Electric test pen
* [The name of the utility model shall indicate the theme of the patent for utility model concisely and accurately. Names shall not contain non-technical words, and trademarks, models, names, place names or commodity names shall not be used. The name should be exactly the same as the name in the request, and should not exceed 25 words, and should be written in the middle position above the text on the first page of the manual. ]
According to Paragraph 3 of Article 26 of the Patent Law and Article 18 of the Detailed Rules for the Implementation of the Patent Law, the specification shall give a clear and complete description of the utility model, so that technicians in their technical fields can reproduce the technical scheme of the utility model, solve its technical problems and produce the expected technical effect without creative work. The instructions should be written in the following five parts: technical field; Background technology; Inventive content; Description of the drawings; Specific implementation mode; And write the title in front of each part. ]
Belonging to the technical field
The utility model relates to an electrical test device for indicating the existence of voltage, in particular to an electrical probe which can identify safe and dangerous voltages.
[Technical field: It should be pointed out that the technical scheme of the utility model belongs to or is directly applicable to this technical field. ]
technical background
At present, the well-known electric probe structure is composed of a test contact, a current limiting resistor, a neon tube, a metal spring and a hand contact electrode in series. Touch the test contact with the measured object and get the electric shock electrode by hand. When the measured object has a relatively high voltage, the neon tube will glow, indicating that the measured object is charged. However, there is no dangerous electric shock voltage in the metal shell of many electrical appliances, which only means that distributed capacitance and/or normal resistance induced potential make neon tubes glow. Generally, electric pens can't distinguish between dangerous electric shock voltage and non-dangerous induced potential, which makes it difficult to detect leakage and easy to make wrong judgments.
[Background technology: refers to technologies useful for understanding, searching and examining utility models, and documents reflecting these background technologies can be cited. Background technology is the description of the closest existing technology, and it is the basis for formulating new technical schemes of practical technology. In addition, it is necessary to objectively point out the problems and shortcomings in the background technology, and if the literature is cited, the source should be explained. ]
Summary of the invention
[Summary: It shall include the technical problems to be solved by the utility model, the technical scheme adopted to solve the technical problems and its beneficial effects. ]
In order to overcome the deficiency that the existing electric probe can't distinguish dangerous electric shock voltage from non-dangerous induced potential, the utility model provides an electric probe, which can not only measure whether the measured object is charged, but also conveniently distinguish dangerous electric shock voltage from non-dangerous induced potential.
[Technical problems to be solved: refers to the technical problems to be solved in the prior art.. In view of the defects or deficiencies in the existing technology, the technical problems to be solved by the utility model should be expressed in concise and accurate language, and its technical effects can be further explained, but advertising language should not be used. ]
The technical scheme adopted by the utility model is as follows: in an insulating shell, a test contact, a current limiting resistor, a neon tube and a hand contact electrode are electrically connected, and a shunt resistor branch is arranged to electrically connect the test contact with one end of the shunt resistor, and the other end of the shunt resistor is electrically connected with an identification electrode that can be contacted by a human body. When a human hand touches the identification electrode and the hand contact electrode at the same time, the shunt resistor is connected in parallel with the test contact, the current limiting resistor, the neon tube and the hand contact electrode circuit for testing, and the hand only touches the hand contact electrode, and the neon tube glows, indicating that the measured object is charged. When the human hand touches the electric shock electrode and the identification electrode at the same time, if the measured object has a non-dangerous high potential and the charged potential of the measured object is greatly reduced due to the large internal resistance of the potential source, the neon tube will not emit light; If the measured object has dangerous electric shock voltage, and the charged potential of the measured object will hardly decrease due to the small internal resistance, then the neon tube will always be on, thus achieving the purpose of distinguishing safe voltage.
