Current monitoring instrument suitable for low power consumption

Abstract

The invention relates to the technical field of current monitoring, and discloses a low-power-consumption current monitoring instrument which comprises a shell, keys are installed on the surface of the shell, and an OLED screen is installed at the position, above the keys, of the surface of the shell. Accurate voltage is provided through the 24-bit ADC chip with high resolution and significant digits, the small sampling resistor and the reference voltage circuit, the measurement precision is improved, a corresponding numerical value is obtained by differently inputting the voltage on the two sides of the sampling resistor into the 24-bit ADC chip, the numerical value is read by the main control chip, and the measurement precision is improved. The current of the to-be-tested device is obtained through calculation, a threshold value of current alarm can be set through a key, an OLED screen and a menu programmed by a main control chip, a buzzer is linked for alarming, a log storage core is linked for log storage, or an alarm log is input into the log storage core through a UART, and the OLED screen is used for menu display and real-time current refreshing.

Description

Technical Field

[0001] The present invention relates to the technical field of current monitoring, and more particularly to a current monitoring instrument suitable for low power consumption. Background Art

[0002] In the existing technology, when low-power devices are abnormally started or abnormally current is monitored in high and low temperature test environments, the current low-power device monitoring technology mainly includes the following solutions:

[0003] Existing solution 1: Use 4-5 digit digital tube or multimeter to display current;

[0004] The main defects are: low accuracy, low sampling rate, and complex connection;

[0005] Existing solution 2: abnormal current alarm through external counter and buzzer,

[0006] The main defects are: no time and abnormal power consumption log, difficult to trace and troubleshoot, and complex connection.

[0007] Existing solution 3: Only the debugging interface of the device under test is used to record abnormal startup;

[0008] The main defect is that it can only record the abnormal startup of the system, but cannot record the abnormal power consumption caused by components in different test environments. Even when an abnormality occurs, it may affect the log output of the device under test itself. Therefore, we propose a current monitoring instrument suitable for low power consumption. Summary of the invention

[0009] In order to solve the problems raised in the above background technology, the present invention provides a current monitoring instrument suitable for low power consumption.

[0010] The present invention provides a current monitoring instrument suitable for low power consumption, which adopts the following technical scheme: a current monitoring instrument suitable for low power consumption, comprising a shell, a button is installed on the surface of the shell, an OLED screen is installed on the surface of the shell above the button, a buzzer is installed on the surface of the shell on the right side of the OLED screen, the shell is connected to a system power supply for connecting a power supply through a wire, and power inputs of a device to be tested are installed on both sides of the shell;

[0011] The housing is internally installed with a main control chip, a first OSC oscillator, a level conversion circuit, a 24-bit ADC chip, a second LED module, a reference voltage circuit, a sampling resistor, a voltage sampling circuit, a second OSC oscillator, a log storage chip, and a first LDO module. The input end of the main control chip and the output end circuit of the first LDO module enable the first LDO module to provide power for the main control chip and the OLED screen, buttons, and buzzer. The input end of the first LDO module is electrically connected to the system power supply, the input end of the main control chip is signal-connected to the output end of the first OSC oscillator, the input end of the main control chip is signal-connected to the output end of the power input of the device under test, and a circuit for providing a voltage obtained by a voltage sampling circuit for the power input of the device under test is provided between the main control chip and the power input of the device under test;

[0012] The output end of the main control chip is signal-connected to the input end of the 24-bit ADC chip. A level conversion circuit for enhancing the stability of communication between the main control chip and the 24-bit ADC chip is provided between the main control chip and the 24-bit ADC chip. The input end of the 24-bit ADC chip is electrically connected to the second LED module. The output end of the second LED module is electrically connected to the input end of the reference voltage circuit, so that the second LED module provides power for the reference voltage circuit and the 24-bit ADC chip. The output end of the reference voltage circuit is electrically connected to the input end of the 24-bit ADC chip. The power input of the device under test is connected to the sampling resistor through the voltage sampling circuit. The input end of the 24-bit ADC chip is signal-connected to the output end of the second OSC oscillator.

