A signal acquisition switching circuit

Abstract

This utility model provides a signal acquisition switch circuit, belonging to the field of electrical component measurement technology. It includes at least one test circuit unit, each unit comprising: a first switch branch controllably connected between a positive drive current signal and a first test terminal under the action of a second control signal based on a first control signal; when the first switch branch is on, the second control signal is a negative voltage; a second switch branch controllably connected between a positive detection signal and the first test terminal under the action of the second control signal; a third switch branch controllably connected between a negative detection signal and a second test terminal under the action of the first control signal; and a fourth switch branch controllably connected between a negative drive current signal and the second test terminal under the action of the first control signal. Beneficial effects: Introducing a negative voltage into the control of the electronic switch boosts the signal to a measurable range, enabling weak signal detection; multi-channel measurement enables rapid testing.

Description

Technical Field

[0001] This utility model relates to the field of electrical component measurement technology, and in particular to a signal acquisition switch circuit. Background Technology

[0002] With the continuous development and progress of society, switching circuits are increasingly widely used in various electronic devices and systems. From early manual switches to later controllable relay switches, and now to electronic switches, each plays an important role in different application scenarios. However, manual switches require manual operation and cannot achieve remote control, making it difficult to meet the needs of modern automation and intelligence; controllable relay switches, due to the limitations of their mechanical structure, have a slow switching speed and a short service life, requiring periodic replacement, increasing usage costs and maintenance workload; while electronic switches have advantages such as fast switching speed, they are limited in circuits processing weak signals and cannot guarantee stable signal transmission and processing.

[0003] In the prior art, for example, Chinese patent application CN119310348A discloses a real-time measurement circuit for milliohm-level resistance, which includes a power supply circuit, a voltage divider circuit, an operational amplifier circuit, a boost circuit, an ADC acquisition module, an MCU, and an LED display screen connected in series. The MCU connects to the power supply circuit through a relay switch circuit, and the power supply circuit connects to the voltage divider circuit through a current transformer circuit. The resistance to be measured is measured using a four-wire connection method. The MCU controls the relay to turn on and off the power supply in real time. The signal is processed by voltage divider, operational amplifier, and boost circuit and then acquired in segments. The MCU performs valid acquisition value judgment and A / D conversion, and finally displays the calculated resistance value on the LED display screen.

[0004] However, in actual implementation, the inventors found that in the above solution, the relay acts as a switch in the circuit to connect and disconnect, and supplies power in a cyclical switching manner to achieve resistance measurement. However, due to the limitations of the mechanical structure of the relay itself, the overall measurement speed is slow and cannot meet the needs of rapid testing.

[0005] Furthermore, during the aforementioned tests, especially long-term aging tests, it is necessary to keep the resistor connected to the measuring instrument and maintain the test circuit connection for extended periods, such as hundreds of hours. While existing technologies can achieve multi-channel measurement through relay matrix switching, the measurement circuit itself is fixed and difficult to adjust flexibly. Rewiring is required after the current batch of measurements is completed, resulting in low testing efficiency and an inability to meet the demands of large-scale, high-efficiency testing. Utility Model Content

[0006] To solve the above technical problems, this utility model provides a signal acquisition switch circuit.

[0007] The technical problem solved by this utility model can be achieved by the following technical solution:

[0008] A signal acquisition switching circuit includes at least one test circuit unit, each of the test circuit units comprising:

[0009] Test end;

[0010] The first switch branch is controllably connected between the positive drive current signal and the first terminal of the test terminal under the action of a second control signal based on the first control signal; wherein, when the first switch branch is turned on, the second control signal is a negative voltage;

[0011] The second switch branch is controllably connected between the positive detection signal and the first end of the test terminal under the action of the second control signal;

[0012] The third switch branch is controllably connected between the negative detection signal and the second end of the test terminal under the action of the first control signal;

[0013] The fourth switch branch is controllably connected between the negative drive current signal and the second terminal of the test terminal under the action of the first control signal.

[0014] Preferably, the second control signal is generated by a signal processing module, the signal processing module comprising:

[0015] The first transistor has its gate connected to the first control signal via a first resistor, a second resistor connected between the gate and source of the first transistor, and its drain used to output the second control signal.

[0016] The pull-up branch is connected between the drain of the first transistor and the positive voltage;

[0017] The pull-down branch is controllably connected between the source of the first transistor and the negative voltage under the action of the first control signal.

