Current acquisition circuit and current measurement circuit

Abstract

The embodiment of the utility model provides a current acquisition circuit and a current measurement circuit, and relates to the technical field of current measurement, a micro-control unit adjusts the current amplification factor of the current acquisition circuit by adjusting the use state of each control module according to the initial output current output by the current acquisition circuit, so that the current measurement precision is improved. According to the method, the internal currents of the external devices with different sizes are amplified into the output currents larger than the preset threshold value, and then the current information of the internal currents is obtained according to the output currents so as to measure the internal currents of the external devices. The internal currents with different magnitudes are amplified into the output currents larger than the preset threshold value for processing, and the current values of the currents are negatively correlated with the measurement errors of the currents, so that the measurement errors of the internal currents with different magnitudes are all smaller than the error threshold value corresponding to the preset threshold value; compared with the prior art in which the measurement error of the partial current is greater than the error threshold, the measurement accuracy is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of current measurement, in particular to a current acquisition circuit and a current measurement circuit. Background Art

[0002] At present, low-power design has become a key technical requirement for electronic devices, especially very important for mobile devices, sensor nodes, and Internet of Things devices that rely on battery power supply. Low-power design requires measuring the current in electronic devices.

[0003] In the prior art, workers use ammeters to measure the current in electronic devices.

[0004] In the process of implementing the present application, the inventor found that there are at least the following problems in the prior art: Since the current value of the current is negatively correlated with the degree of interference of the current by external interference signals, that is, the smaller the current value of the current, the greater the interference of the current by external interference signals, and the greater the interference of the current by external interference signals, the greater the measurement error of the current. Then the current value of the current is negatively correlated with the measurement error of the current, that is, the smaller the current value of the current, the greater the measurement error of the current. Workers use ammeters to measure the current in electronic devices, resulting in the measurement error of some currents being greater than the error threshold, leading to low measurement accuracy. Summary of the Utility Model

[0005] The utility model provides a current acquisition circuit and a current measurement circuit to at least solve the problem in the prior art that when workers use ammeters to measure the current in electronic devices, the measurement error of some currents is greater than the error threshold, resulting in low measurement accuracy.

[0006] An embodiment of the utility model provides a current acquisition circuit, which is used to be electrically connected to an external device and a microcontroller unit, and acquire the internal current of the external device and output the current to the microcontroller unit;

[0007] The current acquisition circuit includes n control modules. The acquisition circuit is further configured to adjust the usage state of the i-th control module according to the control signal input by the microcontroller unit to the i-th control module, and determine the current amplification factor according to the parameters of the control modules whose usage states are available, and amplify the internal current into an output current and output it according to the current amplification factor; i is a positive integer less than or equal to n.

[0008] Optionally, the current acquisition circuit further includes an operational amplifier and a first resistor; the non-inverting input terminal of the operational amplifier is used to be electrically connected to the external device and acquire the internal current of the external device; the inverting input terminal of the operational amplifier is electrically connected to the first end of the first resistor, and the output terminal of the operational amplifier is electrically connected to the second end of the first resistor; the inverting input terminal of the operational amplifier is also electrically connected to each control module; the positive terminal of the operational amplifier is used to be electrically connected to an external power supply, and the negative terminal of the operational amplifier is grounded.

[0009] Optionally, each control module includes a second resistor and a switching device; the microcontroller unit includes n control terminals; the first end of each second resistor is electrically connected to the inverting input terminal of the operational amplifier; in the control module, the second end of the second resistor is electrically connected to the first end of the switching device; the second end of the switching device in the i-th control module is electrically connected to the i-th control terminal, the third end of the switching device in the i-th control module is grounded, and the switching device in the i-th control module is used to conduct when the control signal output by the i-th control terminal is at a high level, so that the second end of the second resistor in the i-th control module is grounded, thereby setting the usage state of the i-th control module to be available; and turn off when the control signal output by the i-th control terminal is at a low level, so that the second end of the second resistor in the i-th control module is left open, thereby setting the usage state of the i-th control module to be unused.

[0010] Optionally, the switching device is a triode; in the control module, the second end of the second resistor is electrically connected to the collector of the switching device; the base of the switching device in the i-th control module is electrically connected to the i-th control terminal, and the emitter of the switching device in the i-th control module is grounded.

[0011] Optionally, the switching device is an NPN-type triode.

[0012] Optionally, the switching device is a MOS transistor; in the control module, the second end of the second resistor is electrically connected to the drain of the switching device; the gate of the switching device in the i-th control module is electrically connected to the i-th control terminal, and the source of the switching device in the i-th control module is grounded.

[0013] Optionally, the switching device is an NMOS transistor.

[0014] Optionally, the resistance values of each second resistor are different.

