CN220730313U - Voltage test system and voltage test device - Google Patents

Abstract

The utility model discloses a voltage testing system and a voltage testing device, which relate to the technical field of voltage testing and specifically comprise the following steps: the front-end acquisition circuit is connected to each test point of the circuit board, the switching of multiple test lines is realized through the automatic switching of the test lines, the inconvenience that the connection relation between the test lines and the test points needs to be manually exchanged is avoided, the voltage acquired by the front-end acquisition circuit is converted and processed through the rear-end processing circuit, and the situation that the acquired voltage has noise interference to cause the deviation of the voltage test result output by the main control unit based on the acquired voltage is avoided.

Description

Voltage test system and voltage test device

Technical Field

The present utility model relates to the field of voltage testing technologies, and in particular, to a voltage testing system and a voltage testing apparatus.

Background

In the production link of the circuit board, the voltage on each test point of the circuit board needs to be tested to detect whether the circuit board accords with the use standard, and most of the existing circuit board tests are single-channel tests, namely the test points of the circuit board are connected with the public ground through a single channel so as to test the circuit board.

However, the testing range of the testing method of the circuit board cannot be automatically switched, and is only limited to reading the voltage value of a single channel to the public ground in the testing process, so that a tester needs to manually replace a circuit of the next testing range after detecting the next testing range, and the operation is extremely inconvenient.

Disclosure of Invention

The utility model mainly aims to provide a voltage testing system and a voltage testing device, and aims to solve the technical problem that a conventional circuit board testing method is inconvenient to operate.

In order to achieve the above object, the present utility model provides a voltage test system connected to a test point of a circuit board, the voltage test system comprising:

the input end of the front end acquisition circuit is connected with the test points of the circuit board and is used for acquiring and outputting the voltage of any two test points on the circuit board;

the input end of the back-end processing circuit is connected with the output end of the front-end acquisition circuit, and is used for converting and acquiring the differential voltage of the voltage accessed from the front-end acquisition circuit and converting the acquired differential voltage into a digital signal;

and the input end of the main control unit is connected with the output end of the back-end processing circuit and is used for testing the digital signal accessed from the back-end processing circuit.

Optionally, the front-end acquisition circuit includes:

the output end of the voltage channel switching module is connected with the rear-end processing circuit and is used for switching the voltage acquisition channel;

the input end of the voltage acquisition module is connected to the test point of the circuit board, and the output end of the voltage acquisition module is connected to the voltage input end of the voltage channel switching module and is used for acquiring the voltage on the test point accessed by the conducted voltage channel.

Optionally, the voltage channel switching circuit includes: the first controller of a plurality of, the voltage acquisition module includes: a plurality of voltage acquisition circuits;

the single first controller is connected with the plurality of voltage acquisition circuits;

the voltage acquisition circuit includes: the first resistor, the second resistor, the first clamping diode and the second clamping diode;

one end of the first resistor is connected with the first end of the test point, the other end of the first resistor is connected with the voltage input end of the first controller, one end of the second resistor is connected with the second end of the test point, and the other end of the second resistor is connected with the voltage input end of the first controller;

the first clamping diode is connected to the connecting line of the first resistor and the voltage input end of the first controller, and the second clamping diode is connected to the connecting line of the second resistor and the voltage input end of the first controller.

Optionally, the back-end processing circuit includes:

the input end of the differential module is connected with the output end of the first controller, and the differential module is used for amplifying the difference between the accessed voltages and outputting the amplified difference as the differential voltage;

the input end of the isolation module is connected with the output end of the differential module and is used for isolating the differential voltage;

and the input end of the ADC acquisition module is connected with the output end of the isolation module and is used for acquiring the differential voltage and converting the acquired differential voltage into a digital signal.

Optionally, the differential module includes: the second controller, the third resistor and the first capacitor;

the input end of the second controller is connected with the output end of the first controller, one end of the third voltage is connected to the voltage output end of the second controller, the other end of the third resistor is connected with the input end of the isolation module, and the first capacitor is connected to a connecting line of the third resistor and the input end of the isolation module.

