CN210839532U

CN210839532U - Extension AD sampling device

Info

Publication number: CN210839532U
Application number: CN201921868370.1U
Authority: CN
Inventors: 何江; 王文鹤
Original assignee: Shenzhen Hongyitong Instrument Measures Co ltd
Current assignee: Shenzhen Hongyitong Instrument Measures Co ltd
Priority date: 2019-10-30
Filing date: 2019-10-30
Publication date: 2020-06-23
Anticipated expiration: 2029-10-30

Abstract

The utility model discloses an extension AD sampling device, include: the master control module is provided with a bus bar and sends a control signal through the bus bar; the connecting module is electrically connected with the busbar to transmit control signals; the IO expansion module is electrically connected with the connection module to receive the control signal and select the corresponding protocol channel; a plurality of AD sampling interfaces for inputting sampling signals; and the current limiting filtering module is electrically connected between the IO expansion module and the AD sampling interface so as to filter the sampling signal and transmit the sampling signal in a corresponding protocol channel. The IO expansion module selects the corresponding AD sampling interface according to the control signal, namely, the plurality of AD sampling modules are expanded together, so that the control cost of the whole system is not required to be increased, and the centralized processing and control of the plurality of sampling signals are realized.

Description

Extension AD sampling device

Technical Field

The utility model belongs to the technical field of the technique of AD module and specifically relates to an extension AD sampling device is related to.

Background

Programmable logic controllers are widely used in automation in the field of industrial control. The user can edit the corresponding user program according to the requirement to meet different automatic production requirements. But with high costs, the benefit is not obvious, if with the multi-functional demand that coexists of PLC control will greatly increase the cost of this equipment in same equipment, anchor clamps, tool, shielded cell, also because the space size of equipment need consider the variety and the degree of difficulty of mounting means, consequently the automation control is done through the singlechip at present.

In practical application and improvement of a process technology in the current 3C industry or medical instrument manufacturing, the problem of testing and collecting signals such as current and voltage often has to be considered, and the problem of collecting a plurality of high-precision or low-voltage micro current signals is solved at this time, so that all signals such as current and voltage are difficult to collect, or other signals are difficult to collect by adding a control chip, so that the control cost of the whole system is increased, and the uniform processing of a plurality of collected signals is difficult to realize.

SUMMERY OF THE UTILITY MODEL

The utility model discloses aim at solving the technical problem who exists among the prior art at least. Therefore, the utility model provides an extension AD sampling device can extend AD sampling interface to select the AD sampling interface that corresponds through main control module control IO extension module, through AD sampling interface output sampling signal to main control module, with the input that increases the AD sampling, so that through sampling signal centralized processing and control.

An embodiment of the utility model provides an extension AD sampling device: the method comprises the following steps:

the master control module is provided with a bus bar and sends a control signal through the bus bar;

the connecting module is electrically connected with the busbar to transmit control signals;

the IO expansion module is electrically connected with the connection module to receive the control signal and select the corresponding protocol channel;

a plurality of AD sampling interfaces for inputting sampling signals;

and the current limiting filtering module is electrically connected between the IO expansion module and the AD sampling interface so as to filter the sampling signal and transmit the sampling signal in a corresponding protocol channel.

The utility model discloses extension AD sampling device has following beneficial effect at least: the IO expansion module selects the corresponding AD sampling interface according to the control signal, namely, the plurality of AD sampling modules are expanded together, so that the control cost of the whole system is not required to be increased, and the centralized processing and control of the plurality of sampling signals are realized.

According to the utility model discloses an extension AD sampling device of other embodiments, an extension AD sampling device still includes the reference voltage module, the reference voltage module electricity connect in IO extension module extremely with output reference voltage IO extension module.

According to another embodiment of the present invention, an extended AD sampling apparatus further comprises an input interface, a sampling module, an amplification module, a second dial switch, and a third dial switch;

the sampling module is electrically connected to the input interface and is used for collecting current signals;

the second dial switch is electrically connected to the sampling module to receive and transmit the current signal;

the amplifying module is electrically connected with the sampling module to receive the current signal and output an amplified signal;

the input end of the third dial switch is connected with the sampling module, the amplifying module and the output end of the second dial switch, and the output end of the third dial switch is connected with the IO expansion module.

