JP2000139039A - Power circuit protection device - Google Patents

Abstract

(57) [Abstract] [Problem] An electric device can be stopped by remote control operation.
When the main power switch is turned on, the equipment can be turned on at a stretch from the stoppage state of the electric equipment.In addition, an unexpected power failure occurs in the electric equipment, and the power outage is caused by a natural disaster such as an earthquake. It is possible to avoid an environment in which a user becomes absent during a power outage or a power outage, and the operation of electrical equipment is useless. A power failure detection signal (S2) indicating a possibility of a power failure from a power failure detection circuit (14) when power supply of a commercial AC power supply is stopped for a certain period of time in an operation state or a standby state. A power failure is determined based on the switch open / close signal S3 indicating that the main power switch is turned on from the switch open / close detection circuit 17, and this is stored in the storage means in the microcomputer 10, and when the power supply of the commercial AC power supply is next started, By referring to the stored contents, a tri-life signal is supplied to the solenoid drive circuit 18 so that the main power switch 21-1
Is turned off, and the entire device is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric device having a main power supply circuit and a standby power supply circuit and capable of causing a main circuit portion of the device to perform standby operation when an abnormality occurs in a circuit in the electric device. The present invention relates to a protection device for a power supply circuit for the purpose of protecting the power supply circuit.

[0002]

2. Description of the Related Art FIG. 3 shows a block diagram of a power supply circuit in a conventional electric device. Here, an example in which the electric device is a television receiver will be described.

In FIG. 3, an AC plug 1 is connected to a commercial AC power supply (AC), one line of the AC plug 1 is connected to one input terminal of a first rectifier circuit 4, and the other line is a main power supply. It is connected to the other input terminal of the first rectifier circuit 4 via the switch 3-1 of the AC switch 2 which is a switch and the relay 3 which is a standby switch. A rectified voltage obtained by rectifying and smoothing commercial AC is output from the first rectifier circuit 4. The rectified voltage is converted into a stabilized DC voltage by a main power supply circuit 5 composed of a stabilized power supply circuit such as a switching type power supply circuit, and performs a TV signal processing and a deflection processing of a load circuit 6, here, a television (TV) receiver. A signal to be performed and a deflection processing circuit 61 and a picture tube (CRT) 62 are supplied to the portion.

On the other hand, commercial AC power is supplied to the primary winding 7-1 of the standby transformer 7 via the AC switch 2, and the output of the secondary winding 7-2 is supplied to the second rectifier circuit 8. The rectified output is supplied to the standby power supply circuit 9. Then, the output Vcc of the standby power supply circuit 9 is supplied to a power supply input terminal 101 of the microcomputer 10 which is a control means. The second rectifier circuit 8 outputs a rectified voltage obtained by rectifying and smoothing AC obtained from a commercial AC power supply, and the standby power supply circuit 9 stabilizes the rectified voltage and converts the rectified voltage into a power supply voltage for a microcomputer.

[0005] The output terminal of the second rectifier circuit 8 is connected to one end of a drive winding 3-2 of the relay 3, and the winding 3-2
Is connected to a reference potential point via the collector and emitter of the transistor 11 for relay drive, and the base of the transistor 11 is connected to the on / off terminal 102 of the microcomputer 10. A light receiver 12 is connected to the microcomputer 10 so that the light receiver 12 can receive a remote control signal such as an infrared code from a remote control transmitter 13 which is a remote control means.

In the above configuration, when the AC switch 2 as the main power switch is turned on, the commercial AC power supply A
An AC voltage is supplied from C to a second rectifier circuit 8 via a standby transformer 7, where the AC voltage is rectified and smoothed, and further supplied from a standby power supply circuit 9 to a power input terminal 101 of a microcomputer 10 which is a control means requiring standby operation. To the stabilized power supply voltage Vcc for the microcomputer
Is supplied. The voltage Vcc is also supplied as a power supply for the light receiver 12. At this time, the switch 3-1 of the relay 3, which is a standby switch, is off, and power is not supplied to the main power supply circuit 5 and the main circuit 6 after the first rectifier circuit 4 (standby state). In). Thereafter, when the power key of the remote control transmitter 13 is pressed, an infrared code signal indicating that the power is turned on is input to the light receiver 12, and the microcomputer 10 decodes the code signal and sets the on / off terminal 102 to the standby level (low level). ) To the operation level (high level). When the terminal 102 goes high, the transistor 11 for driving the relay is turned on, whereby the output line (positive output line) of the second rectifier circuit 8 is passed through the winding 3-2 of the relay 3, and further the transistor 11 is turned on. Drive current flows to the reference potential point through the collector / emitter of the relay 3, and the switch 3-1 of the relay 3 is turned on. That is, the standby switch 3 is turned on, the power is supplied to the circuits 5 and 6 after the first rectifier circuit 4, and the TV receiver circuit which is the main circuit 6 is operated.

