阅读说明：本技术 多量程测试电路和多量程测试装置 (Multi-range test circuit and multi-range test device ) 是由 毛广甫 于 2020-06-30 设计创作，主要内容包括：本发明适用于测试技术领域,尤其涉及一种多量程测试电路和多量程测试装置,其中,多量程测试电路包括控制电路和以及多个单通道测试电路,每个单通道测试电路包括至少一个测试通道,每个测试通道对应一个测试量程,在对待测设备进行测试量时,控制电路根据接收到的量程选择指令对各单通道测试电路进行通道选择,包括类型选择和量程组合选择,各单通道测试电路根据通道选择信号连接对应类型和大小的测试通道,从而组合出一与待测设备相匹配的总测试量程,满足待测设备测试的量程需求,提高多通道测试电路的可靠性和兼容性。(The invention is suitable for the technical field of testing, and particularly relates to a multi-range testing circuit and a multi-range testing device, wherein the multi-range testing circuit comprises a control circuit and a plurality of single-channel testing circuits, each single-channel testing circuit comprises at least one testing channel, each testing channel corresponds to one testing range, when the testing amount of equipment to be tested is measured, the control circuit performs channel selection on each single-channel testing circuit according to a received range selection instruction, the channel selection comprises type selection and range combination selection, each single-channel testing circuit is connected with the testing channels of the corresponding type and size according to a channel selection signal, so that a total testing range matched with the equipment to be tested is combined, the testing range requirement of the equipment to be tested is met, and the reliability and the compatibility of the multi-channel testing circuits are improved.)

1. A multi-range test circuit is characterized by comprising a control circuit and a plurality of single-channel test circuits electrically connected with the control circuit, wherein each single-channel test circuit comprises at least one test channel, and each test channel corresponds to one test range;

the control circuit is used for outputting a corresponding channel selection signal to each single-channel test circuit according to the range selection instruction;

and all the single-channel test circuits are used for connecting a plurality of test channels with the total test range matched with the parameters of the equipment to be tested according to the channel selection signal combination, and the total test range is equal to the sum of the test ranges corresponding to the test channels.

2. The multirange test circuit of claim 1, wherein each of the single channel test circuits comprises a voltage test circuit, a current test circuit, and a resistance test circuit, the voltage test circuit comprising a voltage test channel and a voltage test range of a corresponding magnitude, the current test circuit comprising a current test channel and a current test range of a corresponding magnitude, the resistance test circuit comprising a resistance test channel and a resistance test range of a corresponding magnitude;

all the voltage test circuits are used for combining and connecting a plurality of voltage test channels with a total voltage test range matched with parameters of equipment to be tested according to the channel selection signals, and the total voltage test range is equal to the sum of voltage test ranges corresponding to the voltage test channels;

all the current test circuits are used for combining and connecting a total current test range and a plurality of current test channels matched with parameters of equipment to be tested according to the channel selection signals, and the total current test range is equal to the sum of current test ranges corresponding to the current test channels; and

and all the resistance test circuits are used for combining and connecting a plurality of resistance test channels with a total resistance test range matched with the parameters of the equipment to be tested according to the channel selection signals, and the total resistance test range is equal to the sum of the resistance test ranges corresponding to the plurality of resistance test channels.

3. The multirange test circuit of claim 2, wherein each of the voltage test channels is cascaded in sequence through a first switch assembly, each of the voltage test channels comprising a first reference resistor and a first divider resistor;

a first end of the first voltage-dividing resistor of the current stage is connected with a second end of the first voltage-dividing resistor of the previous stage through one first switch component, a second end of the first voltage-dividing resistor of the current stage is connected with a first end of the first voltage-dividing resistor of the next stage through another first switch component, a second end of the first voltage-dividing resistor of the current stage is further connected with a first end of the first reference resistor of the current stage to form a signal output end of the voltage testing channel of the current stage, and a second end of the first reference resistor of the current stage is grounded;

the first switch component is used for being conducted when receiving the channel selection signal so as to serially connect the first voltage dividing resistors of two adjacent stages.