According to the utility model discloses an extension AD sampling device of other embodiments, the reference voltage module includes: a reference voltage unit and a buffer isolation unit;

the reference voltage unit is electrically connected with the IO expansion module and the sampling module to provide a reference voltage signal;

the buffer isolation unit is electrically connected to the reference voltage unit to buffer and isolate the reference voltage signal.

According to another embodiment of the present invention, an extended AD sampling apparatus, said sampling module comprises a first sampling unit, a second sampling unit, and a third sampling unit;

the input end of the first sampling unit is connected to the input interface, and the output end of the first sampling unit is connected to the input end of the second dial switch;

the input end of the second sampling unit is electrically connected to the input interface, and the output end of the second sampling unit is electrically connected to the input end of the second dial switch;

the input end of the third sampling unit is electrically connected to the input interface, and the output end of the third sampling unit is connected to the input end of the third dial switch;

the output end of the second dial switch is connected with the input end of the third dial switch, and the output end of the third dial switch is connected with the IO expansion module.

According to the utility model discloses an extension AD sampling device of other embodiments, current-limiting filtering module includes a plurality of current-limiting filtering units, current-limiting filtering unit includes: the current limiting resistor, the ground resistor and the current limiting filter capacitor;

one end of the current-limiting filter resistor is connected with one end of the AD sampling interface, and the other end of the current-limiting filter resistor is connected with one end of the ground resistor;

the other end of the ground resistor is grounded;

one end of the current-limiting filter capacitor is connected between the current-limiting filter resistor and the ground resistor, and the other end of the current-limiting filter capacitor is grounded.

According to the utility model discloses an extension AD sampling device of other embodiments, the first pin and the sixth pin of input interface are connected with hole interference resistance.

According to another embodiment of the present invention, an extended AD sampling apparatus, the first sampling unit includes: the circuit comprises a first sampling chip, a first dial switch, a thirtieth capacitor, a thirty-first capacitor, a first connecting resistor, a second connecting resistor, a forty-second resistor, a forty-third resistor, a fourth sampling chip, a third dial switch, a thirty-second capacitor, a thirty-first capacitor, a first connecting resistor, a second connecting resistor, a forty-fourth resistor, a forty-second resistor and a forty-third;

the first end of the first dial switch is connected with the output end of the reference voltage unit, the second end of the first dial switch is grounded, and the third end and the fourth end of the first dial switch are connected with the first pin of the first sampling chip;

one end of the thirty-third capacitor is connected with the sixth pin of the first sampling chip, and the other end of the thirty-third capacitor is connected with one end of a forty-second resistor;

one end of the thirty-first capacitor is connected with the second pin of the first sampling chip, and the other end of the thirty-first capacitor is connected with a power supply;

one end of the first connecting resistor is connected with the fourth pin of the first sampling chip, and the other end of the first connecting resistor is connected with the input interface;

one end of the second connecting resistor is connected with a fifth pin of the sampling chip, and the other end of the second connecting resistor is connected with the input interface;

one end of the forty-resistor is connected between the fifth pin of the first sampling chip and the second connecting resistor, and the other end of the forty-resistor is connected between the fourth pin of the first sampling chip and the first connecting resistor;

one end of the forty-second resistor is connected with the input interface, and the other end of the forty-second resistor is connected with the other end of the thirty-third capacitor and the ground;

one end of the forty-third resistor is connected with the sixth pin of the first sampling chip, and the other end of the forty-third resistor is grounded.

