supply Cn.

[0051] Furthermore, relay switch Bk-α is connected to the output of DC / DC power supply Ck in the same stage by a connecting wire Mk. In the example shown in Figure 5, relay switch B2-α is connected to the output of DC / DC power supply C2 by a connecting wire M2, relay switch B3-α is connected to the output of DC / DC power supply C3 by a connecting wire M3, and relay switch Bn-α is connected to the output of DC / DC power supply Cn by a connecting wire Mn.

[0052] (operation) In the power supply circuit 1 according to the first embodiment of the present invention, similar to the power supply circuit 9 in the comparative example, the DC power supply A0 is turned ON, the first stage DC / DC power supply C1 is started, and a voltage is applied to the electronic circuit D1. Furthermore, similar to the power supply circuit 9 in the comparative example, a voltage greater than or equal to a threshold is applied to the second stage relay switch B2, the second stage relay switch B2 transitions to the ON state, the second stage DC / DC power supply C2 is started, a voltage is applied to the electronic circuit D2, and then a voltage greater than or equal to a threshold is applied to the third stage relay switch B3.

[0053] In the power supply circuit 1 according to the first embodiment of the present invention, the second-stage DC / DC power supply C2 applies a voltage greater than or equal to a threshold value to the second-stage relay switch B2-α (second relay switch) via the connecting line M2. As a result, the second-stage relay switch B2-α transitions to the ON state.

[0054] Next, similar to the power supply circuit 9 in the comparative example, relay switch B3 transitions to the ON state, DC / DC power supply C3 is started, and after a voltage is applied to the electronic circuit D3 by DC / DC power supply C3, a voltage greater than or equal to the threshold is applied to relay switch B4.

[0055] In the power supply circuit 1 according to the first embodiment of the present invention, the third-stage DC / DC power supply C3 applies a voltage greater than or equal to the threshold value to the third-stage relay switch B3-α (fourth relay switch) via the connecting line M3. As a result, the third-stage relay switch B3-α transitions to the ON state.

[0056] Subsequently, for k=3,...,n-2, relay switch B(k+1), to which a voltage greater than or equal to the threshold is applied by the preceding DC / DC power supply Ck, transitions to the ON state. The DC / DC power supply C(k+1) in the same stage as the ON-state relay switch B(k+1) is activated, and a voltage is applied to the electronic circuit D(k+1) by the DC / DC power supply C(k+1). A voltage greater than or equal to the threshold is then applied to the next-stage relay switch B(k+2) by the DC / DC power supply C(k+1), and the DC / DC power supply C(k+1) also applies a voltage greater than or equal to the threshold to the relay switch B(k+1)-α in the same stage as the DC / DC power supply C(k+1). This process is repeated.

[0057] Finally, relay switch Bn transitions to the ON state, the nth stage DC / DC power supply Cn is activated, voltage is applied to the nth stage electronic circuit Dn, and the nth stage relay switch Bn-α also transitions to the ON state.

[0058] Figure 6 is a block diagram showing an example configuration of the power supply circuit 1 according to the first embodiment of the present invention at the point when all DC / DC power supplies have finished starting up. Referring to Figure 6, all relay switches B2 to Bn, as well as relay switches B2-α to Bn-α, have transitioned to the ON state, and the DC / DC power supplies C1 to Cn have finished starting up. In this way, by starting up the DC / DC power supplies C1 to Cn at different timings, the inrush current value to the DC / DC power supplies C1 to Cn is suppressed.

[0059] Furthermore, the power supply circuit 1 according to the first embodiment of the present invention can achieve effects that the power supply circuit 9 according to the comparative example cannot. The effects achieved by the power supply circuit 1 according to the first embodiment of the present invention will be explained with reference to Figure 7.

