JP2002318624A - Protecting circuit, electric equipment and method for controlling protecting circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protecting circuit by which an electric equipment is not restored into an on-state even when a control means is reset in the case of stopping power supply due to the detection of abnormality, and to provide the electric equipment provided with the protecting circuit and a method for controlling the protecting circuit. SOLUTION: When an abnormality detecting circuit 9 detects any abnormal state, a microcomputer 6 stops power supply to a load circuit 5 by turning off a relay switch 3 for supplying a power to a main power source 2, and writes power off information in a non-volatile memory 8. When any abnormality is detected, the electric equipment set in the power-on state is stopped, and when the microcomputer 6 is reset, the electric equipment is set in the power-off state as it is. Thus, it is possible to prevent the occurrence of any unstable state such as the failure or smoking of the electric equipment at the time of reset.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protection circuit for an electric device such as a television receiver, an electric device equipped with the same, and a control method of the protection circuit, and more particularly to an improvement in microcomputer firmware.

[0002]

2. Description of the Related Art Many electric devices such as television receivers have a last power function (JP-A-2000-108).
74, etc.). The last power function, for example,
When the power is restored after the power failure (the microcomputer is reset at this time), it is a function to return the electric device to the state before the power failure without any operation by the user. With this last power function, if the power is on before the power failure, the electrical equipment will automatically turn on after the power is restored, and if the power is off before the power failure, the electrical equipment will automatically turn on after the power is restored. The power turns off. The operation based on the last power function is
The state information (power-on information or power-off information) before the power failure is stored in the nonvolatile memory, and after the power is restored, the electric device is returned to the same state as the state based on the state information stored in the nonvolatile memory. Performed by

FIG. 3 is a flowchart showing a method of controlling a protection circuit in a conventional electric device. As shown in FIG. 3, in the conventional electric equipment, when the power supply is manually turned on (step S31), the main power supply is turned on (step S32), power is supplied to the load circuit, and the nonvolatile memory is turned on. The power-on information is written in (step S33). At this time, if there is a power failure (step S34), the main power supply is turned off (step S3).
5) After the power is restored (step S36), the main power supply is returned to the ON state based on the power-on information of the nonvolatile memory (step S37).

[0004]

As described above, in the conventional electric equipment, the last power function operates even when a power failure occurs due to a natural disaster such as an earthquake and the power is restored thereafter.
For this reason, if the power is on before the power failure, the electric device returns to the power on state after the power is restored. However, when the power returns to the on state when flammable materials such as clothing or paper are dropped on the electrical equipment when the power is restored, or when the electrical equipment is exposed to water such as tableware or a water tank, the electrical equipment generates heat. There is a possibility that a failure may occur due to a short circuit or the like, or in the worst case, an unsafe condition such as smoking may occur.

Therefore, the present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to control the control means when the power supply is stopped due to abnormality detection. An object of the present invention is to provide a protection circuit that does not return an electric device to an on state even after resetting, an electric device equipped with the same, and a control method of the protection circuit.

[0006]

According to a first aspect of the present invention, there is provided a protection circuit comprising: a main power supply for supplying power to a load circuit; a switch for turning on / off power supply to the main power supply;
A circuit for controlling an electric device having manual operation means for switching on and off of the switch means, wherein the storage means and a voltage applied to the load circuit are in a normal state where the voltage is within a predetermined range. Abnormality detection means for outputting a detection signal indicating whether or not the state is abnormal, and when the switch means is turned on by the manual operation means, power-on information is written in the storage means, and the switch means is manually operated. Control means for writing power-off information to the storage means when the control means is turned off, and turning off the switch means when the abnormality detection means detects an abnormal state. When the storage means stores power-on information, the switch means is turned on, and when the control means is reset, In a protection circuit for turning off the switch means if the storage means stores power-off information, the control means writes the power-off information to the storage means when the abnormality detection means detects an abnormal state. Features.