[Technical solution: refers to the collection of technical measures taken by the applicant for the technical problems to be solved. Technical measures are usually embodied by technical characteristics. The technical scheme shall clearly and completely explain the shape and structural features of the utility model, explain how the technical scheme solves the technical problems, and explain the scientific principles on which the technical scheme is based when necessary. Mechanical products in the preparation of technical solutions, should describe the necessary parts and their overall structural relationship; For products involving circuits, the connection relationship of circuits shall be described; Mechanical and electrical products should also explain the combination relationship between circuit and mechanical part; When applying for distributed parameters, the mutual position relationship of components should be explained; When it comes to integrated circuits, the model and function of integrated circuits should be clearly disclosed. In this example, the structural features of the electric pen include the connection relationship between the mechanical structure and the circuit, so it is necessary to state the relationship between the main mechanical parts and their overall structure and the connection relationship of the circuit. The technical scheme can not only describe the principle, function, name, function or use of each component. ]
The utility model has the beneficial effects that when testing whether the tested object is charged or not, the safe voltage can be easily distinguished, and only the resistance element is adopted in the shunt branch, so that the structure is simple.
[Beneficial effects: Compared with the prior art, the utility model has the advantages and positive effects of inevitable technical effects directly brought by technical features or generated by technical features. ]
Brief description of drawings
The utility model will be further explained with the attached drawings and examples.
Fig. 1 is the circuit schematic diagram of the utility model.
Fig. 2 is a longitudinal structural view of the first embodiment of the electric probe.
Fig. 3 is a cross-sectional view I-I of fig. 2.
Fig. 4 is a longitudinal structural view of the second embodiment of the electric probe.
In the figure, 1. Test contact, 2. Insulating shell, 3. Spring, 4. Concentric resistor, 5. Current limiting resistance, 6. Shunt resistance, 7. Identification electrode, 8. Neon tube, 9. Spring, 10. Back cover, 1 1.
[Description of drawings: The name and number of each drawing shall be indicated, and each drawing shall be briefly described. If necessary, list the names of the parts shown in the figures. ]
expand on
In the figure 1, the test contact 1, the current limiting resistor 5 and the neon tube 8 are connected in series with the hand contact electrode 1 1, the test contact 1 is connected to one end of the shunt resistor 6, and the other end of the shunt resistor 6 is connected to the identification electrode 7. Usually, the resistance of current limiting resistor is several megaohms. In order to ensure personal safety, the resistance of the shunt resistor is not less than that of the current-limiting resistor, and it is better to take the resistance of the current-limiting resistor as 1-2 times.
In the embodiment shown in fig. 2, the test contact 1 extends into the cavity of the insulating housing 2 at one end and contacts the spring 3, while the other end of the spring 3 contacts the concentric resistor 4. The concentric resistor 4 has an E-shaped longitudinal section, in which the current limiting resistor 5 in the middle cylindrical part is higher than the current limiting resistor 5 in the circular pipe part as the shunt resistor 6, so that one end of the neon tube 8 does not contact the shunt resistor 6 when it contacts the current limiting resistor 5, and one end of the spring 9 contacts the neon tube 8 and the other end contacts the back cover 65433. As shown in fig. 3, the contact claw of the annular elastic metal sheet identification electrode 7 whose edge protrudes toward the center grasps the outer surface of the circular tubular shunt resistor 6, and its outer edge protrudes and is attached to the outer surface of the insulating housing.
In another embodiment shown in fig. 4, one end of the test probe 1 extends into the cavity of the insulating housing 2 and contacts with one end of the current limiting resistor 5 and the shunt resistor 6 arranged in parallel. The other end of the current limiting resistor is in electrical contact with the hand contact electrode 1 1 through the neon tube 8 and the spring 9, and the shunt resistor is in electrical contact with the identification electrode through the spring 13, and there is insulation between the two electrodes.
This is a preferred embodiment of the utility model. Detailed Description of the Invention The shape and structure of the utility model should be described with reference to the attached drawings, the implementation should be consistent with the technical scheme, and the technical features of the claims should be explained in detail to support the claims. The reference signs in the drawings should be written after the names of the corresponding parts, so that the technicians in the technical field can understand and realize them, and if necessary, the action process or operation steps should be explained. If there are multiple embodiments, each embodiment must be consistent with the technical problems to be solved by the utility model and its beneficial effects. ]
Illustrations with drawings (writing examples)