[0060] Figure 7 is a diagram illustrating the effects of the power supply circuit 1 according to the first embodiment of the present invention. Assume that when all relay switches B2 to Bn and relay switches B2-α to Bn-α are switched to the ON state and the DC / DC power supplies C1 to Cn have started up, the operation of the output section Ex of the DC / DC power supply C2 stops for some reason (for example, due to poor contact in the output section Ex), as shown in Figure 7.

[0061] In such a case, as in the comparative example, the DC / DC power supply C2 prevents voltage from being applied to the relay switch B3, which is the next stage after the DC / DC power supply C2, causing the relay switch B3 to transition to the OFF state as shown in Figure 7 (S11). However, in the first embodiment of the present invention, the DC / DC power supply C3 continues to apply a voltage of a magnitude greater than the threshold to the relay switch B3-α via the connecting line M3, so the relay switch B3-α continues to remain in the ON state (S12).

[0062] As a result, the DC power supply A0 continuously applies voltage to the DC / DC power supply C3 via the relay switch B3-α, so the DC / DC power supply C3 continues to operate, and the electronic circuit D3 to which the DC / DC power supply C3 continuously applies voltage also continues to operate (S13).

[0063] In the fourth stage and beyond, the relay switch remains ON, and the DC / DC power supply remains operational. Furthermore, the relay switch Bn of the final stage remains ON, the DC / DC power supply Cn of the final stage remains operational, and the electronic circuit Dn also remains operational (S14). In other words, in the power supply circuit 1 according to the first embodiment of the present invention, even if the output section of any DC / DC power supply other than the first stage DC / DC power supply C1 stops, the possibility that the DC / DC power supplies in the stages following the DC / DC power supply whose output section has stopped will also stop is reduced.

[0064] (effect) According to the first embodiment of the present invention, even if the output section of any DC / DC power supply other than the first stage DC / DC power supply C1 to Cn stops while the startup of the DC / DC power supplies C1 to Cn is complete, the possibility that subsequent DC / DC power supplies will stop is reduced. Therefore, according to the first embodiment of the present invention, it is possible to improve the operating rate of a system having electronic circuits D1 to Dn to which voltage is applied from DC / DC power supplies C1 to Cn.

[0065] The first embodiment of the present invention has been described above.

[0066] <2. Second Embodiment> Next, a second embodiment of the present invention will be described.

[0067] The power supply circuit 1 according to the first embodiment of the present invention has a drawback that, if any DC / DC power supply fails before the power supply A0 is turned ON, it is not possible to start the DC / DC power supplies following the failed DC / DC power supply. The power supply circuit 2 according to the second embodiment of the present invention (Figure 8) improves upon this drawback of the first embodiment of the present invention.

[0068] (composition) First, with reference to Figure 8, an example of the configuration of a power supply circuit according to the second embodiment of the present invention will be described.

[0069] Figure 8 is a block diagram showing an example configuration of a power supply circuit according to a second embodiment of the present invention. Referring to Figure 8, a power supply circuit 2 according to a second embodiment of the present invention is shown. In power supply circuit 2, circuits K1 and K2, which correspond to the power supply circuit 1 (Figure 5) according to a first embodiment of the present invention, are provided in parallel. Among the components of circuit K1, those that differ particularly from the power supply circuit 1 according to a first embodiment of the present invention are highlighted with thick lines.

[0070] As can be seen from this thick line, the circuit K1 according to the second embodiment of the present invention mainly differs from the power supply circuit 1 according to the first embodiment of the present invention (Figure 5) in that it includes relay switches B2-β to Bn-β. Therefore, the following will mainly describe the relay switches B2-β to Bn-β, and a detailed explanation of the components of circuit K1 that are common with the power supply circuit 1 according to the first embodiment of the present invention (Figure 5) will be omitted.

[0071] Circuit K1 includes a relay switch Bk-β as its k-th stage (where k is any integer satisfying 2 ≤ k ≤ n), where n is an integer greater than or equal to 2. Figure 8 shows the relay switch B2-β as the second stage, the relay switch B3-β as the third stage, and the relay switch Bn-β as the nth stage. Relay switch Bk-β is installed in parallel with relay switch Bk.

