CN209946752U

CN209946752U - Conference integrated machine

Info

Publication number: CN209946752U
Application number: CN201920948207.XU
Authority: CN
Inventors: 周美贤; 岑祥庆; 陈永淮; 谢奇君
Original assignee: Guangzhou Touch-Pie Electronic Technology Co Ltd
Current assignee: Guangzhou Touch-Pie Electronic Technology Co Ltd
Priority date: 2019-06-21
Filing date: 2019-06-21
Publication date: 2020-01-14
Anticipated expiration: 2029-06-21

Abstract

The utility model discloses a conference all-in-one machine, which comprises a liquid crystal display screen and a shell, wherein an image processing circuit, a power supply module, a built-in camera and an output interface are arranged in the shell, and the image processing circuit is respectively connected with the liquid crystal display screen, the power supply module, the output interface and the camera interface of the built-in camera; the power module comprises a first direct-current power supply, a second direct-current power supply, a first voltage stabilizing diode, a first triode, a first resistor, a second voltage stabilizing diode, a first MOS (metal oxide semiconductor) tube, a voltage comparator, a second resistor, a third resistor, a fourth resistor, a second triode, a third triode, a fifth resistor and a voltage output end, wherein the first direct-current power supply is connected with the cathode of the first voltage stabilizing diode, the emitting electrode of the first triode, one end of the first resistor, the source electrode of the first MOS tube and one end of the fifth resistor. The utility model discloses circuit structure is comparatively simple, the cost is lower, the security and the reliability of convenient maintenance, circuit are higher.

Description

Conference integrated machine

Technical Field

The utility model relates to an electronic circuit field, in particular to meeting all-in-one.

Background

The conference all-in-one machine integrates the advanced technologies of a touch screen, an industrial control computer, a computer and the like, can realize public information inquiry, and can realize specific requirements of fingerprint attendance checking, card swiping, printing and the like by being matched with peripherals such as a fingerprint instrument, a scanner, a card reader, a micro printer and the like. The touch screen comprises four-wire or five-wire resistance screens, surface acoustic wave screens, infrared screens, holographic nano touch films and other excellent touch screens at home and abroad, and can meet the application requirements of users in different regions and places.

Fig. 1 is a schematic circuit diagram of a power supply portion of a conventional conference all-in-one machine, and it can be seen from fig. 1 that the power supply portion of the conventional conference all-in-one machine uses many components, has a complex circuit structure, has high hardware cost, and is inconvenient to maintain. In addition, because the power supply part of the traditional conference all-in-one machine lacks corresponding circuit protection functions, for example: the safety and reliability of the circuit are poor due to the lack of the current-limiting protection function.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model lies in, to the above-mentioned defect of prior art, provide a circuit structure comparatively simple, the cost is lower, the security and the higher meeting all-in-one of reliability of convenient maintenance, circuit.

The utility model provides a technical scheme that its technical problem adopted is: the conference all-in-one machine is constructed and comprises a liquid crystal display screen and a shell, wherein an image processing circuit, a power supply module, a built-in camera and an output interface are arranged in the shell, the image processing circuit is respectively connected with the liquid crystal display screen, the power supply module, the output interface and the camera interface of the built-in camera, and the camera interface of the built-in camera is arranged at the outer edge of the shell;

