JP2008187871A - Power supply - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply which turns on whenever power is supplied from an AC power supply even if it is configured so as to use a soft switch. <P>SOLUTION: When AC power is newly supplied from a main power supply, a user can select the power supply so as to recover an on/off state just before a supply of the AC power is interrupted or enter into a state selected by the user regardless of the on/off state just before the supply of the AC power is interrupted. The power supply can be turned on immediately when it recovers from an power interruption even if power is interrupted during temporal power-off such as a maintenance. For the user requiring a reduction in power consumption, the power supply can recover the off state when the supply of the AC power recovers even if the supply of the AC power is interrupted during the on state. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power supply device that is switched on / off by a soft switch.

  Conventional electronic devices operate using the AC power supplied from the main power source by converting it into DC power using a switching power source or the like.

  In addition, the power on / off control is implemented by detecting pulses with a mechanical switch that performs on / off control by physically cutting off and returning the AC power supply and a momentary switch such as a push switch. In addition, there is a soft switch that performs on / off control by cutting off and restoring the DC power by combining a microcomputer and an FET.

  A soft switch is widely used because it has a merit that it is easy to take a distance between the inlet and the switch and the switch layout can be flexibly performed.

Generally, in the soft switch, when the power supply from the main power supply is cut off, the on / off state of the power supply is reset. Has also been proposed to restore the original state when the power supply from the main power supply is restored.
Japanese Patent Laid-Open No. 02-155014 JP 2003-076450 A

  In a conventional power supply device using a soft switch, when AC power that is the main power supply is cut off, the power on / off state is reset. Therefore, when the AC power of the main power supply is restored and it is desired to turn the power on again. The switch had to be operated by a person.

  This method can be solved by using the method described in the above-mentioned patent document. However, since these methods are methods for maintaining the power state immediately before the power supply of the main power supply is cut off, a power failure occurs in a power-off state. When the power supply from the main power supply is cut off due to the above, it is necessary for a person to operate the switch after the main power supply is restored in order to turn it on when the main power supply is restored. For this reason, for example, an electronic device having a function that the user wants to start using as soon as the main power source returns, such as a fax function, must wait until the main power source returns.

  The present invention solves the above-described problems, and provides a power supply apparatus that is capable of returning to the main power supply and turning on the power supply even when the power supply from the main power supply is cut off due to a power failure or the like in the power-off state. It is another object of the present invention to provide a power supply device that can be turned off when the main power is restored even when the power supply is turned on and the supply of AC power is cut off.

  The power supply apparatus proposed in the present invention has the following features.

  1. When power is supplied from an AC power supply, the power supply can be switched by a soft switch, connected to a regulator that can supply AC power and DC power Switch means capable of shutting off and restoring power supply to the non-power supply device, a nonvolatile memory for storing the on / off state of the power supply immediately before the power supply from the AC power supply is cut off, and the AC When power is newly supplied from a power supply, the power supply apparatus has a control means for performing power supply control based on information stored in the nonvolatile memory. A power supply apparatus in which a user can select a power supply mode when power is newly supplied via the input means.

  The power supply apparatus according to 2.1, comprising: a non-volatile memory that stores power supply information; and a control unit that performs power supply control based on information stored in the non-volatile memory.

  In the power supply device described in 3.2, the content stored in the nonvolatile memory includes information on the state of the power supply immediately before the power supply from the AC power supply is cut off and the power supply from the AC power supply selected by the user. A power supply that is information about the mode of the power supply when it is newly made.

  In the power supply device described in 4.3, when the power supply from the AC power supply is newly made, the mode selected by the user is immediately referred to by the control means shown in 2 and the power supply from the AC power supply is cut off. When the mode that reproduces the state of the previous power supply is selected, the nonvolatile memory is referred again to perform control according to the stored information, and the power supply immediately before the power supply from the power supply is cut off. A power supply apparatus characterized in that, when a mode for selecting a power source selected by a user is selected regardless of the state, the power source is immediately selected by the user.

  As described above, according to the present invention, it is possible to provide a power supply apparatus that can be turned on immediately upon return of AC power even in a configuration using a switch that does not mechanically hold on and off. As a result, when a power failure occurs temporarily for an electronic device such as a fax machine that is required to be in a normally on state, for example, during maintenance, the power is turned on as soon as the power is restored. It becomes possible. Further, for a user who seeks reduction of power consumption, even when the supply of AC power is cut off in the on state, it can be turned off when the supply of AC power is restored.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 shows an example of an embodiment of the present invention. FIG. 1 is a block diagram illustrating an example of an electronic device using a power supply device proposed in the present invention. In FIG. 1, AC power supplied from the main power source 1 is converted into a predetermined DC voltage by two switching power sources, and then suitable for each load of 5 and 6 by three or four DC-DC converters. It is converted to voltage and power is supplied.