Drawings

Fig. 1 is a block diagram of an embodiment of an extended AD sampling apparatus according to the present invention;

fig. 2 is a schematic circuit diagram of a first voltage stabilizing unit in an embodiment of an extended AD sampling apparatus according to the present invention;

fig. 3 is a schematic circuit diagram of a second voltage stabilizing unit in an embodiment of an extended AD sampling apparatus according to the present invention;

fig. 4 is a schematic circuit diagram of a reference voltage module in an embodiment of an extended AD sampling apparatus according to the present invention;

fig. 5 is a schematic circuit diagram of a current-limiting filter module in an embodiment of an extended AD sampling apparatus according to the present invention;

fig. 6 is a schematic circuit diagram of an IO expansion module in a specific embodiment of an extended AD sampling apparatus according to the present invention;

fig. 7 is a schematic circuit diagram of an AD sampling interface in an embodiment of an extended AD sampling apparatus according to the present invention;

fig. 8 is a schematic circuit diagram of a sampling module in an embodiment of an extended AD sampling apparatus according to the present invention;

fig. 9 is a schematic circuit diagram of an amplifying module in an embodiment of an extended AD sampling apparatus according to the present invention;

fig. 10 is a schematic circuit diagram of a second toggle switch and a third toggle switch in an embodiment of an extended AD sampling apparatus according to the present invention.

Reference numerals: 100. a main control module; 200. a connection module; 300. an IO expansion module; 400. a current limiting filtering module; 410. a current limiting filtering unit; 500. a reference voltage module; 510. a reference voltage unit; 520. a buffer isolation unit; 600. an input interface; 700. a sampling module; 710. a first sampling unit; 720. a second sampling unit; 730. a third sampling unit; 800. an amplifying module; 900. a third toggle switch; 110. an AD sampling interface; 120. a second toggle switch; 131. a first voltage stabilization unit; 132. and a second voltage stabilization unit.

Detailed Description

The conception and the resulting technical effects of the present invention will be described clearly and completely with reference to the following embodiments, so that the objects, features and effects of the present invention can be fully understood. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and other embodiments obtained by those skilled in the art without inventive labor based on the embodiments of the present invention all belong to the protection scope of the present invention.

In the description of the present invention, if an orientation description is referred to, for example, the directions or positional relationships indicated by "upper", "lower", "front", "rear", "left", "right", etc. are based on the directions or positional relationships shown in the drawings, only for convenience of description and simplification of description, and it is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. If a feature is referred to as being "disposed," "secured," "connected," or "mounted" to another feature, it can be directly disposed, secured, or connected to the other feature or indirectly disposed, secured, connected, or mounted to the other feature.

In the description of the embodiments of the present invention, if "a plurality" is referred to, it means one or more, if "a plurality" is referred to, it means two or more, if "greater than", "less than" or "more than" is referred to, it is understood that the number is not included, and if "more than", "less than" or "within" is referred to, it is understood that the number is included. If reference is made to "first" or "second", this should be understood to distinguish between features and not to indicate or imply relative importance or to implicitly indicate the number of indicated features or to implicitly indicate the precedence of the indicated features.

Referring to fig. 1, the embodiment of the utility model discloses an extension AD sampling device, include: main control module 100, link module 200, IO expansion module 300, AD sampling interface 110 and current-limiting filter module 400, main control module 100 is equipped with row mother and sends out control signal through row mother, link module 200 electricity is connected in female arranging in order to receive control signal, IO expansion module 300 electricity is connected in link module 200 in order to receive control signal and select the protocol passageway that corresponds, AD sampling interface 110 is used for inputing sampling signal, and sampling interface sets up a plurality of. The current limiting filter module 400 is electrically connected between the IO extender U1 module and the AD sampling interface 110 to filter and transmit the sampled signals according to the corresponding protocol channels. The control signal includes a load control signal and an IO extension control signal, the IO extension signal is mainly used for being sent to the IO extension module 300 to control the IO extension module 300 to select a corresponding protocol channel, then the corresponding AD sampling interface 110 is controlled to be sent to the main control module 100 through the current limiting filter module 400, the IO extension module 300 and the connection module 200, so the IO extension control signal in the control signal is sent to the IO extension module 300, the IO extension module 300 selects a corresponding protocol channel, and then the sampling signal of the AD sampling interface 110 is sent to the main control module 100 through the protocol channel.