the power supply module comprises a first direct current power supply, a second direct current power supply, a first voltage stabilizing diode, a first triode, a first resistor, a second voltage stabilizing diode, a first MOS (metal oxide semiconductor) tube, a voltage comparator, a second resistor, a third resistor, a fourth resistor, a second triode, a third triode, a fifth resistor and a voltage output end, wherein the first direct current power supply is respectively connected with a cathode of the first voltage stabilizing diode, an emitting electrode of the first triode, one end of the first resistor, a source electrode of the first MOS tube and one end of the fifth resistor, the other end of the first resistor is respectively connected with a collector electrode of the first triode, a cathode of the second voltage stabilizing diode, a grid electrode of the first MOS tube and a collector electrode of the second triode, an anode of the first voltage stabilizing diode and an anode of the second voltage stabilizing diode are both grounded, a base electrode of the first triode is connected with the output end of the voltage comparator, the second direct current power supply is respectively connected with an anode power supply end of the voltage comparator and a non-inverting input end of the voltage comparator, an inverting input end of the voltage comparator is respectively connected with one end of the second resistor and one end of the third resistor, a drain electrode of the first MOS tube is respectively connected with one end of the second resistor, one end of the fourth resistor and a voltage output end, a cathode power supply end of the voltage comparator, the other end of the third resistor and an emitter of the third triode are all grounded, the emitter of the second triode is connected with the other end of the fifth resistor, a base of the second triode is connected with a collector of the third triode, a base of the third triode is connected with the other end of the fourth resistor, and a resistance value of the fifth resistor is 42k omega.

In the conference all-in-one machine, the power module further comprises a first capacitor, one end of the first capacitor is connected with the base of the second triode, the other end of the first capacitor is connected with the collector of the third triode, and the capacitance value of the first capacitor is 280 pF.

In the conference all-in-one machine, the power module further comprises a third diode, a cathode of the third diode is connected with a base of the first triode, an anode of the third diode is connected with an output end of the voltage comparator, and a model of the third diode is S-452T.

In the conference all-in-one machine, the first MOS transistor is a P-channel MOS transistor.

In the conference all-in-one machine, the first triode and the third triode are NPN type triodes, and the second triode is a PNP type triode.

Implement the utility model discloses a conference all-in-one has following beneficial effect: the liquid crystal display screen and the shell are arranged, and an image processing circuit, a power supply module, a built-in camera and an output interface are arranged in the shell; the power module comprises a first direct-current power supply, a second direct-current power supply, a first voltage stabilizing diode, a first triode, a first resistor, a second voltage stabilizing diode, a first MOS (metal oxide semiconductor) tube, a voltage comparator, a second resistor, a third resistor, a fourth resistor, a second triode, a third triode, a fifth resistor and a voltage output end, the power module is compared with a power supply part of a traditional conference all-in-one machine, fewer components and parts are used, hardware cost can be reduced due to the fact that some components and parts are saved, in addition, the fifth resistor is used for conducting current limiting protection on emitter current of the second triode, and therefore the circuit structure is simple, low in cost, convenient to maintain, and high in safety and reliability of the circuit.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic circuit diagram of the power supply portion of a conventional integrated conference machine;

fig. 2 is a schematic structural diagram of an embodiment of the integrated conference machine of the present invention;

fig. 3 is a schematic circuit diagram of the power supply module in the embodiment.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the embodiment of the conference all-in-one machine of the present invention, the schematic structural diagram of the conference all-in-one machine is shown in fig. 2. In fig. 2, the conference all-in-one machine includes a liquid crystal display screen 1 and a casing 2, an image processing circuit 21, a power module 22, a built-in camera 23 and an output interface 24 are arranged in the casing 2, wherein the image processing circuit 21 is respectively connected with the liquid crystal display screen 1, the power module 22, the output interface 24 and the camera interface of the built-in camera 23, and the camera interface of the built-in camera 23 is arranged at the outer edge of the casing 2.

In this embodiment, the number of the built-in cameras 23 is two, and the two built-in cameras 23 are respectively placed above or below the liquid crystal display screen 1. Two built-in cameras 23 are respectively placed on the upper and lower sides/left side/right side/upper and lower opposite angles of the liquid crystal display screen; the angle of the face can be switched by the built-in camera 23 to obtain another visual angle, so that the user experience is good.

In this embodiment, the image processing circuit 21, the built-in camera 23, and the output interface 24 are all implemented by using the structure in the prior art, and the working principle thereof is also the working principle in the prior art, which is not described here.

