KR200352032Y1 - Earth tester having a test mode for electricwireing - Google Patents

Abstract

Disclosed is a ground ohmmeter having a test function in the present invention.

According to the present invention, a buzzer driving circuit including a buzzer for oscillating according to an input frequency of a commercial power source to provide a predetermined sound; A light emitting element connected in parallel with the buzzer driving circuit to display an operation of the buzzer; And a switch for electrically connecting the current auxiliary ground terminal and the buzzer driving circuit through the range, wherein the buzzer driving circuit includes a resistor (R5) for reducing a potential introduced through the current auxiliary ground terminal. And a zener diode (D2, D3) and a buffer (B) for supplying a voltage reduced through the resistor (R5) at a constant voltage, and flowing through the zener diodes (D2, D3) and a buffer (B). Switching operation of the transistor (TR) and the transistor (TR) for switching a current of a predetermined value according to the frequency of the diode (D1) for half-wave rectified commercial power, the commercial power half-wave rectified by the diode (D1) According to the buzzer for providing the oscillation sound.

As described above, the ground resistance meter having a test function adds a switching contact using a range and makes an electrical connection with a predetermined buzzer circuit and an auxiliary auxiliary earth terminal for current through the switching contact, thereby making it difficult to measure ground resistance. Any ground line can be identified at any place, and it is possible to provide convenience of measuring ground resistance by determining whether the potential state of the ground line is higher than the reference value through the oscillation sound by the buzzer circuit without providing a separate tester. .

Description

EARTH TESTER HAVING A TEST MODE FOR ELECTRICWIREING}

The present invention relates to a ground ohmmeter, and more particularly, to a ground ohmmeter having a test function capable of performing a test function together with a ground resistance measurement by adding a test circuit as an internal circuit for measuring the ground resistance.

In general, a ground ohmmeter is a device for artificially injecting a ground current into the ground electrode to be measured to increase the potential of the ground electrode and to measure the ratio of the ground voltage and the ground current. There are two methods of measuring the ground resistance meter: the potentiometer method and the four-electrode method.The potentiometer method includes two auxiliary ground electrodes (potential auxiliary poles and current auxiliary poles) installed at a distance of 10 m in line with the ground electrode to be measured and measured. After the current flows through the auxiliary electrode far away from the ground electrode (20m), the voltage between the near (10m) auxiliary electrode and the ground electrode to be measured is measured and the grounding resistance due to the ratio is measured.

In addition, the four-electrode method is a method of measuring the earth resistivity of the soil, and the four ground electrodes are arranged at equal intervals (approximately 3 m), and an alternating current flows through both outer electrodes to measure the voltage between the two inner electrodes. This is how you calculate resistance.

In addition, there is a hook-on (clamp-on) method, which is a method that can be easily measured without an auxiliary grounding electrode, and is used for measuring ground resistance of a multi-grounding system. Built-in high frequency voltage oscillator (approximately 1600Hz) and power amplifier by battery and inverter circuit, and equipped with two types of CT (injection and detection), the high frequency current is injected through the injection CT The detection CT detects the voltage and current and measures the ground resistance by the ratio. Therefore, this hook-on (clamp-on) ground resistance meter has a feature that can be measured without separating the ground electrode when measuring the ground resistance of the multiple ground system.

The ground ohmmeter is classified into many types according to the measuring method, but in order to measure the resistance of the ground, the ground wire must be used in common. Therefore, no matter what kind of grounding ohmmeter is used, the grounding wire should be distinguished. The measurer uses a separate tester to distinguish the grounding wire through empirical observation. That is, by using a separate tester, the power line, the neutral line and the ground line of the commercial power source are selected through the resistance value of the tester. As a result, there is always an inherent risk of electric shock at high voltages and, in some cases, damage to the equipment.

This is because the ground ohmmeter and the tester for resistance measurement are used to measure the resistance of the ground or the load, and therefore, each equipment has a limited durability to select the power line, the neutral line, and the ground line of the commercial power source. Therefore, there is an urgent need to implement a device capable of performing a test function simultaneously with a ground resistance measurement.

The present invention was devised to solve such a problem, and an object of the present invention is to add a test function to the ground ohmmeter, the ground having a test function can be made more stable and easy extraction of the ground wire before the measurement of the ground resistance In providing an ohmmeter.

1 is a perspective view showing a ground ohmmeter according to the present invention.

2 is a configuration diagram for explaining the operation of the present invention.

3 is a circuit diagram illustrating the buzzer driver of FIG. 2.