Optionally, the isolation module includes: a fourth resistor, an optocoupler isolation device and a reverse voltage follower;

the fourth resistor is connected to the first input end of the optocoupler isolation device, the second input end of the optocoupler isolation device is connected to the output end of the differential module, the output end of the optocoupler isolation device is connected to the input end of the reverse voltage follower, and the output end of the reverse voltage follower is connected to the input end of the ADC acquisition module.

Optionally, the ADC acquisition module includes: a first amplifier, a second amplifier, and a third controller;

the forward input end of the first amplifier is connected with the output end of the differential module, the forward input end of the second amplifier is connected with the output end of the differential module, the differential input end of the third controller is respectively connected with the output end of the first amplifier and the output end of the second amplifier, and the digital signal output end of the third controller is connected with the input end of the main control unit.

Optionally, the voltage testing system further comprises: the input isolation circuit is connected with the main control unit, and the input isolation circuit comprises: a fourth controller and a pull-up resistor;

the signal output end of the fourth controller is connected with the signal input end of the main control unit, and the pull-up resistor is connected to the signal input end of the fourth controller.

Optionally, the voltage testing system further comprises: the output isolation circuit is connected with the main control unit, and comprises: the fifth controller, the fifth resistor, the sixth resistor and the first switching tube;

the input end of the fifth controller is connected with the level output end of the main control unit, the output end of the fifth controller is connected with the control end of the first switching tube, the fifth resistor is connected between the fifth controller and the control end of the first switching tube, the sixth resistor is connected between the control end of the first switching tube and the input end of the first switching tube, and the output end of the first switching tube is connected with a load.

In addition, to achieve the above object, the present utility model also provides a voltage testing apparatus including the voltage testing system as described above, the voltage testing system including:

the input end of the front end acquisition circuit is connected with the test points of the circuit board and is used for acquiring and outputting the voltage of any two test points on the circuit board;

the input end of the back-end processing circuit is connected with the output end of the front-end acquisition circuit, and is used for converting and acquiring the differential voltage of the voltage accessed from the front-end acquisition circuit and converting the acquired differential voltage into a digital signal;

and the input end of the main control unit is connected with the output end of the back-end processing circuit and is used for testing the digital signal accessed from the back-end processing circuit.

According to the technical scheme, the front-end acquisition circuit is connected to each test point of the circuit board, the switching of multiple test lines is realized through the automatic switching of the test lines, the inconvenience that the connection relation between the test lines and the test points needs to be manually changed is avoided, the voltage acquired by the front-end acquisition circuit is converted and processed through the rear-end processing circuit, and the situation that the acquired voltage has noise interference to cause deviation of a voltage test result output by the main control unit based on the acquired voltage is avoided.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic block diagram of a voltage testing system according to the present utility model;

FIG. 2 is a schematic diagram of a front-end acquisition circuit according to the present utility model;

FIG. 3 is a schematic diagram of a back-end processing circuit according to the present utility model;

FIG. 4 is a schematic circuit diagram of a differential module according to the present utility model;

FIG. 5 is a schematic circuit diagram of an isolation module according to the present utility model;

FIG. 6 is a schematic diagram of a circuit configuration of an ADC acquisition module according to the present utility model;

FIG. 7 is a schematic diagram of a circuit structure of an input isolation circuit according to the present utility model;

FIG. 8 is a schematic diagram of a circuit structure of an output isolation circuit according to the present utility model;

fig. 9 is a schematic diagram of a partial circuit structure of the output isolation circuit of the present utility model.

Reference numerals illustrate:

the achievement, functional features and aspects of the present utility model will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that, if directional indications (such as up, down, left, right, front, and rear … …) are included in the embodiments of the present utility model, the directional indications are merely used to explain the relative positional relationship, movement conditions, etc. between the components in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indications are correspondingly changed.

In addition, if there is a description of "first", "second", etc. in the embodiments of the present utility model, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present utility model.

