test pencil

Abstract

The invention discloses an electric test pen, comprising a pen-shaped housing, a circuit board, a microcontroller, a voltage measurement mode switching unit, a sensing unit, and a display unit. The circuit board is provided with a sensing signal input point, a non-contact voltage signal acquisition module, a contact voltage signal acquisition module, and a switching switch. The circuit board is arranged in the pen-shaped housing, the sensing unit is arranged at the front end of the pen-shaped housing and contacts the sensing signal input point; the microcontroller is mounted on the circuit board, the display unit is mounted on the pen-shaped housing and connected to the microcontroller; the voltage measurement mode switching unit is arranged on the pen-shaped housing, and is used to operate the switching switch to switch between the non-contact voltage measurement mode and the contact voltage measurement mode. The electric test pen of the invention has both non-contact voltage measurement and contact voltage measurement functions.

Description

Technical Field

[0001] The invention relates to the field of electrical measurement, in particular to an electrical test pencil. Background Art

[0002] The non-contact electric testers and contact electric testers currently sold on the market are two different categories of measuring electric testers. Since the non-contact electric tester is directly isolated from electricity, the human body will not be electrocuted, which is relatively safe, but it can only measure the approximate AC voltage, while the contact electric tester uses contact to measure voltage, which reduces the current through a large resistor and uses the human body as a grounding conductor to measure the voltage. This will cause the risk of direct electric shock to the human body. Therefore, in general, some electricians will buy these two types of electric testers, first use the non-contact electric tester to determine the strength of the wire or socket, and then use the contact electric tester to measure the voltage of the charged body according to the situation. This will increase the purchase cost. If you forget to bring one of the pens, you cannot conveniently measure the voltage, which is not very convenient to use. Summary of the invention

[0003] The main purpose of the present invention is to provide an electric tester with both non-contact voltage measurement and contact voltage measurement functions.

[0004] In order to achieve the above-mentioned object, the present invention provides an electric test pen, which includes a pen-shaped housing, a circuit board, a microcontroller, a voltage measurement mode switching unit, a sensing unit, and a display unit. The circuit board is provided with a sensing signal input point, a non-contact voltage signal acquisition module, a contact voltage signal acquisition module, and a switch. The circuit board is arranged in the pen-shaped housing, and the sensing unit is arranged at the front end of the pen-shaped housing and contacts the sensing signal input point; the microcontroller is installed on the circuit board, and the display unit is installed on the pen-shaped housing and connected to the microcontroller;

[0005] The voltage measurement mode switching unit is provided on the pen-shaped housing and is used to operate the switch to switch between the non-contact voltage measurement mode and the contact voltage measurement mode;

[0006] The non-contact voltage signal acquisition module is used to acquire the voltage to be detected in a non-contact manner through the sensing unit in a non-contact voltage measurement mode, and output the acquired signal to the microcontroller;

[0007] The contact voltage signal acquisition module is used to acquire the voltage to be detected in a contact manner through the sensing unit in a contact voltage measurement mode, and output the acquired signal to the microcontroller;

[0008] The microcontroller is used to process the signal input by the non-contact voltage signal acquisition module / contact voltage signal acquisition module to obtain the magnitude of the voltage to be detected, and send a corresponding first control signal to the display unit according to the obtained magnitude of the voltage to be detected;

[0009] The display unit is used to display a voltage strength mark corresponding to the acquired voltage to be detected according to the first control signal, so that the user can know the strength of the voltage currently detected by the voltage tester.

[0010] Preferably, the pen-shaped shell includes a hollow pen body and a cover arranged at the front end of the pen body, the circuit board is arranged in the pen body of the pen-shaped shell, and the sensing unit is arranged on the cover of the pen-shaped shell and contacts the sensing signal input point.

[0011] Preferably, the switching switch is a touch switch, and the touch switch is turned on by pressing the touch switch through the voltage measurement mode switching unit, and is turned off by releasing it.

[0012] Preferably, the voltage measurement mode switching unit includes a sliding rod and a pressing sheet, a first through hole is provided on the pen-shaped housing corresponding to the outer end of the sliding rod, and a second through hole is provided on the pressing sheet corresponding to the inner end of the sliding rod, the outer end of the sliding rod passes through the first through hole to extend out of the pen-shaped housing, and the inner end of the sliding rod passes through the second through hole to be used for pressing the touch switch, and the sliding rod is installed on the pen-shaped housing through the pressing sheet so that the sliding rod can slide in the first through hole and the second through hole.

[0013] Preferably, the first through hole is arranged on the front end plate of the cover, the sliding rod is installed on the inner side of the front end plate of the cover through the pressing sheet, and the outer end of the sliding rod extends outward from the front end plate of the cover, and the voltage tester also includes a pen cap for covering the cover, and the pen cap is used to press the outer end of the sliding rod when it is covered on the front end of the cover, so that the inner end of the sliding rod moves toward the touch switch to press the touch switch, and the touch switch is turned on after being pressed, and switched to the non-contact voltage measurement mode, and when the pen cap is removed from the cover, the force on the outer end of the sliding rod is removed, and the touch switch returns to the disconnected state under the action of its own elastic force, and switches to the contact voltage measurement mode.

[0014] Preferably, a convex ring is formed in the middle of the sliding rod, and the convex ring is clamped between the front end plate of the cover head and the pressing sheet to limit the sliding stroke of the sliding rod.

[0015] Preferably, the sensing unit includes a screwdriver holder and a screwdriver rod, the screwdriver holder is mounted on the cover, the screwdriver rod is mounted on the screwdriver holder and extends outward from the cover, and when the pen cap is covered on the cover, it is also used to cover the screwdriver rod in the pen cap, and the screwdriver holder and the screwdriver rod are used to be conductively connected to the sensing signal input point.

[0016] Preferably, the sensing unit also includes a flat sensing piece, a flat receiving portion is provided at the outer end of the pen cap, the sensing piece is provided in the receiving portion of the pen cap, the sensing piece is used to be conductively connected to the screwdriver rod when the pen cap is covered on the cover head, a compression spring is connected to the sensing piece, and the compression spring is used to conductively connect the sensing piece to the screwdriver rod when the pen cap is covered on the cover head.

[0017] Preferably, the screwdriver rod is detachably mounted on the screwdriver seat, a screwdriver head is formed at one end of the screwdriver rod or at both ends of the screwdriver rod, or the screwdriver rod is non-detachably fixed to the screwdriver seat.

[0018] Preferably, the head shape of the screwdriver head is a flat head, a cross head, a Pozidriv head, a star head, a square head, a hexagonal head or a Y-type head.

[0019] Preferably, a contact sheet contacting the sensing signal input point is provided on the circuit board, and a contact spring is provided on the side of the contact sheet facing the screwdriver seat, and the contact spring is used for conductive connection with the screwdriver seat of the sensing unit.

[0020] Preferably, a blind hole is formed on a side of the screwdriver seat facing the contact spring, a magnetic block is provided in the blind hole, and the contact spring is conductively connected to the screwdriver seat via the magnetic block.

[0021] Preferably, a key module is also provided on the circuit board, and the key module includes a power key and a sensitivity key, wherein the power key is used to control the turning on and off of the electric test pen, and the sensitivity key is used to switch the sensitivity range of the electric test pen.

[0022] Preferably, a lighting module is also provided on the circuit board, and the lighting module includes a lighting lamp for lighting, and the lighting lamp extends into the cover head. A light exit window is provided at the front end of the cover head corresponding to the lighting lamp, and the sensitivity key SKEY is also used to turn on and off the lighting lamp.

[0023] Preferably, a function indicator light module is further provided on the circuit board, and the function indicator light module includes a power indicator light indicating that the power is turned on, and the power indicator light is used to light up when the power is turned on.

[0024] Preferably, the display unit uses an LCD display screen, a digital tube or an LED light to display the voltage intensity mark.

[0025] Preferably, the voltage strength indicator is an analog bar, and the display unit displays an analog bar whose number corresponds to the magnitude of the induced voltage according to the first control signal; or the voltage strength indicator is a voltage numerical value.

[0026] Preferably, the display unit indicates the voltage intensity identifier by lighting up the number of LED lamps and / or lighting up LED lamps of different colors according to the first control signal.