4. The multirange test circuit of claim 2, wherein each of the current test channels is cascaded in sequence through a second switch assembly, each of the current test channels comprising a sampling resistor; the first end of the sampling resistor of the current stage is connected with the first end of the sampling resistor of the previous stage and the first end of the sampling resistor of the next stage through the second switch component respectively, the first end of the sampling resistor of the current stage is the signal output end of the current testing channel of the current stage, and the second end of the sampling resistor of the current stage is grounded;

and the second switch component is used for being conducted when receiving the channel selection signal so as to be connected with the sampling resistors of two adjacent stages in parallel.

5. The multi-range test circuit of claim 2, wherein each of the resistance test channels is cascaded in sequence through a third switch component, each of the resistance test channels comprising a reference voltage module, a second voltage divider resistor, and a fourth switch component;

the reference voltage module, the fourth switch component, the second voltage-dividing resistor and the device to be tested are electrically connected in sequence, a first end of the second voltage-dividing resistor of the current stage is connected with a second end of the second voltage-dividing resistor of the previous stage through the third switch component, a second end of the second voltage-dividing resistor of the current stage is connected with a second end of the second voltage-dividing resistor of the next stage through the other third switch component, and two ends of the second voltage-dividing resistor of the current stage and two ends of the device to be tested of the current stage are respectively a signal output end of the resistor testing channel;

the third switch component is used for being conducted when receiving the channel selection signal so as to serially connect the second divider resistors of two adjacent stages;

and the fourth switch component is used for switching off when receiving the channel selection signal so as to cut off the reference voltage output by the reference voltage module at the current stage.

6. The multirange test circuit of claim 2, wherein the single channel test circuit further comprises a plurality of sampling circuits;

the sampling circuits are respectively arranged in the voltage testing channel, the current testing channel and the resistance testing channel and are electrically connected with the control circuit;

the sampling circuits are used for sampling the electrical parameters of the equipment to be tested which is connected with the voltage testing channel, the current testing channel and the resistance testing channel and outputting corresponding sampling data to the control circuit.

7. The multirange test circuit of claim 6, further comprising a communication module, the communication module being connected to the control circuit and an upper computer, respectively;

the upper computer is used for outputting the channel selection instruction to the control circuit through the communication module;

the control circuit is also used for feeding back the sampling data to the upper computer through the communication module.

8. The multirange test circuit of claim 6, further comprising a key selection module for outputting the channel selection instruction, the key selection module being electrically connected to the control circuit.

9. The multi-range test circuit of claim 6, wherein the multi-range test circuit further comprises a display module;

the control circuit is further configured to output the sampling data to the display module to display each sampling data.

10. A multi-range test apparatus comprising a multi-range test circuit according to any one of claims 1 to 9.

Technical Field

The invention belongs to the technical field of testing, and particularly relates to a multi-range testing circuit and a multi-range testing device.

Background

The test equipment can acquire various parameters of the equipment to be tested, such as current, voltage and the like. The existing test equipment is in a single-channel test mode, the test method is single, the precision is low, the error is large, and the test precision requirement cannot be met. For example, the test precision of the test equipment is 0.05%, the error is 5 milliamperes when the current of 10A is tested, the error is 50 milliamperes when the current of 100A is tested, and the error of 50 milliamperes is obviously far greater than 5 milliamperes, so that the test requirement cannot be met.

Disclosure of Invention

The invention aims to provide a multi-range test circuit, and aims to solve the problem that the traditional test equipment cannot meet the test requirement.

A first aspect of an embodiment of the present invention provides a multi-range test circuit, where the multi-range test circuit includes a control circuit and a plurality of single-channel test circuits electrically connected to the control circuit, each single-channel test circuit includes at least one test channel, and each test channel corresponds to one test range;

the control circuit is used for outputting a corresponding channel selection signal to each single-channel test circuit according to the range selection instruction;

and all the single-channel test circuits are used for connecting a plurality of test channels with the total test range matched with the parameters of the equipment to be tested according to the channel selection signal combination, and the total test range is equal to the sum of the test ranges corresponding to the test channels.