<Description of Symbols for Main Drawings>

100: ground resistance meter 101: range

103: ground terminal 105: auxiliary ground terminal for voltage

107: current auxiliary earth terminal 109: meter

111: LED light 113: buzzer

115: check button 201: ground resistance measurement circuit

203: display driver 205: oscillation circuit

207: buzzer driver 209: switching circuit

211: second range switch unit

Ground resistance meter having a test function according to the aspect of the present invention for achieving the above object, in the ground resistance meter with a range for selecting the appropriate resistance value, is oscillated according to the input frequency of the commercial power source to a predetermined sound A buzzer driving circuit comprising a buzzer for providing; A light emitting element connected in parallel with the buzzer driving circuit to display an operation of the buzzer; And a switch for electrically connecting the auxiliary auxiliary terminal for current and the buzzer driving circuit through the range.

Preferably, the light emitting device is a light emitting diode (LED), and the buzzer driving circuit includes a resistor (R5) and a resistor (R5) for reducing the potential flowing through the auxiliary auxiliary earth terminal for current. Zener diodes (D2, D3) and buffer (B) for providing a reduced voltage potential through the constant voltage, and diodes for half-wave rectifying commercial power flowing through the zener diodes (D2, D3) and buffer (B) (D1) and a transistor (TR) for switching a current of a predetermined value according to the frequency of the commercial power supply half-wave rectified by the diode (D1) and for providing an oscillation sound according to the switching operation of the transistor (TR). It is characterized by consisting of a buzzer.

When described in detail based on the accompanying drawings a preferred embodiment of the ground resistance meter having a test function according to the present invention having such a feature as follows. 1 is a perspective view showing a ground ohmmeter according to the present invention. As shown, an analog meter (109) is formed on the front surface of the housing 117 of a predetermined shape, and the ground terminal 103, the auxiliary auxiliary terminal 105 for voltage, and the current are measured on one side. The auxiliary ground terminal 107 is formed. In addition, the detection result according to the measurement gain of the ground resistance to the lower end of the front surface of the housing 117 and the switching switching range 101 for measuring the inspection state and the inspection mode of the inspection switch 119 selected from the range 101. According to the present invention, a test LED 111 for performing a predetermined light emitting display and a buzzer 113 for sound output according to the test result are formed. The check button 115 is a ground resistance measurement switch used when measuring the ground resistance of the range 101.

Figure 2 is a block diagram for explaining the ground resistance meter having a test function according to the present invention for each function. As shown, the ground resistance measurement circuit unit 201 for measuring the ground resistance detected from the auxiliary auxiliary ground terminal 105 and the ground terminal 103 and the current auxiliary ground terminal 107 for voltage, and ground resistance measurement Meter 109 for displaying the ground resistance measured from the circuit unit 201 through an analog method, and supplying a predetermined frequency to provide a voltage of a predetermined value using a transformer to the auxiliary auxiliary terminal 107 for the current. A first range switch unit 213 for selecting each resistance value of the range 101, the switching circuit unit 209 for supplying a switching signal of the oscillation circuit unit 205 and the check button 115; A second range switch unit 211 for selecting a test function from the range 101 and a buzzer driver for operating a predetermined buzzer 113 based on a test result detected by the second range switch unit 211 ( 207) And a display driver 203.

The display driver 203 is preferably composed of a light emitting diode, and may be used as one of the buzzer 113 and the test LED 111 as necessary. On the other hand, the transformer can be configured to minimize the power consumption of the grounding resistance meter according to the lottery form, the power consumption of the grounding resistance meter according to the present invention is increasing the service life of the grounding resistance meter through a low power design of about 40mA. In addition, the meter 109 improves the durability of the measuring instrument due to overcurrent by using a 1 mA indicator, and prevents an excessive force of the measuring instrument itself due to excessive return of the indicator generated when the ground resistance meter is turned on or off.

Looking at the operation of the ground resistance meter having a test function according to the present invention configured as described above are as follows.

First, the user grounds the ground terminal 103 and the ground using a plurality of measurement codes and auxiliary ground rods, and the voltage auxiliary ground terminal 105 and the current auxiliary ground terminal 107 are connected to the ground terminal 103. After the installation through the ground rod into the ground spaced a certain distance from the), the range 101 is set to a resistance value of a predetermined scale.

The resistance value setting of the range 101 provides the contact of the first range switch unit 213 to the output of the oscillating circuit 205 to the auxiliary auxiliary earth terminal 107 for current, and to the secondary auxiliary earth terminal 107 for current. The amount of the supplied voltage is supplied to the ground resistance measurement circuit unit 201, and the voltage detected from the voltage auxiliary ground terminal 105 and the voltage supplied to the current auxiliary ground terminal 107 are compared with the meter. 109 is operated. That is, the ground resistance is calculated through the voltage between the current auxiliary ground terminal 107 and the ground terminal 103 and the current value between the voltage auxiliary ground terminal 105 and the ground terminal 103 and the meter ( 109). In this way, the ground ohmmeter 100 calculates the resistance of the ground based on the Ohm's law.