As described above, taking a TV receiver as an example, the AC switch 2, which is a main power switch, can control the operation of the entire receiver. If the AC switch 2 is turned off, the operation of the entire receiver can be controlled. The receiver is stopped and the power consumption of the receiver becomes zero. On the other hand, the standby switch 3 is connected to the first rectifier circuit 4,
The main power supply circuit 5 and a main part (for example, a signal processing circuit and a deflection circuit system) 6 of the receiver are turned on and off.
When the standby switch 3 is turned on while the AC switch 2 is on, the main circuit 6 can be operated and normal viewing can be performed. When only the standby switch 3 is turned off, image reception can be performed. Stop the operation of the main circuit 6 of the machine,
Minimum required circuits (microcomputer 10 and remote control light receiving circuit 1
Only 2) is operated to wait for an input from the remote control transmitter 13 (this is a standby state). In this standby state, the main circuit 6 can be turned on by remote control operation, and the power consumption can be reduced because the main circuit 6 is not operated.

However, in the above-mentioned electric equipment which can be operated by a remote controller, in the operating state or the standby state, abnormalities are found in various circuits including the standby power supply circuit 9 and the control microcomputer 10 in the electric equipment main body and the main circuit part. If this occurs, the remote control transmitter 1
The operation can be turned off by the operation 3, but the AC switch 2, which is the main power switch, has to go to the vicinity of the device body and turn off the switch 2 manually, which is inconvenient. Further, when it is not necessary from the viewpoint of energy saving, the power consumption can be reduced to zero by turning off the AC switch 2. However, the only way to turn off the AC switch 2 is to manually turn off the switch 2 in the device body. It was troublesome. As described above, the commercial AC power supply and the power supply circuit can be separated only by the action intended by the user.

In the circuit shown in FIG. 3, for example, when the AC switch 2 of the TV receiver is turned off, and then the AC switch 2 is turned on to view the TV set again, the electric equipment is immediately in the operating state. The standby switch 3 must be turned on by pressing the power key of the remote control transmitter 13.
When the C switch 2 was turned on, the operating state could not be started at a stretch.

Further, in the case where a power failure occurs in the operation state or the standby state of the electric equipment, at least the main power switch is maintained in a state where the power supply is kept turned on. At least returns to the standby state, so that at least the standby power supply circuit and the microcomputer are brought into the operating state. For this reason, a power outage occurred in the electrical equipment, and the power outage was caused by a natural disaster such as an earthquake, and then the power outage was restored and the environment became dangerous for the operation of the electrical equipment, or the user was absent during the power outage. Then, even if the power failure is restored and the environment becomes useless even if the electric equipment operates, this cannot be completely avoided.

[0011]

As described above, in a conventional electric device (for example, a TV receiver) which can be operated by a remote controller, when the entire electric device needs to be stopped (all-off) in an operating state or a standby state. However, the main power switch could not be turned off by remote control operation, which was inconvenient. In addition, when the main power switch is turned on from the stop state of the electric device, the device cannot be brought into the operating state at once.
In addition, when a power failure occurs and subsequently recovers from the power failure, at least a part of the circuits of the electric equipment is put into an operating state, and the environment becomes dangerous for the electric equipment to operate during the power failure, or In the case where the user is absent during this time and the power failure recovers after that and the electrical equipment operates, the environment becomes useless, and there is no way to avoid this.

In view of the above problems, the present invention enables an electric device having a main power supply circuit and a standby power supply circuit to stop the electric device (all off) by operating a remote controller. When the main power switch is turned on, it is possible to put the equipment into operation at a stretch from the stop state of the electric equipment, and furthermore, the electric equipment encounters an unexpected power failure, and the power failure is caused by a natural disaster such as an earthquake. A power circuit protection device that can prevent the environment from becoming dangerous to operate, or an environment where the user is absent during a power outage and the electrical equipment operates is wasted. It is intended to provide.