  The switching power supply and each load or DC-DC converter are connected via FETs 7 and 8, and the power supply to each load or DC-DC converter is controlled by turning on / off the FET. I can do it. These FETs are controlled by a microcomputer 9 (hereinafter referred to as a microcomputer for short), and the FETs are turned on / off according to the state of the power supply. That is, when the power is off, the power consumption can be greatly reduced by turning off the switches. In addition, each switch can be turned on / off individually, so that the optimum power can be managed according to the operating state of the electronic device.

  A switch shown in FIG. 10 switches the power on / off state. The switch is composed of a momentary switch that does not mechanically hold the on / off state. When the microcomputer detects a pulse signal generated by pressing the switch, the power is turned on / off according to the current state. . In the nonvolatile memory 11, the current power supply state is recorded, and the value of the power supply is determined by referring to a value according to a mode described later. 12 is a user interface that allows the user to set parameters such as operating conditions of the electronic device, and the mode is set by the user through the key input unit.

  The operation in the above configuration will be described below. FIG. 2 is an example of a flow chart showing the operation when power supply from the main power supply is newly made in the power supply apparatus proposed in the present invention. The control shown in FIG. 2 is realized by nine microcomputers.

  When the supply of AC power from the main power source 1 is started in S21, AC power is converted into DC power by the switching power source 2 and further converted into a predetermined voltage by the DC-DC converter 3 and Power supply to the microcomputer is started. When the power supplied to the microcomputer exceeds a certain value, the microcomputer is activated, and an initialization routine (reset vector) for initializing each port programmed in advance is started in S22.

  When the reset vector is completed and the process proceeds to S23, the microcomputer refers to a variable STMOD indicating a mode for determining a state when the AC power is turned on, which is set in the nonvolatile memory 11 and is set by the user.

  Here, the mode when AC power is turned on will be described. The power supply apparatus proposed in the present invention is characterized by having a plurality of modes for the behavior when AC power is newly supplied. These modes are selected in advance by the user, and are set in the variable STMOD in the nonvolatile memory. Saved. In the example shown in the flowchart of FIG. 2, the “power supply state immediately before the AC power is cut off (STMOD = 00)” and the “power supply regardless of the power supply state just before the AC power is cut off”. In this case, there are four modes of “mode (STMOD = 01, 10, 11)” in which the user is selected. These modes are changed by the user through the key input unit shown in 12, and whenever there is a change, the microcomputer rewrites the value of STMOD stored in the nonvolatile memory.

  In S23, the microcomputer refers to STMOD and performs processing according to the value. First, when STMOD = 00, as described above, the “mode for maintaining the state of the power supply immediately before the AC power is cut off” is selected, so the AC power stored in the nonvolatile memory Refer to the state of the power supply just before the supply is cut off. Hereinafter, a control algorithm for the case where STMOD = 00 will be described.

  In FIG. 2, the state of the power supply immediately before the AC power is cut off is indicated by a variable PWST. When the previous power supply state is OFF, PWST = 00, and only the FET whose previous power supply state is 7 is ON. When PWST = 01, and when both FETs are on, PWST = 10 is written. When PWST = 00, since the immediately preceding power supply state is OFF, the process proceeds to S30 in FIG. 2, and the microcomputer performs control for realizing the power supply OFF state. Taking FIG. 1 as an example, the FETs 7 and 8 are turned off to cut off the power supply to the DC-DC converter and the load, thereby suppressing the power consumption. Similarly, when PWST = 01, 10, each FET is turned on / off in the same manner as in the previous power supply state.

  As an example, the load indicated by 5 in FIG. 1 is a function that is desired to be always turned on during normal times, such as a facsimile communication unit or a network control unit of a printer, and the load indicated by 6 is Assuming that the power consumption circuit is a high power consumption circuit, the mode with PWST = 01 is the low power consumption mode, and the mode with PWST = 10 can be considered as a mode in which the operation is immediately started.

  On the other hand, if STMOD is not 00, the “mode in which the power source is selected by the user regardless of the state of the power source immediately before AC power is cut off” is selected. A process of setting the power source to the state selected by the user without referring is executed. That is, in FIG. 2, the process directly transits from S23 to S30, 31, 32 without going through S27. FIG. 3 shows the operation of the power supply in accordance with the value of each variable when the AC power is turned on in this embodiment.

