JPH02280616A - Overcurrent alarm device - Google Patents

Abstract

PURPOSE:To detect local overload in a simple system by making this device an overcurrent alarm means of attachment plug socket type. CONSTITUTION:An overcurrent alarm device is in the shape of an attachment plug socket, where a detection section io is provided inside a unit case 1, the, current is detected with a Hall element, etc. and the overcurrent is indicated by a light emitting diode, etc. An attachment section 2 is in use by inserting it into a plug socket. A plug connected to an electric appliance is inserted into a socket 3 for use.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention generates an alarm when it detects that an overcurrent flows through a group of loads connected to an indoor electrical wiring system or that a load exceeding a predetermined capacity is connected to an outlet. The present invention relates to a new type of overcurrent alarm unit that issues an alarm, and particularly to an alarm unit that instantly issues an alarm when an overcurrent flows, and is suitable for preventing electrical fires caused by overcurrent.

Conventional technology> Conventionally, overcurrent protection devices used in indoor power distribution include cut-out switches and molded circuit breakers (commonly known as safety breakers) at the power inlet and where branch circuits separate from the main line. installed. In addition, the current limiter (also called an S breaker) installed at the service entrance of metered lighting customers is similar to an electromagnetic or bimetal type circuit breaker, and is a type of current-carrying protector. . A cut-out switch, also known as a safety device or baby switch, is a porcelain switch with a claw-type fuse attached to the inside of the lid, which opens and closes the electrical circuit by opening and closing the lid.

All of the above-mentioned protectors operate to cut off the electrical circuit when the total capacitance value of the electrical loads exceeds a predetermined rated value. On the other hand, recent electrical appliances have become more diverse, and it is not always possible to decide in advance what and where to use them. Also, what kind of useful things may appear in the future? For this reason, electrical outlets are installed indoors so that electrical appliances can be used freely anytime and anywhere, but recently, with the diversification of electrical appliances, several types of electrical appliances can be used from electrical outlets in several places. The use of so-called octopus wiring is increasing. The aforementioned cutout switches and molded circuit breakers are useless against such local overloads. To avoid such local overloads, it is best to understand the current capacity of each electrical appliance and carefully consider whether it is compatible with the outlet being used before using the appliance, but this is not usually the case. In most cases, it is unthinkable and used easily. It is often pointed out that such local overloads cause cords and wires to generate heat, leading to electrical fires.Although electrical appliances are said to be used within the rated current of the outlet, this is not always followed. The reality is that it is not.

<Problems to be solved by the invention> As mentioned above, conventional indoor overcurrent protectors are installed at customer service entrances or branching ports from main lines, and if an overcurrent flows, they cut off the electrical circuit. It was a thing. Therefore, it is not possible to know whether the capacity of electrical appliances connected to an outlet exceeds the rated current value of the outlet, and it is not possible to detect local overloads and notify the users of those appliances of abnormalities. Ta. Detecting these localized overloads using traditional methods requires installing something like a molded circuit breaker or cutout switch at each outlet, but such equipment is not only bulky but also The cost is also high, making it impractical.

The present invention was made to solve the above problems, and detects local overloads in indoor power distribution systems using a simple method and issues an alarm in the event of an abnormality, thereby preventing the occurrence of electrical fires, etc. This provides a unit to prevent this.

Means for Solving the Problems> The unit for solving the above problems is a plug-in outlet type unit that has a magnetic sensing element inside that generates an output in proportion to the current value and an output signal of the sensing element. A circuit for amplifying the current and a circuit for generating an output when the current value exceeds a predetermined value are provided, and when the current value exceeds the predetermined value, a warning buzzer is sounded or an indicator light is activated.

<Operation> The overcurrent alarm unit according to the present invention is a plug-in outlet type unit, and the inside is composed of a small detection element and a circuit, and various electrical appliances can be connected via this unit. Even if you use a power outlet, an alarm will be issued automatically if the rated current value of the outlet is exceeded, so you can notify the outside of heat generation due to local overload and call attention to it before it leads to an electrical fire. can.

