Digital Multimeter

Abstract

The present invention discloses a digital multimeter, which includes a housing, a circuit board and a lens. The circuit board is arranged in the housing. A display screen and a touch key unit are arranged on the front of the housing. The display screen and the touch key unit are both electrically connected to the circuit board. The lens is arranged on the front of the housing and completely covers the display screen and the touch key unit. The side of the housing is provided with a plurality of test pen input jacks for inserting test pens. The digital multimeter of the present invention adopts a touch key unit and adopts a lens to completely cover the display screen and the touch key unit, so that the operation area of ​​the touch key unit has a better waterproof effect, the touch key unit is easy to operate and not easy to be damaged, and the test pen input jack is arranged on the side of the housing, so that the digital multimeter is convenient for thin design, and is more convenient to carry and use.

Description

Technical Field

[0001] The invention relates to the technical field of electrical measurement, and in particular to a digital multimeter. Background Art

[0002] Most of the digital multimeters on the market now have the traditional knob-adjusting function, and there are also a few digital multimeters without knobs that use pure silicone buttons to switch functions. For digital multimeters with knob-adjusting function, you need to rotate the knob to adjust the gear when using it. In this way, the user needs to hold the body of the digital multimeter with one hand and rotate the knob with the other hand. There is no hand to hold the test lead, which is not very convenient to operate. In addition, the knob-adjusting function makes the waterproof effect of the operation panel not good. For digital multimeters with silicone button switching function, users need to press the silicone button hard when adjusting the gear, and the elasticity of the silicone buttons used by each manufacturer is different. Some buttons have strong elasticity, so the operation force needs to be greater. Some silicone buttons have low elasticity and may be stuck when pressed and cannot be reset. In addition, the use of silicone button switching function also has the problem of poor operation panel prevention effect. It is particularly worth noting that the conductive black particles at the bottom of the silicone button are in contact with the circuit board for a long time, and will fail after long-term use.

[0003] In addition, no matter it is a digital multimeter with a knob gear adjustment function or a digital multimeter using a pure silicone button switching function, the test lead input jack is set on the front of the digital multimeter, which makes the overall multimeter thicker and inconvenient to carry and operate. In particular, a digital multimeter using a silicone button switching function is not convenient to operate with one hand due to its thick thickness. Summary of the invention

[0004] The main purpose of the present invention is to provide a thin digital multimeter, aiming to realize the convenience of carrying and using the digital multimeter.

[0005] In order to achieve the above-mentioned purpose, the present invention proposes a digital multimeter, which includes a shell, a circuit board and a lens. The circuit board is arranged in the shell, and a display screen and a touch button unit are provided on the front of the shell. The display screen and the touch button unit are electrically connected to the circuit board. The lens is arranged on the front of the shell and completely covers the display screen and the touch button unit. The side of the shell is provided with multiple test pen input jacks for inserting test pens.

[0006] Preferably, the touch button unit is a capacitive touch button or a resistive touch button.

[0007] Preferably, the shell has a panel, a back panel opposite to the panel, and a side wall located between the panel and the back panel, the multiple test pen input jacks are arranged on the side wall of the shell, and a display window is opened on the panel of the shell facing the display screen. The touch button unit includes a touch part and a connecting part, the touch part includes multiple touch buttons, and the connecting part is used to be electrically connected to a circuit board. Corresponding button marks are respectively provided on the lens or the touch button unit corresponding to the multiple touch buttons to indicate the touch position of the touch button, and the corresponding touch button can be operated by touching the touch position indicated by the touch button mark on the lens surface.

[0008] Preferably, the side wall comprises a top wall and a bottom wall that are arranged opposite to each other, and a left wall and a right wall that are arranged opposite to each other, and the plurality of test lead input jacks are arranged on the bottom wall.

[0009] Preferably, the outer surface of the panel of the shell is provided with a groove for accommodating the touch portion of the touch button unit, and the panel of the shell is provided with a through hole at the edge of the groove for the connecting portion of the touch button unit to pass through and be electrically connected to the circuit board.

[0010] Preferably, the shell includes a front shell and a back shell, and a receiving space is formed by the front shell and the back shell. The circuit board and the display screen are arranged in the receiving space. The panel is formed on the front shell, and the back plate is formed on the back shell. A bottom baffle is provided at the bottom end of the back shell, and the multiple test pen input jacks are provided on the bottom baffle. A plurality of jack spring clips are provided on the circuit board, and each jack spring clip is provided in a corresponding test pen input jack.