[0027] Preferably, the display unit includes an LCD display screen, and the circuit board is also provided with a dual-color backlight module, which includes two light-emitting diodes that emit different colors respectively, for lighting two different colors of backlight for the LCD display screen.

[0028] Preferably, the display unit is used to display corresponding text and / or symbols in the non-contact voltage measurement mode, to display corresponding text and / or symbols in the contact voltage measurement mode, and / or to display a battery undervoltage symbol when the battery is undervoltage.

[0029] Preferably, a buzzer alarm module is also provided on the circuit board, and the buzzer alarm module includes a buzzer. The microcontroller is also used to control the buzzer to emit a frequency sound corresponding to the induced voltage according to the size of the induced voltage. The buzzer alarm module further includes a signal light, and the microcontroller is also used to control the signal light to light up at a brightness corresponding to the induced voltage, or control the signal light to emit a flashing frequency corresponding to the induced voltage.

[0030] Preferably, the sensitivity range of the non-contact voltage measurement mode includes a high sensitivity range of 12V to 1000V and a low sensitivity range of 48V to 1000V.

[0031] Preferably, the sensitivity range of the non-contact voltage measurement mode includes a high sensitivity range of 12V to 1000V and a low sensitivity range of 48V to 1000V. When measuring under the high sensitivity range of 12V to 1000V, the high sensitivity range of 12V to 1000V is divided into multiple intervals, and the different color backlights of the LCD display are lit by the dual-color backlight module, different levels of prompt sounds are emitted by the buzzer BUZ, and / or different numbers of analog bars are displayed on the LCD display to indicate the voltage interval in which the detection voltage is located;

[0032] When measuring in the 48V-1000V low sensitivity range, the 48V-1000V low sensitivity range is divided into multiple intervals, and different color backlights of the LCD display are lit by the dual-color backlight module, different levels of prompt sounds are emitted by the buzzer BUZ, and / or different numbers of analog bars are displayed on the LCD display to indicate the voltage interval in which the detection voltage is located;

[0033] Preferably, when measuring in the contact voltage measurement mode, the voltage detection range is 12 to 250 V, and the voltage detection range is divided into multiple intervals. The different color backlights of the LCD display are lit by the dual-color backlight module, and / or different numerical values ​​are displayed on the LCD display to indicate the voltage interval in which the detection voltage is located.

[0034] Preferably, a lighting module is further provided on the circuit board, and the lighting module includes a lighting lamp for lighting, and the lighting lamp extends into the cover head, and a light exit window is provided at the front end of the cover head corresponding to the lighting lamp.

[0035] Preferably, the switching switch is a toggle switch, and the voltage measurement mode switching unit includes a toggle key arranged on the pen body, and the toggle key is used to operate the toggle switch to switch between the non-contact voltage measurement mode and the contact voltage measurement mode.

[0036] Preferably, a phase sequence signal acquisition module and a key module are further provided on the circuit board. The key module includes a function switch key FUNC. The function switch key FUNC is used to switch between a non-contact voltage measurement mode and a non-contact phase sequence measurement mode.

[0037] Preferably, a function indicator light module is further provided on the circuit board, and the function indicator light module includes a phase sequence indicator light indicating a non-contact phase sequence measurement mode, and the phase sequence indicator light is lit when switching to the non-contact phase sequence measurement mode.

[0038] Preferably, the phase sequence signal acquisition module is used to acquire the phase sequence of the three-phase line to be detected in a non-contact manner through the sensing unit in a non-contact phase sequence measurement mode, and output the acquired signal to the microcontroller;

[0039] The microcontroller is also used to process the signal input by the phase sequence signal acquisition module to obtain a phase sequence detection result, and send a corresponding second control signal to the display unit according to the phase sequence detection result;

[0040] The display unit is used to display the phase sequence detection result accordingly according to the second control signal.

[0041] Preferably, the display unit is further used to display corresponding text and / or symbols in the non-contact phase sequence measurement mode; and / or

[0042] The display unit is also used to display a right-handed symbol in the measurement result to indicate a positive phase sequence, and to display a left-handed symbol in the measurement result to indicate a negative phase sequence.

[0043] Preferably, the display unit includes an LCD display screen, and the circuit board is also provided with a dual-color backlight module, which includes two light-emitting diodes that emit different colors respectively. The dual-color backlight module is used to light up different color backlights of the LCD display screen to respectively indicate the positive phase sequence and the reverse phase sequence when displaying the phase sequence measurement results.

[0044] The electric test pen proposed by the present invention can realize both non-contact measurement of voltage and contact measurement of voltage by setting a non-contact voltage signal acquisition module, a contact voltage signal acquisition module and a switching switch. Only one electric test pen is needed to be carried, and the non-contact measurement of voltage and the contact measurement of voltage can be realized. The electric test pen is convenient to carry and use. When measuring voltage, non-contact measurement can be selected first, and contact measurement can be adopted when it is determined that the voltage is within a safe range, so that the personal safety of the user can be guaranteed and a higher measurement accuracy can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a structural schematic diagram of a preferred embodiment of the electric test pencil of the present invention.

[0046] Figure 2 yes Figure 1 The exploded diagram of the electric tester is shown.

[0047] Figure 3 yes Figure 1 The schematic diagram of the electric tester shown is an exploded view from another perspective.

[0048] Figure 4 yes Figure 1 Top view of the voltage tester shown.

[0049] Figure 5 yes Figure 1 The test pencil shown is along Figure 4 Section view along line AA.

[0050] Figure 6 yes Figure 1 The test pencil shown is along Figure 4 Cross-sectional view along line BB.

[0051] Figure 7 It is a circuit principle block diagram of a preferred embodiment of the electric tester of the present invention.

[0052] Figure 8-Figure 15 This is a circuit diagram of a preferred embodiment of the electric tester of the present invention, wherein: Figure 8 It shows the connection relationship between the microcontroller and each module. Fig. 9It is the circuit schematic diagram of the non-contact voltage signal acquisition module, the contact voltage signal acquisition module and the phase sequence signal acquisition module. Fig.10 This is the circuit schematic diagram of the key module. Fig.11 This is the circuit schematic diagram of the power supply module. Fig.12 This is the circuit schematic diagram of the function indicator light module. Fig.13 This is the circuit schematic diagram of the lighting module. Fig.14 This is the circuit schematic diagram of the dual-color backlight module. Fig.15 This is the circuit schematic diagram of the buzzer alarm module.

[0053] Fig.16 yes Figure 1 The first embodiment of the display content of the display unit of the test pencil is shown.

[0054] Fig.17 yes Figure 1 The second embodiment of the display content of the display unit of the test pencil is shown.

[0055] Fig.18 yes Figure 1 The third embodiment of the display content of the display unit of the test pencil is shown.

[0056] In order to make the technical solution of the present invention clearer and more understandable, it will be further described in detail below with reference to the accompanying drawings. DETAILED DESCRIPTION

[0057] Reference Figures 1 to 7 The preferred embodiment of the present invention provides an electric test pen, which includes a pen-shaped housing 51, a circuit board 52, a microcontroller U1, a voltage measurement mode switching unit 53, a sensing unit 54, and a display unit 55. The circuit board 52 is provided with a sensing signal input point 520, a non-contact voltage (NCV) signal acquisition module 521, a contact voltage (CVT) signal acquisition module 522, and a switch SW1. The circuit board 52 is arranged in the pen-shaped housing 51, and the sensing unit 54 is arranged at the front end of the pen-shaped housing 51 and contacts the sensing signal input point 520; the microcontroller U1 is installed on the circuit board 52, and the display unit 55 is installed on the pen-shaped housing 51 and connected to the microcontroller U1.

[0058] The voltage measurement mode switching unit 53 is provided on the pen-shaped housing 51 and is used to operate the switch SW1 to switch between the non-contact voltage measurement mode and the contact voltage measurement mode;

[0059] The non-contact voltage signal acquisition module 521 is used to acquire the voltage to be detected in a non-contact manner through the sensing unit 54 in a non-contact voltage measurement mode, and output the acquired signal to the microcontroller U1;

[0060] The contact voltage signal acquisition module 522 is used to acquire the voltage to be detected in a contact manner through the sensing unit 54 in the contact voltage measurement mode, and output the acquired signal to the microcontroller U1;

[0061] The microcontroller U1 is used to process the signal input by the non-contact voltage signal acquisition module 521 / contact voltage signal acquisition module 522 to obtain the magnitude of the voltage to be detected, and send a corresponding first control signal to the display unit 55 according to the magnitude of the voltage to be detected;

[0062] The display unit 55 is used to display a voltage strength mark corresponding to the acquired voltage to be detected according to the first control signal, so that the user can know the strength of the voltage currently detected by the voltage tester.

