CN102567265B - Touch module switching circuit for all-in-one computer - Google Patents

Abstract

An all-in-one touch module switching circuit, including a USB display circuit, a touch module, a USB interface, first and second diodes, and a USB switching chip, and the voltage pin of the USB interface is connected to the anode of the first diode , is also connected to the input terminal of the switching chip through a resistor, the input terminal is grounded through a resistor, the cathode of the first diode is connected to the voltage terminal of the switching chip and the voltage pin of the touch module, and the data pin of the USB interface is connected to Switch the two input terminals of the chip, the anode of the second diode is connected to the power supply pin of the display circuit, the cathode is connected to the cathode of the first diode, and the two data pins of the display circuit are connected to the other two input terminals of the switching chip , the two output terminals of the switching chip are connected to the two data pins of the touch module. The all-in-one machine touch module switching circuit can make the all-in-one machine be used as a display by another computer.

Description

All-in-one touch module switching circuit

technical field

The invention relates to a switching circuit of a touch module of an all-in-one machine.

Background technique

At present, the all-in-one computer (Allinone computer) has been more and more widely used in work and life, and the touch module (touch panel and USB control panel) therein has also become the standard equipment of the all-in-one computer. Since the all-in-one machine has been integrated in a casing, its appearance is similar to a monitor of a desktop computer. If the all-in-one machine can be used as a display by another computer, the functions of the all-in-one machine can be expanded and its added value can be increased.

Contents of the invention

In view of the above, it is necessary to provide a touch module switching circuit for an all-in-one machine, through which the touch module switching circuit for an all-in-one machine can be used as a display by another computer.

An all-in-one touch module switching circuit, including a USB display circuit, a touch module, a USB interface, first and second diodes, a USB switching chip, first and second resistors, the USB interface The voltage pin is connected to the anode of the first diode, and also connected to the input end of the USB switch chip through the first resistor, the input end of the USB switch chip is grounded through the second resistor, and the first diode The cathode is connected to the voltage terminal of the USB switching chip and the voltage pin of the touch module, and the two data pins of the USB interface are respectively connected to the first switching input terminal and the third switching input terminal of the USB switching chip. The anode of the two diodes is connected to the power pin of the USB display circuit, the cathode is connected to the cathode of the first diode, and the two data pins of the USB display circuit are respectively connected to the second switching input of the USB switching chip terminal and the fourth switching input terminal, the first switching output terminal and the second switching output terminal of the USB switching chip are respectively connected to the two data pins of the touch module, if the input terminal of the USB switching chip is high level, The first switching input end is electrically connected to the first switching output end, and the third switching input end is electrically connected to the second switching output end; if the input end of the USB switching chip is low level, the second switching input end is electrically connected to the first switching output end, and the fourth switching input end is electrically connected to the second switching output end.

The above-mentioned all-in-one touch module switching circuit detects whether it is connected to an external computer through the USB interface, and if it is connected to an external computer, it controls the USB switching chip to switch the communication between the touch module and the USB interface, so that the external computer can The all-in-one machine is used as a monitor, and the operation is very convenient.

Description of drawings

The present invention will be described in further detail below in conjunction with preferred embodiment with reference to accompanying drawing:

FIG. 1 is a circuit diagram of a preferred embodiment of the switching circuit of the all-in-one machine touch module of the present invention.

Description of main component symbols

All-in-one machine touch module switching circuit 100

USB interface 10

USB display circuit 20

Touch module 30

Voltage Converter 40

USB switching chip 50

first diode D1

second diode D2

Resistors R1-R3

detailed description

Please refer to FIG. 1 , the all-in-one machine touch module switching circuit 100 of the present invention is applied to the all-in-one machine, and is used to make the all-in-one machine be used as a display by another computer. The preferred implementation of the all-in-one machine touch module switching circuit 100 The method includes a USB display circuit 20 and a touch module 30, when the USB display circuit 20 is connected to the corresponding USB pin (voltage pin VCC, data pin D+ and D-, ground pin GND) of the touch module 30 At this time, the all-in-one machine can realize the communication between the internal motherboard of the all-in-one machine and the touch panel in the touch module 30 through the USB display circuit 20 and the touch module 30, thereby realizing the display and control of the touch panel, because the USB display circuit 20 and the touch module 30 are in the prior art, so no specific description is given here.

The preferred embodiment of the all-in-one touch module switching circuit 100 also includes a USB interface 10, a first diode D1, a second diode D2, a voltage converter 40, a USB switching chip 50 and three A resistor R1-R3. Among them, the USB switching chip 50 of model MAX4906EF is selected in this embodiment, which includes an input terminal IN, an enable terminal /QP, a voltage terminal V+, a ground terminal GND, a first switching input terminal NO1, a first Two switch input terminals NC1, one third switch input terminal NO2, one fourth switch input terminal NC2, one first switch output terminal COM1 and one second switch output terminal COM2, when the enable terminal /QP is low, the USB The switching chip 50 is in a normal working state. In the normal working state, if the input terminal IN is at a high level, the first switching input terminal NO1 is electrically connected to the first switching output terminal COM1, and the third switching input terminal NO2 is connected to the second switching output terminal. The electrical connection between terminals COM2 is realized; if the input terminal IN is at low level, the second switching input terminal NC1 is electrically connected to the first switching output terminal COM1, and the fourth switching input terminal NC2 is connected to the first switching output terminal COM1. An electrical connection is realized between the two switching output terminals COM2.