Further, the protection circuit according to the present invention has an auxiliary power supply for supplying power to the control means.

[0008] The protection circuit according to claim 3 is characterized in that the storage means is a nonvolatile memory.

Further, the protection circuit according to claim 4 is characterized in that the abnormal state includes a power failure state, and the control means is reset by power recovery.

Further, the protection circuit according to the fifth aspect of the present invention is characterized in that the storage means stores power-off information when the control means resets after the abnormality detection means has detected an abnormal state. When is off, a predetermined operation is not accepted and a partial operation is disabled.

Further, a protection circuit according to a sixth aspect of the present invention includes a load circuit, a main power supply for supplying power to the load circuit, switch means for turning on / off the power supply to the main power supply, Manual operation means for switching on / off, storage means, and a detection signal indicating whether a voltage applied to the load circuit is in a normal state within a predetermined range or an abnormal state out of the predetermined range. Abnormality detecting means for writing power-on information to the storage means when the switch means is turned on by the manual operation means, and power-off information to the storage means when the switch means is turned off by the manual operation means. Control means for writing information and turning off the switch means when the abnormality detection means detects an abnormal state, wherein the control means is reset. When the storage means stores power-on information, the switch means is turned on when the storage means stores power-off information, and when the control means resets, the switch means is turned off when the storage means stores power-off information. The control unit writes power-off information in the storage unit when the abnormality detection unit detects an abnormal state.

Further, the electric device according to claim 7 is characterized in that it has an auxiliary power supply for supplying electric power to the control means.

Further, the electric device according to claim 8 is characterized in that the storage means is a nonvolatile memory.

According to a ninth aspect of the present invention, in the electric apparatus, the manual operation means includes a main body operation unit provided in the electric apparatus main body.

According to a tenth aspect of the present invention, in the electric device, the manual operation means includes a remote operation unit provided separately from the electric device main body.

In the electric device according to the eleventh aspect, the switch means may be configured such that the storage means stores power-off information when the control means resets after the abnormality detection means detects an abnormal state. Is turned off, the control means enters a remote operation disabled state in which operation from the remote operation unit is not accepted.

According to a twelfth aspect of the present invention, the abnormal state includes a power failure state, and the resetting of the control means is performed by a power recovery.

According to a thirteenth aspect of the present invention, the power-on information is stored in the storage means when the switch means for turning on / off the power supply to the load circuit main power supply is turned on by the manual operation means. Writing, power-off information is written in the storage means when the switch means is turned off by the manual operation means, and the voltage applied to the load circuit is in a normal state where the voltage is within a predetermined range or deviates from the predetermined range. When the abnormality detecting means that outputs a detection signal indicating whether the abnormal state is detected detects the abnormal state, the switch means is turned off and the power-off information is written in the storage means, and the control means is reset. The switch means is turned on if the storage means stores power-on information, and the storage means is reset when the control means is reset. There has been characterized by turning off the switch means if the stored power-off information.

Further, in the control method of the protection circuit according to the present invention, the storage means stores power-off information when the control means resets after the abnormality detection means has detected an abnormal state. When the switch unit is off, a predetermined operation is not accepted and a partial operation is disabled.

Further, a control method of a protection circuit according to claim 15 is characterized in that the abnormal state includes a power failure state, and the control means is reset by a power recovery.

[0021]

FIG. 1 is a block diagram schematically showing a configuration of an electric device (including a protection circuit) according to an embodiment of the present invention. Here, the electric device is, for example, a television receiver. However, the present invention is applicable to all electric devices other than the television receiver and its protection circuit as long as the device has a last power function that returns to a state based on the state information stored in the memory when the microcomputer is reset. Applicable.