Referring to fig. 1, fig. 1 is a schematic block diagram of a voltage testing system according to the present utility model, where the voltage testing system is connected to a test point of a circuit board, and the voltage testing system includes:

the front-end acquisition circuit 10 is connected with the test points of the circuit board, and is used for acquiring and outputting the voltage of any two test points on the circuit board, specifically, the front-end acquisition circuit 10 in the embodiment can be connected with all the test points of the circuit board, and the test lines connected with the test points are conducted according to the connected test instructions, so that the switching of different test lines is satisfied, and the switching of the test lines is realized under the condition that the test lines are not required to be pulled and plugged;

the input end of the back-end processing circuit 20 is connected with the output end of the front-end acquisition circuit 10, and is used for converting and acquiring differential voltage of the voltage accessed from the front-end acquisition circuit 10, and is also used for converting the acquired differential voltage into a digital signal, specifically, the back-end processing circuit 20 in the embodiment can calculate the differential voltage of the accessed voltage and isolate the differential voltage, so that the differential signal is more gentle, the isolated differential voltage can be acquired and converted into the digital signal, and the processing of the voltage test by the main control unit 30 is easy;

the input end of the main control unit 30 is connected to the output end of the back-end processing circuit 20, so as to test the digital signal accessed from the back-end processing circuit 20, and the main control unit 30 in this embodiment may be other main control units 30 with control and calculation functions, such as an ARM single-chip microcomputer.

Specifically, referring to fig. 2, the front-end acquisition circuit 10 includes:

the output end of the voltage channel switching module 60 is connected with the back-end processing circuit 20 and is used for switching a voltage acquisition channel;

the input end of the voltage acquisition module 70 is connected to a test point of the circuit board, and the output end of the voltage acquisition module 70 is connected to the voltage input end of the voltage channel switching module 60, so as to acquire the voltage on the test point to which the conducted voltage channel is connected.

Further, the voltage channel switching circuit includes: the voltage acquisition module 70 includes: a plurality of voltage acquisition circuits;

the single first controller U1 is connected to the plurality of voltage acquisition circuits;

the voltage acquisition circuit includes: the first resistor, the second resistor, the first clamping diode and the second clamping diode;

one end of the first resistor is connected with the first end of the test point, the other end of the first resistor is connected with the voltage input end of the first controller U1, one end of the second resistor is connected with the second end of the test point, and the other end of the second resistor is connected with the voltage input end of the first controller U1;

the first clamping diode is connected to a connecting line of the first resistor and the voltage input end of the first controller U1, and the second clamping diode is connected to a connecting line of the second resistor and the voltage input end of the first controller U1.

Referring to fig. 2, taking two first controllers U1 and two voltage acquisition circuits as examples in the embodiment, the application process is as follows: the test personnel inputs a control instruction on an instruction input pin of the first controller U1, based on the control instruction, the first controller U1 correspondingly starts a voltage input end corresponding to the control instruction, a test circuit of a voltage acquisition circuit connected with a test point of the circuit board is connected to the voltage input end, and when the voltage input end is conducted, the connected test circuit is conducted, and the voltage on the test point connected with the voltage acquisition circuit of the test circuit is acquired.

For example, the tester inputs a 001 control command h_a1/h_b1/h_c1 on the command input pin a/BC of the first controller U1 (1), and the voltage input end of the x1 pin and the output end of the x pin are correspondingly turned on, so that the test circuit 2 of the voltage acquisition circuit connected with the x1 pin and the 2 pin of the test point J2 of the circuit board is turned on, and the x1 pin at this time is connected with the voltage on the 2 pin of the test point J2 of the circuit board to the first controller U1 (1), so that the output end p_out of the x pin of the first controller U1 (1) outputs the voltage on the 2 pin of the test point J2 of the circuit board to the differential module 80; the control command h_a2/h_b2/h_c2 of 001 is input on the command input pin a/BC of the first controller U1 (2), and the voltage input end of the x1 pin and the output end of the x pin are correspondingly conducted at this time, so that the test circuit 1 of the voltage acquisition circuit connected with the x1 pin and the 2 pin of the test point J1 of the circuit board is conducted, and the voltage on the 2 pin of the test point J1 of the circuit board is connected with the x1 pin at this time to the first controller U1 (2), so that the voltage on the 2 pin of the test point J1 of the circuit board is output to the differential module 80 by the output end n_out of the x pin of the first controller U1 (2).

