CN210720551U

CN210720551U - Test pencil

Info

Publication number: CN210720551U
Application number: CN201921286879.5U
Authority: CN
Inventors: 杨晓峰; 李发友
Original assignee: Dongguan Huabo Precision Measuring Instrument Technology Co ltd
Current assignee: Dongguan Huabo Precision Measuring Instrument Technology Co ltd
Priority date: 2019-08-08
Filing date: 2019-08-08
Publication date: 2020-06-09
Anticipated expiration: 2029-08-08

Abstract

The utility model discloses a test pencil, which comprises a pencil-shaped shell, a circuit board, a microcontroller, an induction unit and a display unit, wherein the circuit board is provided with an induction signal input point and a non-contact voltage signal acquisition module, and the circuit board is arranged in the pencil-shaped shell; the microcontroller is arranged on the circuit board, and the display unit is arranged on the pen-shaped shell and connected with the microcontroller; the induction unit comprises a screwdriver seat and a screwdriver rod, the screwdriver seat is arranged on the cover head of the pen-shaped shell, the screwdriver rod is arranged on the screwdriver seat and extends out of the cover head, the screwdriver seat and the screwdriver rod are used for being in conductive connection with the induction signal input point, and the end part of the screwdriver rod is provided with the screwdriver head; the display unit is used for displaying a voltage intensity mark corresponding to the acquired voltage to be detected so that a user can know the strength of the detection voltage of the current test pencil. The utility model discloses a test pencil has non-contact voltage and voltage measurement function and screwdriver function concurrently.

Description

Test pencil

Technical Field

The utility model relates to an electrical measurement field especially relates to a test pencil.

Background

The non-contact test pencil sold in the market at present does not usually have the function of a screwdriver, but the test pencil with the function of the screwdriver can usually only realize contact measurement and cannot realize non-contact voltage measurement, and the two test pencils have no way of realizing non-contact measurement and have the function of the screwdriver. In addition, the existing non-contact test pencil usually indicates whether the object to be tested is electrified or not by only lighting the indicator lamp, so that the intensity of the detection voltage cannot be intuitively known, and the use is not safe.

SUMMERY OF THE UTILITY MODEL

A primary object of the present invention is to provide a test pencil with non-contact voltage and voltage measuring function and screwdriver function.

In order to achieve the above object, the present invention provides a test pencil, which comprises a pencil-shaped housing, a circuit board, a microcontroller, an induction unit and a display unit, wherein the circuit board is provided with an induction signal input point and a non-contact voltage signal acquisition module, the circuit board is arranged in the pencil-shaped housing, and the induction unit is arranged at the front end of the pencil-shaped housing and contacts with the induction signal input point; the microcontroller is mounted on the circuit board, and the display unit is mounted on the pen-shaped housing and connected with the microcontroller;

the pen-shaped shell comprises a hollow pen body, a cover head arranged at the front end of the pen body and the circuit board arranged in the pen body of the pen-shaped shell;

the induction unit comprises a screw driver seat and a screw driver rod, the screw driver seat is arranged on the cover head, the screw driver rod is arranged on the screw driver seat and extends out of the cover head, the screw driver seat and the screw driver rod are used for being in conductive connection with the induction signal input point, and a screw driver head is arranged at the end part of the screw driver rod;

the non-contact voltage signal acquisition module is used for acquiring the voltage to be detected in a non-contact mode through the induction unit and outputting the acquired signal to the microcontroller;

the microcontroller is used for processing the signal input by the non-contact voltage signal acquisition module to acquire the size of the voltage to be detected and sending a corresponding control signal to the display unit according to the acquired size of the voltage to be detected;

and the display unit is used for displaying a voltage intensity identification corresponding to the acquired voltage to be detected according to the control signal so that a user can know the strength of the detection voltage of the current test pencil.

Preferably, the test pencil further comprises a pencil cap for covering the cap, the pencil cap being used for covering the screwdriver rod in the pencil cap when the pencil cap is arranged at the front end of the cap.

Preferably, the induction unit further comprises a flat induction sheet, a flat accommodating part is arranged at the outer end of the pen cap, the induction sheet is arranged in the accommodating part of the pen cap, and the induction sheet is used for conducting conductive connection with the screwdriver rod when the pen cap covers the cap head.