As shown in FIG. 1, an electric apparatus according to the present embodiment includes a connection plug 1 connected to a commercial power supply line (outlet), and a main power supply receiving power supply via the connection plug 1. 2, a relay switch 3 for turning on / off the power supply to the main power supply 2, and a transistor 4 for controlling on / off of the relay switch 3.
And a load circuit 5 to which power is supplied from the main power supply 2. The circuit for turning on / off the power supply to the main power supply 2 is not limited to the illustrated circuit.

Further, the electric device according to the present embodiment includes a microcomputer 6 for controlling the on / off of the transistor 4 and the like.
An auxiliary power supply 7 for supplying power to the microcomputer 6, a non-volatile memory 8 for storing various control information, and whether a voltage applied to the load circuit 5 by the main power supply 2 is within a predetermined range or not. An abnormality detection circuit 9 that outputs a detection signal indicating whether an abnormal state is out of a predetermined range. These components 6 to 9 constitute a protection circuit 10 for an electric device. Incidentally, the auxiliary power supply 7 may include a rechargeable battery, in which case the nonvolatile memory 8
Alternatively, other types of storage media can be used.

The electric device according to the present embodiment is provided in the main body of the electric device, and operates a main body operation unit 11 for switching the relay switch 3 on and off. It has a remote control unit (remote control) 12 that can perform operations, and a light receiving unit 13 that receives a control command (infrared pulse) from the remote control 12.

Next, the operation of the electric device of the present embodiment having the above configuration (that is, the method of controlling the protection circuit according to the present invention) will be described. When turning on the power in the electric device according to the present embodiment, the user performs a power-on operation using main body operation unit 11 or remote controller 12. With this operation, a power-on command is input to the microcomputer 6.
The microcomputer 6 turns on the relay switch 3 by turning on the transistor 4, and as a result, the connection plug 1
Further, power is supplied to the main power supply 2 via the relay switch 3. The main power supply 2 receiving the power supplies the load circuit 5 with power. Further, the microcomputer 6 that has received the power-on command writes power-on information in the nonvolatile memory 8.

When turning off the power of the electric device in the electric device according to the present embodiment, the user performs a power-off operation using the main body operation unit 11 or the remote controller 12. With this operation, a power-off command is input to the microcomputer 6. The microcomputer 6 turns off the relay switch 3 by turning off the transistor 4, so that the power supply to the main power supply 2 is stopped. As a result, the power supply to the load circuit 5 is also stopped. Further, the microcomputer 6 receiving the power-off instruction rewrites the power-on information of the nonvolatile memory 8 with the power-off information.

When the abnormality detection circuit 9 detects an abnormal state when the power is turned on, an abnormality detection signal is input to the microcomputer 6, and the microcomputer 6 turns off the transistor 4 to turn off the relay switch 3. here,
The abnormal state refers to a state where the output voltage of the main power supply 2 is out of a predetermined range (normal state), and includes, for example, a power failure state. Furthermore, in the electric device according to the present embodiment, when the abnormality detection signal is input to the microcomputer 6, the power-on information of the nonvolatile memory 8 is rewritten to the power-off information. The monitoring position of the abnormal state (for example, abnormal voltage) is not limited to the output terminal of the main power
May be another position (a position at which information on the voltage applied to the load circuit 5 can be indirectly detected), such as the input terminal of the load circuit 5, the input terminal or the output terminal of the auxiliary power supply 7.

Further, in the electric equipment according to the present embodiment, when the nonvolatile memory 8 stores the power-on information when the microcomputer 6 is reset, the transistor 4 is turned on and the power to the main power supply 2 is turned on. Restart supply. On the other hand, if the nonvolatile memory 8 stores the power-off information when the microcomputer 6 is reset, the transistor 4 is kept off and the power supply to the main power supply 2 is not restarted. Therefore, even if a power failure occurs and the electric device in the power-on state stops, and then the power is restored and the microcomputer 6 is reset, the power-off information is written in the non-volatile memory 8 at the time of the power failure. The electric device remains in the power-off state.