An extended AD sampling apparatus further comprises a reference voltage module 500, an input interface 600, a sampling module 700, an amplification module 800, a second dip switch 120 and a third dip switch 900. The reference voltage module 500 is electrically connected to the IO extension module 300 and the sampling module 700 to output reference voltage to the IO extension module 300 and the sampling module 700, the sampling module 700 is electrically connected to the input interface 600 and is used for collecting current signals, and the AD sampling interface 110 mainly collects voltage signals, so that the current signals and the voltage signals are collected, so that the main control module 100 can perform corresponding control on the sampling signals more accurately. The amplifying module 800 is electrically connected to the sampling module 700 to receive the current signal and output an amplified signal, the second dial switch 120 is electrically connected to the sampling module 700 to receive and transmit the current signal, the third dial switch 900 is electrically connected to the sampling module 700, the amplifying module 800 and the IO extension module 300, the third dial switch 900 transmits the current signal according to the second dial switch 120, the amplified signal transmitted by the amplifying dial block and the circuit signal transmitted by the sampling module 700 to the IO extension module 300, and transmits the corresponding current signal to the main control module 100 along the IO extension module 300 according to the control signal transmitted by the main control module 100, thereby realizing the acquisition of the multipath current signals.

The utility model provides an extension AD sampling device still includes constant voltage power supply module, and constant voltage power supply module mainly used supplies power for each module to guarantee that each module can normally and use steadily.

The reference voltage module 500 includes a reference voltage unit 510 and a buffer isolation unit 520, wherein the reference voltage unit 510 is electrically connected to the IO expansion module 300 and the sampling module 700 to provide a reference voltage signal to the IO expansion module 300 and the sampling module 700, and the buffer isolation unit 520 is electrically connected to the reference voltage unit 510 to buffer and isolate the reference voltage signal. The reference voltage unit 510 mainly provides a whole device reference voltage, and the reference voltage is also a reference voltage. Because the precision of the AD sampling mainly depends on the precision of the AD sampling chip, the sensitivity of the sensor, the precision of the amplifying module 800, the precision of the power supply, and the precision of the reference voltage module 500, the precision of the whole AD sampling is not only related to the precision of the AD sampling chip, but also has a great relationship with the precision of the power supply voltage, the reference voltage during the AD conversion is the standard voltage of the internal T-line network, the reference voltage can be regarded as the highest upper limit voltage (not exceeding the power supply voltage), and when the signal voltage is lower, the reference voltage can be reduced to improve the resolution. After the reference voltage is changed, the voltage values in the same binary representation will be different, the largest binary representation is the reference voltage, the reference voltage needs to be taken into consideration when calculating the actual voltage, and the reference voltage is sent by the reference voltage module 500, so the stability of the reference voltage has a great influence on the performance of the device.

The sampling module 700 includes: the input end of the first sampling unit 710 is connected to the input interface 600, the output end of the first sampling unit 710 is connected to the input end of the second dial switch 120, the input end of the second sampling unit 720 is electrically connected to the input interface 600, and the output end of the second sampling unit 720 is electrically connected to the input end of the second dial switch 120; an input end of the third sampling unit 730 is electrically connected to the input interface 600, and an output end of the third sampling unit 730 is connected to an input end of the third dial switch 900. The first sampling unit 710, the second sampling unit 720 and the third sampling unit 730 collect corresponding current signals, and then the second toggle 120 and the third toggle 900 adjust each other, so that when the IO extender U1 selects a corresponding protocol channel, the corresponding sampling unit is controlled to output the current signal. For example, the second dial switch 120 outputs one of the current signals when the current signal is selected for transmission, and then the third dial switch 900 selects the current signal from the current signal and the current signal sent by the third sampling unit 730, so as to transmit one of the current signals to the main control module 100, so that three current signals are selected by the two dial switches, and the three channels of the current signal are expanded, so as to collect more current signals.

Example two: referring to fig. 2 and 3, the regulated power supply module includes a first voltage regulation unit 131 and a second voltage regulation unit 132, the first voltage regulation unit 131 is electrically connected between the power supply and each power module to transmit a first voltage regulation signal to each power module, and the second voltage regulation unit 132 is electrically connected between the power supply and each power module to transmit a second voltage regulation signal to each power module. The first voltage stabilization unit 131 comprises a first voltage stabilization chip and a first peripheral circuit, the model of the first voltage stabilization chip is MAX74, the second voltage stabilization unit 132 comprises a second voltage stabilization chip and a second peripheral circuit, the model of the second voltage stabilization chip is REG1117-3.3, the power supply outputs a stable 5V voltage after passing through the first voltage stabilization chip, and outputs a stable 3.3V voltage after passing through the second voltage stabilization chip.