Fig. 3 is a schematic circuit diagram of the power module in this embodiment, in fig. 3, the power module 22 includes a first dc power VCC, a second dc power VDD, a first zener diode D1, a first transistor Q1, a first resistor R1, a second zener diode D2, a first MOS transistor M1, a voltage comparator a1, a second resistor R2, a third resistor R3, a fourth resistor R4, a second transistor Q2, a third transistor Q3, a fifth resistor R5, and a voltage output Vo, wherein the first dc power VCC is respectively connected to a cathode of the first zener diode D1, an emitter of the first transistor Q1, one end of the first resistor R1, a source of the first MOS transistor M1, and one end of the fifth resistor R5, the other end of the first resistor R1 is respectively connected to a collector of the first transistor 46q 48, a cathode of the second zener diode D5, a cathode of the first MOS transistor M1, and a collector 573q 57324, the anode of the first zener diode D1 and the anode of the second zener diode D2 are both grounded, the base of the first triode Q1 is connected to the output terminal of the voltage comparator a1, the second dc power VDD is connected to the positive power terminal of the voltage comparator a1 and the non-inverting input terminal of the voltage comparator a1, the inverting input terminal of the voltage comparator a1 is connected to one end of the second resistor R2 and one end of the third resistor R3, the drain of the first MOS transistor M1 is connected to one end of the second resistor R2, one end of the fourth resistor R4 and the voltage output Vo, and the negative power terminal of the voltage comparator a1, the other end of the third resistor R3 and the emitter of the third triode Q3 are both grounded, the emitter of the second triode Q2 is connected with the other end of the fifth resistor R5, the base of the second triode Q2 is connected with the collector of the third triode Q3, and the base of the third triode Q3 is connected with the other end of the fourth resistor R4.

Compared with the power supply part of the traditional conference all-in-one machine in fig. 1, the power supply module 22 has the advantages of fewer used components, simpler circuit structure and convenient maintenance, and can reduce the hardware cost due to the saving of some components. In addition, the fifth resistor R5 is a current limiting resistor, and is used for current limiting protection of the emitter current of the second transistor Q2. The current limiting protection principle is as follows: when the emitter current of the second triode Q2 is large, the emitter current of the second triode Q2 can be reduced by the fifth resistor R5 to keep the second triode Q2 in a normal working state, so that the situation that components in the circuit are burnt out due to too large current is avoided, the safety and reliability of the circuit are high, and the technical effect better than that of the conventional technology is achieved by fewer components.

It should be noted that, in the present embodiment, the resistance of the fifth resistor R5 is 42k Ω. It should be noted that, in this embodiment, the resistance of the fifth resistor R5 may be adjusted according to specific situations, that is, the resistance of the fifth resistor R5 may be increased or decreased according to specific situations.

This power module 22 can be stabilized power supply voltage at 5V, provides stable operating current simultaneously, consequently can effectively ensure built-in camera 23 steady operation, takes out high quality picture, effectively prevents simultaneously that power supply from being snapshotted in the twinkling of an eye heavy current and damaging.

In this embodiment, the first MOS transistor M1 is a P-channel MOS transistor, the first transistor Q1 and the third transistor Q3 are both NPN transistors, and the second transistor Q2 is a PNP transistor. Certainly, in practical applications, the first MOS transistor M1 may also be an N-channel MOS transistor, and the first transistor Q1 and the third transistor Q3 may also be NPN transistors, but the circuit structure is also changed accordingly.

In this embodiment, the voltage comparator a1 is of type LM293, the first transistor Q1 and the third transistor Q3 are of type SS8050, and the second transistor Q2 is of type SS 8550. The model of the first MOS transistor M1 is IRF 4435. The first zener diode D1 has a model number of 1N 5986B. The second zener diode D2 is model 1N 4744A.

In this embodiment, the power module 22 further includes a first capacitor C1, one end of the first capacitor C1 is connected to the base of the second transistor Q2, and the other end of the first capacitor C1 is connected to the collector of the third transistor Q2. The first capacitor C1 is a coupling capacitor for preventing interference between the second transistor Q2 and the third transistor Q3, so as to further enhance the safety and reliability of the circuit.