[0072] Therefore, each of the relay switches from the second stage B2-β to the nth stage Bn-β is connected to the DC power supply A0.

[0073] Relay switch Bk-β (where k is any integer satisfying 2 ≤ k ≤ n) is connected to the DC / DC power supply Ck of the same stage. In the example shown in Figure 8, relay switch B2-β is connected to DC / DC power supply C2, relay switch B3-β is connected to DC / DC power supply C3, and relay switch Bn-β is connected to DC / DC power supply Cn.

[0074] Furthermore, relay switch Bk-β is connected to the output of DC / DC power supply Fk, which is in the same stage as itself in circuit K2. In the example shown in Figure 8, relay switch B2-β is connected to the output of DC / DC power supply F2, relay switch B3-β is connected to the output of DC / DC power supply F3, and relay switch Bn-β is connected to the output of DC / DC power supply Fn.

[0075] Circuit K2 comprises a DC / DC power supply F1 and an electronic circuit G1 as its first stage configuration. Furthermore, circuit K2 comprises a relay switch Ek, a DC / DC power supply Fk and an electronic circuit Gk as its k-th stage configuration (where k is any integer satisfying 2 ≤ k ≤ n), where n is an integer of 2 or greater. The configuration of circuit K2 that is particularly different from the power supply circuit 1 according to the first embodiment of the present invention is highlighted with a thick line.

[0076] As can be seen from this thick line, the circuit K2 according to the second embodiment of the present invention mainly differs from the power supply circuit 1 according to the first embodiment of the present invention (Figure 5) in that it includes relay switches E2-β to En-β. Therefore, the following will mainly describe the relay switches E2-β to En-β, and a detailed explanation of the components of circuit K2 that are common with the power supply circuit 1 according to the first embodiment of the present invention (Figure 5) will be omitted.

[0077] The connections between the internal components of circuit K2 are the same as those between the internal components of circuit K1. For example, in the first embodiment of the present invention, relay switch Bk-α is connected to DC / DC power supply Ck of the same stage as itself, and similarly, in the second embodiment of the present invention, relay switch Ek-α is connected to DC / DC power supply Fk of the same stage as itself.

[0078] Relay switch Ek-β (where k is any integer satisfying 2 ≤ k ≤ n) is connected to the DC / DC power supply Fk of the same stage. In the example shown in Figure 8, relay switch E2-β is connected to DC / DC power supply F2, relay switch E3-β is connected to DC / DC power supply F3, and relay switch En-β is connected to DC / DC power supply Fn.

[0079] Furthermore, relay switch Ek-β is connected to the output of the DC / DC power supply C(k-1) in circuit K1, which is one stage prior to it. In the example shown in Figure 8, relay switch E2-β is connected to the output of DC / DC power supply C1, relay switch E3-β is connected to the output of DC / DC power supply C2, and relay switch En-β is connected to the output of DC / DC power supply C(n-1) (not shown).

[0080] (Operation when there are no malfunctions) First, let's explain the case where none of the DC / DC power supplies are faulty before DC power supply A0 is turned on.

[0081] In such cases, when the DC power supply A0 is turned ON, the DC / DC power supplies C1 to Cn are activated in circuit K1, similar to the power supply circuit 1 according to the first embodiment of the present invention, voltage is applied to the electronic circuits D1 to Dn, relay switches B2 to Bn transition to the ON state, and relay switches B2-α to Bn-α also transition to the ON state.

[0082] In circuit K2, similar to the power supply circuit 1 according to the first embodiment of the present invention, the DC / DC power supplies F1 to Fn are activated, voltage is applied to the electronic circuits G1 to Gn, and relay switches E2 to En transition to the ON state, as well as relay switches E2-α to En-α transition to the ON state.