In one embodiment, each of the single-channel test circuits includes a voltage test circuit, a current test circuit and a resistance test circuit, the voltage test circuit includes a voltage test channel and a voltage test range of a corresponding magnitude, the current test circuit includes a current test channel and a current test range of a corresponding magnitude, and the resistance test circuit includes a resistance test channel and a resistance test range of a corresponding magnitude;

all the voltage test circuits are used for combining and connecting a plurality of voltage test channels with a total voltage test range matched with parameters of equipment to be tested according to the channel selection signals, and the total voltage test range is equal to the sum of voltage test ranges corresponding to the voltage test channels;

all the current test circuits are used for combining and connecting a total current test range and a plurality of current test channels matched with parameters of equipment to be tested according to the channel selection signals, and the total current test range is equal to the sum of current test ranges corresponding to the current test channels; and

and all the resistance test circuits are used for combining and connecting a plurality of resistance test channels with a total resistance test range matched with the parameters of the equipment to be tested according to the channel selection signals, and the total resistance test range is equal to the sum of the resistance test ranges corresponding to the plurality of resistance test channels.

In one embodiment, each of the voltage testing channels is sequentially cascaded through a first switch component, and each of the voltage testing channels includes a first reference resistor and a first divider resistor;

a first end of the first voltage-dividing resistor of the current stage is connected with a second end of the first voltage-dividing resistor of the previous stage through one first switch component, a second end of the first voltage-dividing resistor of the current stage is connected with a first end of the first voltage-dividing resistor of the next stage through another first switch component, a second end of the first voltage-dividing resistor of the current stage is further connected with a first end of the first reference resistor of the current stage to form a signal output end of the voltage testing channel of the current stage, and a second end of the first reference resistor of the current stage is grounded;

the first switch component is used for being conducted when receiving the channel selection signal so as to serially connect the first voltage dividing resistors of two adjacent stages.

In one embodiment, each of the current testing channels is sequentially cascaded through a second switch component, and each of the current testing channels includes a sampling resistor; the first end of the sampling resistor of the current stage is connected with the first end of the sampling resistor of the previous stage and the first end of the sampling resistor of the next stage through the second switch component respectively, the first end of the sampling resistor of the current stage is the signal output end of the current testing channel of the current stage, and the second end of the sampling resistor of the current stage is grounded;

and the second switch component is used for being conducted when receiving the channel selection signal so as to be connected with the sampling resistors of two adjacent stages in parallel.

In one embodiment, the resistance test channels are respectively and sequentially cascaded through a third switch component, and each resistance test channel comprises a reference voltage module, a second voltage-dividing resistor and a fourth switch component;

the reference voltage module, the fourth switch component, the second voltage-dividing resistor and the device to be tested are electrically connected in sequence, a first end of the second voltage-dividing resistor of the current stage is connected with a second end of the second voltage-dividing resistor of the previous stage through the third switch component, a second end of the second voltage-dividing resistor of the current stage is connected with a second end of the second voltage-dividing resistor of the next stage through the other third switch component, and two ends of the second voltage-dividing resistor of the current stage and two ends of the device to be tested of the current stage are respectively a signal output end of the resistor testing channel;

the third switch component is used for being conducted when receiving the channel selection signal so as to serially connect the second divider resistors of two adjacent stages;

and the fourth switch component is used for switching off when receiving the channel selection signal so as to cut off the reference voltage output by the reference voltage module at the current stage.

In one embodiment, the single channel test circuit further comprises a plurality of sampling circuits;

the sampling circuits are respectively arranged in the voltage testing channel, the current testing channel and the resistance testing channel and are electrically connected with the control circuit;

the sampling circuits are used for sampling the electrical parameters of the equipment to be tested which is connected with the voltage testing channel, the current testing channel and the resistance testing channel and outputting corresponding sampling data to the control circuit.

In one embodiment, the multi-range test circuit further comprises a communication module, and the communication module is respectively connected with the control circuit and the upper computer;

the upper computer is used for outputting the channel selection instruction to the control circuit through the communication module;

the control circuit is also used for feeding back the sampling data to the upper computer through the communication module.

In one embodiment, the multi-range test circuit further includes a key selection module for outputting the channel selection instruction, and the key selection module is electrically connected to the control circuit.

