Miniature current measurement adapter

Abstract

The utility model discloses a miniature current measurement adapter, comprising a switching module used for selecting different current ranges, an amplification conversion module used for amplifying current signals and converting the current signals into voltage signals, and a power supply module used for providing a bipolar power supply. The input end of the switching module is electrically connected with a current input interface of an adapter, and the output end of the switching module is electrically connected with the input end of the amplification conversion module; and the output end of the amplification conversion module is electrically connected with the voltage output interface of the adapter. According to the miniature current measurement adapter, the load voltage during current measurement can be remarkably reduced, and the measurement precision can be improved.

Description

Technical Field

[0001] The utility model relates to an adapter, in particular to a micro current measurement adapter. Background Art

[0002] Existing multimeters often suffer from a voltage load issue when measuring current. When measuring current directly, a voltage drop occurs when the current passes through the multimeter's built-in shunt resistor, affecting the voltage of the circuit being measured. This effect is particularly pronounced in circuits using low-voltage power supplies. Furthermore, the accuracy of multimeters when measuring low currents is typically lower than their DC voltage measurement range. Utility Model Content

[0003] The purpose of the utility model is to overcome the above-mentioned problems and provide a micro current measurement adapter, which can significantly reduce the load voltage when measuring current, thereby improving measurement accuracy.

[0004] The purpose of the utility model is achieved through the following technical solutions:

[0005] A micro current measurement adapter includes a switching module for selecting different current ranges, an amplification and conversion module for amplifying and converting current signals into voltage signals, and a power supply module for providing bipolar power supply;

[0006] The input end of the switching module is electrically connected to the current input interface of the adapter, and the output end of the switching module is electrically connected to the input end of the amplifying and converting module; the output end of the amplifying and converting module is electrically connected to the voltage output interface of the adapter.

[0007] The working principle of the above-mentioned micro current measurement adapter is:

[0008] When working, first select the corresponding current range on the switching module; connect the current input interface of the adapter to the object to be measured, and connect the voltage output interface of the adapter to the multimeter; the current of the object to be measured flows to the switching module through the current input interface of the adapter, and a small voltage drop is generated in the switching module; then it flows down to the amplification and conversion module, which converts the current into a voltage signal and amplifies it. Then, the voltage signal is output to the multimeter through the voltage output interface of the adapter, and the multimeter converts the voltage signal into a voltage value and displays it.

[0009] In a preferred solution of the present invention, the switching module includes at least two detection resistors with different resistance values, and the detection resistors are arranged in parallel and provided with a parallel switch.

[0010] Furthermore, there are three detection resistors, with corresponding resistance values ​​of 10kΩ, 10Ω and 10mΩ, respectively corresponding to three current ranges: 0-1000nA, 0-1000μA and 0-1000mA.

[0011] Furthermore, in the 0-1000nA mode, a 10kΩ detection resistor is connected to the circuit, and 10Ω and 10mΩ are in a non-working state.

[0012] Furthermore, in the 0-1000 μA mode, the 10 kΩ detection resistor and the 10 Ω detection resistor are connected in parallel to the circuit, and the 10 mΩ is in an inoperative state.

[0013] Furthermore, in the 0-1000mA mode, a 10kΩ detection resistor, a 10Ω detection resistor, and a 10mΩ detection resistor are connected in parallel to the circuit.

[0014] Specifically, three sense resistors with different resistance values ​​are used to measure current in three current ranges:

[0015] nA Range: Using a 10kΩ shunt resistor and a load voltage of 10μV / nA, the output conversion voltage is 0 to 1000mV in the 0 to 1000nA range.

[0016] μA Range: Based on the nA range, a 10Ω shunt resistor is connected in parallel via a switch, resulting in a load voltage of 10μV / μA. In the 0 to 1000μA range, the output conversion voltage is 0 to 1000mV.

[0017] mA Range: In addition to the nA and μA ranges, a 10mΩ shunt resistor is connected in parallel via a switch, resulting in a load voltage of 10μV / mA. In the 0-1000mA range, the output conversion voltage is 0-1000mV.

[0018] In a preferred embodiment of the present invention, the amplification conversion module is a low-offset / drift, low-noise, and precision amplifier.

[0019] In a preferred solution of the present invention, the power supply module adopts a virtual ground to divide the power supply circuit.

[0020] A preferred embodiment of the present invention further includes a power detection module for detecting the power level of the power module, the power detection module being electrically connected to the power module. The power detection module detects the power level of the power module in real time and can issue an alert when the battery voltage falls below a preset threshold, allowing for timely battery replacement.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The utility model can significantly reduce the load voltage when measuring current, which is beneficial to improving measurement accuracy.

[0023] 2. By setting a bipolar power supply, the ability to measure positive and negative currents is ensured.

[0024] 3. Low battery detection function ensures long-term stable operation and reliability of measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a front view of the micro current measurement adapter of the present utility model.

[0026] Figure 2 This is a circuit diagram of the switching module of the present invention.

[0027] Figure 3 This is a circuit diagram of the amplification conversion module of the present utility model.

[0028] Figure 4 This is a circuit diagram of the power module of the present utility model. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described below in conjunction with embodiments and drawings, but the implementation methods of the present invention are not limited thereto.