[0011] Preferably, a top baffle is provided at the top of the back shell, a non-contact voltage sensing sheet is provided at the top of the circuit board, the top baffle is provided with a sensing sheet accommodating portion for accommodating the non-contact voltage sensing sheet, and the sensing sheet accommodating portion protrudes outward to form a protrusion.

[0012] Preferably, a switch button is provided on the top baffle, and the switch button is used to control the opening and closing of the digital multimeter.

[0013] Preferably, the multiple touch buttons include an intelligent measurement button, a manual measurement button, a large current / small current measurement switch button, a maximum / minimum value measurement button, an AC / DC measurement switch button, and a data hold function on / off button.

[0014] Preferably, a plurality of jack reminder lights are provided on the circuit board corresponding to the plurality of test lead input jacks, and the plurality of jack reminder lights are respectively used to light up when there are test leads in the corresponding test lead input jacks to remind the user to insert the test leads into the corresponding test lead input jacks.

[0015] Preferably, corresponding socket reminder marks are respectively provided on the lens or on the panel of the housing corresponding to the multiple socket reminder lights.

[0016] Preferably, the digital multimeter further comprises a plurality of first light-guiding elements, each of which is arranged opposite to a corresponding socket indicator light and is used for guiding the light emitted by the socket indicator light to the corresponding socket indicator mark on the lens.

[0017] Preferably, the first light guide element includes a light input portion and a light output portion, the light input portion of the first light guide element is installed on the inner surface of the panel of the shell, and the panel of the shell is provided with a light output hole for inserting the light output portion of the first light guide element corresponding to each first light guide element.

[0018] Preferably, the plurality of test lead input jacks are arranged in a row at intervals on the bottom wall of the housing, and the plurality of first light guide elements are arranged in a row and correspond to the plurality of test lead input jacks respectively.

[0019] Preferably, the number of the test lead input jacks is four, namely a large current measurement input jack, a small current measurement input jack, a common terminal input jack, and a voltage / resistance measurement input jack.

[0020] Preferably, the plurality of test lead input jacks are arranged on the bottom baffle, the outer ends of the plurality of test lead input jacks are connected through the bottom baffle, and a reinforcing rib is connected between two adjacent test lead input jacks, and the reinforcing rib is also connected to the bottom baffle.

[0021] Preferably, a first positioning portion is provided on the face shell corresponding to the test pen input jack, and a second positioning portion is provided on the back shell corresponding to the test pen input jack, and the second positioning portion is installed and positioned by the first positioning portion and the second positioning portion, and the first positioning portion 1171 and the second positioning portion are both formed with arc-shaped positioning grooves, and the inner surface of the face shell is formed with two first card grooves arranged opposite to each other, and the left and right ends of the bottom baffle are respectively clamped in the two first card grooves, and the inner surface of the face shell is also formed with a second card groove connected between the two first card grooves, and one side edge of the bottom baffle is clamped in the second card groove.

[0022] Preferably, the digital multimeter further comprises an illumination lamp, which is mounted on the back of the circuit board, and the back plate of the housing is provided with a light exit window corresponding to the illumination lamp, and a lampshade is provided at the light exit window.

[0023] Preferably, a lighting key is provided on the side wall of the housing, and the lighting key is used to control the turning on and off of the lighting.

[0024] Preferably, a non-contact voltage / live line measurement switching button is further provided on the side wall of the housing, and the non-contact voltage / live line measurement switching button is used to switch between the non-contact voltage measurement function and the live line detection function.

[0025] Preferably, a continuity test indicator light is also provided on the circuit board, and the continuity test indicator light is used to emit light of corresponding color according to the continuity test result to indicate the continuity test result when the continuity test is performed. The digital multimeter also includes a second light guide element, and the panel of the shell is provided with a light outlet corresponding to the light outlet part of the second light guide element, and the second light guide element is used to guide the light emitted by the continuity test indicator light to the lens through the light outlet for display.

[0026] Preferably, the circuit board includes a first plate body and a second plate body, the first plate body and the second plate body are staggered with each other in the thickness direction of the shell, the first plate body is arranged corresponding to the display screen, the second plate body is arranged corresponding to the touch button unit, the bottom end of the first plate body is electrically connected to the top end of the second plate body, and the second plate body is arranged closer to the panel 111 relative to the first plate body.

[0027] Preferably, the back shell of the digital multimeter is provided with a battery compartment for installing batteries, the back plate is provided with a compartment opening corresponding to the battery compartment, a detachable battery cover is installed on the back shell for closing the compartment opening, and the battery compartment is arranged opposite to the second plate body.