[0018] Preferably, the pull-up branch includes:

[0019] A fourth resistor is connected between the drain of the first transistor and the positive voltage;

[0020] The first capacitor is connected between the positive voltage and the ground terminal.

[0021] Preferably, the pull-down branch includes:

[0022] An optocoupler is provided, wherein the anode of the optocoupler is connected to the first control signal via a third resistor, the cathode of the optocoupler is connected to the ground terminal, the drain of the optocoupler is connected to the source of the first transistor, and the source of the optocoupler is connected to the negative voltage.

[0023] Preferably, the pull-down branch further includes:

[0024] The second transistor has its gate connected to the drain of the first transistor, its drain connected to the source of the first transistor, and its source connected to the ground terminal.

[0025] Preferably, it further includes:

[0026] The fifth resistor is connected between the first control signal and the control terminals of the third and fourth switch branches.

[0027] Preferably, the first switch branch, the second switch branch, the third switch branch, and the fourth switch branch have the same on / off state.

[0028] Preferably, the first switch branch, the second switch branch, the third switch branch, and the fourth switch branch all employ insulated gate bipolar transistors.

[0029] Preferably, the test terminal includes a sixth resistor, one end of which serves as the first end of the test terminal, and the other end of which serves as the second end of the test terminal.

[0030] Preferably, when the test circuit unit comprises multiple units, the multiple test circuit units are connected in parallel.

[0031] The advantages or beneficial effects of this utility model's technical solution are as follows:

[0032] This invention introduces a negative voltage into the electronic switch control, which can boost the signal to a measurable range, enabling the detection of weak signals and enhancing the reliability of signal measurement results; through multi-channel measurement, it can improve the speed of the test circuit and achieve rapid testing. Attached Figure Description

[0033] Figure 1 This is a block diagram of a single-channel signal acquisition switch circuit in a preferred embodiment of the present invention.

[0034] Figure 2 This is a schematic diagram of the signal processing module in a preferred embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram of a single-channel signal acquisition switch circuit in a preferred embodiment of the present invention.

[0036] Figure 4 This is a block diagram of the multi-channel signal acquisition switch circuit in a preferred embodiment of the present invention. Detailed Implementation

[0037] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0038] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0039] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention.

[0040] Example 1

[0041] In a preferred embodiment of this utility model, based on the above-mentioned problems existing in the prior art, a signal acquisition switching circuit is provided, including a test circuit unit, such as... Figure 1 As shown, the first test circuit unit 100 includes:

[0042] Test terminal 1;

[0043] The first switch branch 2 is controllably connected between the positive drive current signal I+ and the first terminal of the test terminal 1 under the action of the second control signal K01' controlled by the first control signal K01; wherein, when the first switch branch 2 is turned on, the second control signal K01' is a negative voltage;

[0044] The second switch branch 3 is controllably connected between the positive detection signal V+ and the first terminal of the test terminal 1 under the action of the second control signal K01'.

[0045] The third switch branch 4 is controllably connected between the negative detection signal V- and the second terminal of the test terminal 1 under the action of the first control signal K01;

[0046] The fourth switch branch 5 is controllably connected between the negative drive current signal I- and the second terminal of the test terminal 1 under the action of the first control signal K01.

[0047] Specifically, while existing electronic switches have advantages such as fast switching speed, they are limited in circuits that process weak signals and cannot guarantee stable signal transmission and processing.

[0048] In this embodiment, when testing materials with high impedance characteristics, the electrical measurement signal can be increased to a measurable range by increasing the voltage value, thereby greatly enhancing the reliability of the signal measurement results.

[0049] Specifically, when testing the positive drive current signal I+ and the positive detection signal V+, a negative voltage is introduced into the electronic switch control of the first switch branch 2 and the second switch branch 3. Regardless of the voltage values ​​of the positive drive current signal I+ and the positive detection signal V+, as long as they are positive voltages, the electronic switches of the first switch branch 2 and the second switch branch 3 can be opened, enabling the testing of weak signals, improving the speed of the test circuit, and achieving rapid testing.

[0050] In a preferred embodiment, the second control signal K01' is generated by the signal processing module 6, such as... Figure 2 As shown, the signal processing module 6 includes:

[0051] The first transistor Q5 has its gate connected to the first control signal K01 via the first resistor R1. A second resistor R2 is connected between the gate and the source of the first transistor Q5. The drain of the first transistor Q5 is used to output the second control signal K01'.

