Waveform detection circuit and waveform detection method

Abstract

The invention belongs to the related technical field of oscillographic circuits, and particularly relates to a waveform detection circuit and a waveform detection method. A switching circuit is arranged in a waveform detection circuit and is used for acquiring an electric signal of a workpiece in a period; a detection circuit is arranged and is connected to the output end of the switching circuit; the detection circuit is provided with a first threshold end, a second threshold end, a detection end and a voltage output end, the output end of the switching circuit is connected with the detection end, the first threshold end inputs a first voltage, and the second threshold end inputs a second voltage, so that the first voltage and the second voltage form a voltage range; the main control circuit is connected with the voltage output end; wherein if the electric signal is in the voltage range, the voltage output end outputs a first level to the main control circuit, and if the electric signal is out of the voltage range, the voltage output end outputs a second level opposite to the first level to the main control circuit. Therefore, the waveform can flexibly adjust the detection range, and the situation that the waveform cannot be read in some special voltage ranges is avoided.

Description

Technical Field

[0001] This invention belongs to the technical field of oscilloscope circuits, and particularly relates to a waveform detection circuit and a waveform detection method. Background Technology

[0002] An oscilloscope is a commonly used electronic testing device, primarily used to display the waveform of voltage changing over time. It can monitor and analyze signal parameters such as waveform, frequency, amplitude, and period in real time. Its principle can be summarized as acquiring an electrical signal and converting it into a waveform signal of a certain amplitude, which is then displayed on the oscilloscope.

[0003] In existing testing products, under normal circumstances, the highest and lowest values ​​of the standard effective signal are relatively constant. For example, the highest effective signal value is usually 5V or 3.3V, and the lowest effective signal value is usually 0V. However, in some special products, the highest effective signal value may only be 2 / 3 of the normal value, and the lowest effective signal value may be larger than 0V. When performing waveform testing with existing oscilloscopes, there may be problems with detection. Furthermore, under conditions of large electrical signal fluctuations, oscilloscopes cannot stably detect waveforms. For example, in digital signal testing, the oscilloscope may fail to display the waveform due to the set threshold. Summary of the Invention

[0004] To address the technical problem that "oscilloscopes fail to detect or detect unstable non-standard valid signals from some products," this invention proposes a waveform detection circuit and a waveform detection method.

[0005] The present invention solves the above-mentioned technical problems through the following technical solutions: In a first aspect, the present invention provides a waveform detection circuit, comprising: A switching circuit is used to acquire electrical signals from a workpiece within a cycle. A detection circuit is connected to the output terminal of the switching circuit. The detection circuit is provided with a first threshold terminal, a second threshold terminal, a detection terminal, and a voltage output terminal. The output terminal of the switching circuit is connected to the detection terminal. A first voltage is input to the first threshold terminal, and a second voltage is input to the second threshold terminal, so that the first voltage and the second voltage form a voltage range. The main control circuit is connected to the voltage output terminal; If the electrical signal is within the voltage range, the voltage output terminal outputs a first level to the main control circuit; if the electrical signal is outside the voltage range, the voltage output terminal outputs a second level opposite to the first level to the main control circuit.

[0006] A switching circuit is incorporated into the waveform detection circuit to acquire the workpiece's electrical signal within a cycle. A detection circuit is connected to the output of the switching circuit. The detection circuit includes a first threshold terminal, a second threshold terminal, a detection terminal, and a voltage output terminal. The output of the switching circuit is connected to the detection terminal. A first voltage is input to the first threshold terminal, and a second voltage is input to the second threshold terminal, forming a voltage range. A main control circuit is connected to the voltage output terminal. If the electrical signal is within the voltage range, the voltage output terminal outputs a first level to the main control circuit; if the electrical signal is outside the voltage range, the voltage output terminal outputs a second level, opposite to the first level, to the main control circuit. This allows for flexible adjustment of the waveform detection range, preventing the waveform from being unreadable in certain specific voltage ranges.

[0007] In some implementations, the switching circuit is provided with a switch K, the input terminal of which is connected to the waveform output terminal of the workpiece, and the output terminal of which is connected to the detection circuit.

[0008] In some implementations, a step-down circuit is provided between the output of the switching circuit and the detection circuit to reduce the voltage of the electrical signal to a preset range.