[0028] Preferably, a battery positioning groove is provided on the inner surface of the battery cover to position and limit the battery.

[0029] Preferably, a first fuse and a second fuse are provided on the second plate body of the circuit board, and the first fuse and the second fuse are used for overcurrent protection during large current measurement and small current measurement, respectively. The first fuse and the second fuse are located on the left and right sides of the battery compartment, respectively.

[0030] A digital multimeter proposed by the present invention has a touch key unit and uses a lens to completely cover the display screen and the touch key unit, so that the operation area of ​​the touch key unit has a better waterproof effect, the touch key unit is easy to operate and not easy to be damaged, and the test pen input jack is arranged on the side of the shell, so that the digital multimeter is convenient for thin design and is more convenient to carry and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of a preferred embodiment of the digital multimeter of the present invention.

[0032] Figure 2 yes Figure 1 The structure diagram of the digital multimeter shown is viewed from another perspective.

[0033] Figure 3 yes Figure 1 Exploded schematic diagram of a digital multimeter shown.

[0034] Figure 4 yes Figure 2 Exploded schematic diagram of a digital multimeter shown.

[0035] Figure 5 yes Figure 3 A further exploded view of some of the components in the DMM shown.

[0036] Figure 6 yes Figure 4 A further exploded view of some of the components in the DMM shown.

[0037] Figure 7 yes Figure 1 Examples of button labels, jack prompt labels, and display contents in the digital multimeter shown.

[0038] Figure 8 is with Figure 1 A schematic structural diagram of an embodiment of a protective cover adapted for a digital multimeter is shown.

[0039] Fig. 9 yes Figure 8 The protective sleeve is provided on Figure 1 Schematic diagram on a digital multimeter shown.

[0040] Fig.10 yes Fig. 9 Schematic diagram showing the protective case and digital multimeter from another perspective.

[0041] 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

[0042] Reference Figures 1 to 6 A preferred embodiment of the present invention provides a digital multimeter, which includes a housing 11, a circuit board 12 and a lens 13. The circuit board 12 is arranged in the housing 11, and a display screen 14 and a touch key unit 15 are arranged on the front of the housing 11, and the display screen 14 and the touch key unit 15 are both electrically connected to the circuit board 12. The lens 13 is arranged on the front of the housing 11 and completely covers the display screen 14 and the touch key unit 15, and a plurality of test pen input jacks 16 for inserting test pens are arranged on the side of the housing 11. The "complete coverage" means that the lens 13 completely covers the display screen 14 and the touch key unit 15 area and the lens 13 does not open a through hole for the display screen 14 and the touch key unit 15 area.

[0043] The digital multimeter of this embodiment uses a touch button unit 15 and a lens 13 to completely cover the display screen 14 and the touch button unit 15, so that the operation area of ​​the touch button unit 15 has a better waterproof effect, the touch button unit 15 is easy to operate and not easy to be damaged, and the test lead input jack 16 is arranged on the side of the shell 11, so that the digital multimeter is convenient for thin design, and is more convenient to carry and use.

[0044] The touch key unit 15 is a capacitive touch key or a resistive touch key.

[0045] The housing 11 comprises a panel 111 , a back panel 112 opposite to the panel 111 , and a side wall (not numbered in the figure) between the panel 111 and the back panel 112 . The plurality of test lead input jacks 16 are disposed on the side wall of the housing 11 .

[0046] A display window 111 is provided on the panel 111 of the housing 11, facing the display screen 14. The touch key unit 15 includes a touch portion 151 and a connection portion 152, wherein the touch portion 151 includes a plurality of touch keys, and the connection portion 152 is used to connect to the circuit board 12. Corresponding key marks are respectively provided on the lens 13 or on the touch key unit 15 corresponding to the plurality of touch keys to indicate the touch positions of the touch keys, and the corresponding touch keys can be operated by touching the touch positions indicated by the key marks on the surface of the lens 13. The key marks can be provided on the lens 13 or on the touch key unit 15 by silk screen printing, preferably on the lens 13.

