CN209946859U

CN209946859U - Touch display

Info

Publication number: CN209946859U
Application number: CN201920860392.7U
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 Technology Co ltd
Priority date: 2019-06-06
Filing date: 2019-06-06
Publication date: 2020-01-14
Anticipated expiration: 2029-06-06

Abstract

The utility model discloses a touch display, which comprises a singlechip, a touch chip, a voltage reduction module, a key module, a state indication module and a power module, wherein the singlechip, the voltage reduction module, the key module, the state indication module and the power module are all connected with the touch chip; the power module comprises a transformer, a rectifier bridge, a first capacitor, a relay, a first resistor, a first diode, a second resistor, a second diode, a first triode, a second triode, a third resistor, a second triode, a fourth resistor, a third diode, a second capacitor, a fifth resistor, a fourth diode, a third triode and a third capacitor, one end of a primary coil of the transformer is connected with one end of 220V alternating current, and the other end of the primary coil of the transformer is connected with the other end of the 220V alternating current. Implement the utility model discloses a touch display has following beneficial effect: the circuit structure is simpler, the cost is lower, convenient maintenance, the security and the reliability of circuit are higher.

Description

Touch display

Technical Field

The utility model relates to a display field, in particular to touch display.

Background

The touch display can enable a user to operate the host machine by lightly touching icons or characters on a computer display screen with fingers, so that the operation of a keyboard and a mouse is avoided, and the man-machine interaction is more straightforward. The method is mainly applied to information inquiry, leadership office work, electronic games, song and dish ordering, multimedia teaching, air ticket/train ticket pre-sale and the like of halls in public places. The products are mainly classified into capacitive touch screens, resistive touch screens and surface acoustic wave touch screens. The power supply part of the traditional touch display uses more components, the circuit structure is complex, the hardware cost is high, and the maintenance is inconvenient. In addition, since the power supply part of the conventional touch display lacks a corresponding circuit protection function, 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, a circuit structure is comparatively simple, the cost is lower, the security and the higher touch display of reliability of convenient maintenance, circuit is provided.

The utility model provides a technical scheme that its technical problem adopted is: the touch display is constructed and comprises a single chip microcomputer, a touch chip, a voltage reduction module, a key module, a state indication module and a power module, wherein the single chip microcomputer, the voltage reduction module, the key module, the state indication module and the power module are all connected with the touch chip;

the power module comprises a transformer, a rectifier bridge, a first capacitor, a relay, a first resistor, a first diode, a second resistor, a second diode, a first triode, a second triode, a third resistor, a second triode, a fourth resistor, a third diode, a second capacitor, a fifth resistor, a fourth diode, a third triode and a third capacitor, one end of a primary coil of the transformer is connected with one end of 220V alternating current, the other end of the primary coil of the transformer is connected with the other end of the 220V alternating current, one end of a secondary coil of the transformer is connected with one input end of the rectifier bridge, the other end of the secondary coil of the transformer is connected with the other input end of the rectifier bridge, one output end of the rectifier bridge is respectively connected with one end of a contact of the relay and one end of the first capacitor, and the other end of the contact of the relay is respectively connected with one end of the first resistor, the second resistor, the third resistor, the, One end of a second resistor is connected with a collector of a first triode, the other end of the first resistor is respectively connected with a cathode of the first diode and an anode of the second diode, the other end of the second resistor is respectively connected with a base of the first triode and a collector of the second triode, an emitter of the second triode is connected with one end of a third resistor, an emitter of the first triode is respectively connected with a cathode of the third diode, one end of a fifth resistor, an anode of a fourth diode and one end of a third capacitor, an anode of the third diode is connected with one end of a coil of the relay, the other end of the coil of the relay is respectively connected with a cathode of the second diode, one end of a fourth resistor, a base of the second triode and one end of a second capacitor, and the other end of the fifth resistor is connected with a base of the third triode, the cathode of the fourth diode is connected with the emitter of the third triode, the other output end of the rectifier bridge is respectively connected with the other end of the first capacitor, the anode of the first diode, the other end of the third resistor, the other end of the fourth resistor, the other end of the second capacitor, the collector of the third triode and the other end of the third capacitor, and the fourth diode is S-123T in model.

In the touch display of the present invention, the power module further includes a fourth capacitor, one end of the fourth capacitor is connected to the base of the first triode, the other end of the fourth capacitor is connected to the collector of the second triode, and the capacitance of the fourth capacitor is 420 pF.

In the touch display of the present invention, the power module further includes a sixth resistor, one end of the sixth resistor is connected to the emitter of the first triode, the other end of the sixth resistor is connected to the cathode of the third diode, and the resistance of the sixth resistor is 32k Ω.

In the touch display of the present invention, the power module further includes a fifth diode, a cathode of the fifth diode is connected to the base of the second triode, an anode of the fifth diode is connected to one end of the second capacitor, and a model of the fifth diode is E-183.

In the touch display of the present invention, the first transistor and the second transistor are NPN transistors, and the third transistor is a PNP transistor.