[0009] In some implementations, the step-down circuit includes multiple step-down resistors and a selector switch. The step-down resistors are connected in parallel and have different resistance values. The selector switch is located across the two ends of the step-down resistors and is used to connect any one of the step-down resistors between the output of the switching circuit and the detection circuit.

[0010] In some implementations, an amplifier circuit is provided between the output of the switching circuit and the detection circuit to amplify and filter the electrical signal.

[0011] In some implementations, the amplifier circuit includes an amplifier and a first resistor R1. The electrical signal includes a positive signal and a negative signal. The amplifier is provided with a positive input terminal, a negative input terminal and an output terminal. The positive input terminal receives the positive signal and the negative input terminal receives the negative signal. The output terminal is connected to the detection terminal through the first resistor R1.

[0012] In some embodiments, the detection circuit includes a first comparator and a second comparator. A first terminal of the first comparator is connected to a first threshold terminal, and a second terminal of the first comparator is connected to the output terminal of an amplifier. A first terminal of the second comparator is connected to a second threshold terminal, and a second terminal of the second comparator is connected to the output terminal of the amplifier. The output terminals of the first and second comparators are connected to form a voltage output terminal. The main control circuit has a power supply terminal, a voltage output terminal connected to one end of a fifth resistor, and the other end of the fifth resistor connected to the power supply terminal. The first end of the first comparator is the positive terminal, and the first end of the second comparator is the negative terminal.

[0013] In some implementations, a first isolation circuit is provided between the voltage output terminal and the main control circuit. The isolation circuit is used to isolate the output voltage from the main control circuit.

[0014] In some implementations, the main control circuit includes a main control chip U1, which is provided with a voltage detection terminal, a first voltage output terminal and a second voltage output terminal. The first voltage output terminal outputs a first voltage, and the second voltage output terminal outputs a second voltage. The voltage detection terminal is connected to the voltage output terminal.

[0015] Secondly, the present invention proposes a waveform detection method, applied in the waveform detection circuit described in the first aspect, the steps of which include: The first and second preset voltages are set, and the main control circuit obtains the trigger signal of the switching circuit and records the current first time segment. The main control circuit acquires the electrical signal sent by the workpiece within a preset period after the first time segment, and saves all the second time segments and corresponding voltage values ​​within the preset period as a first sequence; The main control circuit obtains the highest value of the voltage value of the first sequence and determines whether the highest value of the voltage value meets the voltage range through the voltage output terminal; if it meets the voltage range, the voltage value obtained in the second time segment is the effective voltage value.

[0016] The beneficial effects of the waveform detection circuit and waveform detection method of the present invention are: A switching circuit is incorporated into the waveform detection circuit to acquire the workpiece's electrical signal within a cycle. A detection circuit is connected to the output of the switching circuit. This detection circuit includes a first threshold terminal, a second threshold terminal, and a voltage output terminal. The first threshold terminal receives a first voltage, and the second threshold terminal receives a second voltage, forming a voltage range. A main control circuit is connected to the voltage output terminal. If the electrical signal is within the voltage range, the voltage output terminal outputs a first voltage level to the main control circuit; if the electrical signal is outside the voltage range, the voltage output terminal outputs a second voltage level, opposite to the first level, to the main control circuit. This allows for flexible adjustment of the waveform detection range, preventing the waveform from being unreadable in certain specific voltage ranges. Attached Figure Description

[0017] Figure 1 The structure of the waveform detection circuit of embodiment 1 of the present invention. Figure 1 ; Figure 2 The structure of the waveform detection circuit of the present invention is shown in Embodiment 2. Figure 2 ; Figure 3 The principle of Embodiment 2 of the waveform detection circuit of the present invention Figure 1 ; Figure 4The principle of embodiment 3 of the waveform detection circuit of the present invention Figure 1 ; Figure 5 The principle of embodiment 3 of the waveform detection circuit of the present invention Figure 2 ; Figure 6 This is a structural diagram of Embodiment 4 of the waveform detection method of the present invention.

[0018] Specific implementation methods: It should be noted that, unless otherwise specified, the embodiments and technical features in the embodiments of the present invention can be combined with each other, and the detailed descriptions in the specific embodiments should be understood as explanations of the spirit of the present invention and should not be regarded as undue limitations on the present invention.

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the specific technical solutions of the present invention will be further described in detail below with reference to the accompanying drawings of the embodiments of the present invention. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0020] In the embodiments of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of the present invention, unless otherwise stated, "a plurality of" means two or more.