The USB interface 10 includes a voltage pin VCC, two data pins D+ and D−, and a ground pin GND. The voltage pin VCC of the USB interface 10 is connected to the anode of the first diode D1, and also connected to the input terminal IN of the USB switch chip 50 through the resistor R1, and the input terminal IN is grounded through the resistor R2. The cathode of the first diode D1 is connected to the input terminal Vin of the voltage converter 40 and the voltage pin VCC of the touch module 30, the ground terminal GND of the voltage converter 40 is grounded, and the output terminal Vout is connected to the USB The voltage terminal V+ of the chip 50 is switched.

The data pins D+ and D− of the USB interface 10 are respectively connected to the first switch input terminal NO1 and the third switch input terminal NO2 of the USB switch chip 50 , and the ground pin GND of the USB interface 10 is grounded. The anode of the second diode D2 is connected to the power pin VCC of the USB display circuit 20 , and the cathode is connected to the cathode of the first diode D1 . The data pins D+ and D− of the USB display circuit 20 are respectively connected to the second switch input terminal NC1 and the fourth switch input terminal NC2 of the USB switch chip 50 , and the ground pin GND of the USB display circuit 20 is grounded. The first switching output terminal COM1 and the second switching output terminal COM2 of the USB switching chip 50 are respectively connected to the data pins D+ and D− of the touch module 30 , and the ground pin GND of the touch module 30 is grounded. The enable terminal /QP of the USB switching chip 50 is grounded through the resistor R3.

In this embodiment, the voltage converter 40 is used to convert the 5V voltage received by the USB interface 10 into the 3.3V voltage required by the USB switch chip 50. If the voltage required by the USB switch chip 50 in other embodiments is just 5V, the voltage converter 40 does not need to be set. In this embodiment, the resistance value of the resistor R1 preferably ranges from 100KΩ to 1MΩ, the resistance value of the resistor R2 is twice that of R1, and the resistance value of the resistor R3 preferably ranges from 1KΩ to 10KΩ.

When working, if the USB interface 10 is not connected to an external computer, the input terminal IN of the USB switching chip 50 is at a low level, and the second switching input terminal NC1 is electrically connected to the first switching output terminal COM1. The fourth switch input terminal NC2 is electrically connected to the second switch output terminal COM2, that is, the all-in-one machine works alone at this time.

When the all-in-one machine needs to be used as a display of an external computer, the USB interface of the external computer is directly connected to the USB interface 10. At this time, the input terminal IN is at a high level, and the first switching input terminal NO1 and the second switching input terminal NO1 are connected to the USB interface 10. An electrical connection is realized between a switching output terminal COM1, and an electrical connection is realized between the third switching input terminal NO2 and the second switching output terminal COM2, that is, the external computer communicates with the touch module 30, that is, The external computer uses the all-in-one machine as a display, and the operation is very convenient.

Claims (3)

1. a touch module switching circuit for all-in-one computer, comprise a USB display circuit and a touch-control module, it is characterized in that: this touch module switching circuit for all-in-one computer also comprises a USB interface, first and second diode, one USB switches chip, first and second resistance, the voltage pin of this USB interface is connected to the anode of the first diode, also be connected to by this first resistance the input end that this USB switches chip, this USB switches the input end of chip by this second resistance eutral grounding, the negative electrode of this first diode is connected to this USB and switches the voltage end of chip and the voltage pin of this touch-control module, two data pin of this USB interface are connected to the first switching input end and the 3rd switching input end that this USB switches chip respectively, the anode of this second diode is connected to the power pins of this USB display circuit, negative electrode is connected to the negative electrode of this first diode, two data pin of this USB display circuit are connected to the second switching input end and the 4th switching input end that this USB switches chip respectively, the first switching output terminal and second that this USB switches chip switches two data pin that output terminal is connected to this touch-control module respectively, if the input end that this USB switches chip is high level, this first switches input end and this first switches between output terminal and realize being electrically connected, 3rd switches input end and this second switches between output terminal and realize being electrically connected, if it is low level that this USB switches the input end of chip, this second switches input end and this first switches between output terminal and realize being electrically connected, the 4th switching input end and this second switch between output terminal and realize being electrically connected.

2. touch module switching circuit for all-in-one computer as claimed in claim 1, is characterized in that: be also connected by an electric pressure converter between the voltage end that negative electrode and this USB of this first diode switch chip.

3. touch module switching circuit for all-in-one computer as claimed in claim 1, is characterized in that: the resistance value scope of this first resistance is 100K Ω-1M Ω, and the resistance value of this second resistance is the twice of the first resistance.