In one embodiment, the multi-range test circuit further comprises a display module;

the control circuit is further configured to output the sampling data to the display module to display each sampling data.

A second aspect of an embodiment of the present invention provides a multi-range test apparatus including the multi-range test circuit as described above.

The invention adopts the control circuit and the plurality of single-channel test circuits to form the multi-channel test circuit, when the test quantity of the equipment to be tested is tested, the control circuit performs channel selection on each single-channel test circuit according to the received range selection instruction, wherein the channel selection comprises type selection and range combination selection, and each single-channel test circuit is connected with the test channel with the corresponding type and size according to the channel selection signal, so that a total test range matched with the equipment to be tested is combined, the test range requirement of the equipment to be tested is met, and the reliability and the compatibility of the multi-channel test circuit are improved.

Drawings

FIG. 1 is a schematic diagram of a first structure of a multi-channel test circuit according to an embodiment of the present invention;

FIG. 2 is a diagram illustrating a second structure of a multi-channel test circuit according to an embodiment of the invention;

FIG. 3 is a schematic structural diagram of a voltage testing channel according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a current test channel according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a resistance test channel according to an embodiment of the present invention;

fig. 6 is a schematic diagram of a third structure of a multi-channel test circuit according to an embodiment of the invention.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

A first aspect of an embodiment of the present invention provides a multi-range test circuit.

As shown in fig. 1, fig. 1 is a schematic view of a first structure of a multi-channel test circuit according to an embodiment of the present invention, in this embodiment, the multi-range test circuit includes a control circuit 10 and a plurality of single-channel test circuits electrically connected to the control circuit 10, each single-channel test circuit includes at least one test channel, and each test channel corresponds to one test range;

the control circuit 10 is used for outputting a corresponding channel selection signal to each single-channel test circuit according to the range selection instruction;

and all the single-channel test circuits are used for connecting a plurality of test channels with the total test range matched with the parameters of the equipment to be tested according to the channel selection signal combination, and the total test range is equal to the sum of the test ranges corresponding to the test channels.

In this embodiment, each single-channel test circuit may include at least one test channel, and may perform tests on multiple different parameters of the device under test, such as tests on parameters of voltage, resistance, current, temperature, and the like, each test channel corresponds to a test range, the multiple single-channel test circuits may perform separate tests on different parameters of the device under test, the multiple single-channel test circuits have signal terminals, and are connected to the device under test to perform parameter tests, but when the parameters of the device under test are greater than the test range in the current test channel of each single-channel test circuit, the test requirements may not be satisfied.

For example, in fig. 1, assuming that the current test range of the current test channel of the first single-channel test circuit 20 is 0-10A, the current test range of the current test channel of the second single-channel test circuit 30 is 0-20A, and the current test range of the current test channel of the third single-channel test circuit 40 is 0-20A, when the current parameter of the device to be tested is 25A, none of the current test channels of the single-channel test circuits can meet the test requirement, at this time, a channel selection instruction can be output to the control circuit 10 according to the current parameter of the device to be tested through the upper computer or the key selection module, the control circuit 10 further outputs a channel selection signal to the corresponding single-channel test circuit to combine and combine the corresponding current test channels, for example, the current test channel of the first single-channel test circuit 20 and the current test channel of the second single-channel test circuit 30 can be combined and combined, therefore, the total test range of 10A-30A can be combined to meet the test requirement of the equipment to be tested, and when the current parameter of the equipment to be tested is 45A, the current test channels of the three single-channel test circuits can be combined and combined, so that the total test range of 30A-50A is combined, the current parameter of the equipment to be tested is matched, and the test requirement of the equipment to be tested is met.

According to different parameter types and sizes of the equipment to be tested, corresponding channel selection instructions can be output to the control circuit 10, and the control circuit 10 further controls the test channels with the same type and corresponding ranges in the single-channel test circuits to be connected in a combined mode, so that the total test range matched with the parameters of the equipment to be tested is combined in a self-adaptive mode.

In this embodiment, the control circuit 10 may be a controller, for example, a single chip, an MCU, a CPU, or other structures, the single-channel test circuit may be one or a combination of a voltage test circuit, a current test circuit, a resistance test circuit, and a temperature test circuit, and the specific structure may be selected according to the test requirements of the device to be tested.