[0021] Furthermore, in the embodiments of the present invention, directional terms such as "upper," "lower," "left," and "right" are defined relative to the positions in which the components are schematically placed in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the position of the components in the accompanying drawings.

[0022] In the embodiments of the present invention, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium.

[0023] In embodiments of the present invention, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0024] In embodiments of the present invention, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" or "for example" in embodiments of the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant information in a specific manner.

[0025] Example 1: like Figure 1 As shown, this embodiment proposes a waveform detection circuit, including: Switching circuit 1 is used to acquire the electrical signal of the workpiece within a cycle; The detection circuit 2 is connected to the output terminal of the switching circuit 1. The detection circuit 2 is provided with a first threshold terminal U2_2, a second threshold terminal U2_5, a first detection terminal U2_6\U2_4 and a voltage output terminal U2_7\U2_1. The output terminal of the switching circuit 1 is connected to the first detection terminal U2_6\U2_4. The first threshold terminal U2_2 is input with a first voltage, and the second threshold terminal U2_5 is input with a second voltage, so that the first voltage and the second voltage form a voltage range. Main control circuit 3 is connected to voltage output terminals U2_7 and U2_1; If the electrical signal is within the voltage range, the voltage output terminals U2_7 and U2_1 output a first level to the main control circuit 3. If the electrical signal is outside the voltage range, the voltage output terminals U2_7 and U2_1 output a second level opposite to the first level to the main control circuit 3.

[0026] Specifically, switch circuit 1 is used to acquire the electrical signal of the workpiece within a cycle. More specifically, the workpiece can output positive and negative signals through DMMV+ and DMMV- respectively. Switch circuit 1 can be a relay, switch, etc. Switch circuit 1 can be manually or controlled by a chip to enable the switch to detect the electrical signal within a certain time. Detection circuit 2 is connected to the output terminal of switch circuit 1. Detection circuit 2 is equipped with a first threshold terminal U2_2 and a second threshold terminal U2_5. The first threshold terminal U2_2 sets a first voltage, and the second threshold terminal U2_5 sets a second voltage, i.e., upper and lower limits, so that the first voltage and the second voltage form a voltage range. By adjusting the values ​​of the first voltage and the second voltage, the voltage range is adjusted to adapt to the detection of different products. At the same time, before testing the product, the voltage range can be set by presetting the first voltage and the second voltage without the need for oscilloscope adjustment, thereby improving the testing time. In some implementations, the detection circuit 2 can be implemented using a comparator, a voltage detection chip, a hardware combination of multiple components (using two Zener diodes to set the upper and lower limits respectively: when the input voltage is higher than the lower Zener diode breakdown voltage and lower than the upper Zener diode breakdown voltage, the transistor conducts and outputs a high level, etc.), a microcontroller, etc. After acquiring the electrical signal from the first detection terminals U2_6 and U2_4, the voltage range formed by the first voltage and the second voltage is compared. If the electrical signal is within the voltage range, the voltage output terminals U2_7 and U2_1 output a first level to the main control circuit 3; if the electrical signal is outside the voltage range, the voltage output terminals U2_7 and U2_1 output a second level opposite to the first level to the main control circuit 3. After the detection circuit 2 detects the result, it transmits either the first level or the second level to the main control circuit 3. The main control circuit 3 judges the input electrical signal according to the high or low level and converts it into a waveform signal for display. The first level and the second level can be high or low levels in the conventional sense. When the first level is high, the second level is low, and vice versa.

[0027] A switching circuit 1 is set in the waveform detection circuit to acquire the electrical signal of the workpiece within a period; and a detection circuit 2 is set and connected to the output terminal of the switching circuit 1. The detection circuit 2 is equipped with a first threshold terminal U2_2, a second threshold terminal U2_5, a first detection terminal U2_6 / U2_4, and a voltage output terminal U2_7 / U2_1. The output terminal of the switching circuit 1 is connected to the first detection terminal U2_6 / U2_4. The first threshold terminal U2_2 is input with a first voltage, and the second threshold terminal U2_5 is input with a second voltage, so that the first voltage and the second voltage form a voltage range; and a main control circuit 3 is connected to the voltage output terminal U2_7 / U2_1. Wherein, if the electrical signal is within the voltage range, the voltage output terminal U2_7 / U2_1 outputs a first level to the main control circuit 3. If the electrical signal is outside the voltage range, the voltage output terminal U2_7 / U2_1 outputs a second level opposite to the first level to the main control circuit 3. This allows the waveform to be flexibly adjusted in the detection range, avoiding the inability to read in some special voltage ranges.

