WO2006033219A1

WO2006033219A1 - Circuit protecting device

Info

Publication number: WO2006033219A1
Application number: PCT/JP2005/015708
Authority: WO
Inventors: Kunihiro Miyata
Original assignee: Pioneer Corporation
Priority date: 2004-09-24
Filing date: 2005-08-30
Publication date: 2006-03-30
Also published as: JP2007329978A

Abstract

A circuit protecting device for protecting a circuit component from a large current, which is generated due to generation of a required output voltage by using an input voltage of a nonstandard low voltage value, even the circuit component is of a same type as the conventional one. The circuit protecting device is provided with a switching power supply part (6) which generates a stabilized direct current as a driving power supply by using an alternating current, a voltage detecting part (5) which detects whether the voltage value of the alternating current is less than a threshold value, and a control part (10) which controls to stop direct current generation by using the alternating current when the voltage value of the alternating current is less than the threshold value.

Description

Specification

Circuit protection device

Technical field

[0001] The present application belongs to the technical field of circuit protection devices.

Background art

[0002] Electronic elements such as transistors used in electronic devices are generally operated by direct current. Therefore, in order to operate the electronic device in accordance with its specifications, it is necessary to supply a direct current having a stable voltage value as the driving power. As a device for supplying this stabilized direct current, a so-called direct current stabilization is provided. Power supply devices have been used in the past

[0003] A typical example of the stabilized DC power supply is a switching power supply. This switching power supply is a type of stabilized DC power supply that is controlled by a so-called switching method, and uses a commercial AC power supply or a DC power supply as an input, and uses this as a high-speed switching action of a semiconductor, so that it exceeds the audible frequency. It is converted into high-frequency power and then controlled and rectified to obtain a direct current with a predetermined voltage value. It is characterized by its small size, “light weight” and high efficiency. Recently, it has been widely used as a power supply for most electronic devices including information equipment and communication equipment.

[0004] Here, in the switching power supply device, for example, when an alternating current having a voltage value about half of the voltage value standardized as the commercial AC power supply (in Japan, 100 volts AC) is input. However, as long as the time is short, the same amount of power can be supplied to the electronic device as when the AC of the standardized original voltage value is input.

However, in the above-described conventional switching power supply device, for example, when an alternating current having a voltage value more than twice the standardized voltage value is applied, the switching power supply device itself is overvoltaged. Although an overvoltage protection device is used to protect against switching, a circuit protection device is used to protect the switching power supply when an alternating current having a voltage value less than the standardized voltage value is applied. I was not there Disclosure of the invention

Problems to be solved by the invention

[0006] On the other hand, for the electronic devices described above, for example, an electronic device for 100 volt input (for example, for Japan and North America) and an electronic device for 220 volt to 230 volt input (for example, for Europe) At the production site, at the final stage of production, the rated power supply power is actually applied to each completed electronic device to check the operation of each electronic device. A process of hesitation is required. And in this case, there is a potential for accidents in which 100 VAC for Japan is accidentally applied to electronic equipment for Europe. May not be noticed by the inspector in charge.

[0007] However, as described above, even if an AC voltage of 100 volts is accidentally applied to an electronic device equipped with a switching power supply device for Europe, the switching power supply device has an AC voltage of 220 volts or more. About twice as much as when a standardized input voltage (220 to 230 volts) is applied in order to supply load power with the same amount of power as when 230 volts is applied. Current flows to the primary side, and as a result, the circuit components constituting the primary side are damaged.

[0008] Therefore, in the prior art which should deal with this problem, even if a large current flows due to the application of an input voltage having a value less than the standardized voltage value, the product is safe. When selecting each circuit component that constitutes the primary side, it is necessary to assume that an input voltage with a low voltage value outside the standard is input, and as a result, the circuit component itself is enlarged. In addition, there is a problem that the manufacturing cost increases.

[0009] Therefore, the present application has been made in view of the above-mentioned problems, and an example of the purpose is to use an input voltage with a low voltage value outside the standard while using circuit parts and the like similar to the conventional ones. It is an object of the present invention to provide a circuit protection device capable of protecting the circuit component from a large current caused by generating a necessary output voltage by using.