[0063] The electric tester of the embodiment of the present invention, by providing a non-contact voltage (NCV) signal acquisition module 521, a contact voltage (CVT) signal acquisition module 522 and a switching switch SW1, only needs to carry one electric tester, which can realize both non-contact measurement of voltage and contact measurement of voltage, and is convenient to carry and use. When measuring voltage, non-contact measurement can be selected first, and contact measurement can be used when it is determined that the voltage is within a safe range, which can ensure the personal safety of the user and achieve a higher measurement accuracy.

[0064] In this embodiment, the pen-shaped housing 51 includes a hollow pen body 56, a cover 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. The sensing unit 54 is disposed on the cover 57 of the pen-shaped housing 51 and contacts the sensing signal input point 520. The pen body 56 and the cover 57 can both be made of insulating materials.

[0065] The pen body 56 has an annular engagement groove 561 on one end thereof facing the cap 57. The rear end of the cap 57 is inserted into the engagement groove of the pen body 56 and can be combined together by gluing or ultrasonic welding. The battery cover 58 is connected to the rear end of the pen body 56 by screw threads.

[0066] In this embodiment, the switch SW1 is a touch switch, and the touch switch (switch SW1) is turned on by pressing the touch switch (switch SW1) through the voltage measurement mode switching unit 53, and is turned off by releasing it.

[0067] The voltage measurement mode switching unit 53 includes a sliding rod 59 and a pressing piece 60. A first through hole 511 is provided on the pen-shaped housing 51 corresponding to the outer end of the sliding rod 59, and a second through hole 601 is provided on the pressing piece 60 corresponding to the inner end of the sliding rod 59. The outer end of the sliding rod 59 passes through the first through hole 511 to extend out of the pen-shaped housing 51, and the inner end of the sliding rod 59 passes through the second through hole 601 to press the touch switch (switching switch SW1). The sliding rod 59 is installed on the pen-shaped housing 51 through the pressing piece 60 so that the sliding rod 59 can slide in the first through hole 511 and the second through hole 601.

[0068] In this embodiment, the first through hole 511 is provided on the front end plate of the cover 57, the sliding rod 59 is installed on the inner side of the front end plate of the cover 57 through the pressing sheet 60, and the outer end of the sliding rod 59 extends outward from the front end plate of the cover 57. The test pen also includes a cap 61 for covering the cover 57. When the cap 61 covers the front end of the cover 57, it is used to press the outer end of the sliding rod 59, so that the inner end of the sliding rod 59 moves toward the touch switch (switching switch SW1) and presses the touch switch (switching switch SW1). After being pressed, the touch switch (switching switch SW1) is turned on and switched to the non-contact voltage measurement mode. When the cap 61 is removed from the cover 57, the force acting on the outer end of the sliding rod 59 is removed, and the touch switch (switching switch SW1) returns to the disconnected state under the action of its own elastic force and switches to the contact voltage measurement mode.

[0069] The pen cap 61 is covered on the front end of the cover head 57 to realize pressing the touch switch (switching switch SW1) to switch to the non-contact voltage measurement mode. The pen cap 61 can be made of insulating material. In this way, in the non-contact voltage measurement mode, the pen cap 61 can be used to insulate the sensing unit 54 to avoid direct contact between the sensing unit 54 and the charged object to be measured, prevent the burning of the test pen due to misoperation, and ensure the personal safety of the user.

[0070] When the switch SW1 is a touch switch, the operation of pressing the touch switch (switch SW1) of the voltage measurement mode switching unit 53 is not limited to the method of pressing the pen cap 61 in this embodiment. In other embodiments, the first through hole 511 can also be set on the pen body 56 of the pen-shaped housing 51. In this case, it is necessary to adjust the installation direction of the sliding rod 59 accordingly, and install the sliding rod 59 on the pen body 56 through the pressing piece 60. In this way, the user can press the sliding rod 59 by hand to press the touch switch (switch SW1) to switch on and switch to the non-contact voltage measurement mode. When the hand is released, the touch switch (switch SW1) is reset and disconnected, and switched to the contact voltage measurement mode; or a button is set on the pen body 56 of the pen-shaped housing 51 corresponding to the sliding rod 59, and the touch switch (switch SW1) is pressed by pressing the button to press the sliding rod 59 to switch on and switch to the non-contact voltage measurement mode. When the hand is released, the touch switch (switch SW1) is reset and disconnected, and switched to the contact voltage measurement mode. When the pen cap 61 is not used to press the touch switch (switching switch SW1), the pen cap 61 can be retained or removed.

[0071] The switch SW1 is not limited to a touch switch. In other embodiments, other types of switches, such as a toggle switch, may be used. In this case, the voltage measurement mode switching unit 53 may be replaced by a toggle key, which may be provided on the pen body 56. By operating the toggle key, the toggle switch (switch SW1) may be controlled to be turned on and off, thereby switching between the non-contact voltage measurement mode and the contact voltage measurement mode. In this case, the pen cap 61 may be retained or removed.

[0072] In this embodiment, an external thread 571 is formed on the outer surface of the front end of the cap 57, and an internal thread (not marked) is correspondingly formed on the inner surface of the rear end of the pen cap 61. By rotating the pen cap 61, the internal thread of the pen cap 61 is combined with the external thread of the cap 57, so that the pen cap 61 is covered on the cap 57 without falling off freely.

[0073] The combination method of the pen cap 61 and the cover head 57 is not limited to the present embodiment. In other embodiments, other detachable connection methods may be adopted. For example, a first snap-fit ​​structure (e.g., a snap block / snap position) is provided on the cover head 57, and a second snap-fit ​​structure (e.g., a snap position / snap block) is correspondingly provided on the pen cap 61 to match it. By plugging and / or rotating the pen cap 61, the second snap-fit ​​structure of the pen cap 61 can interact with or disengage from the first snap-fit ​​structure of the cover head 57, so that the pen cap 61 can be covered on the cover head 57 or the pen cap 61 can be removed from the cover head 57.

[0074] In this embodiment, further, a convex ring 591 is formed in the middle portion of the sliding rod 59, and the convex ring 591 is clamped between the front end plate of the cover head 57 and the pressing plate 60 to limit the sliding stroke of the sliding rod 59, so as to prevent the sliding rod 59 from falling off from the first through hole 511 and the second through hole 601, and prevent the sliding rod 59 from excessively pressing the touch switch (switching switch SW1) and damaging the touch switch (switching switch SW1).

[0075] In this embodiment, the sensing unit 54 includes a screwdriver seat 541 and a screwdriver rod 542, wherein the screwdriver seat 541 is mounted on the cover 57, and the screwdriver rod 542 is mounted on the screwdriver seat 541 and extends outward from the cover 57. When the pen cap 61 is covered on the cover 57, it is also used to cover the screwdriver rod 542 in the pen cap 61. The screwdriver seat 541 and the screwdriver rod 542 are used to be conductively connected to the sensing signal input point 520. The screwdriver seat 541 and the screwdriver rod 542 can both be made of conductive materials such as metal.

[0076] In this embodiment, the sensing unit 54 further includes a flat sensing piece 543. A flat receiving portion 611 is provided at the outer end of the pen cap 61. The sensing piece 543 is provided in the receiving portion 611 of the pen cap 61. The sensing piece 543 is used to be electrically connected to the screwdriver rod 542 when the pen cap 61 is covered on the cover head 57. By providing the flat sensing piece 543 and the flat receiving portion 611, when performing non-contact voltage measurement on the socket, it can be conveniently inserted into the socket jack, so that the sensing piece 543 is as close to the wiring terminal of the socket as possible, which can improve the accuracy of non-contact voltage measurement.