[0028] Example 2: like Figures 2-3 As shown, this embodiment further explains and optimizes the circuit structure proposed in Embodiment 1: In some embodiments, the switching circuit 1 is provided with a switching element K, the input terminal of the switching element K is connected to the waveform output terminal of the workpiece, and the output terminal of the switching element K is connected to the detection circuit 2.

[0029] Specifically, more specifically, the workpiece can output positive and negative signals through DMMV+ and DMMV- respectively. The switching circuit 1 is equipped with a switch K. In some preferred embodiments, the switch K is a push switch, so that the waveform can be acquired within a certain period of time by touching the switch. In other optional embodiments, the switch K can be a relay, switch, etc., and the switch K can be turned on and off automatically or manually to achieve the acquisition of electrical signals within the required period.

[0030] In some embodiments, a step-down circuit 4 is provided between the output terminal of the switching circuit 1 and the detection circuit 2 to reduce the voltage of the electrical signal to a preset range.

[0031] Specifically, a step-down circuit 4 is provided between the output terminal of the switching circuit 1 and the detection circuit 2. The step-down circuit 4 can reduce the voltage of the electrical signal to a preset range, such as the 0~12V range that the detection circuit 2 can identify, so that the voltage in different ranges can be detected and oscillated through the step-down circuit 4.

[0032] In some preferred embodiments, the step-down circuit 4 includes multiple step-down resistors and a selection switch. The step-down resistors are connected in parallel and have different resistance values. The selection switch is located at both ends of the step-down resistors and is used to connect any step-down resistor between the output terminal of the switching circuit 1 and the detection circuit 2.

[0033] Specifically, the step-down circuit 4 includes multiple step-down resistors and a selection switch. The step-down resistors are connected in parallel with different resistance values ​​to accommodate different detection voltages, thereby stepping down the voltage to a preset range through different step-down resistors. In some optional embodiments, the step-down resistors can be step-down chips.

[0034] In some embodiments, an amplifier circuit 5 is provided between the output terminal of the switching circuit 1 and the detection circuit 2 to amplify and filter the electrical signal.

[0035] Specifically, the output terminal of the switching circuit 1 is provided with an amplifier circuit 5. The amplifier circuit 5 can be an amplifier circuit composed of transistors or an amplifier circuit composed of operational amplifiers. Its purpose is to filter and amplify the signal so that the detection circuit 2 can accurately identify the signal.

[0036] In some embodiments, the amplifier circuit 5 includes an amplifier and a first resistor R1. The electrical signal includes a positive signal and a negative signal. The amplifier is provided with a positive input terminal, a negative input terminal and an output terminal. The positive input terminal receives the positive signal and the negative input terminal receives the negative signal. The output terminal is connected to the first detection terminals U2_6\U2_4 through the first resistor R1.

[0037] Specifically, amplifier circuit 5 is configured as an amplifier and a first resistor R1. The electrical signal typically includes a positive signal and a negative signal. The amplifier also has a positive input terminal, a negative input terminal, and an output terminal. Furthermore, it includes a positive power input terminal, a negative power input terminal, and a ground terminal. The positive and negative power input terminals can be powered by 12V, either from an external chip or an MCU. The ground terminal is grounded. The positive and negative input terminals are connected to the positive and negative signals respectively. The amplifier output terminal is connected to the input terminal of detection circuit 2, thereby amplifying and filtering the signal and integrating the positive and negative signals. Simultaneously, the output terminal is connected to the first detection terminals U2_6 and U2_4 through the first resistor R1, allowing the voltage at the output terminal to be compared with the voltage range formed by the first and second voltages of detection circuit 2.

[0038] In some embodiments, the detection circuit 2 includes a first comparator and a second comparator. The first terminal of the first comparator is connected to the first threshold terminal U2_2, and the second terminal of the first comparator is connected to the output terminal of the amplifier. The first terminal of the second comparator is connected to the second threshold terminal U2_5, and the second terminal of the second comparator is connected to the output terminal of the amplifier. The output terminals of the first comparator and the output terminals of the second comparator are connected to form voltage output terminals U2_7 and U2_1. The main control circuit 3 is equipped with a power supply terminal. The voltage output terminals U2_7 and U2_1 are connected to one end of the fifth resistor, and the other end of the fifth resistor is connected to the power supply terminal. The first end of the first comparator is the positive terminal, and the first end of the second comparator is the negative terminal.

