CN215833594U

CN215833594U - Polarity tester for current transformer

Info

Publication number: CN215833594U
Application number: CN202121245587.4U
Authority: CN
Inventors: 王路明; 王一瑭
Original assignee: Deqing Gig Electronic Co ltd
Current assignee: Deqing Gig Electronic Co ltd
Priority date: 2021-06-04
Filing date: 2021-06-04
Publication date: 2022-02-15
Anticipated expiration: 2031-06-04

Abstract

A polarity tester for a current transformer belongs to the technical field of current transformers. The utility model comprises a qualified current transformer, a primary current wire passing through a central hole of the qualified current transformer, a transformer connected in series with the primary current wire, a load resistor and a switch, and a light-emitting diode arranged between two secondary current wires of the qualified current transformer; the primary current wire penetrates through the middle hole of the current transformer to be detected, and the two secondary current wires of the qualified current transformer are in homopolar lap joint with the two secondary current wires of the current transformer to be detected. The utility model has simple structure, convenient use, lower cost and convenient maintenance.

Description

Polarity tester for current transformer

Technical Field

The utility model relates to the technical field of current transformers, in particular to a polarity tester of a current transformer.

Background

The current transformer generally comprises a primary winding, a secondary winding, an iron core, a framework, a shell, a connecting terminal and the like which are insulated from each other. The working principle of the transformer is basically the same as that of a transformer, the number of turns of a primary winding is small, the primary winding is directly connected in series in a power supply circuit, and when primary load current passes through the primary winding, the generated alternating magnetic flux induces to generate secondary current which is reduced in proportion; the secondary winding has more turns and is connected with secondary loads of current coils such as instruments, relays, transmitters and the like in series to form a closed loop, and because the primary winding and the secondary winding have equal ampere turns, the load impedance in the actual operation of the current transformer is very small, and the secondary winding is close to a short-circuit state and is equivalent to a transformer in short-circuit operation.

The current transformer should be tested for polarity before and after handover and overhaul to prevent wrong polarity during wiring, which may cause malfunction of the protection device in the relay circuit and the metering circuit and may not be able to perform correct measurement.

In the prior art, as the utility model patent with patent number ZL201520024759.3 discloses a current transformer polarity tester, include: the polarity test circuit board is arranged in the shell; the polarity test circuit board comprises: a controller and a DC charging power supply; a primary wiring channel for accessing a primary winding of the current transformer to be tested and a secondary wiring channel for accessing a secondary winding of the current transformer to be tested are arranged on the shell; the primary wiring channel is connected with a direct current charging power supply inside the shell; the secondary wiring channel is connected with the controller in the shell; the shell is also provided with a display screen, and a control pin of the display screen is connected with the controller. The tester has a complex structure, high cost and difficult maintenance.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the problems in the prior art and provides a polarity tester of a current transformer, which has the advantages of simple structure, convenience in use, lower cost and convenience in maintenance.

The purpose of the utility model is realized by the following technical scheme:

a polarity tester for a current transformer comprises a qualified current transformer, a primary current wire penetrating through a central hole of the qualified current transformer, a transformer connected in series with the primary current wire, a load resistor, a switch and a light-emitting diode arranged between two secondary current wires of the qualified current transformer; the primary current wire penetrates through a middle hole of the current transformer to be detected, and the two secondary current wires of the qualified current transformer are in homopolar lap joint with the two secondary current wires of the current transformer to be detected.

The use principle of the utility model is as follows: the qualified current transformer and the current transformer to be tested are transformers with the same specification. When the current transformer to be detected is not connected, the secondary current generated by the secondary current wire of the qualified current transformer enables the light-emitting diode to emit light, and after the current transformer to be detected is connected, if the polarity is correct, the secondary current generated by the current transformer to be detected can correctly act on the light-emitting diode, namely the current passing through the light-emitting diode is enhanced, the brightness of the light-emitting diode is enhanced, and the fact that the polarity of the current transformer to be detected is correct is indicated; if the electrode of the current transformer to be tested is reversed, that is, the secondary current line of the qualified current transformer is in homopolar lap joint with the secondary current line of the current transformer to be tested on the surface, for example, the red line (positive electrode) of the qualified current transformer and the secondary current line of the current transformer to be tested are in lap joint with each other, and the black line (negative electrode) of the qualified current transformer are in lap joint with each other, but because the electrode of the current transformer to be tested is wrong, the output end of the red line is actually negative electrode, and the output end of the black line is actually positive electrode, the secondary current generated by the current transformer to be tested acts on the light-emitting diode in a reverse direction, so that the current generated by the qualified current transformer is offset, the light-emitting diode is turned off, and the polarity error of the current transformer to be tested is explained.

Preferably, one end of the primary current wire, which is connected with the switch, is provided with a conducting strip, and one end of the switch is provided with an elastic clamping piece, so that the structure is convenient to disassemble and assemble, and the operation of enabling the primary current wire to penetrate through a hole in the current transformer to be tested is facilitated.