[0052] Pull-up branch 61 is connected between the drain of the first transistor Q5 and the positive voltage;

[0053] The pull-down branch 62 is controllably connected between the source of the first transistor Q5 and the negative voltage under the action of the first control signal K01.

[0054] Preferably, the positive voltage is the positive power supply voltage VCC, and the negative voltage is the negative power supply voltage -VCC.

[0055] When the first control signal K01 is low, the first transistor Q5 enters the cutoff state. The voltage of the second control signal K01' output from the drain of the first transistor Q5, i.e., the voltage at point A, becomes high due to the pull-up effect, and its level is the positive power supply voltage VCC. At this time, the electronic switches of the first switch branch 2 and the second switch branch 3 are also in the cutoff state. Simultaneously, because the first control signal K01 is low, the voltage at point C is low, and the electronic switches of the third switch branch 4 and the fourth switch branch 5 are also in the cutoff state. All four switch branches in the circuit are in the open state, and neither the test voltage nor the current can pass through; therefore, there is no output at the two ends of test terminal 1.

[0056] When the first control signal K01 is high, the first transistor Q5 is turned on, and the drain voltage of the first transistor Q5, i.e., the voltage at point A, is pulled down to -VCC, which is a negative voltage value. At this time, the electronic switches of the first switch branch 2 and the second switch branch 3 are also in the on state. Since the first control signal K01 is high, the voltage at point C is high, and the electronic switches of the third switch branch 4 and the fourth switch branch 5 are also in the on state. At this time, the entire circuit is fully conductive, the detection circuit forms a closed loop, and there is an output at both ends of test terminal 1, realizing the signal acquisition and transmission function.

[0057] In a preferred embodiment, such as Figure 3 As shown, the pull-up branch 61 includes:

[0058] The fourth resistor R4 is connected between the drain of the first transistor Q5 and the positive voltage;

[0059] The first capacitor C1 is connected between the positive voltage and the ground terminal GND.

[0060] Specifically, in this embodiment, a fourth resistor R4 is provided between the drain of the first transistor Q5 and the positive power supply voltage VCC to limit current and divide voltage.

[0061] By setting a first capacitor C1 between the positive power supply voltage VCC and the ground terminal GND, a filtering function is achieved, which can effectively reduce interference signals in the circuit.

[0062] In a preferred embodiment, the pull-down branch includes:

[0063] Optocoupler U1 has its anode connected to the first control signal K01 via the third resistor R3, its cathode connected to the ground terminal GND, its drain connected to the source of the first transistor Q5, and its source connected to a negative voltage.

[0064] Specifically, when the first control signal K01 is low, the optocoupler U1 is in the off state; when the first control signal K01 is high, the optocoupler U1 is in the on state, causing the voltage at point A to be pulled down to a negative voltage.

[0065] In a preferred embodiment, the drop-down branch 62 further includes:

[0066] The second transistor Q6 has its gate connected to the drain of the first transistor Q5, its drain connected to the source of the first transistor Q5, and its source connected to the ground terminal GND.

[0067] Specifically, in this embodiment, when the voltage at point A is -VCC, the second transistor Q6 is turned off; when the voltage at point A is VCC, the second transistor Q6 is turned on, and the voltage at point B is pulled down to GND.

[0068] In a preferred embodiment, it further includes:

[0069] The fifth resistor R5 is connected between the first control signal K01 and the control terminals of the third switch branch 4 and the fourth switch branch 5.

[0070] Specifically, a fifth resistor R5 is set before the control terminals of the third switch branch 4 and the fourth switch branch 5 to serve as a current limiter and voltage divider.

[0071] In this embodiment, the first switch branch 2 includes a first switch transistor Q1, the gate of the first switch transistor Q1 is connected to the second control signal K01', the source of the first switch transistor Q1 is connected to the positive drive current signal I+, and the drain of the first switch transistor Q1 is connected to the first terminal of the test terminal 1.

[0072] The second switch branch 3 includes a second switch transistor Q2. The gate of the second switch transistor Q2 is connected to the second control signal K01', the source of the second switch transistor Q2 is connected to the positive detection signal V+, and the drain of the second switch transistor Q2 is connected to the first terminal of the test terminal 1.

