JPH0843439A - Clamp ammeter - Google Patents

Abstract

PURPOSE:To obtain a clamp ammeter that can easily measure the current in a two-wire power cord and is of portable type for storage and handling. CONSTITUTION:When an electric wire is inserted into a circular iron core 12, a coil 14 generates a current proportional to a current (AC) in the electric wire. The coil 14 is connected with a current measuring circuit 16 and liquid crystal display 18. The title clamp ammeter 14 is provided integrally with a line splitter 30. When a current in a two-wire cord is subject to measurement, a plug 32 is inserted into a power plug socket. Then a plug on the cord end of an electrical apparatus is inserted into a plug socket 34 and a switch of the electrical apparatus is turned on. An AC current is allowed to flow a through wire 36a of the line splitter 30 and a magnetic field is generated in the core 12, then an AC current is allowed to flow coil 14. The AC current is detected by the circuit 16, and the display 18 indicates the current value as a result.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly detects a magnetic field formed around a low piezoelectric path or the like to measure a current flowing through the electric line, and also a current flowing through a two-wire type electric line (cord). The present invention relates to a clamp ammeter that can easily measure.

[0002]

2. Description of the Related Art Conventionally, a clamp ammeter for detecting a magnetic field generated by a current flowing through a low piezoelectric path or the like to obtain the current value is well known. The clamp ammeter includes an openable / closable annular core and the annular core. An electric current is measured by having a coil wound around and inserting one electric wire (electric path) to be measured into the annular core. That is, when an alternating current flows in the electric wire, a current is generated in the coil wound around the annular iron core, so that the current flowing in the electric wire can be measured by detecting the current flowing in the coil with a current measuring circuit. become.

[0003]

By the way, when the power cord of an electric device or the like is of a two-wire type, a reciprocating current flows through the power cord, and magnetic fluxes in opposite directions act to cancel each other. Even if the clamp sensor of the clamp ammeter is clamped to the power cord, it is impossible to measure the current.

Therefore, conventionally, an electric current is caused to flow through a power cord of an electric device or the like via a cord separator called a line splitter, the electric path is separated at this line splitter, and a clamp ammeter is clamped on one electric path. The sensor was clamped and the current flowing there was measured.

[0005]

However, when current is measured using this line splitter, the plug of the line splitter is inserted into the power outlet, the plug of the electric device is inserted into the outlet of the line splitter, and the electric device is turned on. In such a state, the clamp sensor of the clamp ammeter had to be bitten by the line splitter to measure the current, so that the measurement of the current was complicated and troublesome.

Further, since the line splitter is a small article, it easily slips into other equipment during storage, and if it is desired to use it, it must be searched for between other equipment, which is extremely inconvenient.

Further, when measuring the current, the clamp ammeter and the line splitter have to be carried separately, which is also inconvenient to carry.

It is an object of the present invention to provide a clamp ammeter which can easily measure the current flowing through a two-wire type power cord and which is convenient for storage and carrying.

[0009]

The invention according to this application is
In order to solve the above problems, an annular iron core around which a coil is wound and formed to be openable and closable, a current measuring circuit for measuring a current value flowing through the coil, and a current value measured by the current measuring circuit are displayed. The current indicator and the line splitter having an electric path inserted through the annular core are integrally provided.

Here, one of the electric paths of the line splitter may be simply inserted through the annular core or may be wound around the annular core.

Furthermore, a voltage detection circuit for detecting the voltage between the electric paths of the line splitter, and a multiplication circuit for multiplying the current value detected by the current measurement circuit and the voltage value detected by the voltage detection circuit. And a power indicator for displaying the result of the multiplication circuit.

[0012]

The current value can be measured only by connecting the line splitter of the clamp ammeter in series between the power cord of the electric device and the power outlet.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of the clamp ammeter according to the embodiment, and as shown in the figure, the clamp sensor 10 has a configuration in which a coil 14 is wound around an annular iron core 12.

When a current-carrying electric wire (not shown) is inserted into the annular core 12, a current proportional to the electric current (AC) flowing through the electric wire is generated in the coil 14. A current measuring circuit 16 including a rectifying circuit for converting an alternating current (AC) current into a direct current and an A / D converter for performing analog-digital conversion is connected to the coil 14, and the current is displayed on the current measuring circuit 16. The liquid crystal display 18 is connected.