[0047] The side wall includes a top wall 113 and a bottom wall 114 that are arranged opposite to each other, and a left wall 115 and a right wall 116 that are arranged opposite to each other. In this embodiment, the plurality of test pen input jacks 16 are arranged on the bottom wall 114. In other embodiments, the plurality of test pen input jacks 16 can also be in other forms, for example, the plurality of test pen input jacks 16 are all arranged on the left wall 115; the plurality of test pen input jacks 16 are all arranged on the right wall 116; the plurality of test pen input jacks 16 are distributed on any two of the left wall 115, the right wall 116 and the bottom wall 114, or the plurality of test pen input jacks 16 are distributed on the left wall 115, the right wall 116 and the bottom wall 114.

[0048] The housing 11 includes a front shell 117 and a back shell 118, which enclose a receiving space (not shown in the figure), and the circuit board 12 and the display screen 14 are arranged in the receiving space. The panel 111 is formed on the front shell 117, and the back plate 112 is formed on the back shell 118. A bottom baffle 119 is provided at the bottom end of the back shell 118, and the bottom baffle 119 constitutes a part of the bottom wall 114 of the housing 11, and the multiple test pen input jacks 16 are arranged on the bottom baffle 119. The circuit board 12 is provided with a plurality of jack springs 121, and each jack spring 121 is arranged in a corresponding test pen input jack 16.

[0049] A top baffle 120 is provided at the top of the back shell 118, a non-contact voltage sensing sheet 122 is provided at the top of the circuit board 12, and a sensing sheet accommodating portion 1201 for accommodating the non-contact voltage sensing sheet 122 is provided on the top baffle 120. The sensing sheet accommodating portion 1201 protrudes outward to form a protrusion 1202, so that the non-contact voltage sensing sheet 122 can be as close to the object to be measured as possible, thereby improving the accuracy of non-contact voltage measurement.

[0050] In this embodiment, a switch button 123 is provided on the top baffle 120 , and the switch button 123 is used to control the opening and closing of the digital multimeter.

[0051] In this embodiment, a groove 1112 is provided on the outer surface of the panel 111 of the shell 11 for accommodating the touch portion 151 of the touch button unit 15, and a through hole 1113 is opened on the edge of the groove 1112 of the panel 111 of the shell 11 for the connection portion 152 of the touch button unit 15 to pass through and be electrically connected to the circuit board 12.

[0052] In this embodiment, in this embodiment, the number of the test lead input jacks 16 is four, namely, a large current measurement input jack 10A, a small current measurement input jack mA, a common terminal input jack COM, and a voltage / resistance measurement input jack V, and the multiple touch keys include a smart measurement key SMART, a manual measurement key MANUAL, a large current / small current measurement switching key mA / A, a maximum / minimum value measurement key MAX / MIN, an AC / DC measurement switching key AC / DC, and a data hold function on / off key HOLD / REL, a total of six touch keys. Figure 7 As shown, an example of key identification corresponding to six touch keys is given. The six touch keys are arranged in two rows and three columns. In actual application, the number and distribution positions of the touch keys can be adjusted according to the designed measurement function requirements.

[0053] The smart measurement button SMART is used to switch into the smart measurement function mode;

[0054] The manual measurement button MANUAL is used to manually switch the measurement function. For example, after powering on, press the manual measurement button MANUAL once to switch to the small current mV measurement function. In this function, AC mV, DC mV, and frequency can be measured; press the AC / DC measurement switch button AC / DC to switch between AC and DC; after powering on, press the manual measurement button MANUAL twice to switch to frequency and duty cycle measurement. In this function, frequency and duty cycle can be measured; after powering on, press the manual measurement button MANUAL three times to switch to capacitance measurement. In this function, capacitance can be measured; after powering on, press the manual measurement button MANUAL four times to switch to diode measurement. In this function, diode can be measured; after powering on, press the manual measurement button MANUAL five times to switch to temperature measurement. In this function, temperature can be measured;

[0055] The high current / low current measurement switching button mA / A is used to switch between high current measurement and low current measurement. For example, after powering on, insert the test lead into the low current measurement input jack mA in any measurement function, and the meter automatically switches to the low current mA measurement function. In this function, you can measure AC uA / mA, DC uA / mA and frequency. Press the AC / DC measurement switching button AC / DC to switch between AC and DC. In any measurement function, insert the test lead into the A jack, and the meter automatically switches to the high current A measurement function. In this function, you can measure AC A, DC A and frequency. Press the AC / DC measurement switching button AC / DC to switch between AC and DC. The high current / low current measurement switching button mA / A can be used to measure low current mA and high current A.

[0056] The MAX / MIN measurement button is used to enter the MAX / MIN mode to detect the maximum (MAX) and minimum (MIN) values ​​of the readings.