Means for solving the problem

[0010] In order to solve the above-described problem, the invention according to claim 1 provides an output using an input voltage. A generating means such as a switching power supply section for generating a voltage, a detecting means such as a voltage detecting section for detecting whether or not the value of the input voltage is less than a preset threshold, and the value of the input voltage Control means such as a control unit for controlling the generation of the output voltage using the input voltage when the value is less than the threshold.

Brief Description of Drawings

FIG. 1 is a block diagram showing the principle of the present application.

FIG. 2 is a block diagram showing a detailed configuration of a switching power supply unit according to the embodiment.

FIG. 3 is a flowchart showing the principle of the present application.

FIG. 4 is a block diagram showing a schematic configuration of the switching power supply according to the first embodiment.

FIG. 5 is a block diagram showing a schematic configuration of a switching power supply according to a second embodiment.

FIG. 6 is a block diagram showing a schematic configuration of a switching power supply device according to a third embodiment.

FIG. 7 is a block diagram showing a schematic configuration of a switching power supply device according to a fourth embodiment. Explanation of symbols

[0012] 1 outlet

2, 2B switch

2A fuse

3 Rectifier

4, 7 capacitors

5 Voltage detector

5A1, 5B1, 5C1, 5D1, 10A3, 10B5, 10B6, 10B9, 10B10, 10C3, 10D3, 10D4 Resistance

5A2, 5B2, 5C2, 5D2 Zener diode

6 Switching power supply

8 Diode

9 lance

10 Control unit

10A1, 10A2, 10B1, 10B2, 10B7, 10C1, 10C2, 10D1, 10D2 10B3 Light emitting device

10B4 Photo detector

10B8 Switch controller

11, 12 switch

B, BA, BB, BC, BD Switching power supply

BEST MODE FOR CARRYING OUT THE INVENTION

Next, the best mode for carrying out the present application will be described with reference to the drawings. Each embodiment described below is an embodiment when the present application is applied to a switching power supply device using commercial alternating current as its power source.

[0014] (I) Principle of the present application

First, before specifically describing each embodiment, the principle of the present application will be described with reference to FIGS. 1 to 3.

FIG. 1 is a block diagram illustrating the principle of the present application, FIG. 2 is a block diagram illustrating details of the switching power supply unit according to the present application, and FIG. 3 is a flowchart according to the operation of the present application.

As shown in FIG. 1, a switching power supply B according to the present application includes terminals 1A and 1B that are inserted into an AC outlet or the like as a power source in a production factory and receive AC supply as the power source. An outlet 1 provided, a rectifier 3 having a configuration similar to the conventional one, capacitors 4 and 7, a voltage detection unit 5 as a detection means, and a switching power supply unit 6 as a generation means having a configuration similar to the conventional one The diode 8, the transformer 9, and the control unit 10 as control means. Here, in FIG. 1, only the primary side circuit in the transformer 9 is shown for the sake of simplicity of explanation.

Further, as shown in FIG. 2, the switching power supply unit 6 includes a voltage detection switch similar to the conventional one.

6A, drive circuit 6B, and switching element 6C such as a transistor.

[0018] In the present application having the above configuration, as an alternating current applied to both terminals 1A and 1B of outlet 1, in addition to a normal voltage value (for example, 220 volts), an alternating current of, for example, 100 volts is improperly applied. It is assumed that there are cases. When an alternating current having a voltage value less than the standard value is improperly applied to both terminals 1A and 1B, the primary side power of the transformer 9 is accordingly accompanied. When the pressure value decreases below the standard value, the voltage after the decrease is detected as an abnormal voltage as a detection signal Sv in the voltage detection unit 5, and when the abnormal voltage is detected, the switching power supply is based on the detection signal Sv. Stop the power supply by the unit 6 itself. This stop operation protects each circuit shown in Fig. 1 from the large current generated due to the abnormal voltage.