In this embodiment, the command input pins C, B and a of the first controller U1 are defined in binary, that is, the control command h_c/h_b/h_a of 000 corresponds to the voltage input terminal of the x0 pin and the output terminal of the x pin, the control command h_c/h_b/h_a of 011 corresponds to the voltage input terminal of the x3 pin and the output terminal of the x pin, the control command h_c/h_b/h_a of 100 corresponds to the voltage input terminal of the x4 pin and the output terminal of the x pin, the control command h_c/h_b/h_a of 101 corresponds to the voltage input terminal of the x5 pin and the output terminal of the x pin, the control command h_c/h_b/h_a of 110 corresponds to the voltage input terminal of the x6 pin and the output terminal of the x pin, and the control command h_c/h_b/h_a of 111 corresponds to the voltage input terminal of the x7 pin, and if there are other command input terminals, then the binary conversion is performed in sequence. The command input pin of the first controller U1 is equal to the total number of the test lines of the connected voltage acquisition circuit.

It should be noted that, if there is a new voltage acquisition circuit, the test line between the voltage acquisition circuit and the first controller U1 may be connected to any one of the voltage input pins x4 to x 7; the VCC pin of the first controller U1 is connected to the 3.3V voltage (i.e., vcc_mcu_3.3V) of the main control unit 30; the VEE pin is connected with a voltage of-3.3V (namely VCC_ -3.3V); the GND pin is grounded.

Regarding the voltage acquisition circuit portion, because there are 2 pins at one test point in this embodiment, 2 test lines for accessing the 2 test points are provided in one voltage acquisition circuit, and the first resistor or the second resistor accessed on the test line is a voltage dividing resistor with different resistance values, which is used for matching the voltage measurement range of different ranges, if the test point is a larger voltage, a test line with a larger range is accessed in the early stage, if the test point is a smaller voltage, a test line with a smaller range is accessed in the early stage, so as to improve accuracy and satisfy the measurement between different ranges (it should be noted that, in this embodiment, the switching of different ranges forms a range switching circuit through the voltage dividing resistor, the operational amplifier and the analog switch, wherein the operational amplifier provides a common ground reference in a virtual ground manner, the analog switch performs the selection of a range channel, and the voltage dividing resistor performs the appropriate matching of the voltage).

While the first clamping diode connected between the first resistor and the voltage input terminal of the first controller U1, respectively, and the second clamping diode connected between the second resistor and the voltage input terminal of the first controller U1 function to control the voltage connected from the test point within a safe range, improving the stability and safety of the voltage acquisition circuit, wherein the first clamping diode and the second clamping diode as shown in fig. 2 each respectively connect to a voltage of 2.5V (i.e., vcc_2v5) and a voltage of-2.5V (i.e., vcc_ -2V 5), it should be noted that the division of the first resistor and the second resistor in this embodiment relates to the pin of the test point to which it connects, the division of the first clamping diode and the second clamping diode in this embodiment relates to the resistor to which it connects, in the same voltage acquisition circuit, the resistors connected to the same test point pin are called a first resistor or a second resistor, as shown in fig. 2, the resistors R4, R5 and R6 connected to the test point J1 pin 1 are called a first resistor, the clamp diodes D1 and D2 connected to the first resistor are called a first clamp diode, the resistors R1, R2 and R3 connected to the test point J1 pin 2 are called a second resistor, the clamp diodes D3 and D4 connected to the second resistor are called a second clamp diode, the resistors R7, R8 and R9 connected to the test point J2 pin 1 are called a first resistor, the clamp diodes D5 and D6 connected to the first resistor are called a first clamp diode, the resistors R10, R11 and R12 connected to the test point J2 pin 2 are called a second resistor, and the clamp diodes D7 and D8 connected to the second resistor are called a second clamp diode.

In addition, the functions of the command input pins C, B and A in the first controller U1 are the same, and are all control commands for accessing the input of a tester, and the signals of the first controller U1 (1) and the first controller U1 (2) are CD74HCT4051M96.