[0057] The AC / DC measurement switching button is used to switch between AC measurement and DC measurement;

[0058] The data hold function on / off button HOLD / REL is used to turn the data hold function on or off.

[0059] In this embodiment, a plurality of jack prompt lights 123 are provided on the circuit board 12 corresponding to the plurality of test lead input jacks 16, and the plurality of jack prompt lights 123 are respectively used to light up when there is a test lead in the corresponding test lead input jack 16 to prompt the user to insert the test lead into the corresponding test lead input jack 16. Corresponding jack prompt marks are respectively provided on the lens 13 or on the panel 111 of the housing 11 corresponding to the plurality of jack prompt lights 123. The jack prompt mark can be set on the lens 13 or on the panel 111 of the housing 11 by silk screen printing, preferably on the lens 13.

[0060] In this embodiment, the digital multimeter further includes a plurality of first light guide elements 17, each of which is disposed opposite to a corresponding socket indicator light 123 and is used to guide the light emitted by the socket indicator light 123 to the corresponding socket indicator mark on the lens 13. Figure 7 As shown in the figure, four examples of jack prompt labels are given, which correspond to the large current measurement input jack 10A, the small current measurement input jack mA, the common terminal input jack COM, and the voltage / resistance measurement input jack V. The voltage / resistance measurement input jack V can be used for live wire detection, resistance measurement, capacitance measurement, diode measurement, continuity measurement, voltage measurement, frequency measurement, duty cycle measurement and temperature measurement. Figure 7 The jack prompt label corresponding to the jack prompt light 123 of the medium voltage / resistance measurement input jack V provides the symbols corresponding to these functions.

[0061] The first light guide element 17 includes a light input portion 171 and a light output portion 172. The light input portion 171 is installed on the inner surface of the panel 111 of the shell 11. The panel 111 of the shell 11 is provided with a light output hole 1114 for inserting the light output portion 172 of the first light guide element 17 corresponding to each first light guide element 17.

[0062] The plurality of test lead input jacks 16 are arranged in a row on the bottom wall 114 of the housing 11, and the plurality of first light guide elements 17 are arranged in a row and are respectively arranged corresponding to the plurality of test lead input jacks 16. In this embodiment, the number of the test lead input jacks 16 is four, namely, a large current measurement input jack 10A, a small current measurement input jack mA, a common terminal input jack COM, and a voltage / resistance measurement input jack V. The four test lead input jacks 16 are arranged in a row on the bottom wall 114 of the housing 11, and the four first light guide elements 17 are arranged in a row and are respectively opposite to the four test lead input jacks 16, such as Figure 7 shown.

[0063] In this embodiment, a plurality of test lead input jacks 16 are provided on the bottom baffle 119, the outer ends of the plurality of test lead input jacks 16 are connected through the bottom baffle 119, and a reinforcing rib 1191 is connected between two adjacent test lead input jacks 16, and the reinforcing rib 1191 is also connected to the bottom baffle 119. By providing the reinforcing rib 1191, the stability of the test lead input jack 16 can be ensured, and the test lead input jack 16 can be prevented from shaking when the test lead is inserted or from being damaged by applying force during the insertion and removal process.

[0064] The front shell 117 is provided with a first positioning portion 1171 corresponding to the test lead input jack 16, and the back shell 118 is provided with a second positioning portion 1181 corresponding to the test lead input jack 16, and the second positioning portion 1181 is installed and positioned by the first positioning portion 1171 and the second positioning portion 1181. The first positioning portion 1171 and the second positioning portion 1181 are both formed with arc-shaped positioning grooves.

[0065] The inner surface of the face shell 117 is formed with two first slots 1172 arranged opposite to each other, and the left and right ends of the bottom baffle 119 are respectively clamped in the two first slots 1172. The inner surface of the face shell 117 is also formed with a second slot 1173 connected between the two first slots 1172, and one side edge of the bottom baffle 119 is clamped in the second slot 1173. By providing the first slot 1172 and the second slot 1173, the bottom baffle 119 can be installed, positioned and limited, so as to facilitate the installation of the bottom baffle 119.

[0066] The digital multimeter further includes an illumination lamp 18, which is mounted on the back of the circuit board 12. The back plate 112 of the housing 11 is provided with a light exit window 1121 corresponding to the illumination lamp 18. A lampshade 19 is provided at the light exit window 1121.

[0067] A lighting key 20 is disposed on the side wall of the housing 11 , and the lighting key 20 is used to control the lighting 18 to be turned on and off.