The effect of the coupling capacitor is: an ac signal is passed from a previous stage to a next stage. The coupling method is also a direct coupling and a transformer coupling method. The direct coupling efficiency is highest, the signal is not distorted, but the adjustment of the front and rear two-stage working points is complex and mutually involved. In order to prevent the working point of the next stage from being affected by the previous stage, the previous stage and the next stage need to be separated in terms of direct current, and meanwhile, the alternating current signal can be smoothly transmitted from the previous stage to the next stage. They can both transmit AC signals and cut off DC, so that the working points of the front and rear stages are not involved. However, the difference is that the phase of the signal is delayed a little when the signal is transmitted by a capacitor, and the high frequency component of the signal is lost a little when the signal is transmitted by a transformer. Generally, a capacitor is commonly used as a coupling element in small signal transmission, and a transformer is commonly used as a coupling element in large signal or strong signal transmission. The utility model discloses in adopt first electric capacity C1 as coupling element, can make the operating point of back one-level not receive the influence of preceding one-level like this, also make the operating point of third triode Q3 not receive the influence of second triode Q2 exactly. The first capacitor C1 is an inter-stage coupling capacitor, and functions to isolate the dc bias circuits of the front and rear stages of the second transistor Q2 and the third transistor Q3, so as to prevent the static operating points of the front and rear stages from affecting each other. The working principle of the method utilizes the working principle of interstage coupling electricity in the prior art, and the mastiff is not described herein.

It should be noted that, in the present embodiment, the capacitance of the first capacitor C1 is 280 pF. Of course, in practical applications, the capacitance value of the first capacitor C1 may be adjusted accordingly, that is, the capacitance value of the first capacitor C1 may be increased or decreased accordingly.

In this embodiment, the power module 22 further includes a third diode D3, a cathode of the third diode D3 is connected to a base of the first transistor Q1, and an anode of the third diode D3 is connected to an output terminal of the voltage comparator a 1. The third diode D3 is a current limiting diode, and is used for current limiting protection of the base current of the first transistor Q1. The current limiting protection principle is as follows: when the emitter current of the second triode Q2 is large, the emitter current of the second triode Q2 can be reduced by the fifth resistor R5 to keep the second triode Q2 in a normal working state, so that the elements in the circuit are not burnt out due to the large current, and the safety and reliability of the circuit are further enhanced.

It should be noted that in the present embodiment, the third diode D3 has a model number S-452T. Of course, in practical applications, the third diode D3 may also be another type of diode with similar functions.

In short, in this embodiment, compared with the power supply part of the conventional conference all-in-one machine, the power supply module 22 uses fewer components, has a simpler circuit structure, is convenient to maintain, and can reduce the hardware cost due to the fact that some components are saved. In addition, since the power supply module 22 is provided with a current limiting resistor, the safety and reliability of the circuit are high.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A conference all-in-one machine is characterized by comprising a liquid crystal display screen and a shell, wherein an image processing circuit, a power supply module, a built-in camera and an output interface are arranged in the shell, the image processing circuit is respectively connected with the liquid crystal display screen, the power supply module, the output interface and the camera interface of the built-in camera, and the camera interface of the built-in camera is arranged at the outer edge of the shell;

2. The all-in-one conference machine according to claim 1, wherein the power supply module further comprises a first capacitor, one end of the first capacitor is connected with the base electrode of the second triode, the other end of the first capacitor is connected with the collector electrode of the third triode, and the capacitance value of the first capacitor is 280 pF.

3. The conference all-in-one machine of claim 2, wherein the power supply module further comprises a third diode, a cathode of the third diode is connected with a base electrode of the first triode, an anode of the third diode is connected with an output end of the voltage comparator, and the type of the third diode is S-452T.

4. The all-in-one conference machine according to any one of claims 1 to 3, wherein the first MOS transistor is a P-channel MOS transistor.

5. The all-in-one conference machine according to any one of claims 1 to 3, wherein the first triode and the third triode are both NPN type triodes, and the second triode is a PNP type triode.