[0013]

According to a first aspect of the present invention, there is provided a power supply circuit protection device comprising: a main power supply switch for turning on / off electric power supplied from a commercial AC power supply; A second switch for detecting on / off of the main power switch; a winding unit for turning off the main power switch and the second switch by supplying a drive current; A solenoid-type interlock switch including a manual operation unit for manually turning on and off the second switch; and power supplied from the commercial AC power supply via the main power supply switch. A standby power supply circuit for supplying DC power to at least the control means, and a power supply A standby switch for turning on and off a power supply; and a main switch for supplying power from the commercial AC power supply through the main power switch and the standby switch to supply DC power to the load circuit in an electric device. A power supply circuit, a solenoid drive circuit for supplying a current to the winding of the solenoid type interlocking switch based on a drive signal to turn off a main power supply switch, and power supply of the commercial AC power supply is lost for a certain period of time or more. A power failure detection circuit that outputs a first detection signal indicating the possibility of a power failure based on the output potential of the standby power supply circuit, and a second switch of the solenoid-type interlock switch, A switch open / close detection circuit for outputting a second detection signal indicating ON / OFF of a main power switch according to ON / OFF of a second switch; Control means that operates at a voltage based on a power supply from a road, and indicates a possibility of a power failure from the power failure detection circuit when the power supply of the commercial AC power supply is stopped for at least a certain time in at least a standby state. Based on the first detection signal and the second detection signal indicating that the main power switch is turned on from the switch open / close detection circuit, it is determined that a power failure has occurred, and this is stored in storage means. Control means for supplying a drive signal to the solenoid drive circuit based on the contents stored in the storage means at the time of start to control the main power switch to be turned off.

In the first aspect of the present invention, the control means includes:
At least in a standby state, when the power supply of the commercial AC power supply AC has been lost for a certain period of time (at the time of a power failure), a power failure detection signal, which is a first detection signal indicating a possibility of a power failure from the power failure detection circuit, and a switch open / close A power failure is determined based on a switch open / close signal, which is a second detection signal indicating that the main power switch is turned on from the detection circuit, and the power failure is stored in a storage unit in the control unit. At the time of start (at the time of recovery from power failure), a drive signal is supplied to the solenoid drive circuit by referring to the contents stored in the storage means to control the main power switch to be turned off, and the entire electric device is stopped. As a result, electrical equipment suffers a power outage,
The power outage was caused by a natural disaster such as an earthquake, and then the power outage was recovered and the environment became dangerous for the operation of the electrical equipment, or the user was absent during the power outage and it would be useless to operate the electrical equipment Even in an environment, the solenoid-type interlock switch is automatically turned off, and such a situation can be avoided.

According to a second aspect of the present invention, in the power supply circuit protection device according to the first aspect, the power failure detection circuit is charged with an output from the standby power supply circuit and supplies power to the control means. Even if a power failure occurs in the electric device, the first capacitor having a capacity capable of supplying power capable of operating the control unit for a certain period of time or more, and charged by an output from the standby power supply circuit, A second capacitor having a smaller capacity than the first capacitor;
A switching transistor having a collector and an emitter connected between an output terminal of the first capacitor and a reference potential point via a resistor; and a switching transistor provided between an output terminal of the second capacitor and a base of the switching transistor. A circuit for determining an output potential of the standby power supply circuit when the switching transistor is turned on, wherein the switch open / close detection circuit includes an output terminal of the first capacitor, the output terminal of the solenoid type interlock switch. And a collector / emitter connected between the output terminal of the first capacitor and a reference potential point via a resistor, and providing a collector output indicating the on / off state of the main power switch. A second switch transistor that outputs a signal as a reference, and the other end of the second switch of the solenoid-operated interlock switch as a base. Provided between potential point, said second
And a circuit of a resistor and a capacitor for supplying a base current to the second switch transistor when the switch is turned on.

According to a third aspect of the present invention, in the power supply circuit protection device according to the first or second aspect, the control means can control on / off of the standby switch based on a key operation of a remote control means. And a drive signal is supplied to the solenoid drive circuit based on a key operation of a remote control means to turn off the main power switch and the second switch.

According to the third aspect of the present invention, it is possible to stop the electric device by operating the remote controller (all off), and the user can turn off the main power switch all the time without going to the vicinity of the electric device. Power consumption can be reduced to zero.

[0018]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a power supply circuit protection device according to one embodiment of the present invention. The same parts as those in FIG. 3 are denoted by the same reference numerals. FIG. 2 shows a configuration example of the solenoid-type interlocking switch in FIG.

In FIG. 1, an AC plug 1 is connected to a commercial AC power supply (AC), one line of the AC plug 1 is connected to one input terminal of a first rectifier circuit 4, and the other line is connected to a solenoid ( It is connected to the other input terminal of the first rectifier circuit 4 via the main power switch (AC switch) 21-1 of the (electromagnet) type interlock switch 21 and the switch 3-1 of the relay 3 which is a standby switch. A rectified voltage obtained by rectifying and smoothing commercial AC is output from the first rectifier circuit 4. The rectified voltage is converted into a stabilized DC voltage by a main power supply circuit 5 composed of a stabilized power supply circuit such as a switching type power supply circuit and supplied to a load circuit 6 which is a main part of the electric equipment.