[0068] A non-contact voltage / live measurement switch button 21 is also provided on the side wall of the housing 11, and the non-contact voltage / live measurement switch button 21 is used to switch between the non-contact voltage measurement function and the live detection function. For example, after powering on, press the non-contact voltage / live measurement switch button 21 in any measurement function to enter the non-contact voltage NCV measurement function; press the non-contact voltage / live measurement switch button 21 again to cyclically switch between the non-contact voltage NCV measurement and live measurement Live functions; and long press the non-contact voltage / live measurement switch button 21 or the smart measurement button SMART or the manual measurement button MANUAL to exit the non-contact voltage / live measurement function. The back shell 118 of the digital multimeter is provided with a battery compartment 22 for installing a battery 23, and the battery 23 is used to power the entire digital multimeter. The back panel 112 is provided with a compartment opening (not shown in the figure) corresponding to the battery compartment 22, and a detachable battery cover 24 is installed on the back shell 118 to close the compartment opening to facilitate the installation and removal of the battery 23.

[0069] The inner surface of the battery cover 24 is provided with a battery positioning groove 241 to position and limit the battery 23. By providing the battery positioning groove 241, the installation and fixation of the battery 23 is made more reliable.

[0070] In this embodiment, the circuit board 12 is further provided with a continuity test indicator light 25, and the continuity test indicator light 25 is used to emit a corresponding color of light according to the continuity test result to indicate the continuity test result when performing the continuity test, for example, emitting green light for connection and emitting red light for disconnection. The digital multimeter also includes a second light guide element 26, and the panel 111 of the housing 11 is provided with a light outlet 1115 corresponding to the light outlet portion 261 of the second light guide element 26, and the second light guide element 26 is used to guide the light emitted by the continuity test indicator light 25 to the lens 13 through the light outlet 1115 for display.

[0071] In this embodiment, the circuit board 12 includes a first plate body 127 and a second plate body 128, the first plate body 127 and the second plate body 128 are mutually staggered in the thickness direction of the housing 11 of the digital multimeter, the first plate body 127 is arranged corresponding to the display screen 14, the second plate body 128 is arranged corresponding to the touch key unit 15, the bottom end of the first plate body 127 is electrically connected to the top end of the second plate body 128, the second plate body 128 is arranged closer to the panel 111 than the first plate body 127, and the battery compartment 22 is arranged opposite to the second plate body 128. By staggering the first plate body 127 and the second plate body 128 in the thickness direction of the housing 11 of the digital multimeter, the first plate body 127 is used to place the display screen 14, and the battery compartment 22 is arranged opposite to the second plate body 128, so that the thickness of the overall digital multimeter can be made as thin as possible, which is more conducive to the thin design of the digital multimeter.

[0072] In this embodiment, a first fuse F1 and a second fuse F2 are provided on the second plate body 128 of the circuit board 12, and the first fuse F1 and the second fuse F2 are used for overcurrent protection during large current measurement and small current measurement, respectively. The first fuse F1 and the second fuse F2 are located on the left and right sides of the battery compartment 22, respectively.

[0073] Figure 8 is with Figure 1 A schematic structural diagram of an embodiment of a protective cover 29 adapted to a digital multimeter is shown. Fig. 9 yes Figure 8 The protective sleeve is provided on Figure 1 The schematic diagram on the digital multimeter shown, Fig.10 yes Fig. 9 The protective cover 29 is a schematic diagram of the protective cover and the digital multimeter from another perspective. The protective cover 29 is used to be mounted on the housing 11 of the digital multimeter to protect the digital multimeter.

[0074] The front opening of the protective cover 29 includes a rear wall 290 and a side wall (not shown) extending forward from the periphery of the rear wall 290. The side wall of the protective cover 29 is provided with a plurality of first through holes 291 for the test leads to be inserted into the corresponding test lead input jacks 16 of the digital multimeter. The rear wall 291 of the protective cover 29 is provided with a second through hole 292 for the lighting lamp 18 of the digital multimeter to emit light. The side wall of the protective cover 29 is also provided with a third through hole 293 for the protrusion 1202 of the sensor sheet accommodating portion 1201 of the digital multimeter to extend out. The side wall of the protective cover 29 is also provided with a fourth through hole 294 for the switch button 123 of the digital multimeter to extend out. The side wall of the protective cover 29 is also provided with a fifth through hole 295 for the non-contact voltage / live wire measurement switching button 21 of the digital multimeter to extend out. The side wall of the protective cover 29 is also provided with a sixth through hole 296 for the non-contact voltage / live wire measurement switching button 21 of the digital multimeter to extend out.