[0083] (Operation in case of malfunction) Next, referring to Figure 9, we will explain the case where one of the DC / DC power supplies fails before the DC power supply A0 is turned ON.

[0084] Figure 9 illustrates a case in the second embodiment of the present invention where one of the DC / DC power supplies fails before the DC power supply A0 is turned ON. Here, as a specific example, we assume that the DC / DC power supply F1 in circuit K2 fails before the DC power supply A0 is turned ON.

[0085] In such cases, when the DC power supply A0 is turned ON, the DC / DC power supplies C1~Cn in circuit K1 start up normally, voltage is applied to the electronic circuits D1~Dn, relay switches B2~Bn transition to the ON state, and relay switches B2-α~Bn-α also transition to the ON state.

[0086] On the other hand, in circuit K2, because DC / DC power supply F1 is faulty, the DC / DC power supply F1 does not apply a voltage greater than the threshold to the relay switch E2, which is the next stage after DC / DC power supply F1. As a result, relay switch E2 remains in the OFF state (S21). Consequently, because DC power supply A0 does not apply voltage to DC / DC power supply F2 via relay switch E2, relay switch E2-α (the seventh relay switch), which does not receive voltage from DC / DC power supply F2 (the fifth DC / DC power supply), also remains in the OFF state (S22).

[0087] However, a voltage greater than the threshold is applied to relay switch E2-β (the eighth relay switch) by the activated DC / DC power supply C1 (the first DC / DC power supply). This causes relay switch E2-β to transition to the ON state (S23). Then, DC power supply A0 applies voltage to DC / DC power supply F2 via relay switch E2-β, which has transitioned to the ON state, thereby activating DC / DC power supply F2. As a result, DC / DC power supply F2 applies voltage to electronic circuit G2. When voltage is applied to electronic circuit G2, electronic circuit G2 transitions to the operating state (S24). Subsequently, DC / DC power supply F2 applies a voltage greater than the threshold to relay switch E3.

[0088] Subsequently, for k=2,...,n-2, the relay switch E(k+1) to which a voltage greater than or equal to the threshold is applied by the preceding DC / DC power supply Fk transitions to the ON state, the DC / DC power supply F(k+1) in the same stage as the relay switch E(k+1) that has transitioned to the ON state is activated, a voltage is applied to the electronic circuit G(k+1) by the DC / DC power supply F(k+1), a voltage greater than or equal to the threshold is applied to the relay switch E(k+2) in the next stage of the DC / DC power supply F(k+1), and a voltage greater than or equal to the threshold is applied to the relay switch E(k+1)-α in the same stage as the DC / DC power supply F(k+1), and this process is repeated.

[0089] Finally, the relay switch En transitions to the ON state, the nth stage DC / DC power supply Fn is activated, and a voltage is applied to the nth stage electronic circuit Gn.

[0090] In the example shown in Figure 9, we assumed that one of the DC / DC power supplies in circuit K2 failed before the DC power supply A0 was turned on. However, even if one of the DC / DC power supplies in circuit K1 failed before the DC power supply A0 was turned on, the possibility of the DC / DC power supplies in the stages following the failed DC / DC power supply stopping is reduced.

[0091] As an example, let's assume that DC / DC power supply C1 in circuit K1 is faulty before DC power supply A0 is turned ON. In this case, when DC power supply A0 is turned ON, DC / DC power supplies F1~Fn in circuit K2 start up normally, voltage is applied to electronic circuits G1~Gn, relay switches E2~En transition to the ON state, and relay switches E2-α~En-α also transition to the ON state. Here, DC / DC power supply F1 corresponds to the fourth example of a DC / DC power supply, and relay switch E2 corresponds to the fifth example of a relay switch.

[0092] On the other hand, in circuit K1, because DC / DC power supply C1 is faulty, the DC / DC power supply C1 does not apply a voltage greater than the threshold to the relay switch B2, which is the next stage after DC / DC power supply C1. As a result, relay switch B2 remains in the OFF state. Consequently, DC power supply A0 does not apply voltage to DC / DC power supply C2 via relay switch B2, and therefore relay switch B2-α, which does not receive voltage from DC / DC power supply C2, also remains in the OFF state.