Meanwhile, the single-channel test circuit can be designed according to different test types, and the number of the internal test channels and the size of the corresponding test range can be correspondingly selected, so that specific limitations are not required.

The invention adopts the control circuit 10 and the plurality of single-channel test circuits to form the multi-channel test circuit, when the test quantity of the equipment to be tested is tested, the control circuit 10 performs channel selection on each single-channel test circuit according to the received range selection instruction, including type selection and range combination selection, and each single-channel test circuit is connected with the test channel with the corresponding type and size according to the channel selection signal, thereby combining a total test range matched with the equipment to be tested, meeting the test range requirement of the equipment to be tested and improving the reliability and compatibility of the multi-channel test circuit.

As shown in fig. 2, in one embodiment, each single channel test circuit includes a voltage test circuit, a current test circuit and a resistance test circuit, for example, the first single-channel test circuit 20 includes a first voltage test circuit 21, a first current test circuit 22, and a first resistance test circuit 23, the second single-channel test circuit 30 includes a second voltage test circuit 31, a second current test circuit 32, and a second resistance test circuit 33, the third single-channel test circuit 40 includes a third voltage test circuit 41, a third current test circuit 42, and a third resistance test circuit 43, each voltage test circuit includes a voltage test channel and a voltage test range of a corresponding size, each current test circuit includes a current test channel and a current test range of a corresponding size, and each resistance test circuit includes a resistance test channel and a resistance test range of a corresponding size;

all the voltage test circuits are used for connecting a plurality of voltage test channels of which the total voltage test range is matched with the parameters of the equipment to be tested according to the channel selection signal combination, and the total voltage test range is equal to the sum of the voltage test ranges corresponding to the voltage test channels;

all the current test circuits are used for combining and connecting a plurality of current test channels of which the total current test ranges are matched with the parameters of the equipment to be tested according to the channel selection signals, and the total current test ranges are equal to the sum of the current test ranges corresponding to the current test channels; and

and all the resistance test circuits are used for connecting a plurality of resistance test channels of which the total resistance test ranges are matched with the parameters of the equipment to be tested according to the channel selection signal combination, and the total resistance test ranges are equal to the sum of the resistance test ranges corresponding to the plurality of resistance test channels.

In this embodiment, in order to meet and match the test requirements of more types of devices under test, each single-channel test circuit includes a voltage test circuit, a current test circuit, and a resistance test circuit, each of the voltage test circuit, the current test circuit, and the resistance test circuit is provided with a voltage test channel, a current test channel, and a resistance test channel, and a corresponding voltage test range, a corresponding current test range, and a corresponding resistance test range, for example, when the voltage of the device under test needs to be tested, the control circuit 10 outputs a corresponding voltage selection signal to the voltage test circuits in the single-channel test circuits according to the received channel selection instruction, so as to connect the corresponding number of voltage test channels in combination, the number of connected test channels is selected correspondingly according to the voltage parameters of the device under test and the test ranges of the test channels, therefore, a total voltage test range matched with the voltage parameters of the equipment to be tested is combined, the voltage test requirement of the equipment to be tested is met, and similarly, the test channels of the resistance test circuit and the current test circuit are combined and connected according to the same method.

As shown in fig. 3, in an embodiment, the voltage test channels are respectively cascaded in sequence through a first switch component K1, and each voltage test channel includes a first reference resistor R0 and a first voltage dividing resistor;

the first end of the first voltage-dividing resistor of the current stage is connected with the second end of the first voltage-dividing resistor of the previous stage through a first switch component K1, the second end of the first voltage-dividing resistor of the current stage is connected with the first end of the first voltage-dividing resistor of the next stage through another first switch component K1, the second end of the first voltage-dividing resistor of the current stage is also connected with the first end of the first reference resistor R0 of the current stage to form a signal output end of the voltage testing channel of the current stage, and the second end of the first reference resistor R0 of the current stage is grounded;

the first switch component K1 is configured to be turned on when receiving the channel selection signal, so as to serially connect the first voltage dividing resistors of two adjacent stages.