Implement the utility model discloses a touch display has following beneficial effect: the single chip microcomputer, the touch chip, the voltage reduction module, the key module, the state indication module and the power module are arranged; the power module includes the transformer, the rectifier bridge, first electric capacity, the relay, first resistance, first diode, the second resistance, the second diode, first triode, the second triode, the third resistance, the second triode, the fourth resistance, the third diode, the second electric capacity, the fifth resistance, the fourth diode, third triode and third electric capacity, this power module compares with traditional touch display's power supply part, the components and parts that it used are less, owing to saved some components and parts, can reduce the hardware cost like this, in addition, the fourth diode is used for carrying out current-limiting protection, therefore the utility model discloses circuit structure is comparatively simple, the cost is lower, convenient maintenance, the security and the reliability of circuit are higher.

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 structural diagram of an embodiment of a touch display device according to the present invention;

fig. 2 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 touch display of the present invention, a schematic structural diagram of the touch display is shown in fig. 1. In fig. 1, the touch display includes a single chip microcomputer 1, a touch chip 2, a voltage reduction module 3, a key module 4, a status indication module 5 and a power module 6, and the single chip microcomputer 1, the voltage reduction module 3, the key module 4, the status indication module 5 and the power module 6 are all connected with the touch chip 2. The voltage reduction module 3 is used for reducing the input voltage and then outputting the reduced voltage; the key module 4 is used for sensing finger touch; the state indicating module 5 is used for indicating and sensing the touch by the key module 4; when the key module 4 is touched, a touch signal is output to the singlechip 1.

It should be noted that in this embodiment, the single chip microcomputer 1, the touch chip 2, the voltage reduction module 3, the key module 4, and the state indication module 5 all adopt any structure capable of implementing their functions in the prior art, and the working principle also uses the working principle in the prior art, which is not described here.

Fig. 2 is a schematic circuit diagram of a power module in this embodiment, in fig. 2, the power module 6 includes a transformer T, a rectifier bridge Z, a first capacitor C1, a relay K, a first resistor R1, a first diode D1, a second resistor R2, a second diode D2, a first transistor Q1, a second transistor Q2, a third resistor R3, a second transistor Q2, a fourth resistor R4, a third diode D3, a second capacitor C2, a fifth resistor R5, a fourth diode D4, a third transistor Q3, and a third capacitor C3, one end of a primary coil of the transformer T is connected to one end of 220V ac power, the other end of the primary coil of the transformer T is connected to the other end of 220V ac power, one end of a secondary coil of the transformer T is connected to one input end of the rectifier bridge Z, one output end of the rectifier bridge Z is connected to one end of a contact point of the relay K and one end of the first capacitor C1, the other end of the contact of the relay K is respectively connected with one end of a first resistor R1, one end of a second resistor R2 and the collector of a first triode Q1, the other end of a first resistor R1 is respectively connected with the cathode of a first diode D1 and the anode of a second diode D2, the other end of a second resistor R2 is respectively connected with the base of a first triode Q1 and the collector of a second triode Q2, the emitter of a second triode Q2 is connected with one end of a third resistor R3, the emitter of a first triode Q1 is respectively connected with the cathode of a third diode D3, one end of a fifth resistor R5, the anode of a fourth diode D4 and one end of a third capacitor C3, the anode of a third diode D3 is connected with one end of the coil of the relay K, the other end of the coil of the relay K is respectively connected with the cathode of a second diode D2, one end of a fourth resistor R4, one end of a base of a second triode Q2 and one end of a second capacitor C2, the other end of the fifth resistor R5 is connected with the base of the third triode Q3, the cathode of the fourth diode D4 is connected with the emitter of the third triode Q3, and the other output end of the rectifier bridge Z is connected with the other end of the first capacitor C1, the anode of the first diode D1, the other end of the third resistor R3, the other end of the fourth resistor R4, the other end of the second capacitor C2, the collector of the third triode Q3 and the other end of the third capacitor C3.

Compared with the power supply part of the traditional touch display, the power supply module 6 has the advantages of fewer used components, simpler circuit structure and convenience in maintenance, and can reduce the hardware cost due to the fact that some components are saved. In addition, the fourth diode D4 is a current limiting diode for performing current limiting protection on the emitter current of the triode Q3, and the principle of the current limiting protection is as follows: when the emitter current of the third triode Q3 is large, the fourth diode D4 can reduce the emitter current of the third triode Q3 to keep the third triode Q3 in a normal working state, so that the elements in the circuit are not burnt out due to too large current, and the safety and reliability of the circuit are high. It should be noted that in the present embodiment, the model of the fourth diode D4 is S-123T, and certainly, in practical applications, other models of diodes with similar functions may be adopted as the fourth diode D4.