[0013] Preferably, the output end of the main control chip is connected to the input end signal of the OLED screen, the input end of the main control chip is connected to the output end signal of the button, and the output end of the main control chip is connected to the input end signal of the buzzer.

[0014] Preferably, the input voltage of the system power supply is 5-18V.

[0015] Preferably, the button has five function buttons, namely a menu button, an up scroll button, a down scroll button, a confirmation button, and a return button.

[0016] Preferably, the voltage sampling circuit and the power input of the device under test are divided to 3.3V through resistors R2 and R3 for calculation to obtain the input voltage of the device under test.

[0017] Preferably, a Kelvin connection is used between the sampling resistor and the 24-bit ADC chip, and the voltage drop signal of the sampling resistor is differentially input to the 24-bit ADC chip.

[0018] Preferably, the current monitoring instrument performs the following steps for current monitoring:

[0019] Step 1: Provide 5-18V power to the instrument through the system power supply, set the alarm current threshold, then connect the power input of the device under test to the device under test, and start the instrument. The OLED screen displays the main interface;

[0020] Step 2: After the instrument is started, the main control chip detects the voltage of the device to be tested, and then calculates the current through the ADC data in the 24-bit ADC chip and the current calculation formula;

[0021] Step 3: The main control chip determines whether the current input by the 24-bit ADC chip exceeds the set alarm current threshold;

[0022] When the preset threshold is not exceeded, the main control chip displays the current and voltage information through the OLED screen;

[0023] When the preset threshold is exceeded, the main control chip displays the current and voltage information on the OLED screen and gives an alarm through a buzzer, and also stores the alarm information in the log storage chip;

[0024] Step 4: The main control chip obtains the voltage of the power input of the device under test through the voltage sampling circuit of the peripheral device. The voltage sampling circuit divides the voltage to 3.3V through resistors R2 and R3 for calculation. Then the main control chip transmits the voltage and current to the OLED screen to display the current and voltage.

[0025] Preferably, the current calculation formula in step 2 is:

[0026]

[0027] Vref is the reference voltage provided by the reference voltage circuit, ADCvalue is the value read from the 24-bit ADC chip, and Rs is the resistance value of the sampling resistor.

[0028] In summary, the present invention includes the following beneficial technical effects:

[0029] The present invention improves the measurement accuracy by providing a relatively accurate voltage through a 24-bit ADC chip with high resolution and effective number of bits, a small sampling resistor and a reference voltage circuit, obtains a corresponding value by inputting the voltage difference on both sides of the sampling resistor into the 24-bit ADC chip, and the main control chip reads the value, and then calculates the current of the device to be tested. The threshold value of the current alarm can be set through a button, an OLED screen, and a menu programmed by the main control chip, and a buzzer alarm and a log storage core are linked to store the log, or the alarm log is input into the log storage core through a UART, wherein the OLED screen is used for menu display and real-time current refresh. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1is a schematic diagram of the structure of an instrument in an embodiment of the present invention;

[0031] Figure 2 is a schematic diagram of the system block diagram structure in an embodiment of the present invention;

[0032] Figure 3 It is a schematic diagram of the structure of a workflow diagram in an embodiment of the present invention;

[0033] Figure 4 is a schematic diagram of the reference voltage circuit structure in an embodiment of the present invention;

[0034] Figure 5 is a schematic diagram of the structure of a level conversion circuit in an embodiment of the present invention;

[0035] Figure 6 is a schematic diagram of the structure of a voltage sampling circuit in an embodiment of the present invention;

[0036] Figure 7 Schematic diagram of the sampling resistor connection structure in an embodiment of the present invention.