[0039] Specifically, the detection circuit 2 includes a first comparator and a second comparator, which are used to set the upper and lower limits of the voltage range, respectively. The first terminal of the first comparator is connected to the first threshold terminal U2_2, and a first level is input at the first threshold terminal U2_2. The first level is used as a reference level input to serve as the upper or lower limit of the voltage range. The first terminal of the second comparator is connected to the second threshold terminal U2_5, and a second level is input at the second threshold terminal U2_5. The second level is used as a reference level input to serve as the upper or lower limit of the voltage range. The voltage range is formed by combining the first level and the second level. The second terminals of the first comparator and the second comparator are set as the first detection terminals U2_6 and U2_4. The electrical signal obtained by the switching circuit 1 is amplified by the amplifier circuit 5 and then input to the second terminals of the first comparator and the second comparator, respectively. This allows the first comparator and the second comparator to compare whether the input electrical signal is within the voltage range. If the electrical signal is within the voltage range, the voltage output terminals U2_7 and U2_1 output a first level to the main control circuit 3. If the electrical signal is outside the voltage range, the voltage output terminals U2_7 and U2_1 output a second level opposite to the first level to the main control circuit 3. Both the first comparator and the second comparator have a positive terminal, a negative terminal, and a comparator output terminal. The first terminal of the first comparator can be the negative terminal of the first comparator, and the first terminal of the second comparator can be the negative terminal of the second comparator. The second terminal of the first comparator can be the positive terminal of the second comparator, and the second terminal of the second comparator can be the positive terminal of the second comparator. The output terminals of the first comparator and the second comparator are connected and output to the main control circuit 3 as voltage output terminals U2_7\U2_1.

[0040] In some more specific embodiments, the first resistor R1 is 10K, and the first comparator and the second comparator can be set in the second chip U2. The second chip U2 can be a TLV1702, which includes two or more comparators. The first terminal of the first comparator is the IN-1 terminal of the second chip U2, the second terminal of the first comparator is the IN+1 terminal of the second chip U2, and the comparator output terminal of the first comparator is OUT1. The first terminal of the second comparator is the IN-2 terminal of the second chip U2, the second terminal of the second comparator is the IN+1 terminal of the second chip U2, and the comparator output terminal of the second comparator is OUT2. In this embodiment, OUT1 and OUT2 are interconnected and connected to the main control circuit 3. Furthermore, the IN+1 terminal and the IN+2 terminal are grounded through the second resistor R2, which can be 10K.

[0041] The main control circuit 3 has a power supply terminal. The voltage output terminals U2_7 and U2_1 are connected to one end of a fifth resistor, and the other end of the fifth resistor is connected to the power supply terminal. The first terminal of the first comparator is the positive terminal, and the first terminal of the second comparator is the negative terminal. By pulling up the voltage through the fifth resistor and by reversing the connection of the first threshold terminal U2_2 and the second threshold terminal U2_5 to the positive and negative terminals of the first comparator, respectively, a low-level output is achieved when the voltage is within the specified range. When the voltage is outside the specified range, although the two comparators output one high and one low level, the voltage will be pulled high by the fifth resistor, resulting in a high-level output.

[0042] In some embodiments, a first isolation circuit 6 is provided between the voltage output terminals U2_7\U2_1 and the main control circuit 3. The isolation circuit is used to isolate the output voltage from the main control circuit 3.

[0043] Specifically, the first isolation circuit 6 includes a third chip U3, which is used for signal isolation. Through the third chip U3, instability of electrical signals during transmission is avoided. The third chip U3 can be an NS18240, which mainly includes a first isolation input terminal and a first isolation output terminal for connecting to the main control circuit 3.

[0044] Example 3: like Figures 4-5 As shown, this embodiment further explains and optimizes the structure of the main control circuit 3: In some embodiments, the main control circuit 3 includes a main control chip U1. The main control chip U1 is provided with a second detection terminal U1_PC25, a first voltage output terminal U1_OUT1 and a second voltage output terminal U1_OUT2. The first voltage output terminal U1_OUT1 outputs a first voltage, and the second voltage output terminal U1_OUT2 outputs a second voltage. The second detection terminal U1_PC25 ​​is connected to the voltage output terminals U2_7 and U2_1.