Preferably, the conductive sheet is provided with a protrusion, the elastic clamping sheet is provided with a limiting hole, and the structure further ensures the connection stability of the conductive sheet and the elastic clamping sheet and the reliability of the test.

Preferably, the qualified current transformer is arranged on one side of the conducting strip, which is far away from the switch, and the current transformer to be tested is arranged between the conducting strip and the qualified current transformer. The structure enables the output ends of the qualified current transformer and the current transformer to be tested to be lapped more conveniently.

Preferably, the primary current line between the qualified current transformer and the conducting strip has a length which can simultaneously penetrate through a plurality of current transformers to be tested, so that the testing efficiency is improved.

Preferably, the specification of the transformer is 220V/12V and 50W.

In the present invention, the specification of the load resistor is preferably 22 Ω and 25W.

Preferably, the specifications of the qualified current transformer and the current transformer to be tested are 1 (10) A/1mA, 0.1 and 20R.

The utility model has the advantages that:

1. the use is convenient, and the polarity test of the current transformer can be effectively met;

2. the structure is simple, the conventional electric elements can be adopted for self-lapping, and the popularization and the use are easy;

3. easy dismounting, the maintenance of being convenient for.

Drawings

FIG. 1 is a schematic diagram of a polarity tester for a current transformer according to the present invention;

FIG. 2 is a schematic diagram of the switch of the present invention;

in the figure: 1-qualified current transformer; 2-primary current line; 3-a transformer; 4-load resistance; 5-a switch; 51-a resilient clip; 6-a light emitting diode; 7-current transformer to be tested.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

A polarity tester of a current transformer comprises a qualified current transformer 1, a primary current wire 2 penetrating through a hole in the qualified current transformer 1, a transformer 3 connected in series on the primary current wire 2, a load resistor 4, a switch 5 and a light-emitting diode 6 arranged between two secondary current wires of the qualified current transformer 1; the primary current wire 2 penetrates through a middle hole of the current transformer 7 to be detected, and two secondary current wires of the qualified current transformer 1 are in homopolar lap joint with two secondary current wires of the current transformer 7 to be detected. The specification of the transformer 3 is 220V/12V and 50W, the specification of the load electricity and 4 is 22 omega and 25W, and the specifications of the qualified current transformer 1 and the current transformer 7 to be tested are 1 (10) A/1mA, 0.1 and 20R.

Specifically, primary current line 2 is connected the one end of switch 5 is equipped with the conducting strip, the one end of switch 5 is equipped with elastic clamping piece 51, structure easy dismounting, the operation that the primary current line of being convenient for passed the current transformer mesopore that awaits measuring. And, be equipped with the arch on the conducting strip, be equipped with spacing hole on the elasticity clamping piece 51, the structure has further ensured the stability that conducting strip and elasticity clamping piece are connected, ensures the reliability of test.

In addition, the qualified current transformer 1 is arranged on one side of the conducting strip, which is far away from the switch 5, and the current transformer 7 to be tested is arranged between the conducting strip and the qualified current transformer 1. The structure enables the output ends of the qualified current transformer and the current transformer to be tested to be lapped more conveniently. And the primary current line between the qualified current transformer 1 and the conducting strip has the length of simultaneously penetrating through the plurality of current transformers 7 to be tested so as to improve the testing efficiency, and during testing, the output end of the qualified current transformer can be sequentially lapped with the output ends of different current transformers to be tested for testing.

The above description is only a preferred embodiment of the present invention, and the present invention is not limited to the above embodiment, and any changes or substitutions that can be easily made by those skilled in the art within the technical scope of the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A polarity tester of a current transformer is characterized by comprising a qualified current transformer, a primary current wire penetrating through a central hole of the qualified current transformer, a transformer connected in series on the primary current wire, a load resistor, a switch and a light emitting diode arranged between two secondary current wires of the qualified current transformer; the primary current wire penetrates through a middle hole of the current transformer to be detected, and the two secondary current wires of the qualified current transformer are in homopolar lap joint with the two secondary current wires of the current transformer to be detected.

2. The polarity tester of claim 1, wherein the primary current line is connected to the switch by a conductive strip, and the switch is provided with a resilient clip at one end.

3. The polarity tester of claim 2, wherein the conductive plate has a protrusion, and the elastic clip has a hole for limiting.

4. The polarity tester of claim 2, wherein the qualified current transformer is disposed on a side of the conductive plate away from the switch, and the current transformer to be tested is disposed between the conductive plate and the qualified current transformer.

5. The current transformer polarity tester of claim 4, wherein the primary current line between the qualified current transformer and the conducting strip has a length that passes through a plurality of current transformers to be tested simultaneously.

6. The polarity tester of claim 1, wherein the transformer has a specification of 220V/12V, 50W.

7. The polarity tester of claim 1, wherein said load resistor has a specification of 22 Ω and 25W.

8. The polarity tester of claim 1, wherein the specifications of the qualified current transformer and the current transformer to be tested are 1 (10) A/1mA, 0.1 and 20R.