[0015] Second aspect, embodiments of the present invention provide a current acquisition circuit and a current measurement circuit, including: a microcontroller unit and the current acquisition circuit as described in the first aspect;

[0016] The current acquisition circuit is used to be electrically connected to an external device and acquire the internal current of the external device;

[0017] The current acquisition circuit is electrically connected to the microcontroller unit. The current acquisition circuit includes n control modules. The current acquisition circuit is further configured to adjust the usage state of the i-th control module according to the control signal input by the microcontroller unit to the i-th control module, and determine the current amplification factor according to the parameters of the control modules whose usage states are available, and amplify the internal current into an output current and output it according to the current amplification factor; i is a positive integer less than or equal to n;

[0018] The microcontroller unit is configured to generate control signals input to each control module according to the current value of the initial output current output by the current acquisition circuit; the initial output current is the output current generated by the current acquisition circuit after amplifying the internal current according to the initial current amplification factor.

[0019] Optionally, the current measurement circuit further includes a display device; the display device is electrically connected to the microcontroller unit, and the display device is used to display the current information.

[0020] Optionally, the microcontroller unit is further configured to be electrically connected to the external device and control the working state of the external device.

[0021] In the embodiments of the present invention, the microcontroller unit adjusts the current amplification factor of the current acquisition circuit by adjusting the usage state of each control module according to the initial output current output by the current acquisition circuit, so that the internal currents of external devices of different sizes are all amplified into output currents greater than a preset threshold. Then, according to the output current, the current information of the internal current is obtained to realize the measurement of the internal current of the external device. In this process, since internal currents of different sizes are amplified into output currents greater than the preset threshold for processing, and the current value of the current is negatively correlated with the current measurement error, the measurement errors of internal currents of different sizes are all less than the error threshold corresponding to the preset threshold. Compared with the prior art where the measurement errors of some currents are greater than the error threshold, the measurement accuracy is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required for the description of the embodiments of the present utility model. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 is a schematic structural diagram of a current acquisition circuit provided by an embodiment of the present utility model;

[0024] Figure 2 is a schematic structural diagram of a current measurement circuit provided by an embodiment of the present utility model;

[0025] Figure 3 is a specific schematic structural diagram of the current acquisition circuit provided by an embodiment of the present utility model;

[0026] Figure 4 is another specific schematic structural diagram of the current acquisition circuit provided by an embodiment of the present utility model.

[0027] Reference numerals:

[0028] 10 - microcontroller unit; 20 - current acquisition circuit; 21 - control module; 22 - operational amplifier; 23 - feedback resistor module; 30 - display device; 40 - external device. Specific embodiments

[0029] To make the above objects, features, and advantages of the present utility model more obvious and understandable, the following will further describe the present utility model in detail with reference to the drawings and specific embodiments.

[0030] Refer to Figure 1 , an embodiment of the present utility model provides a current acquisition circuit 20, which is used to be electrically connected to an external device 40 and a microcontroller unit 10, and collect the internal current of the external device 40 and output the current to the microcontroller unit 10; the current acquisition circuit 20 includes n control modules 21, and the acquisition circuit 20 is further configured to adjust the usage state of the i-th control module 21 according to the control signal input by the microcontroller unit 10 to the i-th control module 21, and determine the current amplification factor according to the parameters of the available control modules 21 according to the usage state, and amplify the internal current into an output current and output it according to the current amplification factor; n is a positive integer, and i is a positive integer less than or equal to n.

[0031] It should be noted that the current acquisition circuit 20 is specifically configured to determine the current amplification factor of the current acquisition circuit 20 according to the parameters of the controllable control module 21 in the usage state, and amplify the internal current into an output current according to the current amplification factor, and output the output current through the output terminal of the current acquisition circuit 20, where the current value of the output current is greater than a preset threshold; the microcontroller unit 10 is configured to generate a control signal input to each control module 21 according to the current value of the initial output current output by the current acquisition circuit 20; the initial output current is the output current generated by the current acquisition circuit 20 after amplifying the internal current according to the initial current amplification factor; the input terminal of the microcontroller unit 10 is electrically connected to the output terminal of the current acquisition circuit 20, and the microcontroller unit 10 is further configured to generate current information of the internal current according to the output current; the microcontroller unit 10 includes a comparator, and the comparator is configured to compare the current value of the output current with the preset threshold, and in the case where the current value of the output current is less than or equal to the preset threshold, adjust the control signal input to each control module 21 to increase the current amplification factor of the current acquisition circuit 20; in the case where the current value of the output current is greater than the preset threshold, keep the control signal input to each control module 21 unchanged to keep the current amplification factor of the current acquisition circuit 20 unchanged.

[0032] The external device 40 may be an electronic device, such as a mobile device (such as a mobile phone) powered by a battery, a sensor node, and an Internet of Things device, etc.; the internal current of the external device 40 may be the internal current when the external device 40 is in the usage state, or may be the internal current when the external device 40 is in the standby state.

[0033] In the case where the control signal input to the i-th control module 21 is at a high level, the usage state of the i-th control module 21 is set to be available; in the case where the control signal input to the i-th control module 21 is at a low level, the usage state of the i-th control module 21 is set to be unavailable;

[0034] The parameter of the control module 21 may be a resistance value; in some embodiments, the parameters of each control module 21 may be the same; in other embodiments, the parameters of each control module 21 may be different.