On the other hand, when measuring ground resistance in an area where such measurement is not easy, for example, in a building or downtown, there is often a case where the ground is completely packed or there is no place to use the auxiliary earthing rod. It may be used for measurement. Although the ground measuring point of the building includes an underground electric room, it is not easy to measure the auxiliary ground rod from the ground. Therefore, a water pipe or an iron pipe buried deep in the ground is used, and when the water pipe is buried in a straight line in parallel with a tree, or when measuring ground resistance using a commercial wire, the potential state of the ground line is determined and used.

Accordingly, the user switches the range 101 of the ground ohmmeter 100 to the test mode 119, wherein the second range switch unit 101 is a current auxiliary ground terminal 107 and a buzzer driver 207. Is electrically connected. In addition, the ground terminal 103 is grounded through a predetermined ground plane (grounding network), and then makes contact with the ground line to use the ground rod connected to the current auxiliary ground terminal 107.

Accordingly, the current auxiliary ground terminal 107 is connected to the ground line through the second range switch unit 211, which is grounded to the ground through the buzzer driver 207 and the display driver 203. If the ground line has a potential of a predetermined value, the auxiliary drive unit 207 is operated to turn on the buzzer 113 and a separate light emitting diode is operated to indicate that the potential of the ground line is higher than a reference value.

3 is a circuit diagram illustrating a buzzer driver according to the present invention. As illustrated, the current auxiliary ground terminal 107 is connected to the resistor R5 through the second range switch unit 211 to reduce the potential of a predetermined value. The reduced voltage is converted into a constant voltage by the zener diodes D2 and D3 and flows to the cathode side of the diode D1 through the buffer B formed of the NAND gate. Since the incoming potential is an alternating voltage, the diode D1 half-wave rectifies the input alternating voltage and turns on the transistor TR through the resistor R3. Accordingly, the transistor TR receives a half wave signal to the base and performs switching corresponding to the half wave signal.

As the buzzer 113 is connected to the collector terminal of the transistor TR, the buzzer 113 generates an oscillation sound according to the switching operation of the transistor TR. In addition, as the resistor R4 and the light emitting diode LED are connected to the anode side of the diode D1, the light emitting diode LED performs a blinking operation together with a turn-on operation of the transistor TR. Thus, the user can recognize the potential state of a specific terminal through the buzzer and the light emitting diode.

What has been described above is only one embodiment for a ground resistance meter having a test function according to the present invention, the present invention is not limited to the above embodiment, as claimed in the utility model registration claims below Without departing from the gist of the present invention, any person having ordinary knowledge in the field to which the present invention belongs will have the technical spirit of the present invention to the extent that various modifications can be made.

The ground resistance meter having a test function according to the present invention adds a switching contact using a range and makes an electrical connection with a predetermined buzzer circuit and an auxiliary earth terminal for current through the switching contact, so that the ground resistance measurement is not easy. Any ground line can be identified at any place, and it is possible to provide convenience of measuring ground resistance by determining whether the potential state of the ground line is higher than the reference value through the oscillation sound by the buzzer circuit without providing a separate tester. .

Claims (5)

In the ground resistance meter provided with a range for selecting the appropriate resistance value and an indicator (FS) for indicating the resistance value, A buzzer driving circuit including a buzzer for oscillating according to an input frequency of commercial power to provide a predetermined sound; A light emitting element connected in parallel with the buzzer driving circuit to display an operation of the buzzer; And And a switch for electrically connecting the auxiliary auxiliary terminal for current and the buzzer driving circuit through the range. The ground resistance meter according to claim 1, wherein the light emitting element is a light emitting diode (LED). The ground resistance meter of claim 1, wherein the resistance indicator is used with a capacity of 1 mA to improve durability of the instrument due to overcurrent. The ground ohmmeter according to claim 1, wherein the ground ohmmeter comprises an internal transformer of a lottery type, and the power consumption is minimized by designing a low power switching element. 2. The buzzer driving circuit of claim 1, wherein the buzzer driving circuit includes a resistor (R5) for reducing a potential introduced through the current auxiliary ground terminal, and a Zener for providing a reduced voltage through the resistor (R5) at a constant voltage. By the diodes D2 and D3 and the buffer B, the diode D1 for half-wave rectifying the commercial power flowing through the zener diodes D2 and D3 and the buffer B, and by the diode D1. A ground having a detection function, comprising a transistor (TR) for switching a current of a predetermined value according to the frequency of a half-wave rectified commercial power supply and a buzzer for providing an oscillation sound according to the switching operation of the transistor (TR). Ohmmeter.