[0019] Note that, as the stop operation, specifically, the operation itself of the switching power supply unit 6 is stopped by the control signal Sec from the control unit 10 according to the detection result of the voltage detection unit 5 (shown below) In the case of the first embodiment or the second embodiment) and the switch 2 (or a fuse corresponding to this) shown in FIG. 1 is cut off by the control signal Scs from the control unit 10, the AC from the outlet 1 There are two methods, that is, when the operation of the switching power supply unit 6 is stopped as a result (in the case of the third embodiment or the fourth embodiment described below).

[0020] And, the present application having such a configuration exerts its effect most, for example, by combining a plurality of types of products each having a plurality of types of alternating currents having different voltage values as driving power. This is the case of production on one production line. That is, for example, as shown in FIG. 3, in the production line, procurement (part S1), assembly preparation (step S 2) and assembly (parts including the circuit protection device according to the present application) for assembly are confirmed. In the operation confirmation process (Step S4) and sampling inspection process (Step S5) of all products that are executed after the completion of each process of Step S3), an alternating current with a voltage value lower than the rating is erroneously detected. When supplied as drive power, according to the present application, the operation of the switching power supply unit 6 is stopped, or the AC supply itself from the outlet 1 is stopped, thereby protecting each circuit shown in FIG. Can do it. Further, as a result, the switching power supply B itself stops, so that the examiner can recognize an error in the AC voltage value applied to the outlet 1 and correct each detection process (steps S4 and S4). The effect that S5) can be redone is also expected. As a result, in the subsequent shipping process (step S6), more products can be shipped without being destroyed by incorrect power supply.

[0021] (iD im Next, the first embodiment of the present application based on the above-described principle will be specifically described with reference to FIG. In FIG. 4, the same members as those shown in FIG. 1 are denoted by the same member numbers, and detailed description thereof is omitted.

As shown in FIG. 4, the switching power supply BC according to the first embodiment includes the outlet 1, the rectifier 3, the capacitors 4 and 7, the switching power supply unit 6, the diode 8 and the transformer 9 shown in FIG. 1 includes a resistor 5C1 and a transistor diode 5C2 that function as the voltage detector 5 shown in FIG. 1, transistors 10C1 and 10C2, and resistors 10C3 and 10C4 that function as the controller 10 shown in FIG. In this configuration, the transistor 10C2 is connected between the power supply VCC as the driving power source of the switching power supply unit 6 and the ground.

Next, the operation will be described.

When an AC voltage less than the standard value is applied to the outlet 1, the voltage across the capacitor 4 will decrease to below the standard value, which means that the force S, resistor 5C1, tuner diode 5C2, and resistor 10C4 Is detected by a decrease in the base voltage of the transistor 10C1, and the transistor 10C1 is turned off.

[0024] When the transistor 10C1 is turned off, the voltage at the base terminal of the transistor 10C2 rises, and as a result, the transistor 10C2 is turned on and the power supply VCC is grounded through the resistor 10C3. Become.

As a result, the switching power supply 6 itself is not supplied with power from the power supply VCC, and the operation of the switching power supply 6 is stopped. As a result, the function as the switching power supply BC is stopped, and each circuit is protected.

[0026] In order to realize the above operation, the resistance value of the resistor 5C1 and the rated value of the corner diode 5C2 are input according to a non-standard voltage value that can be input to the outlet 1. Each value should be able to reliably turn off the transistor 10C1.

As described above, according to the switching power supply BC of the first embodiment, when the AC voltage value as an input becomes less than the standard value, the operation of the switching power supply BC using the AC is stopped. Therefore, even when circuit parts similar to the conventional ones are used, the large current caused by generating the necessary direct current using alternating current having a value less than the standard value. The circuit component can be protected from the above.

[0028] Further, when a constant value of direct current is obtained from alternating current whose value fluctuates using the switching power supply unit 6, even if the voltage value of the alternating current is less than the standard value, the value is less than the standard value. It is possible to protect circuit components from large currents caused by generating the necessary direct current using alternating current.