Preferably, a compression spring is connected to the sensing piece, and the compression spring is used for electrically connecting the sensing piece and the screwdriver rod when the pen cap covers the cap.

Preferably, the sensing piece is provided with a spring piece protruding towards one side of the sensing piece.

Preferably, the display unit adopts an LCD display screen or a nixie tube display screen, the voltage intensity marks are analog bars, and the display unit is used for displaying the analog bars with the number corresponding to the magnitude of the induced voltage according to the control signal; or

The voltage intensity mark is a voltage value, and the display unit is used for displaying the voltage value corresponding to the magnitude of the induction voltage according to the control signal.

Preferably, the screwdriver rod is detachably mounted on the screwdriver seat, and the screwdriver head is formed at one end of the screwdriver rod or formed at both ends of the screwdriver rod; or the screwdriver rod is fixed on the screwdriver seat in an undetachable manner, and the screwdriver head is formed at the outer end of the screwdriver rod.

Preferably, the head shape of the screwdriver head is a straight line, a cross, a Chinese character 'mi', a star shape, a square head, a hexagonal head or a Y shape.

Preferably, the circuit board is provided with a contact piece contacting with the induction signal input point, one side of the contact piece facing the screwdriver seat is provided with a contact spring, and the contact spring is used for being in conductive connection with the screwdriver seat of the induction unit.

Preferably, a blind hole is formed in one side, facing the contact spring, of the screwdriver seat, a magnetic suction block is arranged in the blind hole, and the contact spring is electrically connected with the screwdriver seat through the magnetic suction block.

The utility model provides a pair of test pencil has non-contact voltage and voltage measurement function and screwdriver function concurrently, and it is more convenient to use to come according to through setting up display element 55 the control signal shows with what acquireed waits to detect the corresponding voltage intensity sign of voltage magnitude, can supply the user to learn current test pencil measuring voltage's power more directly perceivedly.

Drawings

Fig. 1 is a schematic structural diagram of a preferred embodiment of the test pencil of the present invention.

Fig. 2 is an exploded view of the test pencil of fig. 1.

Fig. 3 is an exploded view of the test pencil of fig. 1 from another perspective.

Fig. 4 is a top view of the test pencil of fig. 1.

Fig. 5 is a cross-sectional view of the test pencil of fig. 1 taken along line a-a of fig. 4.

Fig. 6 is a cross-sectional view of the test pencil of fig. 1 taken along line B-B of fig. 4.

Fig. 7 is a schematic block diagram of the circuit of a preferred embodiment of the test pencil of the present invention.

Fig. 8-15 are schematic circuit diagrams of a preferred embodiment of the test pencil of the present invention, wherein fig. 8 shows a connection relationship between the microcontroller and each module, fig. 9 is a schematic circuit diagram of the non-contact voltage signal acquisition module, fig. 10 is a schematic circuit diagram of the key module, fig. 11 is a schematic circuit diagram of the power supply module, fig. 12 is a schematic circuit diagram of the function indicator module, fig. 13 is a schematic circuit diagram of the lighting lamp module, fig. 14 is a schematic circuit diagram of the dual-color backlight module, and fig. 15 is a schematic circuit diagram of the buzzer alarm module.

Fig. 16 is a first embodiment of the display unit of the test pencil of fig. 1.

In order to make the technical solution of the present invention clearer and more clear, the following detailed description will be made with reference to the accompanying drawings.

Detailed Description

Referring to fig. 1 to 7, the preferred embodiment of the present invention provides a test pencil, which includes a pen-shaped housing 51, a circuit board 52, a microcontroller U1, a sensing unit 54 and a display unit 55. The circuit board 52 is provided with an induction signal input point 520 and a non-contact voltage (NCV) signal acquisition module 521, the circuit board 52 is arranged in the pen-shaped housing 51, and the induction unit 54 is arranged at the front end of the pen-shaped housing 51 and is in contact with the induction signal input point 520; the microcontroller U1 is mounted on the circuit board 52 and the display unit 55 is mounted on the pen housing 51 and connected to the microcontroller U1.