[0077] Furthermore, a compression spring 544 is connected to the sensing piece 543, and the compression spring 544 is used to electrically connect the sensing piece 543 to the screwdriver rod 542 when the pen cap 61 is covered on the cover head 57. By providing the compression spring 544, the electrically conductive connection between the sensing piece 543 and the screwdriver rod 542 can be made more reliable, so as to improve the accuracy of non-contact voltage measurement. In other embodiments, the compression spring 544 may not be provided, and an end of the sensing piece 543 close to the screwdriver rod 542 may be bent to form a spring sheet, and the screwdriver rod 542 may contact the spring sheet to make the electrically conductive connection between the sensing piece 543 and the screwdriver rod 542 more reliable.

[0078] Furthermore, the sensing piece 543 has a spring piece 5431 protruding toward one side thereof. The spring piece 5431 can make the sensing piece 543 more tightly combined with the receiving portion 611 when inserted into the receiving portion 611 of the pen cap 61, and is not easy to fall off from the receiving portion 611.

[0079] Furthermore, the outer peripheral surface of the pen cap 61 is provided with an anti-skid protrusion 612 , which can play an anti-skid role when the pen cap 61 is rotated.

[0080] In this embodiment, the screwdriver rod 542 is detachably mounted on the screwdriver seat 541, and screwdriver heads 5421 and 5422 are formed at both ends of the screwdriver rod 542, respectively. The head shape of one screwdriver head 5421 is a flat head, and the head shape of the other screwdriver head 5422 is a cross head. The arrangement of the screwdriver head is not limited to this. In other embodiments, the screwdriver rod 542 may have a screwdriver head formed on only one end; the head shape of the screwdriver head may also be other shapes such as a Pozidrivium, a star, a square head, a hexagonal head or a Y-shaped head; the head shapes of the screwdriver heads at both ends of the screwdriver rod 542 may also be the same, and the model and size may be the same or different. In other embodiments, the screwdriver rod 542 may also be non-detachably mounted on the screwdriver seat 541.

[0081] The screwdriver seat 541 is provided with a mounting hole 5411, and the mounting hole 5411 may be a polygonal hole or a flat hole. In the present embodiment, the mounting hole 5411 is a regular hexagonal hole. The cross-sectional shape of the screwdriver rod 542 matches the shape of the mounting hole 5411 of the screwdriver seat 541. Thus, the screwdriver rod 542 can be prevented from rotating relative to each other after being inserted into the mounting hole 5411 of the screwdriver seat 541.

[0082] In this embodiment, a contact piece 62 in contact with the sensing signal input point 520 is provided on the circuit board 52, and a contact spring 63 is provided on the side of the contact piece 62 facing the screwdriver seat 541. The contact spring 63 is used to be conductively connected to the sensing unit 54, specifically to be conductively connected to the screwdriver seat 541 of the sensing unit 54.

[0083] Furthermore, a blind hole 5412 is formed on one side of the screwdriver seat 541 facing the contact spring 527, and a magnetic block 64 is provided in the blind hole 5412. The contact spring 527 is conductively connected to the screwdriver seat 541 through the magnetic block 64, and can attract the screwdriver rod 542 to prevent the screwdriver rod 542 from falling from the screwdriver seat 541.

[0084] In this embodiment, a power supply module 526 is further disposed on the circuit board 52 . The power supply module 526 includes a battery BAT. The battery BAT is disposed in the pen body to supply power to the entire test pen.

[0085] In this embodiment, a key module 527 is further provided on the circuit board 52. The key module 527 includes a power key PWKEY. The power key PWKEY is used to control the turning on and off of the tester.

[0086] Furthermore, the button module 527 also includes a sensitivity key SKEY, and the sensitivity key SKEY is used to switch the sensitivity range of the electric tester.

[0087] In this embodiment, the circuit board 52 is further provided with a lighting module 528, and the lighting module 528 includes a lighting LED 2 for lighting, so as to facilitate use in a dark environment. The lighting LED 2 extends into the cover 57, and a light exit window 572 is provided at the front end of the cover 57 corresponding to the lighting LED 2.

[0088] In this embodiment, the sensitivity key SKEY is also used to turn on and off the lighting lamp LED2, that is, the sensitivity key SKEY is a function-multiplexing key. In specific implementation, the sensitivity range can be switched by a short press (for example, pressing time <1 second), and the lighting lamp LED2 can be turned on and off by a long press (for example, pressing time >2 seconds).

[0089] In this embodiment, a function indicator light module 532 is further provided on the circuit board 52. The function indicator light module 532 includes a power indicator light LED 3 indicating that the power is turned on. The power indicator light LED 3 is used to light up when the power is turned on.

[0090] The display unit 55 may use an LCD display screen, a digital tube or an LED light to display the voltage intensity mark.

[0091] When the display unit 55 uses an LCD display screen or a digital tube, the voltage strength mark can be an analog bar, and the display unit 55 displays an analog bar of a number corresponding to the magnitude of the induced voltage according to the first control signal; the voltage strength mark can also be a voltage value.

[0092] When the display unit 55 uses LED lights, multiple LED lights of the same color can be used, and the voltage strength indicator is the number of LED lights that are lit. The fewer the number of LED lights that are lit, the smaller the voltage, and the more the number of LED lights that are lit, the greater the voltage. It can also be that a LED light or LED light group that can emit multiple (no less than two) colors is used, and the voltage strength indicator is the color of the LED lights that are lit, and the LED lights or LED light groups emit different colors to indicate the corresponding voltage strength. Of course, the voltage strength indicator can also be indicated by a combination of the number and color of the LED lights that are lit.

[0093] In this embodiment, the display unit 55 includes an LCD display screen 551, and a lens 65 is provided on the outer surface of the LCD display screen 551. A dual-color backlight module 529 is also provided on the circuit board 52. The dual-color backlight module 529 includes two light-emitting diodes that emit different colors, namely, a ninth light-emitting diode LED9 and a tenth light-emitting diode LED10. The dual-color backlight module 529 can light up two different colors of backlight for the LCD display screen 551, such as a green backlight and a red backlight. Of course, two backlights of other colors can also be used.

[0094] The lens 65 covers the key module 527 area, and the lens 65 is provided with through holes 651 corresponding to each key of the key module 527 (power key PWKEY, sensitivity key SKEY, function switch key FUNC) for each key to pass through.

[0095] The display unit 55 is also used to display corresponding text and / or symbols (for example, display “NCV”) in the non-contact voltage measurement mode, and to display corresponding text and / or symbols (for example, display “CVT”) in the contact voltage measurement mode.

[0096] The display unit 55 is further used to display a battery BAT undervoltage symbol to prompt the battery BAT undervoltage when the battery BAT is undervoltage.

[0097] In this embodiment, the circuit board 52 is further provided with a buzzer alarm module 530, and the buzzer alarm module 530 includes a buzzer BUZ. The microcontroller U1 is also used to control the buzzer to emit a frequency sound corresponding to the induced voltage according to the magnitude of the induced voltage.

[0098] In this embodiment, the buzzer alarm module 530 may further include a signal light LED1, and the microcontroller U1 is further used to control the signal light LED1 to light up at a brightness corresponding to the induced voltage or to control the signal light LED1 to emit a flashing frequency corresponding to the induced voltage. In other embodiments, the buzzer alarm module 530 may not be provided with a signal light LED1.

[0099] In this embodiment, when the test pen is in use, all the indicators of the function indicator module 532 are lit for a predetermined time (e.g., 0.5 seconds) by pressing the power key PWKEY to turn on the test pen, and then the test pen enters the non-contact voltage (NCV) measurement mode, and the two-color backlight module 529 turns on the green backlight of the LCD display screen 551; the LCD display screen 551 displays as follows: Fig.16 Interface A in (the actual backlight of interface A is green).

[0100] When measuring in non-contact voltage (NCV) measurement mode:

[0101] 1. The buzzer BUZ prompt sound is divided into three levels: slow prompt, medium prompt, and fast prompt;

[0102] 2. The sensitivity range includes 12V~1000V high sensitivity range and 48V~1000V low sensitivity range.