In the electric device according to the present embodiment, the nonvolatile memory 8 stores the power-off information when the microcomputer 6 is reset after the abnormality detection circuit 9 detects the power failure state. When the switch 4 is off, the microcomputer 6 enters a remote control disabled state in which the microcomputer 6 does not receive an operation from the remote controller 12. As a result, the user can be informed that the abnormal state has been detected, and the safety can be ensured by preventing an inadvertent restart. Although the case where only the operation of the remote controller 12 is disabled has been described, it is possible to select whether all the operations of the remote controller 12 are disabled or some of the operations are disabled. Further, if necessary, a part of the main body operation unit 11 can be disabled.

FIG. 2 is a flowchart showing a control method of the protection circuit 10 in the electric equipment according to the present embodiment. As shown in FIG. 2, in the electric device according to the present embodiment, when the power supply is manually turned on (step S21), the main power supply 2 is turned on (step S22), and power is supplied to the load circuit 5. The power-on information is supplied to the nonvolatile memory 8 (step S2).
3). At this time, if there is a power failure (step S24), the main power supply 2 is turned off (step S25), and the power-on information of the nonvolatile memory 8 is rewritten to the power-off information (step S26). Thereafter, when power is restored (step S27), the microcomputer 6 is reset (except for some functions).
Then, based on the power-off information of the non-volatile memory, the main power supply 2 remains in the off state, and the remote controller 12 is disabled (step S28). When there is a predetermined reset operation (reset operation by the main body operation unit) (step S29), the microcomputer 6 is completely reset.

As described above, if the electric equipment (the protection circuit or the control method thereof) according to the present embodiment is used,
Even if a power failure occurs due to a natural disaster such as an earthquake and the power-on electrical device stops, and the last power function operates when the power is restored, the electrical device remains in the power-off state after the power recovery. Therefore, even if flammable materials are dropped on the electric device or water is splashed on the electric device when the power is restored, the electric device does not fail or cause unsafe conditions such as smoking.

[0032]

As described above, according to the protection circuits of the first to fifth aspects, when an abnormality is detected and the electric device in the power-on state is stopped, and the control means is reset thereafter, the electric device is turned off. Since it remains in the off state, there is an effect that an unsafe state such as a failure of an electric device or smoking is not caused at the time of reset.

Further, according to the protection circuit of the present invention, it is possible to inform the user of the detection of the abnormal state, and to ensure the safety by preventing an inadvertent restart. effective.

According to the electric equipment of the present invention, when an abnormality is detected, the electric equipment in the power-on state is stopped, and when the control means is reset thereafter, the electric equipment remains in the power-off state. Therefore, there is an effect that an unsafe state such as a failure of an electric device or smoking is not caused at the time of reset.

According to the eleventh aspect of the present invention, the user can be notified that an abnormal condition has been detected, and safety can be ensured by preventing an inadvertent restart. effective.

Further, according to the protection circuit control method of the present invention, when an abnormality is detected and the electric device in the power-on state is stopped, and the control means is reset thereafter, the electric device is in the power-off state. Since it is left as it is, there is an effect that at the time of resetting, an unsafe state such as a failure of an electric device or smoking is not caused.

Further, according to the control method of the protection circuit of the present invention, it is possible to inform the user that an abnormal state has been detected, and to ensure safety by preventing inadvertent restart. There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a configuration of an electric device (including a protection circuit) according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a control method of a protection circuit in the electric device according to the present embodiment.

FIG. 3 is a flowchart showing a method of controlling a protection circuit in a conventional electric device.

[Explanation of symbols]

1 connection plug, 2 main power supply, 3 relay switch, 4 transistor, 5 load circuit, 6 microcomputer, 7 auxiliary power supply, 8 nonvolatile memory, 9
Anomaly detection circuit, 10 protection circuit, 11 main body operation section, 12 remote control, 13 light receiving section.