The solenoid type interlock switch 21 has two switches (contacts) 21-1 and 21-2, a drive winding unit 21-3, and a manual operation unit 21-4. The opening / closing operation (on / off) of 21-2 is linked. Also two switches
Among the switches 21-1 and 21-2, the first switch 21-1 is a main power switch for opening and closing the AC line, and the second switch 21-2 is used for detecting the opening and closing of the main power switch 21-1. In the solenoid type interlock switch 21, the two switches 21-1, 21-2
Is opened and closed (on / off) by the user's manual operation unit 21-4
When the two switches 21-1 and 21-2 are in the closed state (ON), the two switches 21-1 and 21-2 are formed by the force of the magnetic field generated by applying a drive current to the winding part 21-3.
Can be opened (off). Note that the two switches 21-1 and 21-2 cannot be turned on by controlling the drive current.

On the other hand, commercial AC power (AC) is supplied to the primary winding 7-1 of the standby transformer 7 through the main power switch 21-1, and the output of the secondary winding 7-2 is supplied to the second winding 7-2. The power is supplied to a rectifier circuit 8 and the rectified output is supplied to a standby power supply circuit 9 composed of a stabilized power supply circuit such as a switching power supply circuit. The output terminal of the standby power supply circuit 9 is connected to a power failure detection circuit 14 described later. The output V of the standby power supply circuit 9
a is set to a voltage Vb through a power failure detection circuit 14, and a microcomputer (hereinafter abbreviated as a microcomputer) 1
0 power supply terminal 101.

Further, the output terminal of the standby power supply circuit 9 is connected to one end of a winding 3-2 of the relay 3, and the other end of the winding 3-2 is connected to a reference via the collector and emitter of the transistor 11 for driving the relay. Connected to the potential point. The transistor 1
1 is connected to an on / off terminal 102 of the microcomputer 10 and the base is connected to a relay on / off terminal of the microcomputer 10.
The off signal S1 is supplied. A light receiver 12 is connected to the microcomputer 10.
Receiving a remote control signal such as an infrared code from a remote control transmitter 13 as a remote control means,
It is supplied to the microcomputer 10 as a remote control electric signal S0.

The power failure detection circuit 14 includes a standby power supply circuit 9
Is connected to the step-down regulator 15 and the diode D3.
A first capacitor C3 for charging is connected in series to a reference potential point, while a diode D4 and a second capacitor C4 for charging are connected in series to a reference potential point, and a diode D3 and a capacitor C3 are connected. The connection point of
1 and the collector / emitter of the transistor TR1 to the reference potential point.
4 is connected to a Zener diode D5 and a resistor R2,
The transistor TR1 is connected via a circuit 16 comprising R3.
It is configured to connect to the base. The first capacitor C3 is provided for a certain period of time or more until the microcomputer 10 determines that the power failure has occurred, even if the electrical equipment experiences a power failure.
It has a sufficient capacity to supply a power supply for operating the microcomputer 10. The diode D3 is provided to make it difficult to discharge the capacitor C3 during a power failure. The second capacitor C4 has such a capacity that the transistor TR1 is not turned off when the commercial AC power supply is stopped for a short period of time less than a certain period of time (hereinafter referred to as an instantaneous interruption). The diode D4 is provided to make the capacitor C4 difficult to discharge. The circuit 16 is a circuit for determining the output potential of the standby power supply circuit 9 when the transistor TR1 is turned on. The connection point A is connected to the anode of the Zener diode D5, and the cathode is connected to the resistor R5.
2 and R3 are connected in series to a reference potential point, and a resistor R2
, R3 are connected to the base of the transistor TR1. The connection point between the resistor R1 and the collector of the transistor TR1 is connected to the power failure detection terminal 103 of the microcomputer 10. The resistor R1 and the transistor TR1 directly generate a first power failure detection signal S2. When the transistor TR1 is on, the power failure detection signal S2 is at a low level. Is not ".