[0037] Explanation of the accompanying drawings: 1. Shell; 2. Button; 3. OLED screen; 4. Buzzer; 5. Power input of the device under test; 6. System power supply; 7. Main control chip; 8. First OSC oscillator; 9. Level conversion circuit; 10. 24-bit ADC chip; 11. Second LED module; 12. Reference voltage circuit; 13. Sampling resistor; 14. Device under test; 15. Voltage sampling circuit; 16. Second OSC oscillator; 17. Log storage chip; 18. First LDO module. DETAILED DESCRIPTION

[0038] The following is combined with Figure 1-7 The present invention is described in further detail.

[0039] It should be noted that the drawings are schematic and not to scale. For the sake of clarity and convenience, the relative sizes and proportions of the parts shown in the drawings are exaggerated or reduced in size, and any size is only illustrative and not restrictive. In addition, the same reference symbol is used for the same structure, element or accessory appearing in more than two figures to reflect similar features.

[0040] The embodiment of the present invention discloses a current monitoring instrument suitable for low power consumption. Figure 1-7, a current monitoring instrument suitable for low power consumption, comprising a shell 1, a button 2 is installed on the surface of the shell 1, the button 2 has five function buttons, namely a menu button, an up scroll button, a down scroll button, a confirmation button, and a return button, an OLED screen 3 is installed on the surface of the shell 1 above the button 2, a buzzer 4 is installed on the surface of the shell 1 on the right side of the OLED screen 3, the shell 1 is connected to a system power supply 6 for connecting a power supply through a wire, the input voltage of the system power supply 6 is 5-18V to provide power for the entire instrument, power input 5 of a device to be tested is installed on both sides of the shell 1, the output end of the main control chip 7 is signal-connected to the input end of the OLED screen 3, the input end of the main control chip 7 is signal-connected to the output end of the button 2, the output end of the main control chip 7 is signal-connected to the input end of the buzzer 4, and the main control chip 7 controls the buzzer 4 to sound through PWM output;

[0041] The housing 1 is internally installed with a main control chip 7, a first OSC oscillator 8, a level conversion circuit 9, a 24-bit ADC chip 10, a second LED module 11, a reference voltage circuit 12, a sampling resistor 13, a voltage sampling circuit 15, a second OSC oscillator 16, a log storage chip 17, and a first LDO module 18. The input end of the main control chip 7 and the output end circuit of the first LDO module 18 are connected. The output 3.3V power of the first LDO module 18 supplies power to the main control chip 7, the buzzer 4, and the OLED screen 3. The input end of the first LDO module 18 is electrically connected to the system power supply 6. The input end of the main control chip 7 is signal-connected to the output end of the first OSC oscillator 8. The first OSC oscillator 8 provides a clock signal for the main control chip. The input end of the main control chip 7 is signal-connected to the output end of the power input 5 of the device under test. A voltage sampling circuit 15 is provided between the main control chip 7 and the power input 5 of the device under test to provide the power input 5 of the device under test with a voltage calculated by the device under test;

[0042] The output end of the main control chip 7 is connected to the input end of the 24-bit ADC chip 10 by signal connection. A level conversion circuit 9 for enhancing the communication stability between the main control chip 7 and the 24-bit ADC chip 10 is provided between the main control chip 7 and the 24-bit ADC chip 10. The input end of the 24-bit ADC chip 10 is electrically connected to the second LED module 11. The output end of the second LED module 11 is electrically connected to the input end of the reference voltage circuit 12, so that the second LED module 11 provides power for the reference voltage circuit 12 and the 24-bit ADC chip 10. The output end of the reference voltage circuit 12 is electrically connected to the input end of the 24-bit ADC chip 10. The power input 5 of the device under test is connected to the sampling resistor 13 through the voltage sampling circuit 15. The sampling resistor 13 and the 24-bit ADC chip 10 use a Kelvin connection method, and the voltage drop signal of the sampling resistor 13 is differentially input to the 24-bit ADC chip 10.