[0029] Further, when the input AC voltage value is less than the standard value, the supply of the power supply VCC to the switching power supply unit 6 is stopped and the operation of the switching power supply unit 6 is stopped. Circuit components can be protected by electrical operation without using

[0030] Further, since the supply of the power supply VCC itself to the switching power supply unit 6 is stopped, the circuit components can be protected with only a simple configuration and an electrical function.

[0031] (III) Second implementation bear

Next, a second embodiment which is another embodiment of the present application based on the above-described principle will be specifically described with reference to FIG. In FIG. 5, the same members as those shown in FIG. 1 are denoted by the same member numbers, and detailed description thereof is omitted.

As shown in FIG. 5, the switching power supply device BDD according to the second embodiment includes the outlet 1, the rectifier 3, the capacitors 4 and 7, the switching power supply unit 6, the diode 8 and the transformer 9 shown in FIG. 1 includes a resistor 5D1 and a corner diode 5D2 that function as the voltage detection unit 5 shown in FIG. 1, transistors 10D1 and 10D2, and resistors 10D3 and 10D4 that function as the control unit 10 shown in FIG. In this configuration, the transistor 10D2 is connected between the power supply VCC serving as the drive power source of the switching power supply unit 6 and the ground, and the resistor 5D1 and the resistor 10D are connected between the power supply VCC and the base terminal of the transistor 10D1. Ener diode 5D2 is connected in series.

Next, the operation will be described.

When an AC voltage less than the standard value is applied to the outlet 1, the voltage at both ends of the capacitor 7 in addition to the capacitor 4 in the first embodiment also decreases below the standard value. One transistor 5D2 and resistor 10D4 detect that the base voltage of transistor 10D1 drops, and the transistor 10D1 is turned off. It becomes a state.

[0034] Then, when the transistor 10D1 is turned off, the voltage at the base terminal of the transistor 10D2 rises. As a result, the transistor 10D2 is turned on and the power supply VCC is grounded through the resistor 10C3. Become.

Thereby, as in the case of the first embodiment, the power of the power supply VCC is not supplied to the switching power supply unit 6 itself, and the operation of the switching power supply unit 6 is stopped. As a result, the function as the switching power supply BD is stopped, and each circuit is protected.

[0036] In order to realize the above operation, the resistance value of the resistor 5D1 and the rated value of the Zener diode 5D2 were input according to a non-standard voltage value that could be input to the outlet 1. Sometimes it is necessary to have a value that can reliably turn off the transistor 10D1.

[0037] The switching power supply device BD of the second embodiment described above can also achieve the same effects as the switching power supply device BC that works on the first embodiment described above.

[0038] (IV) Third real ¾ shape

Next, a third embodiment, which is still another embodiment of the present application based on the above-described principle, will be specifically described with reference to FIG. FIG. 6 is a block diagram showing a schematic configuration of the switching power supply device according to the third embodiment. In FIG. 6, the same components as those shown in FIG. Detailed description is omitted.

As shown in FIG. 6, the switching power supply device BA according to the third embodiment includes the outlet 1, the rectifier 3, the capacitors 4 and 7, the switching power supply unit 6, the diode 8, and the transformer 9 shown in FIG. As shown in FIG. 1, the resistor 5A1 and the Zener diode 5A2 functioning as the voltage detection unit 5, the transistors 10A1 and 10A2 functioning as the control unit 10 illustrated in FIG. 1, the resistor 10A3 and the switch 11, and the switch 2 illustrated in FIG. It consists of a functional fuse 2A.

[0040] Next, the operation will be described.

When an AC voltage less than the standard value is applied to the outlet 1, the voltage across the capacitor 4 will decrease below the standard value. This is because of the force S, resistance 5A1, and Zener die. This is detected when the base voltage of the transistor 10A1 is lowered by the resistor 5A2 and the resistor 10A3, and the transistor 10A1 is turned off.

