A voltage correction method and apparatus

Abstract

The application discloses a voltage correction method and device, the method comprises the following steps: correcting the feedback value of an AD chip used for collecting the voltage at the load end in a load feedback circuit; avoiding the jump voltage caused by charging the electrolytic capacitor at the output end of the power supply from being taken as the sampling value to participate in the AD correction function calculation through a jump time avoidance algorithm in the sampling process of the AD correction function calculation, so as to improve the accuracy of the AD correction function, and further improve the precision of the feedback value after the AD chip collects the voltage at the load end; and the method further comprises the following steps: correcting the output value of a DA chip used for configuring the voltage at the output end of the power supply in the load feedback circuit, so as to further improve the precision of the output voltage of the DA chip.

Description

Technical Field

[0001] This invention relates to the field of display screen testing equipment technology, and specifically to a voltage correction method and device for improving the accuracy of the open-circuit voltage and load voltage supply at the output terminal of a display screen testing device. Background Technology

[0002] After manufacturing a display screen, manufacturers need to perform a screen test to determine its quality. During this test, the screen testing equipment provides a driving voltage to the screen to enable it to light up. However, the testing equipment is susceptible to problems such as errors in electronic components, system noise, and component aging. Furthermore, once connected to the screen, the internal resistance of both the screen and the transmission lines causes a drop in the voltage supplied to the display, resulting in a significant discrepancy between the actual and theoretical output voltage values. These two factors lead to insufficient output voltage accuracy, preventing the screen from lighting up. To ensure the testing equipment provides the ideal voltage for different screen models, manufacturers calibrate the output voltage of the testing equipment before shipping to meet user requirements.

[0003] Current voltage correction schemes generally employ two methods:

[0004] 1. Digital calibration, which involves acquiring load (display screen) voltage data (display screen power output voltage) through the AD chip (analog-to-digital converter chip) in the display device, correcting the acquired display screen voltage data using an algorithm (e.g., multi-segment fitting correction disclosed in patent No. 201610124865.8), and then calculating the voltage value to be compensated based on the corrected AD chip acquisition value and voltage compensation function. The voltage value to be compensated is then configured into the DA chip (here, the DA chip is an exponential analog-to-digital converter chip, used to cooperate with the BUCK step-down circuit in the power supply device (display screen power supply) to provide a voltage value), thereby cooperating with the power output terminal to output the required voltage to compensate for the transmission loss between the power supply device and the load;

[0005] 2. Use hardware circuits for calibration.

[0006] Using hardware circuits for calibration requires additional circuitry, which is costly; therefore, digital calibration methods are preferred.

[0007] Before the touchscreen device leaves the factory, the manufacturer writes the tested voltage correction function into the control chip (microcontroller or FPGA, etc.). During actual operation, the touchscreen device uses this voltage correction function to correct the load voltage data collected by the AD chip in real time, ensuring the accuracy of the voltage compensation value calculated by the subsequent voltage compensation function. However, the following problems can arise in the process of obtaining the voltage correction function:

[0008] In the AD calibration stage, the host computer provides a fitted potential to the simulated load (used to set the power output voltage of the display device) through the control module. The voltage correction function of the AD chip is calculated using the actual and ideal sampled feedback values. However, to reduce noise and stabilize output, the power output of the display device includes electrolytic capacitors (for filtering and power supply). When the fitted potential decreases, for example from 20V to 16V, the voltage drop causes the electrolytic capacitors at the voltage output to charge (according to the relationship between capacitance and voltage, the capacitance increases when the voltage across the capacitor decreases). This results in a sudden voltage jump, causing a significant drop in voltage. However, current technologies do not consider this jump time interval when calculating the AD chip's voltage correction function. Therefore, some of the collected data values ​​are voltage values ​​within this jump time, leading to a large discrepancy between the collected data and the actual load voltage. Consequently, even with multi-segment fitting, the resulting voltage correction function is inaccurate. This phenomenon also occurs when the voltage value changes from small to large, but when the voltage value rises, the electrolytic capacitor discharges, and the resulting jump time range is very narrow and can be disregarded.

[0009] Meanwhile, previous voltage correction schemes only calibrated the AD chip. Although this improved the accuracy of the acquired voltage, after the host computer collected the accurate acquired voltage, it was necessary to calculate the voltage ΔV that needed to be compensated to the load due to losses under the current connected load using the voltage compensation function. Then, a voltage value was configured to the DA chip at the power output terminal to compensate the output voltage so that the load could work normally. However, due to the influence of factors such as errors in electronic components, system noise, and device aging, the output value of the DA chip would also be inaccurate, which would lead to inaccurate output compensation voltage value. Summary of the Invention

[0010] The purpose of this invention is to provide a voltage correction method and apparatus, which helps to improve the accuracy of the no-load voltage and load voltage supply at the output terminal of a dot-screen device.

[0011] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0012] A voltage correction method is applied to the load feedback circuit of a touch screen device, comprising: correcting the feedback value of an AD chip used to acquire the load terminal voltage in the load feedback circuit;

[0013] The correction of the feedback value of the AD chip used to acquire the load terminal voltage in the load feedback circuit specifically includes:

[0014] The host computer provides multiple sets of first fitted potentials to the analog load terminal, and the first fitted potentials are voltage signals in descending order;

[0015] The control module controls the AD chip to sample the voltage at the analog load terminal at each first fitting potential to obtain the first sample value. When the first fitting potential switches, the AD chip is controlled to sample by a jump time avoidance algorithm to avoid the AD chip using the jump voltage caused by the charging of the electrolytic capacitor at the power output terminal as the first sample value.