In addition, since the connected voltage is input to the differential module 80 for outputting the differential voltage, and the differential voltage is obtained by dividing the voltage by two paths, the first controller U1 (1) and the first controller U1 (2) in fig. 2 need to be connected to the voltages on one test point respectively in the same period, and transmit the voltages to the differential circuit for processing the differential voltage.

Specifically, referring to fig. 3, the back-end processing circuit 20 includes:

the input end of the differential module 80 is connected with the output end of the first controller U1, and is used for processing the difference between the accessed voltages to output single-ended voltage so as to promote the voltage conversion between the accessed two voltages and the processing of the subsequent voltage;

the input end of the isolation module 90 is connected with the output end of the differential module 80, so as to isolate the differential voltage, that is, electrically isolate the differential module 80 and an ADC (Analog-to-digital converter) acquisition module 100, reduce mutual interference between the differential module 80 and the ADC acquisition module 100, and reduce noise;

and the input end of the ADC acquisition module 100 is connected with the output end of the isolation module 90, and is used for acquiring the differential voltage and converting the acquired differential voltage into a digital signal.

Specifically, referring to fig. 4, the differential module 80 includes: the second controller U2, the third resistor R13 and the first capacitor C1;

the input end of the second controller U2 is connected to the output end of the first controller U1, one end of the third voltage is connected to the voltage output end of the second controller U2, the other end of the third resistor R13 is connected to the input end of the isolation module 90, and the first capacitor C1 is connected to a connection line between the third resistor R13 and the input end of the isolation module 90.

As can be seen from fig. 4, the input end of the second controller U2 has an XN input end and an XP input end, the XN input end is connected to the x-pin output end (n_out) of the first controller U1 (2), the XP input end is connected to the x-pin output end (p_out) of the first controller U1 (1), the XN input end and the XP input end are respectively connected to the voltages output by the first controller U1 (2) and the first controller U1 (1), the received voltages are transmitted to the second controller U2, the voltage difference between the two voltages is measured by the second controller U2, a differential voltage is generated based on the measured voltage difference and is output to the Vo pin, and the differential voltage is transmitted to the isolation circuit by the Vo pin.

The filtering circuit is formed by a third resistor R13 and a first capacitor C1, and the third resistor R13 and the first capacitor C1 are connected to a connecting line between the Vo pin and the isolation circuit and act on an alternating current component in a direct current voltage for reducing pulsation in a differential voltage; the Ref pin is used for outputting a reference voltage VREF; the V+ pin is connected to a 3.3V voltage (i.e., VCC_3.3V) and the V-pin is connected to a-3.3V voltage (i.e., VCC_3.3V).

In addition, the model number of the second controller U2 used in the present embodiment is: COS128U.

Specifically, referring to fig. 5, the isolation module 90 includes: a fourth resistor R14, an optocoupler isolation device 110, and a reverse voltage follower 120;

the fourth resistor R14 is connected to the first input terminal of the optocoupler isolation device 110, the second input terminal of the optocoupler isolation device 110 (i.e., vin in fig. 5) is connected to the output terminal of the differential module 80, the output terminal of the optocoupler isolation device 110 is connected to the input terminal of the reverse voltage follower 120, and the output terminal of the reverse voltage follower 120 (i.e., vout in fig. 5) is connected to the input terminal of the ADC acquisition module 100.

The fourth resistor R14 is an input current limiting resistor, and is used for limiting the current of the light emitting diode in the optocoupler isolation device 110 within a certain current value range, the input end is coupled by optical signals, so that complete isolation is achieved electrically, meanwhile, the forward impedance value of the light emitting diode is lower, the internal resistance of an external interference source is generally higher, the interference noise fed to the input end by the interference source is small according to the voltage division principle, ground wire interference or other crosstalk cannot be generated, and the anti-interference capability of the circuit is enhanced.