[0093] However, a voltage greater than the threshold is applied to relay switch B2-β (the sixth relay switch) by the activated DC / DC power supply F2 (the fifth DC / DC power supply). This causes relay switch B2-β to switch to the ON state. Then, DC power supply A0 applies voltage to DC / DC power supply C2 via relay switch B2-β, which has switched to the ON state, causing DC / DC power supply C2 to switch to the ON state. As a result, DC / DC power supply C2 applies voltage to electronic circuit D2, and then DC / DC power supply C2 applies a voltage greater than the threshold to relay switch B3.

[0094] Subsequently, for k=2,...,n-2, relay switch B(k+1), to which a voltage greater than or equal to the threshold is applied by the preceding DC / DC power supply Ck, transitions to the ON state. The DC / DC power supply C(k+1) of the same stage as the ON-state relay switch B(k+1) is activated. The DC / DC power supply C(k+1) applies a voltage to the electronic circuit D(k+1). The DC / DC power supply C(k+1) then applies a voltage greater than or equal to the threshold to the next-stage relay switch B(k+2) of DC / DC power supply C(k+1). The DC / DC power supply C(k+1) then applies a voltage greater than or equal to the threshold to relay switch B(k+1)-α of the same stage as DC / DC power supply C(k+1). This process is repeated.

[0095] Finally, the relay switch Bn transitions to the ON state, the nth stage DC / DC power supply Cn is activated, and a voltage is applied to the nth stage electronic circuit Dn.

[0096] (effect) According to a second embodiment of the present invention, the same effects as those of the first embodiment of the present invention can be achieved.

[0097] Furthermore, according to the second embodiment of the present invention, even if any DC / DC power supply in circuit K2 fails before the power supply A0 is turned ON, the possibility that the DC / DC power supplies in the stages following the failed DC / DC power supply will stop is reduced. Therefore, according to the second embodiment of the present invention, it is possible to further improve the operating rate of a system having electronic circuits G1 to Gn to which voltage is applied from DC / DC power supplies F1 to Fn.

[0098] Furthermore, according to the second embodiment of the present invention, even if any DC / DC power supply in circuit K1 fails before the power supply A0 is turned ON, the possibility that the DC / DC power supplies in the stages following the failed DC / DC power supply will stop is reduced. Therefore, according to the second embodiment of the present invention, it is possible to further improve the operating rate of a system having electronic circuits D1 to Dn to which voltage is applied from DC / DC power supplies C1 to Cn.

[0099] The second embodiment of the present invention has been described above.

[0100] <3. Third Embodiment> Next, a third embodiment of the present invention will be described.

[0101] The power supply circuit 2 according to the second embodiment of the present invention has a drawback that it cannot start the subsequent DC / DC power supplies if both the first stage DC / DC power supply C1 and DC / DC power supply F1 fail before the power supply A0 is turned ON. The power supply circuit 3 according to the third embodiment of the present invention (Figure 10) improves upon this drawback of the second embodiment of the present invention.

[0102] (composition) First, with reference to Figure 10, an example of the configuration of a power supply circuit according to the third embodiment of the present invention will be described.

[0103] Figure 10 is a block diagram showing an example configuration of a power supply circuit according to a third embodiment of the present invention. Referring to Figure 10, a power supply circuit 3 according to the third embodiment of the present invention is shown. Among the components of the power supply circuit 3, those that differ particularly from the power supply circuit 2 according to the second embodiment of the present invention are highlighted with thick lines.