[0103] When measuring in the 12V-1000V high sensitivity range, the 12V-1000V high sensitivity value is divided into multiple intervals, and the two-color backlight module 529 lights up the different color backlights of the LCD display screen 551, the buzzer BUZ emits different levels of prompt sounds, and / or the LCD display screen 551 displays different numbers of analog bars to indicate the voltage interval in which the detection voltage is located. A preferred example is given below:

[0104] a) When 12V<detection voltage<48V (first section), the dual-color backlight module 529 lights up the green backlight of the LCD display 551, the buzzer sounds BUZ at a slow speed, and the LCD display 551 displays the following: Fig.16 Interface B (the actual backlight of interface B is green), that is, the corresponding number of analog bars are displayed to represent the detection voltage;

[0105] b) When 48V≤detection voltage<90V (second interval), the dual-color backlight module 529 lights up the green backlight of the LCD display 551, the buzzer sounds BUZ at a medium speed, and the LCD display 551 displays the following: Fig.16 Interface C in the diagram (the actual backlight of interface C is green), that is, the corresponding number of analog bars are displayed to indicate the magnitude of the detection voltage;

[0106] c) When 90V≤detection voltage (third section), the dual-color backlight module 529 lights up the red backlight of the LCD display screen 551, the buzzer BUZ prompts quickly, and the LCD display screen 551 displays as follows: Fig.16 The interface D in the figure (the actual backlight of the interface D is red) displays a corresponding number of analog bars to represent the detection voltage.

[0107] When measuring in the low sensitivity range of 48V to 1000V, the low sensitivity range of 48V to 1000V is divided into multiple intervals, and the different color backlights of the LCD display are lit by the dual-color backlight module, different levels of prompt sounds are emitted by the buzzer BUZ, and / or different numbers of analog bars are displayed on the LCD display to indicate the voltage interval in which the detection voltage is located. A preferred example is given below:

[0108] d) When 48V<detection voltage<90V (first section), the dual-color backlight module 529 lights up the green backlight of the LCD display 551, the buzzer BUZ slowly prompts, and the LCD display 551 displays as follows: Fig.16Interface B (the actual backlight of interface B is green), that is, the corresponding number of analog bars are displayed to represent the detection voltage;

[0109] e) When 90V≤detection voltage<150V (second interval), the dual-color backlight module 529 lights up the green backlight of the LCD display 551, the buzzer sounds BUZ at a medium speed, and the LCD display 551 displays the following: Fig.16 Interface C in (the actual backlight of interface C is green);

[0110] f) When 150V≤detection voltage (third section), the dual-color backlight module 529 lights up the red backlight of the LCD display 551, the buzzer BUZ prompts quickly, and the LCD display 551 displays as follows: Fig.16 The interface D in the figure (the actual backlight of the interface D is green) displays a corresponding number of analog bars to represent the detection voltage.

[0111] In this embodiment, the thresholds of the sensitivity segments given are only examples and are not limited thereto. In actual application, they can be adaptively adjusted according to specific needs.

[0112] In this embodiment, a grounding point GND is provided on the circuit board 52, and a grounding contact 66 for electrically connecting to the grounding point GND is provided on the pen-shaped housing 51. When measuring in the contact voltage (CVT) measurement mode, the pen cap 61 is removed, and the sensing unit 54 is brought into contact with the object to be measured. The grounding contact 66 is touched by the hand of the measuring person to form a ground wire through the human body, thereby realizing contact voltage (CVT) measurement.

[0113] When measuring in the contact voltage (CVT) measurement mode, the voltage detection range is 12 to 250 V. The voltage detection range is divided into multiple intervals. The two-color backlight module 529 lights up the different color backlights of the LCD display screen 551, and / or the LCD display screen 551 displays different values ​​to indicate the voltage interval in which the detection voltage is located. A preferred example is given below:

[0114] 1) When the detection voltage is less than 12V (the first section), the dual-color backlight module 529 lights up the green backlight of the LCD display screen 551, and the LCD display screen 551 displays as follows: Fig.17 Interface A (the actual backlight of interface A is green) shows the voltage value 000V and the AC symbol;

[0115] 2) When 12V≤detection voltage<50V (second interval), the dual-color backlight module 529 lights up the green backlight of the LCD display screen 551, and the LCD display screen 551 displays as follows: Fig.17 Interface B (the actual backlight of interface B is green) shows the voltage value 012V and the AC symbol;

[0116] 3) When 50V≤detection voltage<250V (third section), the dual-color backlight module 529 lights up the red backlight of the LCD display screen 551, and the LCD display screen 551 displays as follows: Fig.17 Interface C (the actual backlight of interface C is red) displays the voltage value 050V, the AC symbol and the high-voltage lightning symbol;

[0117] 4) When 250V≤detection voltage (fourth section), the dual-color backlight module 529 lights up the red backlight of the LCD display screen 551, and the LCD display screen 551 displays as follows: Fig.17 Interface D (the actual backlight of interface D is red) displays the voltage value 250V, the AC symbol and the high-voltage lightning symbol.

[0118] In this embodiment, the thresholds of the voltage segments given are only examples and are not limited thereto. In actual application, they can be adjusted according to specific needs.

[0119] In this embodiment, a phase sequence signal acquisition module 525 is further provided on the circuit board 52, and the key module 527 includes a function switch key FUNC, and the function switch key FUNC is used to switch between a non-contact voltage measurement mode and a non-contact phase sequence (NCP) measurement mode.

[0120] The function indicator light module 532 includes a phase sequence indicator light LED 4 indicating a non-contact phase sequence (NCP) measurement mode. The phase sequence indicator light LED 4 lights up when switching to the non-contact phase sequence (NCP) measurement mode.

[0121] The phase sequence signal acquisition module 525 is used to acquire the phase sequence of the three-phase line to be detected in a non-contact manner through the sensing unit 54 in a non-contact phase sequence measurement mode, and output the acquired signal to the microcontroller U1;

[0122] The microcontroller U1 is also used to process the signal input by the phase sequence signal acquisition module 525 to obtain a phase sequence detection result, and send a corresponding second control signal to the display unit 55 according to the phase sequence detection result;

[0123] The display unit 55 is used to display the phase sequence detection result accordingly according to the second control signal.

[0124] In this embodiment, the display unit 55 is also used to display corresponding text and / or symbols in the non-contact phase sequence measurement mode. For example, displaying "NCP" indicates that it is in the non-contact phase sequence measurement mode. Displaying a right-handed symbol in the measurement result indicates a positive phase sequence, and displaying a left-handed symbol in the measurement result indicates a reverse phase sequence. The dual-color backlight module 529 is also used to light up different color backlights of the LCD display screen 551 to indicate the positive phase sequence and the reverse phase sequence respectively when displaying the phase sequence measurement result. For example, a green backlight indicates a positive phase sequence, and a red backlight indicates a reverse phase sequence.

[0125] In the contact voltage measurement mode, pressing the function switch key FUNC is invalid, that is, it is not possible to switch to the non-contact phase sequence measurement mode. To enter the non-contact phase sequence measurement mode, you need to cover the pen cap 61 and switch from the contact voltage measurement mode to the non-contact voltage measurement mode. In the non-contact voltage measurement mode, by pressing the function switch key FUNC, you can switch to the non-contact phase sequence measurement mode.

[0126] In this embodiment, the display unit 55 includes an LCD display screen 551 , and the phase sequence measurement process and results are displayed through the LCD display screen 551 .

[0127] The steps for non-contact phase sequence measurement are as follows:

[0128] In the non-contact voltage measurement mode, press the function switch key FUNC to enter the non-contact phase sequence measurement mode. The LCD display 551 shows the following: Fig.17 In the interface A, a flashing character "A" appears, and the symbol "NCP" indicating the non-contact phase sequence measurement mode is displayed;

[0129] Place the induction unit 54 of the tester close to the first line of the three-phase line to be tested. When the phase sequence signal acquisition module 525 completes sampling, the buzzer beeps and the LCD display 551 displays the following: Fig.17 In the interface B, a flashing character "B" appears, and the symbol "NCP" indicating the non-contact phase sequence measurement mode is displayed;

[0130] Place the induction unit 54 of the test pencil close to the second line of the three-phase line to be tested. Similarly, when the phase sequence signal acquisition module 525 completes sampling, the buzzer beeps and the LCD display 551 displays the following: Fig.17 In the interface C, a flashing character "C" appears, and the symbol "NCP" indicating the non-contact phase sequence measurement mode is displayed;

[0131] Place the induction unit 54 of the tester close to the third line of the three-phase line to be tested. Similarly, when the phase sequence signal acquisition module 525 completes sampling, the buzzer BUZ beeps for a long time, and the LCD display screen 551 displays the phase sequence detection result. For different phase sequence detection results, the LCD display screen 551 displays different interfaces. When the phase sequence measurement result is a reverse phase sequence, the LCD display screen 551 displays the following Fig.17 Interface D in the figure, at this time, the dual-color backlight module 529 lights up the red backlight of the LCD display screen 551; when the phase sequence detection result is a positive phase sequence, the LCD display screen 551 displays as follows Fig.17 In the interface E, the dual-color backlight module 529 lights up the green backlight of the LCD display screen 551; when the phase sequence detection result is an error, the LCD display screen 551 displays as follows Fig.17 Interface F in.