[0045] Specifically, the main control circuit 3 includes a main control chip U1, which is an MCU. The main control chip U1 is equipped with a second detection terminal U1_PC25, a first voltage output terminal U1_OUT1, and a second voltage output terminal U1_OUT2. The second detection terminal U1_PC25 ​​is used to connect to the output terminal of the detection circuit 2 to receive the level information after comparison, thereby judging the electrical signal and displaying the result on the oscilloscope in the form of a waveform.

[0046] In some embodiments, a second isolation circuit 7 is further provided between the main control circuit 3 and the detection circuit 2 to isolate the first voltage output terminal U1_OUT1 and the second voltage output terminal U1_OUT2 from the first threshold terminal U2_2 and the second threshold terminal U2_5.

[0047] Specifically, a second isolation circuit 7 is provided between the first voltage output terminal U1_OUT1 and the first threshold terminal U2_2 to isolate the electrical signals and avoid mutual interference. The second isolation circuit 7 also includes a fourth chip U4 and two fifth chips. The fourth chip U4 can be an NS18240 to enable signal isolation, and the fifth chips can be a DAC8411 to amplify and filter the electrical signals, thereby improving signal accuracy. The fourth chip U4 is provided with a second isolated input terminal and a third isolated input terminal to receive the first voltage and the second voltage of the MCU. It is further connected to the first voltage output terminal U1_OUT1 and the second voltage output terminal U1_OUT2 of the MCU, respectively. The fourth chip U4 is also provided with a second isolated output terminal and a third isolated output terminal to output the isolated first voltage and the second voltage, respectively. There can be two fifth chips, connected to the second isolated output terminal and the third isolated output terminal, respectively. The first fifth chip U5-1 is provided with at least an input terminal and an output terminal, and the second fifth chip U5-2 is provided with at least an input terminal and an output terminal. The input terminal of the first fifth chip U5-1 is connected to the first voltage output terminal U1_OUT1, and the output terminal of the first fifth chip U5-1 is grounded through the third resistor R3. The input terminal of the second fifth chip U5-2 is connected to the second voltage output terminal U1_OUT2, and the output terminal of the second fifth chip U5-2 is grounded through the fourth resistor R4.

[0048] Example 4: like Figure 6 As shown, the present invention also proposes a waveform detection method, applied to the waveform detection circuit described in any one of Embodiments 1 to 3, the steps of which include: Step 100: Set the preset first voltage and second voltage, the main control circuit obtains the trigger signal of the switching circuit and records the current first time segment; Specifically, a first and second preset voltage are set. These two voltages are determined based on the product's properties. For example, if the preset effective voltage for the product is 3.2V~2.8V, then the voltage range set can be 3.1V~2.7V to ensure accurate identification of the effective range. The main control circuit typically has a port for acquiring trigger signals, so that the main control circuit triggers timing the instant the switching circuit is turned on.

[0049] Step 200: The main control circuit acquires the electrical signal sent by the workpiece within a preset period after the first time segment, and saves all the second time segments and corresponding voltage values ​​within the preset period as a first sequence; Specifically, after the first time segment, the main control circuit acquires the electrical signal sent by the workpiece within a preset period, that is, the timing period, which is usually 3 seconds. Within the preset period, except for the first time segment, the remaining time segments are continuous second time segments. The main control circuit records the voltage values ​​in the order of the second time segments and saves the time and the corresponding voltage values ​​in the first sequence.

[0050] Step 300: The main control circuit obtains the highest value of the voltage value of the first sequence, and determines whether the highest value of the voltage value meets the voltage range through the voltage output terminal; if it meets the voltage range, the voltage value obtained in the second time segment is the effective voltage value.

[0051] Specifically, the main control circuit finds the highest value of the voltage in the first sequence as the peak value, and uses the detection circuit to determine whether it meets the valid voltage range. The determination method is based on the level transmitted by the voltage output terminal. If it is the first level, it means that the range is met; if it is the second level, it means that the range is not met.