In this embodiment, the pen-shaped housing 51 includes a hollow pen body 56, a cap 57 disposed at the front end of the pen body 56, and a battery cover 58 disposed at the rear end of the pen body 56, the circuit board 52 is disposed in the pen body 56 of the pen-shaped housing 51, and the sensing unit 54 is disposed on the cap 57 of the pen-shaped housing 51 and contacts with the sensing signal input point 520. The pen body 56 and the cap 57 may be made of an insulating material.

In this embodiment, the sensing unit 54 includes a screwdriver seat 541 and a screwdriver rod 542, the screwdriver seat 541 is installed on the cover 57, the screwdriver rod 542 is installed on the screwdriver seat 541 and extends out of the cover 57, and the screwdriver seat 541 and the screwdriver rod 542 are electrically connected to the sensing signal input point 520. The end part of the screwdriver rod is provided with a screwdriver bit. The screwdriver blade 541 and the screwdriver shaft 542 may be made of a conductive material, such as metal.

The non-contact voltage signal acquisition module 521 is configured to acquire a voltage to be detected through the sensing unit 54 in a non-contact manner, and output the acquired signal to the microcontroller U1;

the microcontroller U1 is configured to process a signal input by the non-contact voltage signal acquisition module 521 to obtain a voltage to be detected, and send a corresponding control signal to the display unit 55 according to the obtained voltage to be detected;

the display unit 55 is configured to display a voltage intensity identifier corresponding to the acquired voltage to be detected according to the control signal, so that a user can know the strength of the current voltage detected by the test pencil.

The utility model discloses test pencil has non-contact voltage and voltage measurement function and screwdriver function concurrently, and it is more convenient to use to come according to through setting up display element 55 control signal shows with the corresponding voltage intensity sign of the voltage size that waits to detect that acquires, can supply the user to learn current test pencil measuring voltage's power more directly perceivedly, can ensure user's personal safety to reach higher measurement accuracy.

An annular engaging groove 561 is formed in one end face, facing the cap 57, of the pen body 56, and the rear end of the cap 57 is inserted into the engaging groove of the pen body 56 and can be bonded together through gluing or ultrasonic welding. The battery cover 58 is connected with the rear end of the pen body 56 through threads.

The test pencil further comprises a pencil cap 61 for covering the cap 57, the pencil cap 61 being used for covering the screwdriver rod 542 inside the pencil cap 61 when the front end of the cap 57 is covered. The pen cap 61 can be made of an insulating material, so that the induction unit 54 can be protected in an insulating manner through the pen cap 61, the induction unit 54 is prevented from being in direct contact with an electrified object to be tested, the test pencil is prevented from being burnt due to misoperation, and the personal safety of a user is guaranteed.

In this embodiment, the outer surface of the front end of the cap 57 is formed with an external thread 571, the inner surface of the rear end of the cap 61 is correspondingly formed with an internal thread (not labeled), and the cap 61 is covered on the cap 57 without falling off by rotating the cap 61 to combine the internal thread of the cap 61 with the external thread of the cap 57.

The combination of the cap 61 and the cap 57 is not limited to this embodiment, and in other embodiments, other detachable connection manners may also be adopted, for example, a first fastening structure (e.g., a fastening block/fastening position) is provided on the cap 57, and a second fastening structure (e.g., a fastening position/fastening block) is correspondingly provided on the cap 61, and by inserting and/or rotating the cap 61, the second fastening structure of the cap 61 is combined with or separated from the first fastening structure of the cap 57, so as to cover the cap 61 on the cap 57 or remove the cap 61 from the cap 57.

In this embodiment, the sensing unit 54 further includes a flat sensing piece 543, the outer end of the pen cap 61 is provided with a flat receiving portion 611, the sensing piece 543 is disposed in the receiving portion 611 of the pen cap 61, and the sensing piece 543 is used for electrically connecting with the screwdriver rod 542 when the pen cap 61 covers the cap 57. Through the arrangement of the flat sensing piece 543 and the flat accommodating portion 611, when the socket is subjected to non-contact voltage measurement, the flat sensing piece 543 can be conveniently inserted into the jack of the socket, so that the sensing piece 543 is close to the wiring terminal of the socket as far as possible, and accuracy of the non-contact voltage measurement can be improved.