[0132] When the phase sequence detection is needed again, press the sensitivity key SKEY to clear the previous measurement result, and then perform the detection according to the above non-contact phase sequence measurement steps.

[0133] When the phase sequence detection is completed, press the function switch key FUNC to switch back to the non-contact voltage measurement mode.

[0134] During the above phase sequence detection process, you can turn off the power at any time, press the function switch key FUNC to return to the non-contact voltage measurement mode at any time; or press the sensitivity key SKEY to interrupt the current measurement and restart the measurement.

[0135] In this embodiment, a phase sequence signal acquisition module 525 is further included, so that the electric tester has a phase sequence detection function. In other embodiments, according to actual needs, the phase sequence signal acquisition module 525 may not be included.

[0136] Figure 8-Figure 15 This is a circuit diagram of a preferred embodiment of the electric tester of the present invention, wherein: Figure 8 It shows the connection relationship between the microcontroller U1 and each module. Fig. 9 : is a circuit schematic diagram of a non-contact voltage signal acquisition module 521, a contact voltage signal acquisition module 522 and a phase sequence signal acquisition module 525, Fig.10 is a circuit schematic diagram of the key module 527, Fig.11 is a circuit schematic diagram of the power supply module 526, Fig.12 is a circuit schematic diagram of the function indicator light module 532, Fig.13 is a circuit schematic diagram of the lighting module 528, Fig.14 is a circuit schematic diagram of the dual-color backlight module 529, Fig.15 FIG. 5 is a circuit schematic diagram of the buzzer alarm module 530 .

[0137] like Figure 8As shown, in this embodiment, the model of the microcontroller U1 is preferably CS77P35, but it is not limited to this. The microcontroller U1 can also be other chips that can achieve the same function. The CS77P35 model microcontroller U1 has 38 pins, and the names of the pins are as follows: Figure 8 shown.

[0138] The LCD display screen 551 is connected to the pins 23-38 of the microcontroller U1, and the display content of the LCD display screen 551 is controlled by the microcontroller U1.

[0139] like Fig.11 As shown, it is a circuit schematic diagram of the power supply module 526, and the power supply module 526 includes a battery BAT, a fourth transistor Q4, an eleventh resistor R11, a fifth capacitor C5 and a sixth capacitor C6. The negative electrode of the battery BAT is grounded, the positive electrode of the battery BAT is connected to the drain D of the fourth transistor Q4, one end of the eleventh resistor R11 is grounded and connected to the negative electrode of the battery BAT, the other end of the eleventh resistor R11 is connected to the gate G of the fourth transistor Q4, one end of the fifth capacitor C5 is grounded, the other end of the fifth capacitor C5 is connected to the source S of the fourth transistor Q4, one end of the sixth capacitor C6 is grounded, the other end of the sixth capacitor C6 is connected to the source S of the fourth transistor Q4, and the source S of the fourth transistor Q4 is used to output the supply voltage VDD.

[0140] The power supply voltage VDD is connected to the seventh pin AVDD of the microcontroller U1 , and the fourth transistor Q4 is a P-channel MOS field effect transistor.

[0141] like Fig. 9 , which is a circuit schematic diagram of a non-contact voltage signal acquisition module 521 , a contact voltage signal acquisition module 522 , and a phase sequence signal acquisition module 525 .

[0142] The non-contact voltage signal acquisition module 521 includes a first resistor R1, a second resistor R2 and an eighteenth resistor R18, one end of the switching switch SW1 is connected to the sensing signal input point 520, one end of the eighteenth resistor R18 is connected to the other end of the switching switch SW1, the other end of the eighteenth resistor R18 is connected to the 10th pin AIN1 of the microcontroller U1, one end of the first resistor R1 is connected to the other end of the eighteenth resistor R18, the other end of the first resistor R1 is connected to the 8th pin VS / REF of the microcontroller U1, one end of the second resistor R2 is connected to the other end of the eighteenth resistor R18, and the other end of the second resistor R2 is grounded.

[0143] The contact voltage signal acquisition module 522 includes a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, a twenty-second resistor R22, a twenty-third resistor R23, a twenty-fourth resistor R24, a twenty-fifth resistor R25, a twenty-sixth resistor R26 and a twenty-seventh resistor R27.

[0144] One end of the thirteenth resistor R13 is connected between the sensing signal input point 520 and one end of the switching switch SW1, the other end of the thirteenth resistor R13 is connected to one end of the fourteenth resistor R14, one end of the twenty-second resistor R22 is grounded, the other end of the twenty-second resistor R22 is connected to one end of the seventeenth resistor R17, the fourteenth resistor R14, the fifteenth resistor R15, the sixteenth resistor R16 and the seventeenth resistor R17 are connected in series in sequence, one end of the twenty-third resistor R23 is connected between the sixteenth resistor R16 and the seventeenth resistor R17, and the other end of the twenty-third resistor R23 is connected to the 11th pin PT24 of the microcontroller U1.

[0145] One end of the twenty-fourth resistor R24, the twenty-fifth resistor R25, the twenty-sixth resistor R26 and the twenty-seventh resistor R27 connected in series in sequence is connected to the ground point GND, and the other end of the twenty-fourth resistor R24, the twenty-fifth resistor R25, the twenty-sixth resistor R26 and the twenty-seventh resistor R27 connected in series in sequence is grounded.

[0146] The phase sequence signal acquisition module 525 includes a first comparator U3-A, a first capacitor C1, a second comparator U2-B, a seventh capacitor C7, an eighth capacitor C8, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10 and a third comparator U2-A. The positive input terminal of the first comparator U3-A is connected to the other end of the switching switch SW1, the negative input terminal of the first comparator U3-A is connected to the output terminal of the first comparator U3-A, one end of the first capacitor C1 is connected to the output terminal of the first comparator U3-A, the other end of the first capacitor C1 is connected to the negative input terminal of the second comparator U2-B, one end of the seventh capacitor C7 is connected to the negative input terminal of the second comparator U2-B, the other end of the seventh capacitor C7 is connected to the output terminal of the second comparator U2-B, the positive input terminal of the second comparator U2-B is grounded, one end of the eighth resistor R8 is connected to the negative input terminal of the second comparator U2-B, the other end of the eighth resistor R8 is grounded, one end of the eighth capacitor C8 is connected to the second comparator U2-B, the other end of the eighth resistor R8 is grounded, and one end of the eighth capacitor C8 is connected to the second The output end of the comparator U2-B is connected, the other end of the eighth capacitor C8 is connected to the positive input end of the third comparator U2-A, one end of the ninth resistor R9 is connected between the other end of the eighth capacitor C8 and the positive input end of the third comparator U2-A, the other end of the ninth resistor R9 is grounded and connected to the other end of the eighth resistor R8, one end of the tenth resistor R10 is connected between the other end of the eighth capacitor C8 and the positive input end of the third comparator U2-A, the other end of the tenth resistor R10 is connected to the power supply voltage VDD, the negative input end of the third comparator U2-A is grounded and connected to the positive input end of the second comparator U2-B, and the output end of the third comparator U2-A is connected to the 14th pin PT15 of the microcontroller U1.