[0075] In this embodiment, the side wall of the protective cover 29 includes a top side wall 297 and a bottom side wall 298 that are opposite to each other, and a left side wall 299 and a right side wall 300 that are opposite to each other. The plurality of first through holes 291 are arranged on the bottom side wall 298, the third through hole 293 is arranged on the top side wall 297, the fourth through hole 294 is arranged on the top side wall 297, the fifth through hole 295 is arranged on one of the left side wall 299 and the right side wall 300, and the sixth through hole 296 is arranged on the other of the left side wall 299 and the right side wall 300.

[0076] The left side wall 299 and the right side wall 300 of the protective cover 29 are respectively provided with anti-skid strips 301 and 302. The outer surface of the rear wall 290 of the protective cover 29 is provided with a first anti-skid protrusion 303 near the left side wall 299, the outer surface of the rear wall 290 of the protective cover 29 is provided with a second anti-skid protrusion 304 near the right side wall 300, and the outer surface of the rear wall 290 of the protective cover 29 is provided with a third anti-skid protrusion 305 near the bottom side wall 298. By providing the anti-skid strips 301 and 302, the first anti-skid protrusion 303, the second anti-skid protrusion 304 and the third anti-skid protrusion 305, a good anti-skid effect can be achieved when holding the protective cover 29.

[0077] The rear wall 290 of the protective cover 29 is further provided with a plurality of supporting protrusions 306 , and the plurality of supporting protrusions 306 are used to support the digital multimeter, so as to facilitate picking up the digital multimeter from the placement surface.

[0078] 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. A digital multimeter, characterized in that: The digital multimeter comprises a housing, a circuit board and a lens, wherein the circuit board is arranged in the housing, a display screen and a touch key unit are arranged on the front of the housing, the display screen and the touch key unit are both electrically connected to the circuit board, the lens is arranged on the front of the housing and completely covers the display screen and the touch key unit, and a plurality of test pen input jacks for inserting test pens are arranged on the side of the housing; The touch key unit adopts a capacitive touch key or a resistive touch key; The housing comprises a panel, a back panel opposite to the panel, and a side wall between the panel and the back panel, the multiple test pen input jacks are arranged on the side wall of the housing, a display window is provided on the panel of the housing facing the display screen, the touch key unit comprises a touch portion and a connection portion, the touch portion comprises a plurality of touch keys, the connection portion is used to be electrically connected to a circuit board, corresponding key marks are respectively arranged on the lens or the touch key unit corresponding to the plurality of touch keys to indicate the touch position of the touch key, and the corresponding touch key can be operated by touching the touch position indicated by the touch key mark on the lens surface; The outer surface of the panel of the shell is provided with a groove for accommodating the touch control part of the touch key unit, and the panel of the shell is provided with a through hole at the edge of the groove for the connecting part of the touch key unit to pass through and be electrically connected to the circuit board; The side wall comprises a top wall and a bottom wall which are arranged opposite to each other, and a left wall and a right wall which are arranged opposite to each other, and the plurality of test lead input jacks are arranged on the bottom wall; A plurality of jack prompt lights are arranged on the circuit board corresponding to the plurality of test lead input jacks, and the plurality of jack prompt lights are respectively used to light up when there are test leads in the corresponding test lead input jacks to prompt the user to insert the test leads into the corresponding test lead input jacks; The lens or the panel of the housing is provided with corresponding socket prompt marks corresponding to the plurality of socket prompt lights; The digital multimeter further comprises a plurality of first light guide elements, each of which is arranged opposite to a corresponding socket prompt light and is used to guide the light emitted by the socket prompt light to the corresponding socket prompt mark on the lens; The first light guide element comprises a light entrance portion and a light exit portion, the light entrance portion of the first light guide element is mounted on the inner surface of the panel of the housing, and the panel of the housing is provided with a light exit hole for inserting the light exit portion of the first light guide element corresponding to each first light guide element; The circuit board is also provided with a continuity test indicator light, which is used to emit light of corresponding color according to the continuity test result to indicate the continuity test result when performing the continuity test. The digital multimeter also includes a second light guide element, and the panel of the shell is provided with a light outlet corresponding to the light outlet part of the second light guide element. The second light guide element is used to guide the light emitted by the continuity test indicator light to the lens through the light outlet for display.