Further, a compression spring 544 is connected to the sensing piece 543, and the compression spring 544 is used for electrically connecting the sensing piece 543 and the screwdriver rod 542 when the pen cap 61 covers the cap 57. Through setting up compression spring 544, can be so that the electrically conductive connection between response piece 543 and screwdriver pole 542 is more reliable to improve non-contact voltage measurement's accuracy. In other embodiments, the compression spring 544 may not be disposed, and one end of the sensing piece 543 close to the screwdriver rod 542 is bent to form a spring sheet, so that the conductive connection between the sensing piece 543 and the screwdriver rod 542 is more reliable by the contact between the screwdriver rod 542 and the spring sheet.

Furthermore, the sensing piece 543 protrudes toward one side thereof with a spring 5431, and the sensing piece 543 can be tightly combined with the receiving portion 611 when inserted into the receiving portion 611 of the pen cap 61 by the spring 5431, and is not easily detached from the receiving portion 611.

Furthermore, the outer circumferential surface of the pen cap 61 is further provided with anti-slip protrusions 612, which can play a role of anti-slip when the pen cap 61 is rotated.

In this embodiment, the screwdriver rod 542 is detachably mounted on the screwdriver seat 541, two ends of the screwdriver rod 542 are respectively formed with

screwdriver bits

5421 and 5422, wherein one of the screwdriver bits 5421 has a straight head shape, and the other screwdriver bit 5422 has a cross head shape. The arrangement form of the screwdriver bit is not limited, and in other embodiments, the screwdriver bit may be formed at only one end of the screwdriver rod 542; the head shape of the screwdriver head can also be in a shape like Chinese character 'mi', star, square head, hexagonal head or Y shape; the heads of the screwdriver bits at the two ends of the screwdriver rod 542 may be the same, and the sizes of the heads may be the same or different. In other embodiments, the screwdriver rod 542 may be non-detachably mounted on the screwdriver seat 541.

The screwdriver holder 541 is provided with a mounting hole 5411, the mounting hole 5411 may be a polygonal hole or a flat hole, in this embodiment, the mounting hole 5411 is a regular hexagonal hole, and the cross section of the screwdriver rod 542 is matched with the mounting hole 5411 of the screwdriver holder 541 in shape, so that the screwdriver rod 542 can be prevented from rotating with respect to each other after being mounted in the mounting hole 5411 of the screwdriver holder 541.

In this embodiment, the circuit board 52 is provided with a contact sheet 62 contacting the sensing signal input point 520, a contact spring 63 is disposed on a side of the contact sheet 62 facing the screwdriver seat 541, and the contact spring 63 is used for electrically connecting with the sensing unit 54, specifically, electrically connecting with the screwdriver seat 541 of the sensing unit 54.

Further, a blind hole 5412 is formed in one side, facing the contact spring 527, of the screwdriver base 541, a magnetic attraction block 64 is arranged in the blind hole 5412, the contact spring 527 is in conductive connection with the screwdriver base 541 through the magnetic attraction block 64, and can attract the screwdriver rod 542 to prevent the screwdriver rod 542 from falling from the screwdriver base 541.

In this embodiment, a power supply module 526 is further disposed on the circuit board 52, and the power supply module 526 includes a battery BAT, and the battery BAT is disposed in the pen body to supply power to the entire test pencil.

In this embodiment, the circuit board 52 is further provided with a key module 527, and the key module 527 includes a power key PWKEY for controlling the on and off of the test pencil.

Further, the key module 527 further includes a sensitivity key SKEY, where the sensitivity key SKEY is used to switch the sensitivity range of the test pencil.

In this embodiment, a lighting lamp module 528 is further disposed on the circuit board 52, and the lighting lamp module 528 includes a lighting lamp LED2 for lighting, so as to be convenient for use in a dark environment. The illuminating lamp LED2 extends into the cover head 57, and the front end of the cover head 57 is provided with a light outlet window 572 corresponding to the illuminating lamp LED 2.

In this embodiment, the sensitivity key SKEY is also used to turn on and off the illumination lamp LED2, that is, the sensitivity key SKEY is a function multiplexing key, and when the function multiplexing key is implemented, the sensitivity range can be switched by a short press (for example, press time <1 second), and the switch of the illumination lamp LED2 can be controlled by a long press (for example, press time >2 seconds).