[0073] When the second control signal K01' is VCC, the gate voltages of the first switch Q1 and the second switch Q2 are both high, and both switches Q1 and Q2 are in the off state. No positive drive current signal I+ or positive detection signal V+ is output at test terminal 1. When the second control signal K01' is -VCC, the gate voltages of both switches Q1 and Q2 are low, and they are in the on state. The positive drive current signal I+ and positive detection signal V+ are output at test terminal 1.

[0074] In this embodiment, the third switch branch 4 includes a third switch transistor Q3. The gate of the third switch transistor Q3 is connected to the first control signal K01 through the fifth resistor R5. The source of the third switch transistor Q3 is connected to the negative detection signal V-. The drain of the third switch transistor Q3 is connected to the second terminal of the test terminal 1.

[0075] The fourth switch branch 5 includes a fourth switch transistor Q4. The gate of the fourth switch transistor Q4 is connected to the first control signal K01 through the fifth resistor R5. The source of the fourth switch transistor Q4 is connected to the negative drive current signal I-. The drain of the fourth switch transistor Q4 is connected to the second terminal of the test terminal 1.

[0076] When the first control signal K01 is low, the gate voltages of the third switch Q3 and the fourth switch Q4 are low and in the off state, and there is no negative detection signal V- or negative drive current signal I- output at test terminal 1; when the first control signal K01 is high, the gate voltages of the third switch Q3 and the fourth switch Q4 are high and in the on state, and the negative detection signal V- and negative drive current signal I- are output at test terminal 1.

[0077] In a preferred embodiment, the first switch branch 2, the second switch branch 3, the third switch branch 4, and the fourth switch branch 5 all employ insulated gate bipolar transistors.

[0078] Specifically, in this embodiment, the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4 are all insulated gate bipolar transistors (IGBTs). The first switch Q1 and the second switch Q2 are of the same type, the third switch Q3 and the fourth switch Q4 are of the same type, and the first switch Q1 and the fourth switch Q4 are of different types. Similarly, the second switch Q2 and the third switch Q3 are of different types.

[0079] In a preferred embodiment, the first switch branch 2, the second switch branch 3, the third switch branch 4, and the fourth switch branch 5 have the same on / off state.

[0080] Specifically, when the first control signal K01 is low, the third switch Q3 and the fourth switch Q4 are in the off state; at this time, the second control signal K01' is VCC, and the first switch Q1 and the second switch Q2 are also in the off state.

[0081] When the first control signal K01 is high, the third switch Q3 and the fourth switch Q4 are in the on state; at this time, the second control signal K01' is -VCC, and the first switch Q1 and the second switch Q2 are also in the on state.

[0082] In a preferred embodiment, test terminal 1 includes a sixth resistor R6, one end of which serves as the first end of test terminal 1, and the other end of which serves as the second end of test terminal 2.

[0083] The circuit in this embodiment can be used for the detection of weak signals, where V+ and V- are detection signals, and I+ and I- are drive current signals. The signal voltage values ​​of V+, V-, I+, and I- during the detection process are all less than millivolts (mV), which is much smaller than the turn-on voltage V(th) of the MOSFET.

[0084] The circuit operates as follows: When the first control signal K01 is low, the first transistor Q5 is cut off; simultaneously, the optocoupler U1, the third switch Q3, and the fourth switch Q4 are also cut off. Due to the pull-up effect of the fourth resistor R4, the voltage level at point A is pulled high, reaching the positive power supply voltage VCC. This means the gate voltages of the first and second switches Q1 and Q2 are high, causing them to be cut off. At this time, the entire circuit is open, preventing the flow of test voltage and current, and there is no output signal across the test terminal R6.

[0085] When the first control signal K01 is high, the first transistor Q5 is turned on; simultaneously, the optocoupler U1 is also turned on, pulling the voltage level at point A low to the negative power supply voltage -VCC, thus turning on the first and second switches Q1 and Q2. At the same time, the voltage at point C is also high, turning on the third and fourth switches Q3 and Q4. At this point, the entire circuit is fully operational, forming a complete closed-loop detection circuit, and output signals are generated at test terminal 1.

[0086] It is worth noting that when the circuit is turned on, the gates of the first switch Q1 and the second switch Q2 are pulled down to negative voltage. Therefore, regardless of the voltage values ​​of the positive drive current signal I+ and the positive detection signal V+, as long as they are positive voltages, the gate-source voltage Vgs of the P-channel MOSFET will be less than 0, and the MOSFET can be turned on to realize the detection of weak signals.