According to the voltage testing principle, the voltage testing circuit adopts a resistance voltage division method to perform voltage measurement, the resistance values of the reference resistors in the voltage testing channels are the same, the voltage testing range of the channels can be changed by changing the value of the first voltage dividing resistor, and the larger the resistance value of the first voltage dividing resistor, the larger the voltage testing range, therefore, when the device to be tested needs a larger testing range, the control circuit 10 outputs a channel selection signal, the corresponding first switch component is turned on, thereby connecting the first voltage dividing resistors connected in the voltage testing channels in series, increasing the resistance value of the first voltage dividing resistor and correspondingly increasing the total voltage testing range, for example, in fig. 3, the voltage testing channel of the first voltage testing circuit 21 comprises a first voltage dividing resistor R11 and a reference resistor R0, the voltage testing channel of the second voltage testing circuit 31 comprises another first voltage dividing resistor R12 and a reference resistor R0, according to the different resistance values of the first divider resistors, the two voltage test channels can obtain different voltage test ranges, when the two voltage test channels need to be combined to increase the test range, the first switch component is switched on, the first divider resistor R11 is connected with the other first divider resistor R12 in series, the first switch component is connected with the device to be tested through the signal input end VIN1, the proportional voltage of the device to be tested is obtained from the signal output end VOUT2, and the proportional voltage can be fed back to the sampling module or the sampling circuit so as to obtain the voltage of the device to be tested.

As shown in fig. 4, in one embodiment, the current testing channels are respectively cascaded in sequence through a second switching component K2, and each current testing channel includes a sampling resistor; the first end of the sampling resistor of the current stage is respectively connected with the first end of the sampling resistor of the previous stage and the first end of the sampling resistor of the next stage through a second switch component K2, the first end of the sampling resistor of the current stage is the signal output end of the current testing channel of the current stage, and the second end of the sampling resistor of the current stage is grounded;

and the second switch component is used for being conducted when receiving the channel selection signal so as to be connected with the sampling resistors of two adjacent stages in parallel.

In this embodiment, the current test generally adopts the terminal voltage of obtaining the sampling resistor and then obtains the current magnitude of the equipment to be tested, the size of the sampling resistor determines the test range of the current test channel, the smaller the sampling resistor is, the larger the test range of the current test channel is, the larger the measurable current is, therefore, when the larger current test range is needed, the second switch component K2 can be controlled to be switched on to connect the sampling resistors of each current test channel in parallel to reduce the total sampling resistance value, and the number and the resistance value of the sampling resistors of the specific parallel current test channels are correspondingly selected according to the current parameters of the equipment to be tested.

As shown in fig. 5, in an embodiment, the resistance test channels are sequentially cascaded through a third switch assembly K3, and each resistance test channel includes a reference voltage module, a second voltage-dividing resistor, and a fourth switch assembly K4;

the reference voltage module, the fourth switch component K4, the second divider resistor and the device to be tested are electrically connected in sequence, the first end of the second divider resistor is connected with the second end of the second divider resistor of the previous stage through a third switch component K3, the second end of the second divider resistor of the current stage is connected with the second end of the second divider resistor of the next stage through another third switch component K3, and the two ends of the second divider resistor of the current stage and the two ends of the device to be tested are respectively a signal output end of a resistor test channel;

the third switch component K3 is used for being conducted when receiving the channel selection signal so as to serially connect the second divider resistors of two adjacent stages;

and the fourth switching component K4 is configured to turn off when receiving the channel selection signal, so as to cut off the reference voltage Vref output by the current stage of reference voltage module.