In this embodiment, a function indicator module 532 is further disposed on the circuit board 52, the function indicator module 532 includes a power indicator LED3 for indicating power on, and the power indicator LED3 is configured to light up when the power is on.

The display unit 55 may display the voltage intensity indication by using an LCD display screen, a nixie tube display screen or an LED lamp.

When the display unit 55 adopts an LCD display screen or a nixie tube display screen, the voltage strength identifier may be an analog bar, and the display unit 55 displays the analog bars corresponding to the magnitude of the induced voltage according to the control signal; the voltage strength indicator may also be a voltage value, and the display unit 55 is configured to display the voltage value corresponding to the magnitude of the induced voltage according to the control signal.

When the display unit 55 adopts LED lamps, a plurality of LED lamps of the same color may be adopted, and the voltage intensity is indicated as the number of the lit LED lamps, and the smaller the number of the lit LED lamps is, the smaller the voltage is indicated, and the larger the number of the lit LED lamps is, the larger the voltage is indicated; the LED lamp or the LED lamp group can emit multiple types (not less than two types) of voltage intensity marks, the color of the lighted LED lamp is identified, and the corresponding voltage intensity is represented by emitting different colors through the LED lamp or the LED lamp group. Of course, the voltage intensity indication can also be represented by a combination of the number and color of the lighted LED lamps.

In the present embodiment, the display unit 55 includes an LCD screen 551, and the outer surface of the LCD screen 551 is provided with a lens 65. The circuit board 52 is further provided with a dual-color backlight module 529, the dual-color backlight module 529 includes two light emitting diodes emitting different colors, i.e., a ninth light emitting diode LED9 and a tenth light emitting diode LED10 (see fig. 14), and the dual-color backlight module 529 can illuminate two backlights with different colors, such as a green backlight and a red backlight, for the LCD display 551, and of course, may also illuminate two backlights with other colors.

The lens 65 covers the area of the key module 527, and through holes 651 are respectively formed in the lens 65 corresponding to the keys (the power key PWKEY and the sensitivity key SKEY) of the key module 527 for the keys to pass through.

The display unit 55 is also used to display a letter and/or symbol (e.g., display "NCV") indicating the noncontact voltage measurement mode when in the noncontact voltage measurement mode.

The display unit 55 is further configured to display a battery BAT undervoltage sign to indicate that the battery BAT is undervoltage when the battery BAT is undervoltage.

In this embodiment, the circuit board 52 is further provided with a buzzer alarm module 530, the buzzer alarm module 530 includes a buzzer BUZ, the microcontroller U1 is further configured to control the buzzer BUZ to emit a frequency sound corresponding to the induced voltage according to the magnitude of the induced voltage,

in this embodiment, the buzzer alarm module 530 may further include a signal light LED1, and the microcontroller U1 is further configured to control the signal light LED1 to illuminate the brightness corresponding to the induced voltage or control the signal light LED1 to emit the flashing frequency corresponding to the induced voltage. In other embodiments, the buzzer warning module 530 may not be provided with the signal light LED 1.

In this embodiment, when the test pencil is used, all the indicator lamps of the function indicator lamp module 532 are turned on for a predetermined time (e.g., 0.5 second) by pressing the power key PWKEY when the test pencil is turned on, and then the test pencil enters a non-contact voltage (NCV) measurement mode after being turned on, and the two-color backlight module 529 turns on the green backlight of the LCD display 551; the LCD display 551 displays interface a as in fig. 16 (the actual backlight of interface a is green).

When a non-contact voltage (NCV) measurement mode is performed:

1. the buzzer BUZ prompts sound to be divided into three stages: slow speed prompt, medium speed prompt and fast prompt;

2. the sensitivity range comprises a high sensitivity range of 12V-1000V and a low sensitivity range of 48V-1000V.