[0087] Example 2

[0088] In a preferred embodiment of this utility model, a multi-channel signal acquisition switch circuit is provided, which differs from Embodiment 1 in that: the single channel is changed to a multi-channel circuit, that is, the number of test circuit units is set to two or more.

[0089] When the test circuit unit includes multiple units, the multiple test circuit units are connected in parallel to form a multi-channel measurement. Multiple channels can be measured individually or simultaneously to achieve measurement of multiple arbitrary channels.

[0090] like Figure 4 As shown, the circuit includes a first test circuit unit 100, a second test circuit unit 101, ..., an Nth test circuit unit 10n. The circuit structure of the second test circuit unit 101, ..., the Nth test circuit unit 10n is consistent with the circuit structure of the first test circuit unit 100. The first control signals of the multiple test circuit units can be controlled independently, that is, the levels of the first control signals in the multiple test circuit units can be the same or different.

[0091] For example, a microcontroller unit (MCU) can regulate the high and low levels of K01, K02, ..., Kn, thereby enabling control of N channels, achieving single-channel measurement, or measurement of multiple arbitrary channels.

[0092] The advantages or beneficial effects of adopting the above technical solution are as follows: By introducing negative voltage into the electronic switch control, this utility model can boost the signal to the measurable range, realize the detection of weak signals, and enhance the reliability of the signal measurement results; through multi-channel measurement, the speed of the test circuit can be improved, and rapid testing can be achieved.

[0093] The above are merely preferred embodiments of the present utility model and are not intended to limit the implementation methods and protection scope of the present utility model. Those skilled in the art should realize that any equivalent substitutions and obvious changes made using the content of this specification and illustrations should be included within the protection scope of the present utility model.

Claims

1. A signal acquisition switching circuit, characterized in that, It includes at least one test circuit unit, and each of the test circuit units includes: Test end; The first switch branch is controllably connected between the positive drive current signal and the first terminal of the test terminal under the action of a second control signal based on the first control signal; wherein, when the first switch branch is turned on, the second control signal is a negative voltage; The second switch branch is controllably connected between the positive detection signal and the first end of the test terminal under the action of the second control signal; The third switch branch is controllably connected between the negative detection signal and the second end of the test terminal under the action of the first control signal; The fourth switch branch is controllably connected between the negative drive current signal and the second terminal of the test terminal under the action of the first control signal.

2. The signal acquisition switching circuit according to claim 1, characterized in that, The second control signal is generated by a signal processing module, which includes: The first transistor has its gate connected to the first control signal via a first resistor, a second resistor connected between the gate and source of the first transistor, and its drain used to output the second control signal. The pull-up branch is connected between the drain of the first transistor and the positive voltage; The pull-down branch is controllably connected between the source of the first transistor and the negative voltage under the action of the first control signal.

3. The signal acquisition switching circuit according to claim 2, characterized in that, The pull-up branch includes: A fourth resistor is connected between the drain of the first transistor and the positive voltage; The first capacitor is connected between the positive voltage and the ground terminal.

4. The signal acquisition switch circuit according to claim 2, characterized in that, The pull-down branch includes: An optocoupler is provided, wherein the anode of the optocoupler is connected to the first control signal via a third resistor, the cathode of the optocoupler is connected to the ground terminal, the drain of the optocoupler is connected to the source of the first transistor, and the source of the optocoupler is connected to the negative voltage.

5. The signal acquisition switch circuit according to claim 2, characterized in that, The pull-down branch also includes: The second transistor has its gate connected to the drain of the first transistor, its drain connected to the source of the first transistor, and its source connected to ground.

6. The signal acquisition switch circuit according to claim 1, characterized in that, Also includes: The fifth resistor is connected between the first control signal and the control terminals of the third and fourth switch branches.

7. The signal acquisition switching circuit according to claim 1, characterized in that, The first switch branch, the second switch branch, the third switch branch, and the fourth switch branch have the same on / off state.

8. The signal acquisition switch circuit according to claim 1, characterized in that, The first switch branch, the second switch branch, the third switch branch, and the fourth switch branch all use insulated gate bipolar transistors.

9. The signal acquisition switch circuit according to claim 1, characterized in that, The test terminal includes a sixth resistor, one end of which serves as the first end of the test terminal, and the other end of which serves as the second end of the test terminal.

10. The signal acquisition switching circuit according to claim 1, characterized in that, When the test circuit unit comprises multiple units, the multiple test circuit units are connected in parallel.

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