[0104] As can be seen from this thick line, the power supply circuit 3 according to the third embodiment of the present invention mainly differs from the power supply circuit 2 according to the second embodiment of the present invention (Figure 8) in that it includes a DC / DC power supply f1 (a sixth DC / DC power supply) provided in parallel with the DC / DC power supply F1. Furthermore, the power supply circuit 3 according to the third embodiment of the present invention mainly differs from the power supply circuit 2 according to the second embodiment of the present invention (Figure 8) in that it includes a DC / DC power supply c1 (a seventh DC / DC power supply) provided in parallel with the DC / DC power supply C1.

[0105] Therefore, the following will mainly describe the DC / DC power supplies f1 and c1, and a detailed explanation of the configuration of the power supply circuit 3 that is common with the power supply circuit 2 (Figure 8) according to the second embodiment of the present invention will be omitted.

[0106] Furthermore, diode H1 is provided in series with DC / DC power supply C1, and diode h1 is provided in series with DC / DC power supply c1. Diodes H1 and h1 are provided to protect the other DC / DC power supply in the event that one of the DC / DC power supplies C1 or DC / DC power supply c1 fails.

[0107] Similarly, diode I1 is provided in series with DC / DC power supply F1, and diode i1 is provided in series with DC / DC power supply f1. Diodes I1 and i1 are provided to protect the other DC / DC power supply in the event that one of the DC / DC power supplies F1 or f1 fails.

[0108] (Operation when there are no malfunctions) First, let's assume that none of the DC / DC power supplies are faulty before DC power supply A0 is turned on.

[0109] In such a case, when the DC power supply A0 is turned ON, the DC / DC power supplies C1 and c1 are activated in circuit K1. Then, similar to the second embodiment of the present invention, the DC / DC power supplies C2 to Cn are activated, voltage is applied to the electronic circuits D1 to Dn, and relay switches B2 to Bn transition to the ON state, as well as relay switches B2-α to Bn-α transition to the ON state.

[0110] In circuit K2, DC / DC power supplies F1 and f1 are activated. Then, similar to the second embodiment of the present invention, DC / DC power supplies F2 to Fn are activated, voltage is applied to electronic circuits G1 to Gn, relay switches E2 to En transition to the ON state, and relay switches E2-α to En-α also transition to the ON state.

[0111] (Operation in case of malfunction) Next, referring to Figure 11, we will explain the case where the first stage DC / DC power supply C1 and the first stage DC / DC power supply F1 fail before the DC power supply A0 is turned ON.

[0112] Figure 11 is a diagram illustrating a third embodiment of the present invention in which the first stage DC / DC power supply C1 and the first stage DC / DC power supply F1 fail before the power supply A0 is turned ON.

[0113] In this case, when the DC power supply A0 is turned ON, the first stage DC / DC power supply C1 in circuit K1 is stopped, but the first stage DC / DC power supply c1 is not faulty. Therefore, the DC / DC power supplies C1 to Cn start up normally, voltage is applied to the electronic circuits D1 to Dn, and the electronic circuits D1 to Dn transition to the operating state (S31), and relay switches B2 to Bn transition to the ON state, as well as relay switches B2-α to Bn-α transition to the ON state.

[0114] In circuit K2, the first stage DC / DC power supply F1 is faulty, but the first stage DC / DC power supply f1 is not faulty. Therefore, the DC / DC power supplies F1~Fn start up normally, voltage is applied to the electronic circuits G1~Gn, and the electronic circuits G1~Gn transition to the operating state (S32), and relay switches E2~En transition to the ON state, as well as relay switches E2-α~En-α transition to the ON state.

[0115] (effect) According to a third embodiment of the present invention, the same effects as those of the second embodiment of the present invention can be achieved.

[0116] Furthermore, according to the third embodiment of the present invention, in circuit K1, by providing a first-stage DC / DC power supply c1 in parallel with the first-stage DC / DC power supply C1 (in other words, by making the first-stage DC / DC power supplies redundant), if at least one of DC / DC power supplies C1 and DC / DC power supplies c1 is operating normally, the second and subsequent DC / DC power supplies C2~Cn in circuit K1 will start up normally. Therefore, according to the third embodiment of the present invention, it is possible to further improve the operating rate of a system having electronic circuits D1~Dn to which voltage is applied from DC / DC power supplies C1~Cn.