A line splitter 30 is provided integrally with the clamp ammeter. The line splitter 30 includes a plug 32 to be inserted into a power outlet (not shown), an outlet 34 to be inserted with a plug attached to the tip of a cord of an electric device or the like, and two electric lines 36a for connecting the plug 32 and the outlet 34. , 36b. The one electric path 36 a is inserted into the annular core 12. Here, the plug 32 and the outlet 34 are for domestic use.
Various shapes can be selected for application to various specifications such as 0V to foreign use.

2 and 3 show the appearance of the clamp ammeter of the embodiment, in which the tip of the illustrated clamp sensor 10 is opened by pressing the open / close lever 20. When measuring the electric current, the open / close lever 20 is pushed by hand to open the tip of the clamp sensor 10, an electric wire (not shown) is inserted and arranged in the opening of the clamp sensor 10, and the open / close lever 20 is released to clamp. The tip of the sensor 10 is closed. The liquid crystal display 18 displays the measurement result of the current measuring circuit 16.

Next, the case where the current flowing through the two-wire cord is measured using this clamp ammeter will be described.
First, attach the line splitter 30 of the clamp ammeter to the arrow D
4 is slid in the direction shown in FIG. 4, the plug 32 is projected as shown in FIGS. 4 and 5, and the plug 32 is inserted into a power outlet (not shown).

Next, the plug of the cord tip of the electric device is inserted into the outlet 34 on the back side of the line splitter 30 (see FIG. 5), the switch of the electric device is turned on, and the switch of the clamp ammeter is turned on. An alternating current flows in the electric path 36a of the line splitter 30, a magnetic field is generated in the annular iron core 12, an alternating current flows in the coil 14, the alternating current is detected by the current measuring circuit 16, and the current value is displayed on the liquid crystal display 18. To be done.

In the above embodiment, the one electric path 36a is simply inserted into the annular core 12, but the one electric path 36a may be wound around the annular core 12. In this case, the measurement sensitivity can be increased.

FIG. 6 shows the structure of a clamp ammeter according to another embodiment. The structure for measuring the current is the same as that of FIG. 1, but the voltage between the electric paths 36a and 36b is further increased. And a multiplication circuit 42 for obtaining electric power by multiplying the current value detected by the current measurement circuit 16 and the voltage value detected by the voltage detection circuit 40.
And a liquid crystal display 18 for displaying the electric power obtained by the multiplication circuit 42. The clamp ammeter in this example is
With this configuration, voltage and power can be measured in addition to current.

[0021]

According to the present invention, when measuring a current, a clamp ammeter is simply interposed in series between a power cord of an electric device or the like and a power outlet.
There is an effect that the current flowing through the wire type cord can be easily measured.

Further, according to the present invention, since the clamp ammeter and the line splitter are integrated, the clamp ammeter capable of measuring the current flowing through the two-wire cord can be immediately taken out from the storage location. There is an effect.

Further, according to the present invention, since the clamp ammeter and the line splitter are integrated, there is an effect that the clamp ammeter capable of measuring the current flowing through the two-wire cord is convenient to carry. is there.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a clamp ammeter according to an embodiment of the present invention.

FIG. 2 is a diagram showing an appearance (a line splitter is in a retracted state) of a clamp ammeter according to an embodiment of the present invention.

FIG. 3 is a view taken along the line AA of FIG.

FIG. 4 is a diagram showing a main part of an outer appearance (a line splitter is in a use state) of a clamp ammeter according to an embodiment of the present invention.

FIG. 5 is a view taken along the line BB of FIG.

FIG. 6 is a block diagram showing a configuration of a clamp ammeter according to another embodiment of the present invention.

[Explanation of symbols]

 10 Clamp Sensor 12 Annular Iron Core 14 Coil 16 Current Measuring Circuit 18 Liquid Crystal Display 20 Open / Close Lever 30 Line Splitter 32 Plug 34 Outlet 36a, 36b Electric Circuit 40 Voltage Detection Circuit 42 Multiplier Circuit

Claims (3)

[Claims] 1. An annular iron core around which a coil is wound and formed so as to be opened and closed, a current measuring circuit for measuring a current value flowing through the coil, and a current display for displaying a current value measured by the current measuring circuit. And a line splitter having an electric path inserted into the annular iron core, the clamp ammeter being characterized by being integrally provided. 2. The clamp ammeter according to claim 1, wherein the electric path inserted into the annular core is wound around the annular core. 3. A voltage detection circuit for detecting a voltage between electric circuits in the line splitter, and a multiplication circuit for multiplying a current value measured by the current measurement circuit and a voltage value detected by the voltage detection circuit. And a power indicator for displaying the result of the multiplication circuit.
Or the clamp ammeter described in 2.