In this embodiment, the resistance measurement may be performed by a proportional voltage dividing method, and the reference voltage Vref is applied to the device under test and the second voltage dividing resistor, and the voltages at two ends of the device under test, such as RX1 and RX2, and the resistance value of the device under test can be obtained according to the two voltage values and the resistance value of the second voltage dividing resistor, so that the larger the resistance value of the second voltage dividing resistor is, the larger the resistance value of the device under test can be measured, the larger the corresponding resistance test range is, and therefore, when a larger resistance test range needs to be obtained during the test process, the third switch component K3 may be controlled to be turned on, the fourth switch component K4 of the present stage is turned off, as shown in fig. 5, the resistance test channel of the second resistance test circuit 33 includes the second voltage dividing resistor R22 and the fourth switch component K4, the resistance test channel of the first resistance test circuit 23 includes another second voltage dividing resistor R21 and a fourth switch component K4, when a larger resistance test range needs to be obtained, when the second resistance test circuit 33 serves as the current-stage resistance test circuit, the fourth switch component K4 is disconnected, the fourth switch component K4 in the first resistance test circuit 23 keeps a conducting state, the reference voltage flows into the device to be tested through the second voltage-dividing resistors R21 and R22, the second voltage-dividing resistors R21 and R22 are combined and connected in series to obtain a larger resistance test range, and the resistance value of the device to be tested can be determined by obtaining the voltages at the two ends of the second voltage-dividing resistors R21 and R22 and the voltage of the device to be tested.

Each switch assembly may be a controlled switch assembly, such as a switch device or a switch circuit, such as a relay or a switch tube.

Also, in one embodiment, the single channel test circuit further comprises a plurality of sampling circuits (not shown);

the plurality of sampling circuits are respectively arranged in the voltage testing channel, the current testing channel and the resistance testing channel and are electrically connected with the control circuit 10;

and the sampling circuits are used for sampling the electrical parameters of the equipment to be tested connected with the voltage testing channel, the current testing channel and the resistance testing channel and outputting corresponding sampling data to the control circuit 10.

In this embodiment, still be provided with the sampling circuit respectively in each test channel among each single channel test circuit in order to sample the electrical parameter of the equipment to be tested who connects in test channel, including resistance sampling, current sampling and voltage sampling, and the feedback corresponding sampling data includes voltage sampling data, current sampling data and resistance sampling data to control circuit 10, as shown in fig. 3-5, the specific circuit structure of sampling circuit according to voltage test channel, current test channel and resistance test channel can be structures such as voltmeter or ammeter, specifically selects according to the demand.

As shown in fig. 6, in an embodiment, the multi-range testing circuit further includes a communication module 50, and the communication module 50 is connected to the control circuit 10 and the upper computer respectively;

the upper computer is used for outputting a channel selection instruction to the control circuit 10 through the communication module 50;

the control circuit 10 is further configured to feed back the sampling data to the upper computer through the communication module 50.

In this embodiment, the upper computer is configured to output a channel selection instruction, a channel policy table is stored in the upper computer, a channel merging policy is corresponding to a test range and a test type of the device to be tested, the upper computer issues the corresponding channel selection instruction to the control circuit 10 through the communication module 50, the control circuit 10 controls a working state of a test channel in each single-channel test circuit according to the channel selection instruction, and further achieves a test purpose of adaptively combining multiple ranges, and meanwhile, the control circuit 10 sends acquired current, voltage, and resistance data of each channel to the upper computer through the communication module 50.

The communication module 50 can be a wireless module such as bluetooth and wifi or a wired communication module such as RS232 and RS485, and the specific structure is designed according to the requirement.

Referring to fig. 6, in order to facilitate off-grid control and local selection, in an embodiment, the multi-range test circuit further includes a key selection module 60 for outputting a channel selection instruction, and the key selection module 60 is electrically connected to the control circuit 10.

The key selection module 60 may be a rotary key, a button key, or a touch key, and the tester may operate the key selection module 60 according to the electrical parameters of the device to be tested, so as to output a channel selection instruction to the control circuit 10, so that the control circuit 10 selects and combines test channels of corresponding types and numbers according to the channel selection instruction, so as to meet the test requirements of the device to be tested.

Continuing to refer to fig. 6, in one embodiment, the multi-range test circuit further includes a display module 70;

the control circuit 10 is further configured to output the sampling data to the display module 60 to display each sampling data.

The invention further provides a multi-range testing device, which comprises a multi-range testing circuit, the specific structure of the multi-range testing circuit refers to the above embodiments, and the multi-range testing device adopts all the technical schemes of all the above embodiments, so that the multi-range testing device at least has all the beneficial effects brought by the technical schemes of the above embodiments, and further description is omitted.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present invention, and are intended to be included within the scope of the present invention.