Further, a transistor TR2, a resistor R4,
A switch open / close detection circuit 17 comprising R5 and a capacitor C5 is provided. Switch open / close detection circuit 1
7 is a main power switch of the solenoid type interlock switch 21
The open / close of 21-1 is detected by detecting the open / close of the second switch 21-2. The output Va of the standby power supply circuit 9 is connected to the output terminal of the voltage Vb obtained through the power failure detection circuit 14 by a resistor. R4 and the collector of transistor TR2
While the emitter is connected in series to the reference potential point, the second switch 21-2 of the solenoid type interlocking switch 21, the resistor R5 and the capacitor C5 are connected in series to the reference potential point, and the resistor R5 and the capacitor C5 are connected. Is connected to the base of the transistor TR2. The transistor TR2 in the switch open / close detection circuit 17
Of the microcomputer 10 as a switch open / close signal S3 which is a second detection signal.
4 The switch open / close signal S3 is a low level signal when the transistor TR2 is turned on when the solenoid type interlock switch 21 is turned on.

The winding of the interlocking switch 21 with solenoid
One end of 21-3 is connected to the power supply + B1 obtained from the output terminal of the main power supply circuit 5, and the other end of the winding section 21-3 is connected to the all-off terminal 10 of the microcomputer 10 through the solenoid drive circuit 18.
Connected to 5. The solenoid drive circuit 18 connects the output Va of the standby power supply circuit 9 with the output terminal of the voltage Vb obtained through the power failure detection circuit 14 to the transistor T3 in series with the emitter / collector of the transistor TR3 and the resistor R6.
R4, the resistor R7 is connected between the emitter and base of the transistor TR3, the base of the transistor TR3 is connected to the all-off terminal 105 of the microcomputer 10 via the resistor R8, and the collector of the transistor TR4 is wound. It is configured to be connected to one end of the unit 21-3 and to connect the emitter to a reference potential point. A solenoid on / off signal S4 is supplied from the all-off terminal 105 of the microcomputer 10 to the solenoid drive circuit 18. For example, a low level ON signal turns on the transistors TR3 and TR4 to drive the winding 21-3 from the power supply + B1. A current flows to turn off both the switches 21-1 and 21-2.

The microcomputer 10 as a control means includes a power supply terminal 101 to which a voltage Vb based on the power supply Va is supplied from the standby power supply circuit 9 and a load of electric equipment while the solenoid type interlock switch 21 is turned on. An on / off terminal 102 for outputting a relay on / off signal S1 for turning on / off the relay 3, which is a standby switch, for bringing the circuit 6 into an operation state or a standby state is provided. Further, a power failure detection signal from the power failure detection circuit 14 is provided. A power failure detection terminal 103 for inputting S2 is provided, and a switch open / close detection terminal 104 for detecting on / off of the main power switch 21-1 is further provided. Solenoid on that outputs a solenoid on signal (all off signal) to turn off the entire electrical device by turning off 21-1 A / off terminal (all-off terminal) 105 is provided. A solenoid on / off signal is output from the microcomputer 10 to the solenoid on / off terminal 105. The solenoid on / off signal is normally at a high level when the microcomputer 10 is in an operating state. -1 is forcibly turned off based on a remote control operation or after a power failure
When it is turned off by 0, it is set to a low level.

In the microcomputer 10, a high-level signal indicating “possibility of a power failure” is supplied from the power failure detection circuit 14 to the power failure detection terminal 103, and the switch open / close detection circuit 17 is provided.
When a low-level signal indicating “the main power switch is closed” is supplied to the switch open / close detection terminal 104 from
A storage unit (not shown) is provided for determining that the state is “power failure” and storing the determination result. This storage means is constituted by a non-volatile memory so that the determination result can be stored and held even when the power supply Vb of the microcomputer 10 is at the zero level, that is, when the electric device is in the all-off state.

The microcomputer 10 serving as the control means operates by being supplied with the voltage Vb based on the power supply Va from the standby power supply circuit 9. If the microcomputer 10 is operating, the microcomputer 10 The relay 3 serving as a standby switch can be turned on and off based on the operation of a power key, and the solenoid drive circuit 1 can be controlled based on the operation of an all-off key provided on the remote control transmitter 13.
8 to drive the coil 21 of the solenoid type interlock switch 21
-3 Apply drive current to the main power switch 21-1 and the second
Can be controlled to turn off the switch 21-2.

The remote control transmitter 13 as a remote control means includes, in addition to various keys (including a power key) necessary for various operations of the electric device, an all-purpose device for turning off the electric device by remote control. An off key is provided.

As described above, this embodiment employs the solenoid type interlock switch 21 as shown in FIG.

As shown in FIG. 2, the solenoid type interlocking switch 21 has switches 21-1, 21-2, a coil 21-3, and a manual operation unit 21-4. By pressing this switch, the switches 21-1 and 21-2 can be turned on and off in conjunction with each other. When the switches 21-1 and 21-2 are on (solid line in the figure), the coil 21 is turned on.
By passing a current through -3, the switches 21-1 and 21-2 can be turned off (dotted line in the figure) in conjunction with each other. Coil 21-3
Constitutes a part of a solenoid (electromagnet), and turns off the switches 21-1 and 21-2 by using the electromagnetic force. As the switches 21-1 and 21-2 turn off, the manual operation unit 21-4 also returns to the off position.