[0043] The voltage sampling circuit 15 and the power input 5 of the device under test are divided to 3.3V through resistors R2 and R3 for calculation to obtain the input voltage of the device under test 14. The input end of the 24-bit ADC chip 10 is connected to the output end signal of the second OSC oscillator 16. The second OSC oscillator 16 provides a clock signal for the 24-bit ADC chip.

[0044] Through the above structure, a relatively accurate voltage is provided by a 24-bit ADC chip 10 with high resolution and effective number of bits, a smaller sampling resistor 13 and a reference voltage circuit 12 to improve the measurement accuracy. The voltage difference on both sides of the sampling resistor 13 is input into the 24-bit ADC chip 10 to obtain the corresponding value, and the main control chip 7 reads the value, and then calculates the current of the device under test. The threshold of the current alarm can be set through the menu programmed by the button 2, the OLED screen 3, and the main control chip 7, and the buzzer 4 alarm and the log storage core are linked to store the log, or the alarm log is input into the log storage core 17 through the UART, wherein the OLED screen 3 is used for menu display and real-time current refresh;

[0045] The current monitoring instrument monitors the current in the following steps:

[0046] Step 1: Provide the instrument with 5-18V power through the system power supply 6, set the alarm current threshold, then connect the power input 5 of the device under test to the device under test 14, and start the instrument. The OLED screen 3 displays the main interface;

[0047] Step 2: The instrument starts up, and the voltage of the device to be tested is detected by the main control chip 7, and then the ADC data in the 24-bit ADC chip 10 and the current calculation formula are used:

[0048]

[0049] Vref is the reference voltage provided by the reference voltage circuit 12, ADCvalue is the value read from the 24-bit ADC chip 10, Rs is the resistance value of the sampling resistor 13, and the current is calculated;

[0050] Step 3: The main control chip 7 determines whether the current input by the 24-bit ADC chip 10 exceeds the set alarm current threshold;

[0051] When the current and voltage do not exceed the preset threshold, the main control chip 7 displays the current and voltage information through the OLED screen 3;

[0052] When the preset threshold is exceeded, the main control chip 7 displays the current and voltage information through the OLED screen 3 and alarms through the buzzer 4, and also stores the alarm information in the log storage chip 17;

[0053] Step 4, the main control chip 7 uses the external voltage sampling circuit 15, and the voltage sampling circuit 15 divides the voltage to 3.3V through resistors R2 and R3 for calculation to obtain the voltage of the power input of the device under test 14, and then the main control chip transmits the voltage and current to the OLED screen 3 to display the current and voltage.

[0054] Finally, a few points should be explained: First, in the description of the present invention, it should be noted that, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, which may refer to mechanical connection or electrical connection, or internal communication between two components, or direct connection. "upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may change;

[0055] Secondly: In the drawings of the embodiments disclosed in the present invention, only the structures related to the embodiments disclosed in the present invention are involved, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other;