Referring to fig. 4, the reference voltage unit 510 includes a reference voltage chip, a ninth capacitor C09 and a twelfth capacitor C12, the first pin of the reference voltage chip is connected to the second pin, the third pin of the reference voltage chip is connected to the buffer isolation unit 520, the eighth pin of the reference voltage chip is connected to the power supply, the fourth pin of the reference voltage chip is grounded, one end of the ninth capacitor C09 is connected to the first pin of the first reference voltage chip and the other end is grounded, and one end of the twelfth capacitor C12 is connected to the other end of the first pin of the reference voltage chip. The buffer isolation unit 520 comprises an isolation chip and a tenth capacitor, the isolation chip is REF3125, a first pin of the isolation chip is connected to a second pin of the power supply, the second pin of the isolation chip is connected to a third pin of the reference voltage chip, the third pin of the isolation chip is grounded, and one end of the tenth capacitor C10 is connected to the third pin of the isolation chip and the other end of the tenth capacitor is grounded. The reference voltage chip provides a reference voltage for the whole system, and the isolation chip is used as a voltage follower which generally serves as a buffer stage and an isolation stage, wherein the voltage follower is used for impedance transformation. On the one hand, the input impedance is made high so that the influence on the input signal can be made small, and on the other hand, the output impedance is made low so that the influence of the AD input impedance on the input signal can be reduced.

Referring to fig. 6, the IO expansion module 300 mainly includes an IO expansion device U1, the IO expansion device U1 is connected to a busbar of the main control module 100 through the connection module 200, and protocol channels of SCLK, DIN, DOUT, DRDY, CS, REST are determined through IO ports PE4, PE5, PE6, PC6, and PC7 of the main control module 100, a reference voltage of the entire system is obtained through a REF-OUT port of the IO expansion device U1, and IN0, IN1, IN2, IN3, IN4, IN5, IN6, and IN7 ports of the IO expansion device U1 are multiple analog signal input channels. The IO expander U1 is provided with a fifth capacitor C05 and an eighth capacitor C08, one end of the fifth capacitor C05 is connected with the first pin of the IO expander U1, the other end of the first pin is grounded, and one end of the eighth capacitor C08 is connected with the sixteenth pin of the IO expander U1, and the other end of the sixteenth pin is grounded. The fifth capacitor C05 and the eighth capacitor C08 adopt a design mode close to the AD sampling interface 110 to effectively filter the interference of a power supply in the whole system, provide a stable and reliable power supply for the whole AD sampling device, and reduce the noise interference of the power supply so as to reduce the precision interference of the power supply to the whole AD sampling device.

Referring to fig. 7, the first pin and the sixth pin of the AD sampling interface 110 are connected to two pit interference resistors, in this embodiment, the AD sampling interface 110 has two output interfaces, each AD sampling interface 110 has four output interfaces, the two AD sampling interfaces 110 have two pit interference resistors, and one end of each anti-interference resistor is connected to the ground of the other end of the first pin or the sixth pin of the AD sampling interface 110. The pit interference resistor adopts 0 omega resistor or magnetic bead, and the analog ground and the digital ground are divided in the analog loop through the pit interference resistor, namely mutual interference is avoided. The mutual interference is the voltage caused by the current in two different loops on the PCB wiring, and the ground wire generated by the mutual superposition of the two voltages should form a loop to prevent the generation of high-frequency radiation noise. In general, the pit interference resistance is the best choice by adopting 0 ohm resistance, and 1 can ensure that direct current potentials are equal; 2. single point grounding limits noise; 3. it has attenuation effect on noise of all frequencies (0 ohm also has impedance, and the current path is narrow, so that the noise current can be limited to pass through).