The manual operation unit 21-4 is, for example, of a push-push type, and is turned on when pressed once and turned off when pressed again. switch
In order to shift to the ON state while the 21-1 and 21-2 are OFF, the manual operation unit 21-4 is pressed and turned ON by manual operation.
As the switch with solenoid, there is a commercially available product (for example, manufactured by Alps Electric).

One end of the coil 21-3 is connected to a power source (for example, + B1).
The other end is connected to a reference potential point through the collector / emitter of the transistor TR4. By supplying a high level voltage to the base of the transistor TR4, the transistor TR4 is turned on, thereby turning off the coil from the power supply. A coil current is supplied to a reference potential point through the transistor 21-4 and the transistor TR4, and the switches 21-1 and 21-2 are turned off in conjunction with the electromagnetic force of the coil 21-3.

When the main power switch and the second switches 21-1 and 21-2 are turned off by the all-off (solenoid off) operation of the remote control transmitter 13, the switches 21-1 and 21-2 are turned off.
In order to turn on -2, the manual operation section 21-4 of the solenoid type interlocking switch 21 described above may be pressed to turn on.

Next, the operation of the embodiment shown in FIG. 1 will be described. When electric equipment is normally used (for example, in the case of a television receiver, a user watches a program), by closing the solenoid-type interlock switch 21, the standby power supply circuit 9 is operated, and the output potential Va is generated. , The potential Vb is supplied to the microcomputer 10. As a result, the microcomputer 10 is in an operating state, and the microcomputer 10 can control electric devices. In this state, the relay 3 is still off, and the circuits 5 and 6 after the first rectifier circuit 4 are in a standby state in which power is not turned on.

Next, when the user presses the power key of the remote control transmitter 13, the microcomputer 10 supplies a relay control signal source to the relay drive TR 11 and turns on the relay 3, which is a standby switch. As a result, the commercial AC power is rectified into DC by the first rectifier circuit 4 and supplied to the main power supply circuit 5 so that the main power supply circuit 5 operates and supplies necessary electric power to each part of the electric device. This state is the operation state of the electric device.

Here, the operation of the switch open / close detection circuit 17 will be described. The switch open / close detection circuit 17 uses a main power switch open / close detection switch 21-2 of the solenoid type interlock switch 21. When the switch 21-2 is closed, a base current flows to the transistor TR2 via the resistor R5, TR3 is turned on, and a low-level switch open / close signal S3 is transmitted to the microcomputer 10. Conversely, when switch 21-2 is open, there is no base current of transistor TR2 and T
R2 is turned off, and the switch open / close signal S3 has the potential Vb at the high level via the resistor R4, which is transmitted to the microcomputer 10. However, at this time, the solenoid type interlocking switch 21 is opened, the standby power supply circuit 9 stops operating, the output potential Va drops, and the output Vb of the regulator 15 also drops. The transmitted time is a limited time depending on the discharge time constant of the charging capacitor C3. At this time, since the power of the microcomputer 10 also depends on the output Vb of the capacitor C3, the microcomputer is in an operating state.
0 stores in the nonvolatile memory in the microcomputer 10 that the switch 21-2 of the solenoid type interlocking switch 21 is open, that is, that S3 has become high level. And then
When the solenoid-operated interlocking switch 51 is turned on while the solenoid-operated interlocking switch 21 is turned off, the standby power supply circuit 9 operates, and when the microcomputer 10 starts operating, the microcomputer 10 operates as a high-level signal which is the content stored in the microcomputer. And relaying the relay-on signal source to the base of the relay drive transistor 11 based on this, the relay 3 is turned on and the main power supply circuit 5 can be operated. That is, the solenoid type interlock switch 2
When "1" is input, the electric device can be started up in an operating state at a stretch.

Next, the operation of the power failure detection circuit 14 in a normal use state of the electric equipment will be described. Output V of standby power supply circuit 9
The electric charge is stored in the capacitor C4 through the diode D4. Then, the potential of the capacitor C4, that is, the point A, becomes
When (TR1 base-emitter voltage VBE) + (R2 terminal potential) + (D5 Zener voltage), the base current flows to the transistor TR1, TR1 is turned on and saturation operation is performed, and the power failure detection signal S2 is low level. That is, a state indicating “no power failure” is set.