After the first input end of the optocoupler isolation device 110 is connected to the power supply current VCC through the fourth resistor R14 and the second input end Vin is connected to the differential voltage, the light emitting diode in the optocoupler isolation device 110 at this time emits light to drive the switching tube Q1 in the optocoupler isolation device 110 to be turned on, and the differential voltage isolated from the electrical interference is output to the reverse voltage follower 120, and the reverse voltage follower 120 prevents the differential voltage from being interfered or hopped, so as to generate a plurality of output hops.

The model of the optocoupler isolation device 110 in this embodiment is TLP521, and the model of the reverse voltage follower 120 is RS8552XK.

Specifically, referring to fig. 6, the ADC acquisition module 100 includes: a first amplifier U6, a second amplifier U7, and a third controller U3;

the forward input end of the first amplifier U6 is connected to the output end of the differential module 80, a differential voltage vad+ is connected, the forward input end of the second amplifier U7 is connected to the output end of the differential module 80, a differential voltage Vad "is connected, the differential input end of the third controller U3 is connected to the output end of the first amplifier U6 and the output end of the second amplifier U7, i.e. the AIN0 differential input end of the third controller U3 is connected to the output end of the first amplifier U6, the AIN1 differential input end of the third controller U3 is connected to the output end of the second amplifier U7, and the digital signal output end I/O of the third controller U3 is connected to the input end of the main control unit 30, so as to output the acquired and converted digital signal to the main control unit 30.

The forward input end of the first amplifier U6 and the forward input end of the second amplifier U7 are connected to the output end of the reverse voltage follower 120, the differential voltage output by the reverse voltage follower 120 is collected, the collected differential voltage is amplified and then transmitted to the third controller U3, and the amplified differential voltage is converted into a digital signal by the third controller U3, so that the main control unit 30 can perform voltage testing based on the digital signal.

The model number of the third controller U3 in this embodiment is: ADS1255IDBR, the first amplifier U6 is connected to a 5V supply voltage (i.e., vcc_5v).

Specifically, referring to fig. 7, the voltage testing system further includes: an input isolation circuit 40 connected to the main control unit 30, the input isolation circuit 40 comprising: a fourth controller U4 and a pull-up resistor R';

the signal output end of the fourth controller U4 is connected to the signal input end of the main control unit 30, and the pull-up resistor R' is connected to the signal input end of the fourth controller U4.

In this embodiment, in order to realize the level detection function, the signal input end of the main control unit 30 is further connected to the input isolation circuit 40, the VIA, VIB, VIC, VID of the fourth controller U4 is a four-way input end, connected to a load capable of outputting a level, and defaults to a high level through the pull-up resistor R', when the external pins In5, in6, in7 and In8 are connected to a low level, the fourth controller U4 can supply the isolated low level to the pins I5, I6, I7 and I8 of the control unit through the VOA, VOB, VOC, VOD four-way output end, so that the control unit executes a corresponding action according to the detected level.

The pull-up resistor R' arranged on four input ends of the fourth controller U4 is used for pulling up the input level, and the model number of the fourth controller U4 is pi 140U30.

It should be noted that, when receiving the input command, voltage acquisition switching corresponding to different conducting test lines is performed.

Specifically, referring to fig. 8, the voltage testing system further includes: an output isolation circuit 50 connected to the main control unit 30, the output isolation circuit 50 including: a fifth controller U5, a fifth resistor R15, a sixth resistor R16 and a first switching tube Q1;

the input end (i.e., VIA, VIB and VIC pins in fig. 8) of the fifth controller U5 is connected to the level output end (i.e., O13, O14 and O15 pins in fig. 8) of the main control unit 30, the output end (i.e., VOA, VOB and VOC pins in fig. 8) of the fifth controller U5 is connected to the control end of the first switching tube Q1 through an external interface (i.e., OO13, OO14 and OO15 pins in fig. 8), the fifth resistor R15 is connected between the fifth controller U5 and the control end of the first switching tube Q1, the sixth resistor R16 is connected between the control end of the first switching tube Q1 and the input end of the first switching tube Q1, and the output end of the first switching tube Q1 is connected to a load.

In this embodiment, in order to implement the output control function of the voltage test system, the output isolation circuit 50 is connected to the level output terminal of the main control unit 30.