Referring to fig. 5, the current-limiting filtering module 400 includes a plurality of current-limiting filtering units 410, and the current-limiting filtering units 410 include: the device comprises a current-limiting resistor, a ground resistor and a current-limiting filter capacitor, wherein one end of the current-limiting filter resistor is connected with the AD sampling interface 110, the other end of the current-limiting filter resistor is connected with one end of the ground resistor, and the other end of the ground resistor is grounded; one end of the current-limiting filter capacitor is connected between the current-limiting filter resistor and the ground resistor, and the other end of the current-limiting filter capacitor is grounded. In this embodiment, eight current-limiting filter units 410 are provided, and the current-limiting filter resistor is any one of the twenty-first resistor R21 to the twenty-eighth resistor R28, the ground resistor is any one of the thirty-first resistor R31 to the thirty-eighth resistor R38, and the filter capacitor is any one of the twenty-first capacitor C21 to the twenty-eighth capacitor C28. Current-limiting filter resistance and contrast resistance mainly are in order to prevent under some special circumstances, and AD sampling device's input signal has surpassed the normal input scope of AD sampling, can attenuate in order to protect the AD device to input signal, prevents that the inside device of AD device from being punctured to guarantee that AD sampling device normally works under very abominable environment, can also play the effect that the partial pressure was gathered simultaneously under high-pressure test environment. The current-limiting filter capacitor and the current-limiting filter resistor form a high-pass filter to eliminate the stray signals and the element white noise interference of the sampling signals input by the AD input interface 600.

Referring to fig. 8 and 10, the first sampling unit 710 includes: the circuit comprises a first sampling chip U2, a first toggle switch, a thirtieth capacitor C30, a thirty-first capacitor C31, a first connecting resistor EDA1, a second connecting resistor EDA2, a fortieth resistor C40, a fortieth resistor C42 and a forty-third resistor C43, wherein the model of the first sampling chip U2 is INA213 in the embodiment. The first end of the first dial switch is connected with the output end of the reference voltage unit 510, the second end is grounded, and the third end and the fourth end are connected with the first pin of the first sampling chip U2. One end of a thirty-third capacitor C30 is connected with the sixth pin of the first sampling chip U2, and the other end is connected with one end of a forty-second resistor R42. One end of the thirty-first capacitor C31 is connected to the second pin of the first sampling chip U2, and the other end is connected to the power supply. One end of the first connection resistor EDA1 is connected to the fourth pin of the first sampling chip U2, and the other end is connected to the input interface 600. One end of the second connection resistor EDA2 is connected with the fifth pin of the first sampling chip U2, and the other end is connected with the input interface 600; one end of the forty-fourth resistor R40 is connected between the fifth pin of the first sampling chip U2 and the second connection resistor EDA2, and the other end is connected between the fourth pin of the first sampling chip U2 and the first connection resistor EDA 1; one end of the forty-second resistor R42 is connected to the input interface 600, and the other end is connected to the other end of the thirty-second capacitor C30 and ground.

The second sampling unit 720 includes a second sampling chip U3, a thirty-second capacitor C32, a thirty-third capacitor C33, a forty-fourth resistor R44, a forty-fifth resistor R45, a forty-sixth resistor R46, and a seventy-fifth resistor R75. One end of a thirty-second capacitor C32 is connected with the power supply and the first pin of the second sampling chip U3, and the other end of the thirty-second capacitor C32 is connected with the second pin of the second sampling chip U3 and the ground; one end of a thirty-third capacitor C33 is connected with the fifth pin of the second sampling chip U3, and the other end is grounded; one end of the forty-fourth resistor R44 is connected to the third pin of the second sampling chip U3 and the input interface 600, and the other end is connected to the fourth pin of the second sampling chip U3 and the input interface 600; one end of the forty-fifth resistor R45 is connected to the other end of the fifth pin of the second sampling chip U3, and one end of the forty-sixth resistor R46 is connected to the other end of the input interface 600. One end of the seventy-fifth resistor R75 is connected to the sixth pin of the second sampling chip U3, and the other end is connected to the power supply, and the fifth pin of the second sampling chip U3 is connected to the input end of the second dial switch 120.