[0147] like Fig.10 The circuit diagram of the key module 527 is shown. The key module 527 includes a power key PWWKEY, a sensitivity key SKEY and a function switch key FUNC. One end of the power key PWWKEY is grounded, and the other end of the power key PWWKEY is connected to the 18th pin PT21 of the microcontroller U1. One end of the sensitivity key SKEY is grounded, and the other end of the sensitivity key SKEY is connected to the 20th pin PT23 of the microcontroller U1. One end of the function switch key FUNC is grounded, and the other end of the function switch key FUNCY is connected to the 21st pin PT26 of the microcontroller U1.

[0148] like Fig.12Shown is a circuit schematic diagram of the function indicator light module 532, which includes a twelfth resistor R12, a power indicator light LED3 and a phase sequence indicator light LED4. One end of the twelfth resistor R12 is connected to the power supply voltage VDD, and the other end of the twelfth resistor R12 is connected to the anode of the power indicator light LED3 and is also connected to the anode of the phase sequence indicator light LED4. The cathode of the power indicator light LED3 is connected to the third pin PT12 of the microcontroller U1, and the cathode of the phase sequence indicator light LED4 is connected to the fourth pin PT13 of the microcontroller U1.

[0149] like Fig.12 The circuit schematic diagram of the lighting module 528 is shown, and the lighting module 528 includes a sixth resistor R6, a lighting lamp LED2, a second transistor Q2 and a seventh resistor R7. One end of the sixth resistor R6 is connected to the power supply voltage VDD, the other end of the sixth resistor R6 is connected to the anode of the lighting lamp LED2, the cathode of the lighting lamp LED2 is connected to the collector of the second transistor Q2, the emitter of the second transistor Q2 is grounded, one end of the seventh resistor R7 is connected to the base of the second transistor Q2, and the other end of the seventh resistor R7 is connected to the 19th pin PT22 of the microcontroller U1. The second transistor Q21 is an NPN type transistor.

[0150] like Fig.14 The circuit schematic diagram of the dual-color backlight module 529 is shown. The dual-color backlight module 529 includes a nineteenth resistor R19, a third transistor Q3, a ninth light-emitting diode LED9, a tenth light-emitting diode LED10, a fifth transistor Q5, a twentieth resistor R20 and a twenty-first resistor R21. One end of the nineteenth resistor R19 is connected to the fifteenth pin PT16 of the microcontroller U1, and the other end of the nineteenth resistor R19 is connected to the base of the third transistor Q3. The emitter of the third transistor Q3 is grounded, and the collector of the third transistor Q3 is connected to the cathode of the ninth light-emitting diode LED9. The anode of the light-emitting diode LED9 is connected to one end of the twentieth resistor R20, the other end of the twentieth resistor R20 is connected to the power supply voltage VDD, one end of the twenty-first resistor R21 is connected to the 16th pin PT17 of the microcontroller U1, the other end of the twenty-first resistor R21 is connected to the base of the fifth transistor Q5, the emitter of the fifth transistor Q5 is grounded, the collector of the fifth transistor Q5 is connected to the cathode of the tenth light-emitting diode LED10, the anode of the tenth light-emitting diode LED10 is connected to one end of the twentieth resistor R20, and is connected to the anode of the ninth light-emitting diode LED9.

[0151] like Fig.15The above is a circuit schematic diagram of the buzzer alarm module 530, which includes a fourth resistor R4, a first transistor Q1, a buzzer BUZ, a third resistor R3, a fifth resistor R5 and a signal light LED1. One end of the fourth resistor R4 is connected to the 22nd pin PT27 of the microcontroller U1, and the other end of the fourth resistor R4 is connected to the base of the first transistor Q1. The emitter of the first transistor Q1 is grounded, the collector of the first transistor Q1 is connected to one end of the buzzer BUZ, the other end of the buzzer BUZ is connected to one end of the third resistor R3, and the other end of the third resistor R3 is connected to the power supply voltage VDD. The signal light LED1 is a light emitting diode, and the cathode of the signal light LED1 is connected between the collector of the first transistor Q1 and one end of the buzzer BUZ. The anode of the signal light LED1 is connected to one end of the fifth resistor R5, and the other end of the fifth resistor R5 is connected to the power supply voltage VDD and is connected to the other end of the third resistor R3.

[0152] Figure 8-Figure 15 The circuit schematic diagram is only an example. The circuit structure of the non-contact voltage signal acquisition module 521, the contact voltage signal acquisition module 522, the phase sequence signal acquisition module 525, the button module 527, the power supply module 526, the function indicator light module 532, the function indicator light module 532, the dual-color backlight module 529, and the buzzer alarm module 530 during actual use is not limited to this. The components in each circuit can be adaptively added, deleted, and replaced as needed. As long as the functions of each module can be actually used, they should be included in the protection scope of the invention.

[0153] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An electric test pencil, characterized in that: The electric test pen comprises a pen-shaped housing, a circuit board, a microcontroller, a voltage measurement mode switching unit, a sensing unit, and a display unit. The circuit board is provided with a sensing signal input point, a non-contact voltage signal acquisition module, a contact voltage signal acquisition module, and a switching switch. The circuit board is arranged in the pen-shaped housing, and the sensing unit is arranged at the front end of the pen-shaped housing and contacts the sensing signal input point; the microcontroller is mounted on the circuit board, and the display unit is mounted on the pen-shaped housing and connected to the microcontroller; The voltage measurement mode switching unit is provided on the pen-shaped housing and is used to operate the switch to switch between the non-contact voltage measurement mode and the contact voltage measurement mode; The non-contact voltage signal acquisition module is used to acquire the voltage to be detected in a non-contact manner through the sensing unit in a non-contact voltage measurement mode, and output the acquired signal to the microcontroller; The contact voltage signal acquisition module is used to acquire the voltage to be detected in a contact manner through the sensing unit in a contact voltage measurement mode, and output the acquired signal to the microcontroller; The microcontroller is used to process the signal input by the non-contact voltage signal acquisition module / contact voltage signal acquisition module to obtain the magnitude of the voltage to be detected, and send a corresponding first control signal to the display unit according to the obtained magnitude of the voltage to be detected; The display unit is used to display a voltage strength mark corresponding to the acquired voltage to be detected according to the first control signal, so that the user can know the strength of the current voltage detected by the voltage tester; A grounding point is arranged on the circuit board, and a grounding contact sheet for being electrically connected to the grounding point is arranged on the pen-shaped housing.

2. The electric tester as claimed in claim 1, characterized in that: The pen-shaped shell comprises a hollow pen body and a cover arranged at the front end of the pen body, the circuit board is arranged in the pen body of the pen-shaped shell, and the sensing unit is arranged on the cover of the pen-shaped shell and contacts the sensing signal input point.

3. The electric tester as claimed in claim 2, characterized in that: The switching switch is a touch switch, which is turned on by pressing the touch switch through the voltage measurement mode switching unit, and is turned off by releasing it.

4. The electric test pencil as claimed in claim 3, characterized in that: The voltage measurement mode switching unit includes a sliding rod and a pressing sheet. A first through hole is provided on the pen-shaped housing corresponding to the outer end of the sliding rod, and a second through hole is provided on the pressing sheet corresponding to the inner end of the sliding rod. The outer end of the sliding rod passes through the first through hole to extend out of the pen-shaped housing, and the inner end of the sliding rod passes through the second through hole to press the touch switch. The sliding rod is installed on the pen-shaped housing through the pressing sheet so that the sliding rod can slide in the first through hole and the second through hole.

5. The electric test pencil as claimed in claim 4, characterized in that: The first through hole is arranged on the front end plate of the cover, the sliding rod is installed on the inner side of the front end plate of the cover through the pressing sheet, and the outer end of the sliding rod extends outward from the front end plate of the cover, and the voltage tester also includes a pen cap for covering the cover, and the pen cap is used to press the outer end of the sliding rod when it is covered on the front end of the cover, so that the inner end of the sliding rod moves toward the touch switch to press the touch switch, and the touch switch is turned on after being pressed, and switched to the non-contact voltage measurement mode. When the pen cap is removed from the cover, the force on the outer end of the sliding rod is removed, and the touch switch returns to the disconnected state under the action of its own elastic force, and switches to the contact voltage measurement mode.

6. The electric test pencil as claimed in claim 5, characterized in that: A convex ring is formed in the middle of the sliding rod, and the convex ring is clamped between the front end plate of the cover head and the pressing sheet to limit the sliding stroke of the sliding rod.