When the measurement is carried out under the 12V-1000V high-sensitivity range, the 12V-1000V high-sensitivity measurement is divided into a plurality of sections, different colors of backlight of an LCD display screen 551 are lightened through a two-color backlight module 529, different levels of prompting sound is emitted through a buzzer BUZ, and/or different numbers of simulation bars are displayed through the LCD display screen 551 to represent the voltage section where the detection voltage is located, and a preferable example is given as follows:

a) when the detection voltage is less than 12V and less than 48V (in a first section interval), the two-color backlight module 529 lights the green backlight of the LCD display screen 551, the buzzer BUZ prompts slowly, the LCD display screen 551 displays an interface B (the actual backlight of the interface B is green) shown in FIG. 16, namely, analog bars with corresponding quantity are displayed to represent the detection voltage;

b) when the detection voltage is less than or equal to 48V and less than 90V (in a second section interval), the two-color backlight module 529 lights the green backlight of the LCD display screen 551, the buzzer BUZ prompts at a medium speed, and the LCD display screen 551 displays an interface C (the actual backlight of the interface C is green) shown in FIG. 16, namely, analog bars with corresponding quantity are displayed to represent the detection voltage;

c) when the voltage is not less than 90V (the third section interval), the two-color backlight module 529 lights the red backlight of the LCD display 551, the buzzer BUZ quickly prompts, and the LCD display 551 displays the interface D (the actual backlight of the interface D is red) as shown in fig. 16, that is, displays a corresponding number of analog bars to represent the detected voltage.

When measuring under 48V-1000V low sensitivity range, dividing 48V-1000V low sensitivity range into multi-segment interval, lighting up different color backlight of LCD display screen through two-color backlight module, sending out different grade prompting sound through buzzer BUZ, and/or displaying different number of analog bar to represent voltage interval of detecting voltage through LCD display screen, as following to give a preferred example:

d) when the detection voltage is less than 90V (in the first section interval) at 48V, the two-color backlight module 529 lights the green backlight of the LCD display screen 551, the buzzer BUZ prompts slowly, the LCD display screen 551 displays an interface B (the actual backlight of the interface B is green) in the figure 16, namely, analog bars with corresponding quantity are displayed to represent the detection voltage;

e) when the detection voltage is more than or equal to 90V and less than 150V (in the second section), the two-color backlight module 529 lights the green backlight of the LCD display screen 551, the buzzer BUZ prompts at a medium speed, and the LCD display screen 551 displays an interface C (the actual backlight of the interface C is green) as shown in FIG. 16;

f) when the detection voltage is not less than 150V (in the third section interval), the two-color backlight module 529 lights the red backlight of the LCD display screen 551, the buzzer BUZ prompts quickly, the LCD display screen 551 displays the interface D (the actual backlight of the interface D is green) shown in FIG. 16, that is, the simulation bars with corresponding quantity are displayed to represent the detection voltage.

In this embodiment, the threshold of the sensitivity segment is given as an example, and is not limited to this, and in the practical application process, the threshold may be adaptively adjusted according to specific needs.

Fig. 8-15 are schematic circuit diagrams of a preferred embodiment of the test pencil of the present invention, wherein fig. 8 shows a connection relationship between the microcontroller U1 and each module, fig. 9 is a schematic circuit diagram of the non-contact voltage signal acquisition module 521, fig. 10 is a schematic circuit diagram of the key module 527, fig. 11 is a schematic circuit diagram of the power supply module 526, fig. 12 is a schematic circuit diagram of the function indicator module 532, fig. 13 is a schematic circuit diagram of the lighting lamp module 528, fig. 14 is a schematic circuit diagram of the two-color backlight module 529, and fig. 15 is a schematic circuit diagram of the buzzer alarm module 530.

In the present embodiment, as shown in fig. 8, the model of the microcontroller U1 is preferably CS77P35, but not limited to this, and the microcontroller U1 may be other chips capable of implementing the same function. The model CS77P35 microcontroller U1 has 38 pins, each having the name shown in fig. 8.

The LCD screen 551 is connected with the 23 rd to 38 th pins of the microcontroller U1, and the display content of the LCD screen 551 is controlled by the microcontroller U1.

