JPH0555082U - Voltage detector - Google Patents

Abstract

(57) [Abstract] [Purpose] With a conventional voltage detector, when the voltage is detected from above the insulation coating of the wire, the thickness of the wire changes ± 60%. 100V depending on the size
It is not practical to display the following. It is an object of the present invention to improve the present situation and solve the problem of an indication error that occurs when a voltage is detected from above the insulation coating of an electric wire, and to obtain a voltage detector capable of displaying the voltage stepwise by an accurate numerical value. [Structure] The sensor is made of a high resistance material, and it is configured so that the ground voltage can be measured and displayed on the insulation coating of the electric wire.
A protective cylinder was provided in the main body case to hold a sensor, the sensor was connected to a detection circuit via an amplification circuit, and its end was connected to a power detection LED and an LCD display section.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention is designed to detect voltage from the insulation coating of an electric wire, display the voltage stepwise as a numerical value, measure the voltage, and use the numerical value to safely and easily detect a ground wire or cable disconnection accident. Used for.

[0002]

[Prior Art]

 With the conventional voltage detector, when voltage is detected from above the insulation coating of the wire, only the presence or absence of voltage can be measured. Therefore, for example, it was not possible to measure the voltage drop due to the increase or decrease of the current while touching the wire.

[0003]

[Problems to be solved by the device]

 In the conventional voltage detector, when the voltage is detected from above the insulation coating of the wire, it changes ± 60% when the wire thickness changes. When measuring 200V, 100V or less is displayed depending on the thickness. Therefore, it was not practical. The objective is to improve this situation and solve the problem of indication error that occurs when the voltage is detected on the insulation coating of the wire, and to obtain a voltage detector that can display the voltage stepwise with accurate numerical values. ,

[0004]

【Example】

 An embodiment of the present invention will be described with reference to the drawings, and 1 is a main body case. A protective cylinder 2 is attached to the front end of the main body case 1, and a sensor 3 having a front end formed of a high resistance is held in the holding cylinder 2 so that the input impedance is several hundreds MΩ or more. The input impedance of several hundred MΩ or more reduces the indication error due to the thickness of the wire. Below this, the indication error becomes large, and when it is larger than this, the power is turned on. Display an unstable value. In the experimental example, when the finished outer diameter of vinyl-insulated wire of 100 is measured to be 16 mm, the value was 25 in the case of a sensor with an input impedance of several MΩ as in the conventional voltage detector method. In the present invention, it is 115, and the change is small. If the input impedance is too high, the display error will increase due to the influence of the external environment such as noise, so several hundred MΩ or more is optimal. The reason why the tip of the electrode is formed in a wide T-shape is that the display error due to the thickness decreases as the area in contact with the covered electric wire increases. Since the permittivity of the main body case increases the error in the characteristics, use one with a low permittivity and a low fixed resistivity.

An amplifier circuit is built in the main body case 1 and connected to the sensor 3, and a detection circuit is connected to the amplifier circuit. The end of the detection circuit is connected to the power detection LED 5 and the LCD display 6, and also to the hold switch 6 and the power switch 7. As a result of the experiment, the error values are as follows. ± 5% at the position of the electrode and wire at the tip. ± 5% at temperature change. The difference between when the hot wire is touched and the insulated wire is within ± 10% due to the thickness of the wire. The difference between the measurement and the time when the human body is set to the same potential as the ground potential is 100 when the human body is at ground potential.

[0006]

[Work]

 When the power switch is turned on and the sensor 3 comes into contact with the insulated insulated wire to be measured, the induced voltage is detected through the protective tube 2, and the detection circuit LED 4 is lit by the function of the amplification circuit to notify the presence or absence of voltage and the LCD The indicator lamp of the stage according to the voltage value of the display unit 5 is turned on to recognize the voltage value. Therefore, when the LCD display unit 5 is set in multiple levels such as 100V, 200V, and 400V, the voltage can be grasped numerically and held by the hold switch 6 for confirmation and the electric circuit can be checked. it can.

[0007]

[Effects] As described above, according to the present invention, the sensor is formed of a high-resistance body so that the voltage can be detected from above the insulation cover of the wire. The problem of pointing error was resolved. In addition, since a protective cylinder is provided in the main body case to hold the sensor, this sensor is connected to the detection circuit via the amplification circuit, and the end of the sensor is connected to the power detection LED and the LCD display section, so that the LCD display section is often used. When setting in stages, the voltage can be checked numerically to check the electric circuit. In this way, it is possible to detect electricity without being affected by the thickness of the wire or the thickness of the insulation coating, so there is no need to identify the electric circuit and there is no need to search for bare terminals. It is possible to detect electricity from the ground, and it is possible to distinguish the input voltage of the ground wire or cable and to detect disconnection accidents safely and easily.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

[Explanation of symbols]

 1 Case Main Body 2 Protective Cylinder 3 Sensor 4 Voltage Detector LED 5 LCD Display (Voltage) 6 Hold Switch 7 Power Switch

Claims (3)

[Scope of utility model registration request] 1. A voltage detector characterized in that a sensor is formed of a high resistance material, and a ground voltage can be measured and displayed on an insulating coating of an electric wire. 2. The voltage detector according to claim 1, wherein the tip metal of the sensor is covered with an insulator. 3. A main body case is provided with a protective cylinder for holding a sensor, the sensor is connected to a detection circuit through an amplifier circuit, and its end is connected to a power detection LED and an LCD display section. The voltage detector according to claim 1 or claim 2.