2. The digital multimeter according to claim 1, wherein: The shell body includes a front shell and a back shell, and a receiving space is formed by the front shell and the back shell. The circuit board and the display screen are arranged in the receiving space. The panel is formed on the front shell, and the back plate is formed on the back shell. A bottom baffle is provided at the bottom end of the back shell, and the multiple test pen input jacks are arranged on the bottom baffle. A plurality of jack spring clips are provided on the circuit board, and each jack spring clip is arranged in a corresponding test pen input jack.

3. The digital multimeter as claimed in claim 2, characterized in that: A top baffle is provided at the top of the back shell, a non-contact voltage sensing sheet is provided at the top of the circuit board, and a sensing sheet accommodating portion for accommodating the non-contact voltage sensing sheet is provided on the top baffle, and the sensing sheet accommodating portion protrudes outward to form a protrusion.

4. The digital multimeter as claimed in claim 3, characterized in that: The top baffle is provided with a switch button, and the switch button is used to control the opening and closing of the digital multimeter.

5. The digital multimeter according to claim 1, wherein: The multiple touch buttons include an intelligent measurement button, a manual measurement button, a large current / small current measurement switching button, a maximum / minimum value measurement button, an AC / DC measurement switching button, and a data hold function on / off button.

6. The digital multimeter according to claim 1, wherein: The plurality of test lead input jacks are arranged in a row at intervals on the bottom wall of the housing, and the plurality of first light guide elements are arranged in a row and correspond to the plurality of test lead input jacks respectively.

7. The digital multimeter according to any one of claims 1 to 6, characterized in that: The number of the test lead input jacks is four, namely a large current measurement input jack, a small current measurement input jack, a common terminal input jack, and a voltage / resistance measurement input jack.

8. The digital multimeter according to claim 2, wherein: The multiple test lead input jacks are arranged on the bottom baffle, the outer ends of the multiple test lead input jacks are connected through the bottom baffle, and a reinforcing rib is connected between two adjacent test lead input jacks, and the reinforcing rib is also connected to the bottom baffle.

9. The digital multimeter according to claim 2 or 8, characterized in that: A first positioning portion is provided on the face shell corresponding to the test pen input jack, and a second positioning portion is provided on the back shell corresponding to the test pen input jack. The second positioning portion is installed and positioned by the first positioning portion and the second positioning portion. The first positioning portion and the second positioning portion are both formed with an arc-shaped positioning groove. The inner surface of the face shell is formed with two first card grooves arranged opposite to each other. The left and right ends of the bottom baffle are respectively clamped in the two first card grooves. The inner surface of the face shell is also formed with a second card groove connected between the two first card grooves, and one side edge of the bottom baffle is clamped in the second card groove.

10. The digital multimeter according to claim 1, wherein: The digital multimeter further comprises an illumination lamp, which is mounted on the back of the circuit board. The back plate of the housing is provided with a light exit window corresponding to the illumination lamp, and a lampshade is provided at the light exit window.

11. The digital multimeter according to claim 10, wherein: A lighting key is arranged on the side wall of the shell, and the lighting key is used to control the turning on and off of the lighting.

12. The digital multimeter according to claim 1, wherein: A non-contact voltage / live line measurement switching button is also provided on the side wall of the housing, and the non-contact voltage / live line measurement switching button is used to switch between the non-contact voltage measurement function and the live line detection function.

13. The digital multimeter according to claim 2, wherein: In this embodiment, the circuit board includes a first plate body and a second plate body, and the first plate body and the second plate body are staggered with each other in the thickness direction of the shell. The first plate body is arranged corresponding to the display screen, and the second plate body is arranged corresponding to the touch button unit. The bottom end of the first plate body is electrically connected to the top end of the second plate body, and the second plate body is arranged closer to the panel than the first plate body.

14. The digital multimeter according to claim 13, wherein: The back shell of the digital multimeter is provided with a battery compartment for installing batteries, the back plate is provided with a compartment opening corresponding to the battery compartment, a detachable battery cover is installed on the back shell for closing the compartment opening, and the battery compartment is arranged opposite to the second plate body.

15. The digital multimeter according to claim 14, wherein: The inner surface of the battery cover is provided with a battery positioning groove to position and limit the battery.

16. The digital multimeter according to claim 14, wherein: A first fuse and a second fuse are provided on the second plate body of the circuit board. The first fuse and the second fuse are used for overcurrent protection during large current measurement and small current measurement, respectively. The first fuse and the second fuse are located on the left and right sides of the battery compartment, respectively.

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