[0041] Then, when the transistor 10A1 is turned off, the voltage at the base terminal of the transistor 10A2 increases. As a result, the transistor 10A2 is turned on, and the alternating current applied to the outlet 1 is directly applied to the fuse 2A. The Then, the fuse 2A is blown when a current exceeding the above-mentioned rating flows through the fuse 2A.

[0042] As a result, AC from the outlet 1 is not applied to the rectifier 3 and the switching power supply unit 6, and as a result, the function as the switching power supply device BA is stopped, and each circuit is protected. It becomes.

[0043] In order to realize the above operation, the resistance value of the resistor 5A1 and the rated value of the Zener diode 5A2 were input according to a non-standard voltage value that could be input to the outlet 1. Sometimes it is necessary to have a value that can reliably turn off the transistor 10A1.

In the case of the present embodiment, even when a standard AC value is applied to the outlet 1, a predetermined charging time (hereinafter referred to as charging time t) is stored until the necessary charge is accumulated in the capacitor 4. In this charging time t, the transistor 10A1 is turned off and the transistor 10A2 is turned on. As a result, a current exceeding the rating flows to the fuse 2A, and the fuse 2A may be blown. Therefore, in the switching power supply device BA according to the third embodiment, a switch 11 shown in FIG. 6 is newly provided until the necessary charge is accumulated in the capacitor 4 when the power supply is applied through the outlet 1. The control signal Sc from a microcomputer (not shown) that constitutes the control unit 10 shown in FIG. 1 only during the above accumulation time t (that is, until the voltage across the capacitor 4 reaches a preset rated value). Thus, the control to turn off the switch 11 is performed.

[0045] As described above, according to the switching power supply BA of the third embodiment, the operation of the switching power supply B using the alternating current is stopped when the voltage value of the alternating current becomes less than the standard value as an input. Therefore, even when circuit parts similar to the conventional ones are used, a large current is generated due to the generation of necessary direct current using alternating current having a value less than the standard value. Can do. [0046] Further, when a constant value of direct current is obtained from the alternating current whose value varies using the switching power supply unit 6, even if the alternating voltage value is less than the standard value, the value is less than the standard value. It is possible to protect circuit components from large currents caused by generating the necessary direct current using alternating current.

[0047] Further, when the input AC voltage value is less than the standard value, the operation of the switching power supply unit 6 is stopped by blowing the fuse 2A and stopping the supply itself to the AC rectifier 3 and the like. Therefore, circuit components can be reliably protected.

[0048] (V) Fourth implementation type bear

Finally, a fourth embodiment, which is still another embodiment of the present application based on the above-described principle, will be specifically described with reference to FIG. In FIG. 7, the same members as those shown in FIG. 1 are denoted by the same member numbers, and detailed description thereof is omitted.

As shown in FIG. 7, the switching power supply BB according to the fourth embodiment includes the outlet 1, the rectifier 3, the capacitors 4 and 7, the switching power supply unit 6, the diode 8 and the transformer 9 shown in FIG. 1, resistor 5B1 and Zener diode 5B2 functioning as voltage detection unit 5 shown in FIG. 1, transistors 10B1, 10B2 and 10B7 functioning as control unit 10 shown in FIG. 1, resistors 10B5, 10B6, 10B9 and 10B10, and switch control Section 10B8, light emitting element 10B3 and light receiving element 10B4 functioning as a photocoupler, and switch 2B corresponding to switch 2 shown in FIG.

[0050] Next, the operation will be described.

When an AC voltage less than the standard value is applied to the outlet 1, the voltage across the capacitor 4 will decrease below the standard value.This is because the resistor 5B1, the corner diode 5B2, and the resistor 10B9 This is detected when the base voltage of 10B1 decreases, and the transistor 10B1 is turned off.

[0051] Then, when the transistor 10B1 is turned off, the voltage of the base terminal of the transistor 10B2 increases, and as a result, the transistor 10B2 is turned on and the light emitting element 10B3 emits light. Thus, when the emitted light is received by the light receiving element 10B4, the resistance value of the light receiving element 10B4 itself decreases, and accordingly, the base voltage of the transistor 10B7 decreases, so that the transistor 10B7 is turned off. The As a result, the switch control unit 10B8 operates, and the switch 2B is turned off based on the control signal Ssw output from the switch control unit 10B8.