As shown in fig. 11, a schematic circuit diagram of the power supply module 526 is shown, and a specific example of the power supply module 526 is given in the schematic circuit diagram. Fig. 9 is a schematic circuit diagram of the non-contact voltage signal acquisition module 521. A specific example of the non-contact voltage signal acquisition module 521 is given in the schematic circuit diagram. Fig. 10 is a schematic circuit diagram of the key module 527, which shows a specific example of the key module 527. Fig. 12 is a schematic circuit diagram of the function indicator module 532, and a specific example of the function indicator module 532 is shown in the schematic circuit diagram. Fig. 13 shows a schematic circuit diagram of the illumination lamp module 528, which shows a specific example of the illumination lamp module 528. Fig. 14 shows a schematic circuit diagram of the dual-color backlight module 529, and a specific example of the dual-color backlight module 52 is shown in the schematic circuit diagram. Fig. 15 is a schematic circuit diagram of the buzzer alarm module 530, and a specific example of the buzzer alarm module 530 is shown in the schematic circuit diagram.

The circuit schematic diagrams of fig. 8-15 are only examples, the circuit structures of the non-contact voltage signal collection module 521, the contact voltage signal collection module 522, the phase sequence signal collection module 525, the key module 527, the power supply module 526, the function indicator lamp module 532, the two-color backlight module 529, and the buzzer alarm module 530 during actual use are not limited to this, components in each circuit can be adaptively added, deleted, and replaced as needed, as long as the functions of each module can be actually included in the protection scope of the present invention.

The above only is the preferred embodiment of the present invention, not limiting the scope of the present invention, all the equivalent structures or flow changes made by the contents of the specification and the drawings, or directly or indirectly applied to other related technical fields, are included in the same way in the protection scope of the present invention.

Claims

1. A test pencil is characterized by comprising a pencil-shaped shell, a circuit board, a microcontroller, an induction unit and a display unit, wherein the circuit board is provided with an induction signal input point and a non-contact voltage signal acquisition module, the circuit board is arranged in the pencil-shaped shell, and the induction unit is arranged at the front end of the pencil-shaped shell and is in contact with the induction signal input point; the microcontroller is mounted on the circuit board, and the display unit is mounted on the pen-shaped housing and connected with the microcontroller;

and the display unit is used for displaying a voltage intensity identifier corresponding to the acquired voltage to be detected according to the control signal so that a user can know the intensity of the detection voltage of the current test pencil.

2. The test pencil of claim 1 further comprising a cap for covering said cap, said cap for covering a front end of said cap to cover said screwdriver rod within said cap.

3. The test pencil of claim 2, wherein the sensing unit further comprises a flat sensing piece, the outer end of the pencil cap is provided with a flat receiving portion, the sensing piece is arranged in the receiving portion of the pencil cap, and the sensing piece is used for being in conductive connection with the screwdriver rod when the pencil cap covers the cap head.

4. The test pencil of claim 3 wherein a compression spring is attached to said sensor strip for conductively connecting said sensor strip to said screwdriver rod when said pencil cap is capped over said cap.

5. The test pencil of claim 4 wherein said sensor strip has a spring tab projecting toward one side thereof.

6. The test pencil of claim 1, wherein the display unit adopts an LCD display screen or a nixie tube display screen, the voltage intensity marks are analog bars, and the display unit is configured to display the number of analog bars corresponding to the voltage to be detected according to the control signal; or

The voltage intensity identification is a voltage value, and the display unit is used for displaying the voltage value corresponding to the voltage to be detected according to the control signal.

7. The test pencil of claim 1 wherein the screwdriver rod is detachably mounted on the screwdriver base, the screwdriver head being formed at one end or both ends of the screwdriver rod; or the screwdriver rod is fixed on the screwdriver seat in an undetachable manner, and the screwdriver head is formed at the outer end of the screwdriver rod.

8. The test pencil of claim 7 wherein the head shape of the screwdriver bit is a straight, cross, m, star, square, hex or Y shape.

9. The test pencil of claim 1 wherein the circuit board is provided with a contact piece for contacting the sensing signal input point, and a contact spring is provided on a side of the contact piece facing the screwdriver seat, the contact spring being adapted to be electrically connected to the screwdriver seat of the sensing unit.

10. The test pencil of claim 9 wherein a blind hole is formed on a side of the screwdriver seat facing the contact spring, a magnetic block is disposed in the blind hole, and the contact spring is electrically connected to the screwdriver seat through the magnetic block.