[0035] The current value of the output current is the product of the current value of the internal current and the current amplification factor; the current information of the internal current may be the current value information of the internal current, such as a curve image of the current value of the internal current changing with time, a correspondence table of the current value of the internal current and time, etc.

[0036] Specifically, each control module 21 has a corresponding preset initial control signal. The microcontroller unit 10 (MCU, Microcontroller Unit) inputs the corresponding initial control signal to each control module 21, so that each control module 21 has an initial usage state. According to the parameters of the control module 21 that can be used in the initial usage state, the initial current amplification factor of the current acquisition circuit 20 is determined; the current acquisition circuit 20 acquires the internal current of the external device 40, and according to the initial current amplification factor, amplifies the internal current into an initial output current, and outputs the initial output current through the output terminal of the current acquisition circuit 20, where the initial output current is the product of the current value of the internal current and the initial current amplification factor. The microcontroller unit 10 generates a control signal input to each control module 21 according to the current value of the initial output current. The current acquisition circuit 20 adjusts the usage state of the control module 21 corresponding to the control signal according to the control signal input by the microcontroller unit 10 to each control module 21, and determines the current amplification factor of the current acquisition circuit 20 according to the parameters of the control module 21 that can be used in the usage state, and amplifies the internal current into an output current according to the current amplification factor.

[0037] The microcontroller unit 10 is further specifically configured to calculate the current value of the internal current according to the current value of the output current and the value of the current amplification factor, where the current value of the internal current is the quotient obtained by dividing the current value of the output current by the value of the current amplification factor; and generate the current information of the internal current according to the current value of the internal current.

[0038] For example, the current acquisition circuit 20 includes 3 control modules, and each control module has a corresponding preset initial control signal, that is, the first control module has a corresponding preset initial control signal B1, the second control module has a corresponding preset initial control signal B2, and the third control module has a corresponding preset initial control signal B3. The microcontroller unit 10 inputs the corresponding initial control signal to each control module, so that each control module has an initial usage state, that is, the microcontroller unit 10 inputs the corresponding initial control signal B1 to the first control module, and the current acquisition circuit 20 sets the initial usage state of the first control module to available. The microcontroller unit 10 inputs the corresponding initial control signal B2 to the second control module, and the current acquisition circuit 20 sets the initial usage state of the second control module to unavailable. The microcontroller unit 10 inputs the corresponding initial control signal B3 to the third control module, and the current acquisition circuit 20 sets the initial usage state of the third control module to unavailable.

[0039] The current acquisition circuit 20 determines the initial current amplification factor of the current acquisition circuit 20 according to the parameters of the control modules that are available in the initial use state, that is, the current acquisition circuit 20 determines the initial current amplification factor of the current acquisition circuit 20 according to the parameters of the first control module.

[0040] The current acquisition circuit 20 acquires the internal current of the external device 40 and amplifies the internal current into an initial output current according to the initial current amplification factor; the microcontroller unit 10 generates control signals input to each control module according to the current value of the initial output current, namely, the control signal A1 input to the first control module, the control signal A2 input to the second control module, and the control signal A3 input to the third control module.

[0041] The current acquisition circuit 20 adjusts the use state of the control module corresponding to the control signal according to the control signal input by the microcontroller unit 10 to each control module, that is, the current acquisition circuit 20 sets the use state of the first control module to unused according to the control signal A1 input by the microcontroller unit 10 to the first control module, the current acquisition circuit 20 sets the use state of the second control module to available according to the control signal A2 input by the microcontroller unit 10 to the second control module, and the current acquisition circuit 20 sets the use state of the third control module to unused according to the control signal A3 input by the microcontroller unit 10 to the third control module.

[0042] The current acquisition circuit 20 determines the initial current amplification factor of the current acquisition circuit 20 according to the parameters of the second control module, and amplifies the internal current into an output current according to the current amplification factor. The microcontroller unit 10 calculates the current value of the internal current according to the current value of the output current and the value of the current amplification factor, and then generates the current information of the internal current according to the current value of the internal current.

[0043] In the embodiment of the present invention, the microcontroller unit 10 adjusts the current amplification factor of the current acquisition circuit 20 by adjusting the use state of each control module 21 according to the initial output current output by the current acquisition circuit 20, so that the internal currents of external devices 40 of different magnitudes are all amplified into output currents greater than a preset threshold, and then the current information of the internal current is obtained according to the output current, so as to realize the measurement of the internal current of the external device 40. In this process, since internal currents of different magnitudes are amplified into output currents greater than the preset threshold for processing, and the current value of the current is negatively correlated with the measurement error of the current, the measurement errors of internal currents of different magnitudes are all smaller than the error threshold corresponding to the preset threshold. Compared with the prior art in which the measurement error of some currents is greater than the error threshold, the measurement accuracy is improved.

[0044] Optionally, referring to Figure 3, in some embodiments, the current acquisition circuit 20 further includes an operational amplifier 22 and a feedback resistor module 23; the feedback resistor module 23 includes a first resistor or a plurality of first resistors connected in series; the non-inverting input terminal of the operational amplifier 22 is used to be electrically connected to the external device 40 and acquire the internal current of the external device 40; the inverting input terminal of the operational amplifier 22 is electrically connected to the first end of the feedback resistor module 23, and the output terminal of the operational amplifier 22 is electrically connected to the second end of the feedback resistor module 23; the inverting input terminal of the operational amplifier 22 is also electrically connected to each control module 21; the positive terminal of the operational amplifier 22 is used to be electrically connected to an external power supply, and the negative terminal of the operational amplifier 22 is grounded.