The isolation is performed by the fifth controller U5, and after the internal level is given to the fifth controller U5, the fifth controller U5 converts the internal level into the external level to control the first switching tube Q1 to be opened or closed, so that the operation or the cut-off of the load is controlled.

The resistor between the level output end of the main control unit 30 and the input end of the fifth controller U5 is used for protecting the pin of the input end of the fifth controller U5 from being damaged; the first power supply terminal VDD1 of the fifth controller U5 is connected to the power supply voltage 5V (i.e., vcc_mcu_5v) of the main control unit 30, the second power supply terminal VDD2 of the fifth controller U5 is connected to the isolated power supply (i.e., vo_5v), and when the first switching tube Q1 is turned on, the fifth controller U5 outputs the isolated power supply to the load.

Taking fig. 9 as an example (fig. 9 is taken as an example for describing that the level output end O14 pin of the main control unit 30 outputs a level to the VIB pin of the fifth controller U5), the O14 of the main control unit 30 outputs a high level to the VIB pin, and outputs the high level to the OO14 pin through the VOB pin, and the OO14 pin transmits the high level to the control end of the first switching tube Q1, so as to conduct the first switching tube Q1, and further, the load is introduced to the Out14 pin through an external power supply, so that the operation of the load is controlled; the O14 of the control unit outputs low level to the VIB pin, the VOB pin outputs low level to the OO14 pin, the OO14 pin transmits the low level to the control end of the first switching tube Q1, the first switching tube Q1 is turned off, and the load is controlled to be turned off. The internal structure of the fifth controller U5VIA pin and VOA pin and the fifth controller U5VIC pin and VOC pin are similar to fig. 9 except that the pins are different.

The fifth resistor R15 and the sixth resistor R16 are used for protecting the input end of the control end of the first switching tube Q1, so as to avoid the situation that the first switching tube Q1 is broken down and damaged due to overlarge level.

It should be noted that, according to the output command, the corresponding output isolation circuit 50 is controlled to control the external output power, and the model of the fifth controller U5 is pi 140U30.

The utility model also provides a voltage testing device, which comprises the voltage testing system, wherein the voltage testing system comprises the following components:

the front-end acquisition circuit 10, the input end of the front-end acquisition circuit 10 is connected with the test points of the circuit board, and is used for acquiring and outputting the voltage of any two test points on the circuit board;

the input end of the back-end processing circuit 20 is connected with the output end of the front-end acquisition circuit 10, and is used for converting and acquiring the differential voltage of the voltage accessed from the front-end acquisition circuit 10 and converting the acquired differential voltage into a digital signal;

the input end of the main control unit 30 is connected with the output end of the back-end processing circuit 20, and the main control unit 30 is used for testing the digital signal accessed from the back-end processing circuit 20.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or system. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or system that comprises the element.

The foregoing embodiment numbers of the present utility model are merely for the purpose of description, and do not represent the advantages or disadvantages of the embodiments.

From the above description of the embodiments, it will be clear to those skilled in the art that the above-described embodiment method may be implemented by means of software plus a necessary general hardware platform, but of course may also be implemented by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present utility model may be embodied essentially or in a part contributing to the prior art in the form of a software product stored in a storage medium (e.g. ROM/RAM, magnetic disk, optical disk) as described above, comprising instructions for causing a terminal device (which may be a mobile phone, a computer, a server, or a network device, etc.) to perform the method according to the embodiments of the present utility model.

The foregoing description is only of the preferred embodiments of the present utility model, and is not intended to limit the scope of the utility model, but rather is intended to cover any equivalents of the structures or equivalent processes disclosed herein or in the alternative, which may be employed directly or indirectly in other related arts.