[0053] As a result, AC from the outlet 1 is not applied to the rectifier 3 and the switching power supply unit 6, and as a result, the function as the switching power supply BB is stopped as in the third embodiment. Thus, each circuit is protected.

[0054] In order to realize the above operation, the resistance value of the resistor 5B1 and the Zener diode

The rated value of 5B2 needs to be a value that can reliably turn off the transistor 10B1 when it is input according to a non-standard voltage value that can be input to the outlet 1.

[0055] Also in the present embodiment, the transistor 1OB1 is turned off and the transistor 1 is turned off at the charging time t of the capacitor 4 for the same reason as described in the description of the switch 11 according to the third embodiment. As a result of the switch 10B2 being turned on, the switch 2B is controlled to be turned off. Therefore, in the switching power supply BB according to the fourth embodiment, a switch 12 shown in FIG. Control for turning off the switch 12 and turning off the switch 2B by the control signal Sc from the microphone computer (not shown) constituting the control unit 10 shown in FIG. 1 for the accumulation time t from the timing when the power supply is applied. Is to do.

[0056] As described above, according to the switching power supply BB of the fourth embodiment, when the AC voltage value becomes less than the standard value as an input, the operation of the switching power supply BB using the AC is stopped. Therefore, even when circuit parts similar to the conventional ones are used, the circuit parts are also protected by the large current force caused by generating the necessary direct current using alternating current having a value less than the standard value. Can do.

[0057] Further, when a constant value of direct current is obtained from alternating current whose value fluctuates using the switching power supply unit 6, even if the voltage value of the alternating current is less than the standard value, the value is less than the standard value. It is possible to protect circuit components from large currents caused by generating the necessary direct current using alternating current.

[0058] Further, when the input AC voltage value is less than the standard value, the switch 2B is turned off to stop the supply itself to the AC rectifier 3 or the like, thereby operating the switching power supply unit 6. Since the operation is stopped, the circuit components can be reliably protected.

As described above, according to the configuration of each embodiment of the present application, in the case where a plurality of types of devices having different switching power supply devices and different AC voltage values as power sources are manufactured on the same production line, etc. In other words, it can greatly contribute to the protection of each device, in other words, the improvement of the yield of each device.

Claims

The scope of the claims

[1] generation means for generating an output voltage using an input voltage;

Detecting means for detecting whether or not the value of the input voltage is less than a preset threshold value;

Control means for controlling the generation of the output voltage using the input voltage when the value of the input voltage is less than the threshold; and

A circuit protection device comprising:

[2] In the circuit protection device according to claim 1,

The circuit protection device, wherein the generation unit functions to generate the output voltage having a constant voltage value even when the value of the input voltage varies.

[3] In the circuit protection device according to claim 1 or 2,

The circuit protection device according to claim 1, wherein the generation means is a switching power supply means that operates using the input voltage.

[4] In the circuit protection device according to any one of claims 1 to 3,

When the value of the input voltage is less than the threshold, the control unit stops generating the output voltage by stopping the generation operation of the output voltage in the generation unit. Circuit protection device.

[5] The circuit protection device according to claim 4,

The control means stops the generation of the output voltage by stopping the supply operation of the output voltage in the generation means by stopping the supply of power to the generation means. apparatus.

[6] In the circuit protection device according to any one of claims 1 to 3,

The control means stops the generation of the output voltage by stopping the supply of the input voltage when the value of the input voltage is less than the threshold value. .

[7] The circuit protection device according to claim 6,

The control means stops the generation of the output voltage by blowing a fuse provided on the input voltage supply path and stopping the input voltage supply itself. A circuit protection device.

The circuit protection device according to claim 6,

The control means stops the generation of the output voltage by cutting off the switch means provided on the input voltage supply path and stopping the supply of the input voltage itself. .