[0117] Similarly, in circuit K2, by providing a first-stage DC / DC power supply f1 in parallel with the first-stage DC / DC power supply F1 (in other words, by making the first-stage DC / DC power supplies redundant), if at least one of DC / DC power supplies F1 and f1 is operating normally, the second and subsequent DC / DC power supplies F2~Fn in circuit K2 will start up normally. Therefore, according to the third embodiment of the present invention, it is possible to further improve the operating rate of a system having electronic circuits G1~Gn to which voltage is applied from DC / DC power supplies F1~Fn.

[0118] The third embodiment of the present invention has been described above.

[0119] <4. Conclusion> Although preferred embodiments of the present invention have been described in detail with reference to the attached drawings, the present invention is not limited to such examples. It is clear to any person with ordinary skill in the art to which the present invention belongs that various modifications or alterations can be conceived within the scope of the technical idea described in the claims, and these are also understood to naturally fall within the technical scope of the present invention.

[0120] For example, the above explanation described how each of the electronic circuits D1 to Dn can be either an input or an output device. This output device may be an LED (Light Emitting Diode) bulb, for instance. If each of the electronic circuits D1 to Dn is an LED bulb, then applying voltage to the electronic circuits D1 to Dn can cause the LED bulbs to light up in a chain reaction. [Explanation of Symbols]

[0121] 1~3 Power circuit A0 DC power supply B1~Bn Relay Switch C1~Cn DC / DC power supply c1 DC / DC power supply D1~Dn Electronic circuit E1~En Relay Switch F1~Fn DC / DC power supply f1 DC / DC power supply G1~Gn electronic circuits K1, K2 loop

Claims

1. A first DC / DC power supply that starts up by receiving power from a DC power supply, A first relay switch that transitions to the ON state by receiving power from the activated first DC / DC power supply, A second DC / DC power supply that is activated by receiving power from the DC power supply via the first relay switch in the ON state, A second relay switch is provided in parallel with the first relay switch and transitions to an ON state when power is supplied from the activated second DC / DC power supply, A power supply circuit equipped with the following features.

2. The aforementioned power supply circuit is A third relay switch that transitions to the ON state upon receiving power from the activated second DC / DC power supply, A third DC / DC power supply that is activated by receiving power from the DC power supply via the third relay switch in the ON state, A fourth relay switch is provided in parallel with the third relay switch and transitions to an ON state when power is supplied from the activated third DC / DC power supply, The power supply circuit according to claim 1, comprising:

3. The aforementioned power supply circuit is A fourth DC / DC power supply that starts up by receiving power from the aforementioned DC power supply, A fifth relay switch that transitions to the ON state upon receiving power from the activated fourth DC / DC power supply, A fifth DC / DC power supply that is activated by receiving power from the DC power supply via the fifth relay switch in the ON state, A sixth relay switch is provided in parallel with the first relay switch and transitions to an ON state when power is supplied from the activated fifth DC / DC power supply, The power supply circuit according to claim 1, comprising:

4. The aforementioned power supply circuit is A seventh relay switch is provided in parallel with the fifth relay switch and transitions to an ON state when power is supplied from the activated fifth DC / DC power supply, An eighth relay switch is provided in parallel with the fifth relay switch and transitions to an ON state when power is supplied from the activated first DC / DC power supply, The power supply circuit according to claim 3, comprising:

5. The aforementioned power supply circuit is The system includes a sixth DC / DC power supply connected in parallel with the fourth DC / DC power supply, The power supply circuit according to claim 3.

6. The aforementioned power supply circuit is The system includes a seventh DC / DC power supply connected in parallel with the first DC / DC power supply, A power supply circuit according to any one of claims 1 to 5.

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