Claims (15)

[Claims] 1. An electric apparatus comprising: a main power supply for supplying power to a load circuit; switch means for turning on / off power supply to the main power supply; and manual operation means for turning on / off the switch means. A circuit for controlling, comprising: storage means, and abnormality detection for outputting a detection signal indicating whether a voltage applied to the load circuit is in a normal state within a predetermined range or an abnormal state out of the predetermined range. Means for writing power-on information to the storage means when the switch means is turned on by the manual operation means, and writing power-off information to the storage means when the switch means is turned off by the manual operation means. Control means for turning off the switch means when the abnormality detection means detects an abnormal state, wherein the control means resets Protection means for turning on the switch means if the storage means stores power-on information, and turning off the switch means if the storage means stores power-off information when the control means resets. In the circuit, the control unit writes power-off information to the storage unit when the abnormality detection unit detects an abnormal state. 2. The protection circuit according to claim 1, further comprising an auxiliary power supply for supplying power to said control means. 3. The protection circuit according to claim 1, wherein said storage means is a nonvolatile memory. 4. The protection circuit according to claim 1, wherein the abnormal state includes a power failure state, and the control unit is reset by a power recovery. 5. When a predetermined operation is performed when the switch means is off because the storage means has stored power-off information when the control means resets after the abnormality detection means has detected an abnormal state. The protection circuit according to any one of claims 1 to 4, wherein a part of the protection circuit is set to a non-operational state in which no operation is accepted. 6. A load circuit, a main power supply for supplying power to the load circuit, switch means for turning on / off the power supply to the main power supply, and manual operation means for turning on / off the switch means. Storage means; abnormality detection means for outputting a detection signal indicating whether a voltage applied to the load circuit is in a normal state within a predetermined range or an abnormal state out of the predetermined range; and When turned on by the manual operation means, power-on information is written in the storage means, when the switch means is turned off by the manual operation means, power-off information is written in the storage means, and the abnormality detection means detects an abnormality. Control means for turning off the switch means when a state is detected, and when the control means resets, the storage means An electrical device which turns on the switch means if the switch information is stored, and turns off the switch means if the storage means stores power-off information when the control means resets. The electric device, wherein the control unit writes power-off information to the storage unit when the unit detects an abnormal state. 7. The electric device according to claim 6, further comprising an auxiliary power supply for supplying electric power to said control means. 8. The electric device according to claim 6, wherein said storage means is a nonvolatile memory. 9. The electric device according to claim 6, wherein the manual operation means includes a main body operation unit provided in the electric device main body. 10. The electric device according to claim 6, wherein the manual operation unit includes a remote operation unit provided separately from the electric device main body. 11. The control unit according to claim 1, wherein when the control unit resets after the abnormality detection unit detects an abnormal state, the storage unit stores power-off information and the switch unit is turned off. 11. The electric device according to claim 10, wherein the device is in a remote operation disabled state in which an operation from the remote operation unit is not accepted. 12. The electric device according to claim 6, wherein the abnormal state includes a power failure state, and the control unit is reset by a power recovery. 13. A power-on information is written in a storage means when a switch means for turning on / off the power supply to the load circuit main power supply is turned on by a manual operation means, and the switch means is turned off by the manual operation means. When the power-off information is written into the storage means, a detection signal indicating whether the voltage applied to the load circuit is in a normal state within a predetermined range or an abnormal state out of the predetermined range is output. When the abnormality detecting means detects an abnormal state, the switch means is turned off and power-off information is written in the storage means, and when the control means is reset, the storage means stores power-on information. If the switch means is turned on, and the control means resets, the storage means stores power-off information. The method of the protection circuit, characterized in that to turn off the switch means. 14. When a predetermined operation is performed when said switch means is off because said storage means has stored power-off information when said control means resets after said abnormality detection means has detected an abnormal state. 2. A partly inoperable state in which no operation is accepted.
4. The control method of the protection circuit according to 3. 15. The control method according to claim 13, wherein the abnormal state includes a power failure state, and the control unit is reset by a power recovery.