[0030] See also Figure 1-4 The micro current measurement adapter of this embodiment includes a switching module for selecting different current ranges, an amplification and conversion module for amplifying and converting current signals into voltage signals, and a power supply module for providing a bipolar power supply; the input end of the switching module is electrically connected to the current input interface 1 of the adapter, and the output end of the switching module is electrically connected to the input end of the amplification and conversion module; the output end of the amplification and conversion module is electrically connected to the voltage output interface 2 of the adapter.

[0031] See also Figure 2 The switching module includes at least two detection resistors with different resistance values, and the detection resistors are arranged in parallel and provided with a parallel switch.

[0032] Furthermore, there are three detection resistors, namely R1, R2 and R3, with corresponding resistance values ​​of 10kΩ, 10Ω and 10mΩ, respectively, corresponding to three current ranges: 0~1000nA, 0~1000μA and 0~1000mA.

[0033] Furthermore, in the 0-1000nA mode, the 10kΩ detection resistor R1 is connected to the circuit, and the 10Ω and 10mΩ resistors are in a non-working state.

[0034] Furthermore, in the 0-1000 μA mode, the 10 kΩ detection resistor R1 and the 10 Ω detection resistor R2 are connected in parallel to the circuit, and the 10 mΩ resistor is in a non-working state.

[0035] Furthermore, in the 0-1000 mA mode, a 10 kΩ detection resistor R1 , a 10 Ω detection resistor R2 , and a 10 mΩ detection resistor R3 are connected in parallel to the circuit.

[0036] Specifically, three sense resistors with different resistance values ​​are used to measure current in three current ranges:

[0037] nA Range: Using a 10kΩ shunt resistor and a load voltage of 10μV / nA, the output conversion voltage is 0 to 1000mV in the 0 to 1000nA range.

[0038] μA Range: Based on the nA range, a 10Ω shunt resistor is connected in parallel via a switch, resulting in a load voltage of 10μV / μA. In the 0 to 1000μA range, the output conversion voltage is 0 to 1000mV.

[0039] mA Range: In addition to the nA and μA ranges, a 10mΩ shunt resistor is connected in parallel via a switch, resulting in a load voltage of 10μV / mA. In the 0-1000mA range, the output conversion voltage is 0-1000mV.

[0040] See also Figure 3 The amplification conversion module adopts an ultra-low offset / drift, low-noise precision amplifier and uses a technology called "auto-zero" or "chopper" to continuously eliminate the offset voltage of the main amplifier through a two-stage offset cancellation process driven by an internal clock, thereby achieving extremely low offset voltage and noise.

[0041] See also Figure 4 The power module adopts a virtual ground split power circuit to provide a bipolar power supply through a resistor divider and a buffer amplifier, allowing button battery power supply.

[0042] See also Figure 4 The micro current measurement adapter of this embodiment also includes a power detection module for detecting the power level of the power module. This power detection module is electrically connected to the power module. The power detection module monitors the power level of the power module in real time and can issue an alert when the battery voltage falls below a preset threshold, allowing for timely battery replacement.

[0043] See also Figure 1-4 The working principle of the micro current measurement adapter of this embodiment is as follows:

[0044] When working, first select the corresponding current range on the switching module; connect the current input interface 1 of the adapter to the object to be measured, and connect the voltage output interface 2 of the adapter to the multimeter; the current of the object to be measured flows through the current input interface 1 of the adapter to the switching module, generating a small voltage drop in the switching module; then it flows down to the amplification and conversion module, which converts the current into a voltage signal and amplifies it. Then, the voltage signal is output to the multimeter through the voltage output interface 2 of the adapter, and the multimeter converts the voltage signal into a voltage value and displays it.

[0045] The above is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited to the above content. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A miniature current measurement adapter, characterized in that: It includes a switching module for selecting different current ranges, an amplification and conversion module for amplifying the current signal and converting it into a voltage signal, and a power supply module for providing a bipolar power supply; The input end of the switching module is electrically connected to the current input interface of the adapter, and the output end of the switching module is electrically connected to the input end of the amplifying and converting module; the output end of the amplifying and converting module is electrically connected to the voltage output interface of the adapter.

2. The micro current measurement adapter according to claim 1, characterized in that: The switching module includes at least two detection resistors with different resistance values, and the detection resistors are arranged in parallel and are provided with a parallel switch.

3. The micro current measurement adapter according to claim 2, characterized in that: There are three detection resistors, with corresponding resistance values ​​of 10kΩ, 10Ω and 10mΩ, respectively corresponding to three current ranges: 0-1000nA, 0-1000μA and 0-1000mA.

4. The micro current measurement adapter according to claim 3, characterized in that: In the 0-1000nA mode, the 10kΩ sense resistor is connected to the circuit, and the 10Ω and 10mΩ resistors are inactive.

5. The micro current measurement adapter according to claim 3, characterized in that: In the 0-1000μA mode, the 10kΩ sense resistor and the 10Ω sense resistor are connected in parallel to the circuit, and the 10mΩ is in an inoperative state.

6. The miniature current measurement adapter according to claim 3, characterized in that: In the 0-1000mA mode, a 10kΩ sense resistor, a 10Ω sense resistor, and a 10mΩ sense resistor are connected in parallel to the circuit.

7. The miniature current measurement adapter according to claim 1, characterized in that: The amplification conversion module is a low-offset / drift, low-noise, and precision amplifier.

8. The miniature current measurement adapter according to claim 1, characterized in that: The power supply module uses a virtual ground to divide the power supply circuit.

9. The miniature current measurement adapter according to claim 1, characterized in that: It also includes a power detection module for detecting the power of the power module, and the power detection module is electrically connected to the power module.

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