7. The electric tester as claimed in claim 5, characterized in that: The sensing unit includes a screwdriver seat and a screwdriver rod, wherein the screwdriver seat is mounted on the cover head, and the screwdriver rod is mounted on the screwdriver seat and extends outward from the cover head. When the pen cap is covered on the cover head, it is also used to cover the screwdriver rod in the pen cap. The screwdriver seat and the screwdriver rod are used to be conductively connected to the sensing signal input point.

8. The electric test pencil as claimed in claim 7, characterized in that: The sensing unit also includes a flat sensing piece. A flat receiving portion is provided at the outer end of the pen cap. The sensing piece is provided in the receiving portion of the pen cap. The sensing piece is used to be conductively connected to the screwdriver rod when the pen cap is covered on the cover head. A compression spring is connected to the sensing piece. The compression spring is used to conductively connect the sensing piece to the screwdriver rod when the pen cap is covered on the cover head.

9. The electric tester as claimed in claim 7, characterized in that: The screwdriver rod is detachably mounted on the screwdriver seat, a screwdriver head is formed at one end of the screwdriver rod or at both ends of the screwdriver rod, or the screwdriver rod is non-detachably fixed on the screwdriver seat.

10. The electric tester as claimed in claim 9, characterized in that: The head shape of the screwdriver head is a flat head, a cross head, a Pozidriv head, a star head, a square head, a hexagonal head or a Y-shaped head.

11. The electric tester according to claim 7, characterized in that: A contact sheet in contact with the sensing signal input point is disposed on the circuit board, and a contact spring is disposed on the side of the contact sheet facing the screwdriver seat, and the contact spring is used for conductive connection with the screwdriver seat of the sensing unit.

12. The electric tester according to claim 11, characterized in that: A blind hole is formed on one side of the screwdriver seat facing the contact spring. A magnetic block is arranged in the blind hole. The contact spring is conductively connected to the screwdriver seat via the magnetic block.

13. The electric tester as claimed in claim 1, characterized in that: The circuit board is also provided with a key module, which includes a power key and a sensitivity key. The power key is used to control the on and off of the electric test pen, and the sensitivity key is used to switch the sensitivity range of the electric test pen.

14. The electric tester as claimed in claim 13, characterized in that: The circuit board is also provided with a lighting module, which includes a lighting lamp for lighting. The lighting lamp extends into the cover head, and a light exit window is provided at the front end of the cover head corresponding to the lighting lamp. The sensitivity key SKEY is also used to turn on and off the lighting lamp.

15. The electric tester as claimed in claim 13, characterized in that: The circuit board is also provided with a function indicator light module, and the function indicator light module includes a power indicator light indicating that the power is turned on, and the power indicator light is used to light up when the power is turned on.

16. The electric tester as claimed in claim 1, characterized in that: The display unit uses an LCD display screen, a digital tube or an LED lamp to display the voltage intensity mark.

17. The electric test pencil according to claim 1 or 16, characterized in that: The voltage strength indicator is an analog bar, and the display unit displays the analog bars corresponding to the acquired voltage to be detected according to the first control signal; or the voltage strength indicator is a voltage value.

18. The electric test pencil according to claim 1 or 16, characterized in that: The display unit lights up the number of LED lights and / or lights up LED lights of different colors according to the first control signal to indicate the voltage intensity identifier.

19. The electric tester as claimed in claim 1, characterized in that: The display unit includes an LCD display screen. The circuit board is also provided with a dual-color backlight module. The dual-color backlight module includes two light-emitting diodes that emit different colors respectively, and is used to light up two different colors of backlight for the LCD display screen.

20. The electric tester as claimed in claim 19, characterized in that: The display unit is used to display corresponding text and / or symbols in the non-contact voltage measurement mode, to display corresponding text and / or symbols in the contact voltage measurement mode, and / or to display the battery undervoltage symbol when the battery is undervoltage.

21. The electric tester as claimed in claim 19, characterized in that: The circuit board is also provided with a buzzer alarm module, which includes a buzzer. The microcontroller is also used to control the buzzer to emit a frequency sound corresponding to the obtained voltage to be detected according to the size of the obtained voltage to be detected. The buzzer alarm module further includes a signal light, and the microcontroller is also used to control the signal light to light up to a brightness corresponding to the obtained voltage to be detected, or to control the signal light to emit a flashing frequency corresponding to the obtained voltage to be detected.

22. The electric tester as claimed in claim 13, characterized in that: The sensitivity range of the non-contact voltage measurement mode includes a high sensitivity range of 12V to 1000V and a low sensitivity range of 48V to 1000V.

23. The electric tester as claimed in claim 21, characterized in that: The sensitivity range of the non-contact voltage measurement mode includes a high sensitivity range of 12V to 1000V and a low sensitivity range of 48V to 1000V. When measuring under the high sensitivity range of 12V to 1000V, the high sensitivity range of 12V to 1000V is divided into multiple intervals, and the different color backlights of the LCD display are lit by the dual-color backlight module, different levels of prompt sounds are emitted by the buzzer BUZ, and / or different numbers of analog bars are displayed on the LCD display to indicate the voltage interval in which the detection voltage is located; When measuring in the 48V-1000V low sensitivity range, the 48V-1000V low sensitivity range is divided into multiple intervals, and the different color backlights of the LCD display are lit by the dual-color backlight module, different levels of prompt sounds are emitted by the buzzer BUZ, and / or different numbers of analog bars are displayed on the LCD display to indicate the voltage interval in which the detection voltage is located.

24. The electric tester as claimed in claim 19, characterized in that: When measuring in the contact voltage measurement mode, the voltage detection range is 12 to 250 V. The voltage detection range is divided into multiple intervals. The different color backlights of the LCD display are lit by the dual-color backlight module, and / or different values ​​are displayed on the LCD display to indicate the voltage interval in which the detection voltage is located.

25. The electric tester as claimed in claim 1, characterized in that: The circuit board is also provided with a lighting module, and the lighting module includes a lighting lamp for lighting, and the lighting lamp extends into the cover head, and a light exit window is provided at the front end of the cover head corresponding to the lighting lamp.

26. The electric tester as claimed in claim 2, characterized in that: The switching switch is a toggle switch, and the voltage measurement mode switching unit includes a toggle key arranged on the pen body. The toggle key is used to operate the toggle switch to switch between the non-contact voltage measurement mode and the contact voltage measurement mode.

27. The electric tester according to any one of claims 1 to 8, characterized in that: The circuit board is also provided with a phase sequence signal acquisition module and a key module, wherein the key module includes a function switching key FUNC, and the function switching key FUNC is used to switch between a non-contact voltage measurement mode and a non-contact phase sequence measurement mode.

28. The electric tester according to any one of claims 1 to 8, characterized in that: The circuit board is also provided with a function indicator light module, and the function indicator light module includes a phase sequence indicator light indicating a non-contact phase sequence measurement mode, and the phase sequence indicator light is lit when switching to the non-contact phase sequence measurement mode.

29. The electric test pencil as claimed in claim 27, characterized in that: The phase sequence signal acquisition module is used to acquire the phase sequence of the three-phase line to be detected in a non-contact manner through the sensing unit in a non-contact phase sequence measurement mode, and output the acquired signal to the microcontroller; The microcontroller is also used to process the signal input by the phase sequence signal acquisition module to obtain a phase sequence detection result, and send a corresponding second control signal to the display unit according to the phase sequence detection result; The display unit is used to display the phase sequence detection result accordingly according to the second control signal.

30. The electric test pencil as claimed in claim 29, characterized in that: The display unit is also used to display corresponding text and / or symbols in the non-contact phase sequence measurement mode; and / or The display unit is also used to display a right-handed symbol in the measurement result to indicate a positive phase sequence, and to display a left-handed symbol in the measurement result to indicate a negative phase sequence.

31. The electric tester as claimed in claim 29, characterized in that: The display unit includes an LCD display screen, and a dual-color backlight module is also provided on the circuit board. The dual-color backlight module includes two light-emitting diodes that emit different colors respectively. The dual-color backlight module is used to light up different color backlights of the LCD display screen to respectively indicate the positive phase sequence and the reverse phase sequence when displaying the phase sequence measurement results.

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