[0045] It should be noted that, in the case where the feedback resistor module 23 includes a first resistor, the first end of the feedback resistor module 23 is the first end of the first resistor, and the second end of the feedback resistor module 23 is the second end of the first resistor; in the case where the feedback resistor module 23 includes a plurality of first resistors connected in series, the first end of the feedback resistor module 23 is the first end of the first first resistor in the series-connected first resistors, and the second end of the feedback resistor module 23 is the second end of the last first resistor in the series-connected first resistors.

[0046] Specifically, the parameter of the control module 21 is a resistance value. The operational amplifier 22, the feedback resistor module 23, and the control module 21 form a non-inverting amplifier. Among the multiple control modules 21 of the current acquisition circuit 20, when the number of control modules 21 in the available state is one, the parameter (resistance value) of the control module 21 in the available state is negatively correlated with the current amplification factor of the current acquisition circuit 20. By determining the control module 21 in the available state from the multiple control modules 21 of the current acquisition circuit 20, the current amplification factor is determined, and thus, according to the current amplification factor, the internal current of the external device 40 is amplified into an output current.

[0047] In some embodiments, the model of the operational amplifier 22 can be LM2904DT.

[0048] In the embodiments of the present invention, the feedback resistor module 23 is the feedback resistor of the operational amplifier 22. The operational amplifier 22 amplifies the internal current of the external device 40 into an output current according to the current amplification factor.

[0049] Optionally, refer to Figure 4, in some embodiments, each of the control modules 21 includes a second resistor and a switching device; the parameter of the control module 21 is the resistance value of the second resistor in the control module 21; the microcontroller unit 10 includes n control terminals; the first end of each second resistor is electrically connected to the inverting input terminal of the operational amplifier 22; in the control module 21, the second end of the second resistor is electrically connected to the first end of the switching device; the second end of the switching device in the i-th control module 21 is electrically connected to the i-th control terminal, the third end of the switching device in the i-th control module 21 is grounded, and the switching device in the i-th control module 21 is configured to conduct when the control signal output from the i-th control terminal is at a high level, so that the second end of the second resistor in the i-th control module 21 is grounded, thereby setting the usage state of the i-th control module 21 to be available; and to turn off when the control signal output from the i-th control terminal is at a low level, so that the second end of the second resistor in the i-th control module 21 is left open, thereby setting the usage state of the i-th control module 21 to be unavailable.

[0050] It should be noted that the resistance values of each second resistor may be the same or different, or the resistance values of some of the second resistors in the second resistor are the same; in the control module 21, the switching device is used to control whether the second resistor is grounded, and the types of the switching device include NPN transistors, NMOS transistors, etc. Among them, the NPN transistor is composed of three semiconductors, including two N (Negative Electricity) type semiconductors (electronic semiconductors) and one P (Positive Electricity) type semiconductor (hole type semiconductor). The P-type semiconductor is in the middle, and the two N-type semiconductors are on both sides; the MOS transistor Q1 is a Metal-Oxide-Semiconductor Field-Effect Transistor, and the NMOS transistor is a Negative channel Metal Oxide Semiconductor.

[0051] The control terminals and the control modules 21 are in one-to-one correspondence, and the control signals output from the control terminals and the control modules 21 are in one-to-one correspondence.

[0052] In the embodiments of the present invention, the on and off of the switching device in the control module 21 corresponding to the control signal are controlled by the control signal output from the control terminal, so as to adjust the usage state of the control module 21.

[0053] Optionally, in some embodiments, the switching device is a triode; in the control module 21, the second end of the second resistor is electrically connected to the collector of the switching device; the base of the switching device in the i-th control module 21 is electrically connected to the i-th control terminal, and the emitter of the switching device in the i-th control module 21 is grounded.

[0054] In the embodiments of the present invention, the on-off of the triode in the control module 21 corresponding to the control signal is controlled by the control signal output from the control terminal, so as to adjust the usage state of the control module 21.

[0055] Optionally, in some embodiments, the switching device is an NPN type triode.

[0056] In the embodiments of the present invention, the NPN type triode in the i-th control module 21 conducts when the control signal output from the control terminal is at a high level, so that the second end of the second resistor in the i-th control module 21 is grounded, thereby setting the usage state of the i-th control module 21 to available; it turns off when the control signal output from the i-th control terminal is at a low level, so that the second end of the second resistor in the i-th control module 21 is left open, thereby setting the usage state of the i-th control module 21 to unavailable.

[0057] Optionally, in some embodiments, the switching device is a MOS transistor; in the control module 21, the second end of the second resistor is electrically connected to the drain of the switching device; the gate of the switching device in the i-th control module 21 is electrically connected to the i-th control terminal, and the source of the switching device in the i-th control module 21 is grounded.