[0056] Finally: The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A current monitoring instrument suitable for low power consumption, comprising a housing (1), characterized in that: A button (2) is installed on the surface of the housing (1); an OLED screen (3) is installed on the surface of the housing (1) above the button (2); a buzzer (4) is installed on the surface of the housing (1) to the right of the OLED screen (3); the housing (1) is connected to a system power supply (6) for connecting a power source via an electric wire; and power inputs (5) of a device under test are installed on both sides of the housing (1); The housing (1) is internally installed with a main control chip (7), a first OSC oscillator (8), a level conversion circuit (9), a 24-bit ADC chip (10), a second LED module (11), a reference voltage circuit (12), a sampling resistor (13), a voltage sampling circuit (15), a second OSC oscillator (16), a log storage chip (17), and a first LDO module (18). The input end of the main control chip (7) and the output end circuit of the first LDO module (18) are connected to each other, so that the first LDO module (18) is connected to the main control chip (7). ) and an OLED screen (3), a button (2), and a buzzer (4); an input end of the first LDO module (18) is electrically connected to a system power supply (6); an input end of the main control chip (7) is signal-connected to an output end of a first OSC oscillator (8); an input end of the main control chip (7) is signal-connected to an output end of a power input (5) of a device under test; and a circuit for providing a voltage calculated by a voltage sampling circuit (15) to the power input (5) of the device under test is provided between the main control chip (7) and the power input (5) of the device under test; The output end of the main control chip (7) is signal-connected to the input end of the 24-bit ADC chip (10); a level conversion circuit (9) for enhancing the stability of communication between the main control chip (7) and the 24-bit ADC chip (10) is provided between the main control chip (7) and the 24-bit ADC chip (10); the input end of the 24-bit ADC chip (10) is electrically connected to the second LED module (11); the output end of the second LED module (11) is electrically connected to the input end of the reference voltage circuit (12), so that the second LED module (11) provides power for the reference voltage circuit (12) and the 24-bit ADC chip (10); the output end of the reference voltage circuit (12) is electrically connected to the input end of the 24-bit ADC chip (10); the power input (5) of the device under test is connected to the sampling resistor (13) through the voltage sampling circuit (15); the input end of the 24-bit ADC chip (10) is signal-connected to the output end of the second OSC oscillator (16).

2. The current monitoring instrument suitable for low power consumption according to claim 1, characterized in that: The output end of the main control chip (7) is signal-connected to the input end of the OLED screen (3), the input end of the main control chip (7) is signal-connected to the output end of the button (2), and the output end of the main control chip (7) is signal-connected to the input end of the buzzer (4).

3. The current monitoring instrument suitable for low power consumption according to claim 1, characterized in that: The input voltage of the system power supply (6) is 5-18V.

4. The current monitoring instrument suitable for low power consumption according to claim 1, characterized in that: The button (2) has five function buttons, namely a menu button, an up scroll button, a down scroll button, a confirmation button, and a return button.

5. The current monitoring instrument suitable for low power consumption according to claim 1, characterized in that: The voltage sampling circuit (15) and the power input (5) of the device under test are divided into a voltage within 3.3V of the reference voltage of the main control chip (7) through resistors R2 and R3 for calculation to obtain the input voltage of the device under test (14).

6. The current monitoring instrument suitable for low power consumption according to claim 1, characterized in that: A Kelvin connection is adopted between the sampling resistor (13) and the 24-bit ADC chip (10), and a voltage drop signal of the sampling resistor (13) is differentially input to the 24-bit ADC chip (10).

7. The current monitoring instrument suitable for low power consumption according to claim 1, characterized in that: The method steps for the current monitoring instrument to monitor the current are as follows: Step 1: Provide the instrument with 5-18V power through the system power supply (6), set the alarm current threshold, then connect the power input (5) of the device under test to the device under test (14), and start the instrument. The OLED screen (3) displays the main interface; Step 2: After the instrument is started, the main control chip (7) detects the voltage of the device to be tested, and then calculates the current through the ADC data in the 24-bit ADC chip (10) and the current calculation formula; Step 3: The main control chip (7) divides the voltage through the resistors R2 and R3 of the external voltage sampling circuit (15) to a voltage within 3.3V of the reference voltage of the main control chip (7) for calculation to obtain the voltage of the power input of the device under test (14). The main control chip (7) determines whether the current data input by the 24-bit ADC chip (10) exceeds the set alarm current threshold; When the current does not exceed the preset threshold, the main control chip (7) displays the current and voltage information through the OLED screen (3); When the preset threshold is exceeded, the main control chip (7) displays the current and voltage information through the OLED screen (3) and sounds an alarm through the buzzer (4), and also stores the alarm information in the log storage chip (17).

8. The current monitoring instrument suitable for low power consumption according to claim 7, characterized in that: The current calculation formula in step 2 is: Vref is a reference voltage provided by a reference voltage circuit (12), ADCvalue is a value read from a 24-bit ADC chip (10), and Rs is a resistance value of a sampling resistor (13).

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