[0052] Furthermore, to avoid invalid peak values ​​within the preset period, i.e., uncontrollable voltage jumps, and to prevent these uncontrollable jumps from affecting the normal voltage display in subsequent displays, when a satisfactory second time segment is obtained, adjacent second time segments can be judged. By first finding second time segments on both sides of the highest voltage value that are close to low voltage or close to 0V, a pulse width time is formed by the two second time segments. By setting a certain effective pulse width time, it is determined whether the detected highest value is the required peak value, rather than a high voltage display caused by uncontrollable jumps.

[0053] The sequence numbers of the embodiments are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent device or equivalent process transformation made based on the content of the present invention specification and drawings, or direct or indirect application in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A waveform detection circuit, characterized in that, include: A switching circuit is used to acquire electrical signals from a workpiece within a cycle. The detection circuit includes a first threshold terminal, a second threshold terminal, a detection terminal, and a voltage output terminal. The output terminal of the switching circuit is connected to the detection terminal. A first voltage is input to the first threshold terminal, and a second voltage is input to the second threshold terminal, so that the first voltage and the second voltage form a voltage range. as well as The main control circuit is connected to the voltage output terminal; If the electrical signal is within the voltage range, the voltage output terminal outputs a first level to the main control circuit; if the electrical signal is outside the voltage range, the voltage output terminal outputs a second level opposite to the first level to the main control circuit.

2. The waveform detection circuit according to claim 1, characterized in that, The switching circuit is equipped with a switch K, the input terminal of which is connected to the waveform output terminal of the workpiece, and the output terminal of which is connected to the detection circuit.

3. The waveform detection circuit according to claim 1, characterized in that, A step-down circuit is provided between the output terminal of the switching circuit and the detection circuit to reduce the voltage of the electrical signal to a preset range.

4. The waveform detection circuit according to claim 3, characterized in that, The step-down circuit includes multiple step-down resistors and a selection switch. The step-down resistors are connected in parallel and have different resistance values. The selection switch is located across the two ends of the step-down resistors, and the selection switch allows any one of the step-down resistors to be connected between the output terminal of the switching circuit and the detection circuit.

5. The waveform detection circuit according to claim 1, characterized in that, An amplifier circuit is provided between the output terminal of the switching circuit and the detection circuit to amplify and filter the electrical signal.

6. The waveform detection circuit according to claim 5, characterized in that, The amplification circuit includes an amplifier and a first resistor R1. The electrical signal includes a positive signal and a negative signal. The amplifier has a positive input terminal, a negative input terminal, and an output terminal. The positive input terminal receives the positive signal, and the negative input terminal receives the negative signal. The output terminal and the detection terminal are connected through the first resistor R1.

7. The waveform detection circuit according to claim 6, characterized in that, The detection circuit includes a first comparator and a second comparator. The first terminal of the first comparator is connected to the first threshold terminal, and the second terminal of the first comparator is connected to the output terminal of the amplifier. The first terminal of the second comparator is connected to the second threshold terminal, and the second terminal of the second comparator is connected to the output terminal of the amplifier. The output terminals of the first comparator and the second comparator are connected to form the voltage output terminal. The main control circuit is provided with a power supply terminal, the voltage output terminal is connected to one end of a fifth resistor, the other end of the fifth resistor is connected to the power supply terminal, the first end of the first comparator is the positive terminal, and the first end of the second comparator is the negative terminal.

8. The waveform detection circuit according to claim 1, characterized in that, A first isolation circuit is also provided between the voltage output terminal and the main control circuit, the isolation circuit being used to isolate the output voltage from the main control circuit.

9. The waveform detection circuit according to claim 1, characterized in that, The main control circuit includes a main control chip U1. The main control chip U1 is provided with a voltage detection terminal, a first voltage output terminal and a second voltage output terminal. The first voltage output terminal outputs a first voltage and the second voltage output terminal outputs a second voltage. The voltage detection terminal is connected to the voltage output terminal.

10. A waveform detection method, characterized in that, When applied to the waveform detection circuit as described in any one of claims 1-9, the steps include: The main control circuit sets a preset first voltage and a second voltage, acquires the trigger signal of the switching circuit, and records the current first time segment. The main control circuit acquires the electrical signal sent by the workpiece within a preset period after the first time segment, and saves all the second time segments and corresponding voltage values ​​within the preset period as a first sequence. The main control circuit obtains the highest value of the voltage value of the first sequence, and determines whether the highest value of the voltage value meets the voltage range through the voltage output terminal; if it meets the voltage range, the voltage value obtained in the second time segment is an effective voltage value.

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