The third sampling unit 730 includes: a third sampling chip U4, a thirty-fourth capacitor C34, a thirty-fifth capacitor C35, a thirty-sixth capacitor C36, a forty-seventh resistor R47, and a forty-eighth resistor R48. One end of a thirty-fourth capacitor C34 is connected with the eighth pin of the third sampling chip U4 and the other end of the power supply to ground, and one end of a thirty-fifth capacitor C35 is connected with the seventh pin of the third sampling chip U4 and the other end of the power supply to ground; one end of a thirty-sixth capacitor C36 is connected with the sixth pin of the third sampling chip U4, and the other end is connected with the ground; one end of a forty-seventh resistor R47 is connected with the thirty-fifth capacitor C35 and the seventh pin of the third sampling chip U4, and the other end is grounded; one end of the forty-eighth resistor R48 is connected to the input interface 600, and the other end is grounded, the first pin and the second pin of the third sampling chip U4 are connected to the input interface 600, and the seventh pin of the third sampling chip U4 is connected to the input terminal of the third dial switch 900.

The first sampling chip U2, the second sampling chip U3 and the third sampling chip U4 are current sampling chips to meet different current test requirements without adding other modules due to different test sampling ranges. The main functions of the thirty-first capacitor C31, the thirty-second capacitor C32, the thirty-third capacitor C33, the thirty-fourth capacitor C34, the thirty-fifth capacitor C35 and the thirty-sixth capacitor C36 are to reduce power supply noise. The forty-fourth resistor R40 and the forty-fourth resistor R44 are shunts which are used for expanding the measuring current range of the instrument, and the fixed constant value shunt and the precise alloy resistor are used for current limiting, current equalizing sampling detection of circuits such as the instrument, a communication system, an electronic complete machine, an automatic control power supply and the like; the shunt is also an accurate resistor which can pass large current, when the current flows through the shunt, a millivolt voltage appears at two ends of the shunt, and then the voltage is measured by a millivolt voltmeter and is converted into the current, so that the large current measurement is completed.

Referring to fig. 9 and 10, the amplifying module 800 mainly includes two operational amplifiers, and the specific circuit connection is as shown in the figure, so that the current signals collected by the first sampling chip and the second sampling chip U3 are amplified by the two operational amplifiers, and the final output end of the operational amplifier is connected to the input end of the third dial switch 900, so that the amplified current signals are selectively read by the main control module 100, thereby being more beneficial to the signal control of the main control module 100.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art. Furthermore, the embodiments of the present invention and features of the embodiments may be combined with each other without conflict.

Claims

1. An extended AD sampling apparatus, comprising:

a plurality of AD sampling interfaces for inputting sampling signals;

2. The extended AD sampling apparatus of claim 1, further comprising a reference voltage module electrically connected to the IO extension module to output a reference voltage to the IO extension module.

3. The extended AD sampling apparatus of claim 2, further comprising an input interface, a sampling module, an amplification module, a second dial switch, and a third dial switch;

4. The extended AD sampling apparatus of claim 3, wherein the reference voltage module comprises: a reference voltage unit and a buffer isolation unit;

5. The extended AD sampling apparatus of claim 4, wherein the sampling module comprises a first sampling unit, a second sampling unit, and a third sampling unit;

6. The extended AD sampling apparatus of claim 1, wherein the current-limiting filtering module comprises a plurality of current-limiting filtering units, and the current-limiting filtering units comprise: the current limiting resistor, the ground resistor and the current limiting filter capacitor;

the other end of the ground resistor is grounded;

7. The extended AD sampling device of claim 5, wherein the first pin and the sixth pin of the input interface are connected with pit-disturbance resistors.

8. The extended AD sampling apparatus of claim 5, wherein the first sampling unit comprises: the circuit comprises a first sampling chip, a first dial switch, a thirtieth capacitor, a thirty-first capacitor, a first connecting resistor, a second connecting resistor, a forty-second resistor, a forty-third resistor, a fourth sampling chip, a third dial switch, a thirty-second capacitor, a thirty-first capacitor, a first connecting resistor, a second connecting resistor, a forty-fourth resistor, a forty-second resistor and a forty-third;