Then, due to a power failure or the like, the transistor TR1
Is turned off, the potential at the point A of the capacitor C4 drops, and the potential Vb of the capacitor C3 also drops at a slower fall than the potential of the capacitor C4. However, the potential of the capacitor C3 stays at the original predetermined potential (high-level potential) for a certain period of time. The power failure detection signal S2 is maintained at the time when TR1 is turned off, and becomes a high level signal pulled up by the potential VB. More specifically, when a power failure starts, the standby power supply circuit 9 stops operating and the output Va drops. The potential of the capacitor C4, that is, the point A is (base-emitter voltage VBE of TR1) + (potential of both ends of R2) + (D5
The Zener diode D)
The Zener breakdown of 5 stops, the base input current of TR1 disappears, and TR1 turns off. Then, the power failure detection signal S2
Since the capacity of the capacitor C3 is sufficiently larger than the capacity of the capacitor C4, the high-level potential at the output terminal of the capacitor C3 is connected to the power failure detection terminal 103 of the microcomputer 10 via the resistor R1.
Will be supplied. The microcomputer 10 receiving this signal judges that there is a possibility of a power failure. Further, the microcomputer 10 determines the switch opening / closing signal S3 from the switch opening / closing detection circuit 17 at this time, and when the signal is low level (that is, the solenoid Type interlock switch 21 is closed and the capacitor C3
Is maintained at a high level).
0 is determined to be "in a power outage situation". Then, the microcomputer 10 stores “in a power failure state” in the nonvolatile memory of the endoscope device of the microcomputer 10. That is, microcomputer 1
When 0 is at the S2 high level and at the S3 low level, it is determined that "power failure is occurring" and stored.

After this state, when the electric equipment returns from the power failure, the solenoid type interlock switch 21 is kept closed.
0 operates, the microcomputer 10 refers to the contents stored in the non-volatile memory and sends an ON signal to the relay drive transistor 11 based on the contents (contents of power failure) to drive the relay drive transistor 11 to the winding 3-2 of the relay 3. Apply current and turn on relay switch 3-1. Thereby, the main power supply circuit 5
Works. Next, the microcomputer 10 sends a low-level solenoid ON signal to the solenoid drive circuit 18 so that the transistors TR3 and T3 of the solenoid drive circuit 18
R4 is turned on, a current flows through the winding 21-3 of the solenoid type interlock switch 21, the solenoid type interlock switch 21 is opened (turned off), and the operation of the electric device is stopped.

In the above description with reference to FIG. 1, the output (+ B1) of the main power supply circuit 5 is used as the DC power supply for driving the winding portion 21-3 of the solenoid type interlock switch 21. As standby power supply circuit 9
It is also possible to adopt a configuration using the output (Va) of the above.
With such a configuration, when the power is restored, the microcomputer 1
0 sends an ON signal (low level) to the transistor TR3 for solenoid drive based on the stored content "power failure" to cause a current to flow through the winding portion 21-3 of the solenoid type interlock switch 21 and open the solenoid type interlock switch 21. (Off) to turn off the entire electric device. Thus, the electric device can be brought into a stopped state (all off) without operating the main power supply when the power is restored.

As described above, regardless of whether the electric device is in the standby state or the operating state, when the main power switch is turned off after the main power switch is turned off, the electric device is always set to the operating state. In addition to this, the main power switch can be turned off by remote control operation to improve operability. In addition, since the main power switch is turned off to cut off the commercial power, no power is consumed.

Further, in the circuit shown in FIG. 1, when a power failure occurs when the electric equipment is in an operating state or a standby state (when the interlocking switch 21 is on), it is detected that the power supply is turned off due to the power failure. When the power failure recovers after that, at least the standby power supply circuit and the microcomputer operate. However, based on the storage (that the power failure occurred), the microcomputer supplies a current to the solenoid, and the interlock switch 21 is closed. It is possible to release (turn off) the operating state and stop the operation of the entire electric device. As a result, when power is restored,
When the environment becomes dangerous for the operation of the electrical equipment, or when the power is restored, when the user is absent and the operation of the electrical equipment is unnecessary, it is possible to prevent the electrical equipment from being put into an operating state or a standby state, Safety and economy of electrical equipment can be secured.

[0044]

As described above, according to the present invention, in an electric device having a main power supply circuit and a standby power supply circuit,
By using a solenoid-type interlock switch, it is possible to put the electrical device in a stopped state (all off) by operating a remote controller, and to put the device into an operating state at once by turning on the main power switch from the stopped state of the electrical device. It is also possible that the electrical equipment has experienced an unexpected power outage and that the power outage was due to a natural disaster such as an earthquake, resulting in a dangerous environment for the electrical equipment to operate, or the absence of a user during the power outage. It is possible to avoid an environment in which the electric device is useless even if it operates.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a protection device for a power supply circuit according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of the configuration of a solenoid-type interlocking switch in FIG.