[0058] In the embodiments of the present invention, the on-off of the MOS transistor in the control module 21 corresponding to the control signal is controlled by the control signal output from the control terminal, so as to adjust the usage state of the control module 21.

[0059] Optionally, in some embodiments, the switching device is an NMOS transistor.

[0060] In the embodiments of the present invention, the NMOS transistor in the i-th control module 21 conducts when the control signal output from the control terminal is at a high level, so that the second end of the second resistor in the i-th control module 21 is grounded, thereby setting the usage state of the i-th control module 21 to available; it turns off when the control signal output from the i-th control terminal is at a low level, so that the second end of the second resistor in the i-th control module 21 is left open, thereby setting the usage state of the i-th control module 21 to unavailable.

[0061] Optionally, in some embodiments, the resistance values of each of the second resistors are different.

[0062] In an embodiment of the present utility model, one control module 21 is selected from multiple control modules 21 of the current acquisition circuit 20 as the target control module, the usage status of the target control module is adjusted to available, and the usage status of other control modules 21 is adjusted to unavailable. Specifically, the control signal input by the microcontroller unit 10 to the target control module is a high level, so that the usage status of the target control module is adjusted to available, and the control signal input by the microcontroller unit 10 to other control modules 21 is a low level, so that the usage status of other control modules 21 is adjusted to unavailable. Then, among the multiple control modules 21 of the current acquisition circuit 20, the number of control modules 21 (i.e., the target control module) with an available usage status is one, and the current amplification factor of the current acquisition circuit 20 is the sum of the resistance value ratio and 1. Among them, the resistance value ratio is the quotient obtained by dividing the resistance value of the feedback resistance module 23 by the resistance value of the second resistor in the target control module.

[0063] Since the resistance value of the feedback resistance module 23 is fixed, the resistance value of the second resistor in the target control module is negatively correlated with the current amplification factor of the current acquisition circuit 20.

[0064] Since the resistance values of the second resistors in each control module 21 are different, by selecting different control modules 21 as the target control module, the current amplification factors of the current acquisition circuit 20 are different.

[0065] Therefore, for internal currents of different magnitudes, different control modules 21 are selected as the target control module, so that internal currents of different magnitudes are all amplified into output currents greater than a preset threshold.

[0066] For example, referring to Figure 4 , the preset threshold is p, the feedback resistance module 23 includes a first resistor R4, and the resistance value of the feedback resistance module 23 (i.e., the resistance value of the first resistor R4) is r; the current acquisition circuit 20 includes 3 control modules. Among them, the resistance value of the second resistor R1 of the first control module is 0.5r, the resistance value of the second resistor R2 of the second control module is 2r, and the resistance value of the second resistor R3 of the third control module is 4r;

[0067] The output terminal INPUT of the internal current of the external device (40) is electrically connected to the non-inverting input terminal of the operational amplifier 22, and the output terminal of the operational amplifier 22 is electrically connected to the input terminal ADC of the microcontroller unit 10; the microcontroller unit 10 inputs a control signal A1 to the control terminal IO1 of the first control module, inputs a control signal A2 to the control terminal IO2 of the second control module, and inputs a control signal A3 to the control terminal IO3 of the third control module.

[0068] When the current value of the internal current of the external device 40 is p, the microcontroller unit 10 inputs the corresponding control signal A1 to the first control module as a low level, the switching device Q1 of the first control module is turned off, the current acquisition circuit 20 sets the initial usage state of the first control module as unused, the microcontroller unit 10 inputs the corresponding control signal A2 to the second control module as a high level, the switching device Q2 of the second control module is turned on, the current acquisition circuit 20 sets the initial usage state of the second control module as available, the microcontroller unit 10 inputs the corresponding control signal A3 to the third control module as a low level, the switching device Q3 of the third control module is turned off, and the current acquisition circuit 20 sets the initial usage state of the third control module as unused.

[0069] Then, the current acquisition circuit 20 determines the initial current amplification factor of the current acquisition circuit 20 according to the resistance value of the second resistor R2 of the second control module. The initial current amplification factor of the current acquisition circuit 20 is (1 + r / 2r), that is, 1.5, and the current value of the output current is p multiplied by 1.5, that is, 1.5p (greater than the preset threshold p).

[0070] When the current value of the internal current of the external device 40 is 0.5p, the microcontroller unit 10 inputs the corresponding control signal A1 to the first control module as a high level, the current acquisition circuit 20 sets the initial usage state of the first control module as available, the microcontroller unit 10 inputs the corresponding control signal A2 to the second control module as a low level, the current acquisition circuit 20 sets the initial usage state of the second control module as unused, the microcontroller unit 10 inputs the corresponding control signal A3 to the third control module as a low level, and the current acquisition circuit 20 sets the initial usage state of the third control module as unused.

[0071] Then, the current acquisition circuit 20 determines the initial current amplification factor of the current acquisition circuit 20 according to the resistance value of the second resistor R1 of the first control module. The initial current amplification factor of the current acquisition circuit 20 is (1 + r / 0.5r), that is, 3, and the current value of the output current is 0.5p multiplied by 3, that is, 1.5p (greater than the preset threshold p).