  As described above, according to the present embodiment, even in a power supply device using a momentary switch in which power on / off is not mechanically maintained, it is not affected by the state of the power supply immediately before the AC power is cut off. When AC power is restored, the power can be turned on. Thus, for example, even when the AC input is interrupted due to a power failure or the like in a situation where the power is temporarily turned off by periodic maintenance work, for example, If the “power on mode” is selected, the power can be turned on immediately when AC power is restored. That is, it is effective for electronic devices such as facsimiles and network printers that are required to be turned on under normal AC power supply.

  FIG. 4 shows an example of an embodiment of the present invention. Compared with FIG. 1 shown in the first embodiment, FIG. 4 has a configuration in which the key input unit is deleted and a mechanical switch is added. Since the configuration of the power supply unit and the detailed operation are the same as those in the first embodiment, a description thereof will be omitted.

  Hereinafter, the determination of the mode of the power supply and the behavior when the power supply from the AC power supply is newly performed will be described. The MOD port of the microcomputer in FIG. 4 is a port for determining the power supply mode. When the mechanical switch shown in FIG. 12 is on, the MOD port becomes L. Since the port becomes H, the power supply mode can be determined by turning on / off the mechanical switch. In addition, the mechanical switch is not required to have a high breakdown voltage used for normal AC power on / off, and can be configured at low cost. FIG. 5 shows an example of a flowchart showing the operation in this embodiment when the power supply from the main power supply is newly made. In this embodiment, the state of the power source is a binary value of on / off.

  According to the configuration shown in this embodiment, it is possible not only to set the power supply mode even in an electronic device that does not have a key input unit, but also to set the power supply mode in an environment where AC power is not supplied. Can be changed. In addition, since the power supply mode is not written in the nonvolatile memory, it contributes to reducing the load on the microcomputer and the capacity of the nonvolatile memory. Other effects are the same as in the first embodiment.

  The above example is an example of an embodiment of the present invention and does not limit the scope of application of the present invention. Specifically, in FIGS. 1 and 4, FETs are used as means for switching the return and interruption of the DC power supply, but in FIGS. 1 and 4, the DC-DC converter shown in 4 is used instead of the FET shown in 8. It is also possible to use means for starting and stopping directly. In FIG. 1, the key input unit 12 shown in FIG. 1 is used as an input means for accepting an operation by the user. However, as an example, the printer can also input through a driver from a connected personal computer.

Block diagram showing the overall configuration of the first embodiment The flowchart figure at the time of AC power input of the power supply control apparatus in Example 1. Correspondence table of each variable value and operation at the time of AC power input in Example 1 The block diagram which shows the whole structure of Example 2. FIG. The flowchart figure at the time of AC power input of the power supply control apparatus in Example 2.

Explanation of symbols

1 Main power supply 2 Switching power supply 3, 4 DC-DC converter 5, 6 Load 7, 8 FET
9 Microcomputer 10 Momentary switch 11 Non-volatile memory 12 Mechanical switch 13 Pull-up resistor

Claims (5)

  When power is supplied from an AC power supply, the power supply can be switched by a soft switch, and connected to a regulator that can supply DC power by receiving AC power. In a power supply apparatus having a switching means capable of shutting off and returning power supply to the non-power supply apparatus, the power supply when the power supply from the AC power supply is newly made based on the state of the input means for accepting an operation by the user A power supply device in which the user can select the mode of the above via the input means.   The power supply apparatus according to claim 1, further comprising: a nonvolatile memory that stores power supply information; and a control unit that performs power supply control based on information stored in the nonvolatile memory.   3. The power supply device according to claim 2, wherein the content stored in the nonvolatile memory includes information on the state of the power supply immediately before the power supply from the AC power supply is cut off and the power supply from the AC power supply selected by the user. A power supply that is information about the mode of the power supply when it is newly made.   In the power supply device according to claim 3, when power supply from the AC power supply is newly made, the mode selected by the user is immediately referred to by the control means shown in claim 2, and the power supply from the AC power supply is cut off. When the mode that reproduces the state of the power supply immediately before dripping is selected, the control according to the stored information is performed again with reference to the nonvolatile memory, and immediately before the power supply from the power supply is cut off. A power supply apparatus characterized in that when a mode for selecting a power supply state selected by a user is selected regardless of the power supply state, the power supply is immediately selected by the user.   An electronic device using the power supply device according to claim 1 or 2 or 3 or 4.

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