<Example> An example of the present invention will be described below with reference to the drawings. FIG. 1 is an overall view of the overcurrent alarm unit, which has the shape of a plug socket, and 1 is a unit case in which a detection section 10 is incorporated. 2 is a plug part that is used by inserting it into an outlet. A plug connected to an electric appliance is inserted into the socket 3 of the unit 1, and the insertion part 2 and the socket 3 are connected by a lead wire 4.

Although only one pair of receiver ports 3 is shown here, there may be multiple pairs.

FIG. 2 is a block diagram showing a schematic configuration of the detection section 10 shown in FIG. 1. Reference numeral 11 denotes a sensing element which generates an output voltage 11a when it reacts to a magnetic field.

Since the output voltage 11a is extremely weak, the AC amplifier circuit 12 amplifies the signal. Reference numeral 13 denotes a detection circuit, which has the role of peak-holding the amplified signal 12a. The detection signal 13a that has passed through the detection circuit 13 is compared with a reference value in a comparison circuit 14 to determine whether the detection signal 13a is greater than or equal to a predetermined value. If it is above a predetermined value, an output 14a is generated, passes through the output circuit 15, and the output signal 15a causes the output to become 1.
For example, the alarm buzzer 16 is connected to the rfIIllMJ6. FIG. 3 is an example of a structural diagram of the detection element 11 shown in FIG. Here, a semiconductor Hall element will be explained as an example of the sensing element. The Hall element is a typical magnetic sensing element, in which a control current (Ic) is passed from a to a of the control line 21 in the length direction of the semiconductor board 20, and a magnetic field (B) of 23 is perpendicular to this. ), Ic,
This utilizes the so-called Hall effect in which an electromotive force (Hall voltage) is generated between both ends of the output line 22 in the direction perpendicular to B and b'. In this case, the electromotive force ■ generated is V=
is expressed as −1 cmB (where K is a sensitivity constant). B
When and Ic have an angle θ, the generated electromotive force is ■・co
It becomes sθ. This semiconductor board 20 is generally made of GaA.
S (gallium arsenide) and InSb (indium antimony) are used. As shown in FIG. 1, this sensing element 11 may be placed out of contact with the lead 114, and handling is extremely simple. This lead wire 4
Since the current flowing through is determined by the size of the load, and the generated magnetic field is proportional to the flowing current, overcurrent can be detected by the detection element 11.

In the above example, a Hall element was used as the sensing element 11, but it is not limited to this, and any element may be used as long as it responds to changes in a magnetic field. For example, a magnetoresistive element whose resistance value changes depending on the magnetic field. may also be used.

<Effects of the Invention> As described above, according to the present invention, a small magnetic sensing element, an amplifier circuit, a comparison circuit, a buzzer, etc.
Because it is a lightweight plug-in outlet type unit,
It does not take up much space, is cheap and easy to use, and if an overcurrent flows, an alarm will automatically sound, so there is no need to worry about the ratings of electrical appliances connected to the outlet. This has the effect of being able to prevent electrical fires and the like caused by such problems.

[Brief explanation of drawings]

FIG. 1 is an overall diagram of an overcurrent alarm unit according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a schematic configuration of a detection section.
FIG. 3 is an example of a structural diagram of a sensing element. l... Unit case, 10... Detection section, 11...
- Detection element, 12... AC amplifier circuit, 13... Detection circuit, 14... Comparison circuit, 15... Output circuit, 16
... Alarm buzzer - 20 ... Semiconductor board Figure 2 Figure 3 Figure procedure amendment (method) % formula % 1. Indication of incident Patent application No. 100640 of 1999
Dan Lieu Kei Hou 2, Name of the invention Overcurrent alarm unit 3, Address related to the case of the person making the amendment (residence)

Claims (1)

[Claims] A magnetic field generated by a current, a detection element that responds to changes in the magnetic field, a circuit that amplifies the output signal of the detection element, and a circuit that generates an output when the value of the current exceeds a predetermined value,
An overcurrent alarm unit characterized in that an alarm buzzer, an indicator light, etc. are operated when the value of the current exceeds a predetermined value.