[0072] In some other embodiments, by controlling the number of control modules 21 with an available usage status (i.e., target control modules) among the multiple control modules 21 of the current acquisition circuit 20, the resistance value of the ground resistance electrically connected to the inverting input terminal of the operational amplifier 22 can be controlled. Among the multiple control modules 21 of the current acquisition circuit 20, when the number of target control modules is multiple, the resistance value of the ground resistance is the total resistance value of the second resistors in all the parallel target control modules; among the multiple control modules 21 of the current acquisition circuit 20, when the number of target control modules is one, the resistance value of the ground resistance is the resistance value of the second resistor in the target control module.

[0073] Then, the current amplification factor of the current acquisition circuit 20 is the sum of the resistance value ratio and 1, and the resistance value ratio is the quotient obtained by dividing the resistance value of the feedback resistor module 23 by the resistance value of the ground resistance.

[0074] Since the resistance value of the feedback resistor module 23 is fixed, the resistance value of the ground resistance is negatively correlated with the current amplification factor of the current acquisition circuit 20.

[0075] Since the number of control modules 21 with an available usage status (i.e., target control modules) among the multiple control modules 21 of the current acquisition circuit 20 is different, the resistance value of the ground resistance electrically connected to the inverting input terminal of the operational amplifier 22 is different. Therefore, among the multiple control modules 21 of the current acquisition circuit 20, when the number of control modules 21 with an available usage status (i.e., target control modules) is different, the current amplification factor of the current acquisition circuit 20 is different.

[0076] Therefore, for internal currents of different magnitudes, adjust the number of control modules 21 with an available usage status (i.e., target control modules) among the multiple control modules 21 of the current acquisition circuit 20, so that internal currents of different magnitudes are all amplified into output currents greater than a preset threshold.

[0077] For example, the preset threshold is p, the resistance value of the feedback resistor module 23 is r, the current acquisition circuit 20 includes 3 control modules, namely the first control module, the second control module, and the third control module. Among them, the resistance value of the second resistor R1 of the first control module is r, the resistance value of the second resistor R2 of the second control module is 3r, and the resistance value of the second resistor R3 of the third control module is 4r; the microcontroller unit 10 inputs a control signal A1 to the first control module, the microcontroller unit 10 inputs a control signal A2 to the second control module, and the microcontroller unit 10 inputs a control signal A3 to the third control module.

[0078] When the current value of the internal current of the external device 40 is 2p, the microcontroller unit 10 inputs the corresponding control signal A1 to the first control module at a high level. The current acquisition circuit 20 sets the initial usage status of the first control module to available. The microcontroller unit 10 inputs the corresponding control signal A2 to the second control module at a high level. The current acquisition circuit 20 sets the initial usage status of the second control module to available. The microcontroller unit 10 inputs the corresponding control signal A3 to the third control module at a high level. The current acquisition circuit 20 sets the initial usage status of the third control module to available.

[0079] Then, the current acquisition circuit 20 determines the initial current amplification factor of the current acquisition circuit 20 based on the resistance value of the second resistor R1 of the first control module, the resistance value of the second resistor R2 of the second control module, and the resistance value of the second resistor R3 of the third control module. The initial current amplification factor of the current acquisition circuit 20 is (1 + r / (r + r + 2r)), that is, 1.25. The current value of the output current is 2p multiplied by 1.25, that is, 2.5p (greater than the preset threshold p).

[0080] When the current value of the internal current of the external device 40 is p, the microcontroller unit 10 inputs the corresponding control signal A1 to the first control module at a high level. The current acquisition circuit 20 sets the initial usage status of the first control module to available. The microcontroller unit 10 inputs the corresponding control signal A2 to the second control module at a high level. The current acquisition circuit 20 sets the initial usage status of the second control module to available. The microcontroller unit 10 inputs the corresponding control signal A3 to the third control module at a low level. The current acquisition circuit 20 sets the initial usage status of the third control module to unavailable.

[0081] Then, the current acquisition circuit 20 determines the initial current amplification factor of the current acquisition circuit 20 based on the resistance value of the second resistor R1 of the first control module and the resistance value of the second resistor R2 of the second control module. The initial current amplification factor of the current acquisition circuit 20 is (1 + r / (r + r)), that is, 1.5. The current value of the output current is p multiplied by 1.5, that is, 1.5p (greater than the preset threshold p).

[0082] An embodiment of the present utility model provides a current measurement circuit, including: a microcontroller unit 10 and the aforementioned current acquisition circuit 20; the current acquisition circuit 20 is used for electrically connecting with an external device 40 and acquiring the internal current of the external device 40; the current acquisition circuit 20 is electrically connected with the microcontroller unit 10, the current acquisition circuit 20 includes n control modules 21, and the current acquisition circuit 20 is further used for adjusting the usage state of the i-th control module 21 according to the control signal input by the microcontroller unit 10 to the i-th control module 21, and determining the current amplification factor according to the parameters of the control module (21) whose usage state is available, and amplifying the internal current into an output current and outputting it according to the current amplification factor; n is a positive integer, and i is a positive integer less than or equal to n; the microcontroller unit 10 is used for generating a control signal input to each control module 21 according to the current value of the initial output current output by the current acquisition circuit 20; the initial output current is the output current generated by the current acquisition circuit 20 after amplifying the internal current according to the initial current amplification factor.