Claims (9)

1. A voltage testing system, wherein the voltage testing system is connected to a test point of a circuit board, the voltage testing system comprising:

the input end of the front end acquisition circuit is connected with the test points of the circuit board and is used for acquiring and outputting the voltage of any two test points on the circuit board;

the input end of the back-end processing circuit is connected with the output end of the front-end acquisition circuit, and is used for converting and acquiring the differential voltage of the voltage accessed from the front-end acquisition circuit and converting the acquired differential voltage into a digital signal;

the input end of the main control unit is connected with the output end of the back-end processing circuit and is used for testing the digital signal accessed from the back-end processing circuit;

wherein, front-end acquisition circuit includes:

the output end of the voltage channel switching module is connected with the rear-end processing circuit and is used for switching the voltage acquisition channel;

the input end of the voltage acquisition module is connected to the test point of the circuit board, and the output end of the voltage acquisition module is connected to the voltage input end of the voltage channel switching module and is used for acquiring the voltage on the test point accessed by the conducted voltage channel.

2. The voltage testing system of claim 1, wherein the voltage channel switching module comprises: the first controller of a plurality of, the voltage acquisition module includes: a plurality of voltage acquisition circuits;

the single first controller is connected with the plurality of voltage acquisition circuits;

the voltage acquisition circuit includes: the first resistor, the second resistor, the first clamping diode and the second clamping diode;

one end of the first resistor is connected with the first end of the test point, the other end of the first resistor is connected with the voltage input end of the first controller, one end of the second resistor is connected with the second end of the test point, and the other end of the second resistor is connected with the voltage input end of the first controller;

the first clamping diode is connected to the connecting line of the first resistor and the voltage input end of the first controller, and the second clamping diode is connected to the connecting line of the second resistor and the voltage input end of the first controller.

3. The voltage testing system of claim 2, wherein the back-end processing circuit comprises:

the input end of the differential module is connected with the output end of the first controller, and the differential module is used for amplifying the difference between the accessed voltages and outputting the amplified difference as the differential voltage;

the input end of the isolation module is connected with the output end of the differential module and is used for isolating the differential voltage;

and the input end of the ADC acquisition module is connected with the output end of the isolation module and is used for acquiring the differential voltage and converting the acquired differential voltage into a digital signal.

4. The voltage testing system of claim 3, wherein the differential module comprises: the second controller, the third resistor and the first capacitor;

the input end of the second controller is connected with the output end of the first controller, one end of the third resistor is connected to the voltage output end of the second controller, the other end of the third resistor is connected with the input end of the isolation module, and the first capacitor is connected to a connecting line between the third resistor and the input end of the isolation module.

5. The voltage testing system of claim 4, wherein the isolation module comprises: a fourth resistor, an optocoupler isolation device and a reverse voltage follower;

the fourth resistor is connected to the first input end of the optocoupler isolation device, the second input end of the optocoupler isolation device is connected to the output end of the differential module, the output end of the optocoupler isolation device is connected to the input end of the reverse voltage follower, and the output end of the reverse voltage follower is connected to the input end of the ADC acquisition module.

6. The voltage testing system of claim 5, wherein the ADC acquisition module comprises: a first amplifier, a second amplifier, and a third controller;

the forward input end of the first amplifier is connected with the output end of the differential module, the forward input end of the second amplifier is connected with the output end of the differential module, the differential input end of the third controller is respectively connected with the output end of the first amplifier and the output end of the second amplifier, and the digital signal output end of the third controller is connected with the input end of the main control unit.

7. The voltage testing system of claim 1, wherein the voltage testing system further comprises: the input isolation circuit is connected with the main control unit, and the input isolation circuit comprises: a fourth controller and a pull-up resistor;

the signal output end of the fourth controller is connected with the signal input end of the main control unit, and the pull-up resistor is connected to the signal input end of the fourth controller.

8. The voltage testing system of claim 7, wherein the voltage testing system further comprises: the output isolation circuit is connected with the main control unit, and comprises: the fifth controller, the fifth resistor, the sixth resistor and the first switching tube;

the input end of the fifth controller is connected with the level output end of the main control unit, the output end of the fifth controller is connected with the control end of the first switching tube, the fifth resistor is connected between the fifth controller and the control end of the first switching tube, the sixth resistor is connected between the control end of the first switching tube and the input end of the first switching tube, and the output end of the first switching tube is connected with a load.

9. A voltage testing apparatus, characterized in that it comprises a voltage testing system according to any one of claims 1 to 8.