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

The working principle of the power module 6 is as follows: the power supply voltage is obtained by voltage reduction of a transformer T, rectification of a rectifier bridge Z and filtering of a first capacitor C1, and the relay K is a normally closed contact relay. The first diode D1, the second diode D2 and the first resistor R1 form a start circuit, and the second resistor R2 provides a start bias current for the base of the first transistor Q1. After starting, the base potential of the second triode Q2 is higher than the stable value of the first diode D1, the second diode D2 is reversely biased, and the starting circuit is disabled. The third diode D3 is a circuit protection diode, under normal conditions, the third diode D3 is turned off in the reverse direction, the relay K does not operate, when the output end is short-circuited, the cathode potential of the third diode D3 is approximately grounded, therefore, the base of the first triode Q1 flowing from the second diode D2 starts the bias current to form a loop through the relay K and the third diode D3, the third diode D3 emits light to serve as a light indication, the contact K-1 of the relay K is disconnected at the moment, due to the effect of the second capacitor C2, the time delay function is provided, the repeated operation of the relay K is effectively avoided, when the contact K-1 of the relay K is disconnected due to the short circuit, the circuit loses power, the base voltage of the third triode Q3 is reduced and is conducted, and at the moment, the electric energy stored in the third capacitor C3 discharges to the third triode Q3.

In this embodiment, the power module 6 further includes a fourth capacitor C4, one end of the fourth capacitor C4 is connected to the base of the first transistor Q1, and the other end of the fourth capacitor C4 is connected to the collector of the second transistor Q2. The fourth capacitor C4 is a coupling capacitor for preventing interference between the first transistor Q1 and the second transistor Q2, 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 fourth electric capacity C4 as coupling element, can make the operating point of back one-level not receive the influence of preceding one-level like this, that is to say make second triode Q2's operating point not receive first triode Q1's influence. The fourth capacitor C4 is an inter-stage coupling capacitor, and functions to isolate the dc bias circuits of the front and rear stages of the first transistor Q1 and the second transistor Q2, 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 value of the fourth capacitor C4 is 420 pF. Of course, in practical applications, the capacitance value of the fourth capacitor C4 may be adjusted accordingly, that is, the capacitance value of the fourth capacitor C4 may be increased or decreased accordingly.

In this embodiment, the power module 6 further includes a sixth resistor R6, one end of the sixth resistor R6 is connected to the emitter of the first transistor Q1, and the other end of the sixth resistor R6 is connected to the cathode of the third diode D3. The sixth resistor R6 is a current limiting resistor, and is used for current limiting protection of the emitter current of the first transistor Q1, so as to further enhance the safety and reliability of the circuit. The current limiting protection principle is as follows: when the emitter current of the first triode Q1 is large, the sixth resistor R6 can reduce the emitter current of the first triode Q1 to keep the emitter current in a normal operating state, so that the elements in the circuit are not burnt out due to too large current.

It should be noted that, in the present embodiment, the resistance of the sixth resistor R6 is 32k Ω. Of course, in practical applications, the resistance of the sixth resistor R6 may be adjusted according to specific situations, that is, the resistance of the sixth resistor R6 may be increased or decreased according to specific situations.

In this embodiment, the power module 6 further includes a fifth diode D5, a cathode of the fifth diode D5 is connected to a base of the second transistor Q2, and an anode of the fifth diode D5 is connected to one end of the second capacitor C2. The fifth diode D5 is a current limiting diode, and is used for current limiting protection of the base current of the second transistor Q2, so as to further enhance the current limiting effect. The current limiting protection principle is as follows: when the base current of the second triode Q2 is large, the base current of the second triode Q2 can be reduced by the fifth diode D5 to keep the second triode Q2 in a normal working state, so that the components in the circuit cannot be burnt out due to too large current.

It should be noted that in the present embodiment, the fifth diode D5 has a model number E-183. Of course, in practical applications, the fifth diode D5 may also be another type of diode with similar functions.

In a word, in this embodiment, compared with the power supply part of the conventional touch display, the power supply module 6 has fewer used components, a simpler circuit structure and convenience in maintenance, and can reduce the hardware cost due to the fact that some components are saved. In addition, the power module 6 is provided with a current-limiting diode, so that the safety and the 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 touch display is characterized by comprising a single chip microcomputer, a touch chip, a voltage reduction module, a key module, a state indication module and a power module, wherein the single chip microcomputer, the voltage reduction module, the key module, the state indication module and the power module are all connected with the touch chip;

2. The touch display of claim 1, wherein the power module further comprises a fourth capacitor, one end of the fourth capacitor is connected to the base of the first transistor, the other end of the fourth capacitor is connected to the collector of the second transistor, and the fourth capacitor has a capacitance of 420 pF.

3. The touch display of claim 2, wherein the power module further comprises a sixth resistor, one end of the sixth resistor is connected to the emitter of the first transistor, the other end of the sixth resistor is connected to the cathode of the third diode, and the resistance of the sixth resistor is 32k Ω.

4. The touch display of claim 3, wherein the power module further comprises a fifth diode, a cathode of the fifth diode is connected to the base of the second transistor, an anode of the fifth diode is connected to one end of the second capacitor, and the fifth diode is of type E-183.

5. The touch display of any one of claims 1 to 4, wherein the first transistor and the second transistor are both NPN transistors and the third transistor is a PNP transistor.