[0083] The specific implementation process of the current acquisition circuit 20 in the current measurement circuit is similar to the foregoing, and will not be elaborated here.

[0084] Optionally, referring to Figure 2 , in some embodiments, the current measurement circuit further includes a display device 30; the display device 30 is electrically connected with the microcontroller unit 10, and the display device 30 is used for displaying the current information.

[0085] It should be noted that the display device 30 can be a device that can display information, such as a host computer; the host computer can also generate a test report according to the current information of the internal current of the external device 40.

[0086] In the embodiment of the present utility model, the current information of the internal current is displayed through the display device 30 for the staff to view and analyze the current information of the internal current in real time, so as to know the power consumption situation of the external device 40.

[0087] Optionally, in some embodiments, the microcontroller unit 10 is further used for electrically connecting with the external device 40 and controlling the working state of the external device 40.

[0088] It should be noted that the microcontroller unit 10 sends instructions through a communication protocol to control the external device 40 to switch the working state.

[0089] In the embodiment of the present utility model, by controlling the working state of the external device 40 through the microcontrol unit 10, the external device 40 can be made to be in different working states. Furthermore, when the external device 40 is in different working states, the internal current of the external device 40 is measured respectively.

[0090] In the related art, when using basic test tools such as ammeters and multimeters to measure the internal current of the external device 40, manual measurement is required and it does not have real-time performance.

[0091] However, in the embodiment of the present utility model, by interacting with the external device 40 with the help of an automatic switching mechanism, not only highly accurate real-time current measurement is provided, but also the test process becomes more intelligent and flexible, providing comprehensive support for the optimization of the power management of the external device 40.

[0092] Optionally, in some embodiments, the working states of the external device 40 include a standby state and a usage state.

[0093] It should be noted that the standby state is the sleep state of the external device 40, and the usage state is the normal working state of the external device 40.

[0094] In the embodiment of the present utility model, by controlling the working state of the external device 40 through the microcontrol unit 10, the external device 40 is made to be in the standby state, so that the internal current of the external device 40 can be measured when the external device 40 is in the standby state; by controlling the working state of the external device 40 through the microcontrol unit 10, the external device 40 is made to be in the usage state, so that the internal current of the external device 40 can be measured when the external device 40 is in the usage state.

[0095] In the related art, when the external device 40 is in a low-power state (such as the standby state), compared with when the external device 40 is in a high-power state (such as the usage state), the internal current of the external device 40 is smaller and the degree of interference by external interference signals is greater, resulting in a larger measurement error of the internal current of the external device 40 using basic test tools such as ammeters.

[0096] However, in the embodiment of the present utility model, since internal currents of different magnitudes are amplified into output currents greater than a preset threshold for processing, whether the external device 40 is in a low-power state or in a high-power state, the internal current of the external device 40 is amplified into an output current greater than the preset threshold for processing, so that the measurement errors of internal currents of different magnitudes are all less than the error threshold corresponding to the preset threshold. Compared with the related art, the measurement error of the internal current is reduced and the measurement accuracy is improved.

[0097] In addition, the adjustment mechanism of the current amplification factor improves the flexibility and intelligence of measurement, enabling highly accurate and adjustable current acquisition under different conditions. This design provides an advanced and reliable solution for standby current monitoring, helping to meet the diverse current measurement requirements of different application scenarios.

[0098] The embodiment of the present utility model adopts automated measurement, making the test process more highly integrated and reducing the influence of manual intervention. The embodiment of the present utility model provides the ability to monitor standby current in real time, enabling users to understand the power consumption performance of the device in different operating modes at any time. At the same time, through the remote control of the microcontroller unit 10, users can operate and test the device under test at a remote location. The embodiment of the present utility model emphasizes versatility and is applicable to different types of devices, capable of adapting to various test requirements without the need for large-scale modification or reconfiguration. Through the display device 30 (such as a host computer), users can perform more in-depth data analysis and optimize the power management strategy of the electronic device, which helps to improve the energy efficiency of the electronic device, extend the battery life of the electronic device, and enable the electronic device to better cope with different usage scenarios.

[0099] In summary, in the embodiment of the present utility model, the microcontroller unit 10 adjusts the current amplification factor of the current acquisition circuit 20 by adjusting the usage state of each control module 21 according to the initial output current output by the current acquisition circuit 20, so that the internal currents of external devices 40 of different magnitudes are all amplified into output currents greater than a preset threshold. Then, based on the output current, the current information of the internal current is obtained to achieve the measurement of the internal current of the external device 40. During this process, since internal currents of different magnitudes are amplified into output currents greater than the preset threshold for processing, and the current value of the current is negatively correlated with the measurement error of the current, the measurement errors of internal currents of different magnitudes are all less than the error threshold corresponding to the preset threshold. Compared with the prior art where the measurement error of some currents is greater than the error threshold, the measurement accuracy is improved.