FIG. 3 is a block diagram showing a conventional power supply circuit protection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... AC plug 3 ... Relay (standby switch) 5 ... Main power supply circuit 6 ... Load circuit 9 ... Standby power supply circuit 10 ... Microcomputer (control means) 13 ... Remote control transmitter (remote operation means) 14 ... Power failure detection circuit 17 ... Switch open / close detection circuit 18 ... Solenoid drive circuit 21 ... Solenoid type interlock switch 21-1 ... Main power switch 21-2 ... Second switch 21-3 ... Winding unit 21-4 ... Manual operation unit

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[Procedure amendment]

[Submission date] November 5, 1998 (1998.11.
5)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 2

FIG. 3

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04Q 9/00 301 H04Q 9/00 301E 5K048 351 351 F Term (Reference) 5C026 EA00 5C068 AA06 CA01 CA05 5G004 AA01 AB02 BA08 CA03 DC01 FA01 5G015 FA06 JA32 JA60 5H730 AA17 AS15 CC01 FD21 FD61 FF09 FF19 VV01 XC02 XC20 XX02 XX14 XX21 XX33 XX42 5K048 AA15 BA03 GB06 GB10 HA33

Claims (3)

[Claims] A main power switch for turning on / off power supplied from a commercial AC power supply; a second switch for turning on / off in conjunction with the main power switch and detecting on / off of the main power switch; A winding unit for turning off the main power switch and the second switch by supplying a drive current; and a manual operation unit for manually turning on and off the main power switch and the second switch. A solenoid type interlock switch, power is supplied from the commercial AC power supply via the main power switch, and a standby power supply circuit for supplying DC power to at least a control unit in the device at least during standby operation of the electric device; A standby switch provided at a stage subsequent to the main power switch for turning on / off power supply to a load circuit at a subsequent stage; And a main power supply circuit for supplying DC power to the load circuit in the electric equipment, and a solenoid-operated switch based on a drive signal. A solenoid drive circuit for turning off a main power switch by supplying a current to the winding unit, and when the power supply of the commercial AC power supply is lost for a certain period of time or more, a power failure based on the output potential of the standby power supply circuit is performed. A power failure detection circuit that outputs a first detection signal indicating a possibility; and a power failure detection circuit that is provided to be connected to a second switch of the solenoid-type interlock switch, and that turns on / off a main power switch according to on / off of the second switch. A switch open / close detection circuit for outputting a second detection signal shown in FIG. 1 and control means operable with a voltage based on a power supply from the standby power supply circuit. When the in Kutomo standby state commercial AC power supply of the power supply has lost a certain time or longer, the indicating possible power failure from said failure detection circuit 1
Is determined based on the detection signal and the second detection signal indicating that the main power switch is turned on from the switch open / close detection circuit, and this is stored in the storage means. Then, the power supply of the commercial AC power supply is started. Control means for supplying a drive signal to the solenoid drive circuit based on the contents stored in the storage means to control the main power switch to be turned off. 2. The power failure detection circuit is charged with an output from the standby power supply circuit and supplies power to the control means. Even if a power failure occurs in an electric device, the power failure detection circuit performs the control for a certain time or more. A first capacitor having a capacity capable of supplying power capable of operating the means; a second capacitor charged with an output from the standby power supply circuit and having a capacity smaller than the capacity of the first capacitor; A switching transistor having a collector and an emitter connected between an output terminal of the first capacitor and a reference potential point via a resistor, and a switching transistor provided between an output terminal of the second capacitor and a base of the switching transistor. A circuit for determining an output potential of the standby power supply circuit when the switching transistor is turned on, wherein the switch open / close detection circuit comprises: The output end of the capacitor is connected to one end of the second switch of the solenoid interlock switch, the first
A collector / emitter connected between the output terminal of the capacitor and a reference potential point via a resistor, and outputting a collector output as the second detection signal indicating ON / OFF of a main power switch; A base current is provided between the other end of the second switch of the solenoid type interlock switch and a reference potential point, and supplies the base current to the second switch transistor when the second switch is turned on. The protection device for a power supply circuit according to claim 1, further comprising a resistor and a capacitor circuit. 3. The control means is capable of controlling the on / off state of the standby switch based on a key operation of a remote control means, and is configured to drive a signal to the solenoid drive circuit based on a key operation of the remote control means. The power supply circuit protection device according to claim 1 or 2, wherein the main power switch and the second switch can be turned off by applying a voltage.