[0100] Finally, it should also be noted that in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article, or terminal device comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or terminal device.

[0101] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

[0102] As mentioned above, it is only the specific implementation manner of the present utility model, but the protection scope of the present utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present utility model can easily think of changes or replacements, which should all be covered within the protection scope of the present utility model. Therefore, the protection scope of the present utility model shall be subject to the protection scope of the claims.

Claims

1. A current acquisition circuit (20), characterized in that, It is used for electrically connecting with an external device (40) and a microcontroller unit (10), collecting the internal current of the external device (40), and outputting the current to the microcontroller unit (10). The current acquisition circuit (20) includes n control modules (21). The current acquisition circuit (20) is further configured to adjust the usage state of the i-th control module (21) according to the control signal input by the microcontroller unit (10) to the i-th control module (21), determine the current amplification factor according to the parameter of the control module (21) whose usage state is available, and amplify the internal current into an output current and output it according to the current amplification factor. i is a positive integer less than or equal to n.

2. The current acquisition circuit (20) according to claim 1, wherein The current acquisition circuit (20) further includes an operational amplifier (22) and a feedback resistor module (23); the feedback resistor module (23) includes a first resistor or a plurality of first resistors connected in series. The non-inverting input terminal of the operational amplifier (22) is used for electrically connecting with the external device (40) and collecting the internal current of the external device (40). The inverting input terminal of the operational amplifier (22) is electrically connected to the first end of the feedback resistor module (23), and the output terminal of the operational amplifier (22) is electrically connected to the second end of the feedback resistor module (23); the inverting input terminal of the operational amplifier (22) is also electrically connected to each control module (21). The positive terminal of the operational amplifier (22) is used for electrically connecting with an external power supply, and the negative terminal of the operational amplifier (22) is grounded.

3. The current acquisition circuit (20) according to claim 2, wherein, Each control module (21) includes a second resistor and a switching device; the microcontroller unit (10) includes n control terminals. The first end of each second resistor is electrically connected to the inverting input terminal of the operational amplifier (22); in the control module (21), the second end of the second resistor is electrically connected to the first end of the switching device. The second end of the switching device in the i-th control module (21) is electrically connected to the i-th control terminal, the third end of the switching device in the i-th control module (21) is grounded, and the switching device in the i-th control module (21) is configured to conduct when the control signal output by the i-th control terminal is at a high level, so that the second end of the second resistor in the i-th control module (21) is grounded, thereby setting the usage state of the i-th control module (21) to available; and turn off when the control signal output by the i-th control terminal is at a low level, so that the second end of the second resistor in the i-th control module (21) is left open, thereby setting the usage state of the i-th control module (21) to unused.

4. The current acquisition circuit (20) according to claim 3, characterized in that, The switching device is a triode. In the control module (21), the second end of the second resistor is electrically connected to the collector of the switching device. The base of the switching device in the i-th control module (21) is electrically connected to the i-th control terminal, and the emitter of the switching device in the i-th control module (21) is grounded.

5. The current acquisition circuit (20) according to claim 4, wherein The switching device is an NPN-type triode.

6. The current acquisition circuit (20) according to claim 3, characterized in that, The switching device is a MOS transistor; In the control module (21), the second terminal of the second resistor is electrically connected to the drain of the switching device; The gate of the switching device in the i-th control module (21) is electrically connected to the i-th control terminal, and the source of the switching device in the i-th control module (21) is grounded.

7. The current acquisition circuit (20) according to claim 6, characterized in that, The switching device is an NMOS transistor.

8. The current acquisition circuit (20) according to claim 3, characterized in that, The resistance values of each of the second resistors are different.

9. A current measurement circuit, characterized in that, Comprising: A micro-control unit (10) and a current acquisition circuit (20) according to any one of claims 1 to 8; The current acquisition circuit (20) is used for electrically connecting with an external device (40) and acquiring the internal current of the external device (40); The current acquisition circuit (20) is electrically connected to the micro-control unit (10). The current acquisition circuit (20) includes n control modules (21). The current acquisition circuit (20) is further configured to adjust the usage state of the i-th control module (21) according to the control signal input by the micro-control unit (10) to the i-th control module (21), and determine the current amplification factor according to the parameters of the control modules (21) that are available for use according to the usage state, and amplify the internal current into an output current and output it according to the current amplification factor; i is a positive integer less than or equal to n; The micro-control unit (10) is configured to generate a control signal input to each control module (21) according to the current value of the initial output current output by the current acquisition circuit (20); the initial output current is the output current generated by the current acquisition circuit (20) after amplifying the internal current according to the initial current amplification factor.

10. The current measurement circuit according to claim 9, characterized in that, The current measurement circuit further includes a display device (30); The display device (30) is electrically connected to the micro-control unit (10), and the display device (30) is used for displaying the current information.

11. The current measurement circuit according to claim 9, wherein The micro-control unit (10) is further configured to be electrically connected to the external device (40) and control the working state of the external device (40).

Images