[0016] The calibration host computer controls the meter to sample the voltage at the simulated load terminal under each first fitting potential, obtain the second sample value, and control the meter to sample when the first fitting potential switches, so as to avoid the meter using the jump voltage caused by the charging of the electrolytic capacitor at the power output terminal as the second sample value.

[0017] The host computer performs multi-segment fitting calculations based on the received first and second sampled values ​​to obtain the AD correction function, and sends the AD correction function to the control module for storage. The control module then corrects the feedback value of the AD chip using the AD correction function.

[0018] The jump time avoidance algorithm includes, when the first fitting potential switches, controlling the AD chip and the platform meter to perform multiple samplings, and sorting the first and second sampled values ​​obtained from the multiple samplings in order of size, and selecting the middle sampled value to output to the calibration host computer.

[0019] As a further improvement of the present invention, the AD correction function obtained by the host computer through multi-segment fitting calculation based on the received first and second sample values ​​is as follows:

[0020] V1 = cV AD +d

[0021] Where V1 is the ideal feedback value of the AD chip, V AD The actual feedback value of the AD chip is represented by c and d, which are correction coefficients.

[0022] By using at least two sets of first sampled values ​​as V AD The correction coefficients c and d are calculated by substituting the second sampled value under the same first fitting potential into the AD correction function as V1.

[0023] As a further improvement of the present invention, the step of “correcting the feedback value of the AD chip used to collect the load terminal voltage in the load feedback circuit” further includes correcting the output value of the DA chip used to configure the power output terminal voltage in the load feedback circuit.

[0024] The correction of the output value of the DA chip used to configure the power output voltage in the load feedback circuit specifically includes:

[0025] The host computer provides multiple sets of second fitting potentials to the control module. The second fitting potentials are voltage signals ordered in ascending or descending order. The control module controls the DA chip to configure the power output voltage according to the second fitting potentials.

[0026] The host computer control panel samples the voltage at the power output terminal at each second fitted potential to obtain the third sample value;

[0027] The host computer performs multi-segment fitting calculations based on the second fitted potential and the received third sample value to obtain the DA correction function, and sends the DA correction function to the control module for storage. The control module corrects the output value of the DA chip through the DA correction function.

[0028] As a further improvement of the present invention, the DA correction function obtained by the host computer through multi-segment fitting calculation based on the second fitted potential and the received third sample value is as follows:

[0029] V DA =aV2+b

[0030] Among them, V DA V1 is the ideal output voltage at the power supply output terminal, V2 is the actual output voltage at the power supply output terminal, and a and b are correction coefficients.

[0031] By using at least two sets of second fitted potentials as V DA The third sampled value under the same second fitting potential is used as V2 and substituted into the DA correction function to calculate the correction coefficients a and b.

[0032] A voltage correction device is provided, which is used to correct the feedback value of an AD chip in the load feedback circuit of a touch screen device, wherein the AD chip is used to collect the load terminal voltage of the touch screen device.

[0033] The voltage correction device includes a correction host computer, a control module, and a table.

[0034] The voltage correction device is used to correct the feedback value of the AD chip in the load feedback circuit of the touch screen device, specifically including:

[0035] The calibration host computer is used to provide multiple sets of first fitting potentials to the analog load terminal, wherein the first fitting potentials are voltage signals ordered in descending order;

[0036] The control module is used to control the AD chip to sample the voltage of the analog load terminal at each first fitting potential, obtain the first sample value, and control the AD chip to sample through the jump time avoidance algorithm when the first fitting potential is switched, so as to avoid the AD chip using the jump voltage caused by the charging of the electrolytic capacitor at the power output terminal as the first sample value.

[0037] The calibration host computer is also used to control the instrument to sample the voltage of the simulated load terminal under each first fitting potential, obtain the second sampling value, and control the instrument to sample through the jump time avoidance algorithm when the first fitting potential is switched, so as to avoid the instrument using the jump voltage caused by the charging of the electrolytic capacitor at the power output terminal as the second sampling value.

[0038] The correction host computer is also used to perform multi-segment fitting calculations based on the received first and second sample values ​​to obtain the AD correction function, and send the AD correction function to the control module for storage. The control module corrects the feedback value of the AD chip through the AD correction function.

[0039] The voltage correction device is also used to run a jump time avoidance algorithm;

[0040] The jump time avoidance algorithm includes, when the first fitting potential switches, controlling the AD chip and the platform meter to perform multiple samplings, and sorting the first and second sampled values ​​obtained from the multiple samplings in order of size, and selecting the middle sampled value to output to the calibration host computer.

[0041] As a further improvement of the present invention, before the voltage correction device corrects the feedback value of the AD chip in the load feedback circuit of the screen device, the voltage correction device is also used to correct the output value of the DA chip used to configure the power output voltage in the load feedback circuit.

[0042] The voltage correction device is also used to correct the output value of the DA chip used to configure the power supply output voltage in the load feedback circuit, specifically including:

[0043] The calibration host computer is also used to provide multiple sets of second fitting potentials to the control module. The second fitting potentials are voltage signals ordered in ascending or descending order. The control module controls the DA chip to configure the power output voltage according to the second fitting potentials.

[0044] The calibration host computer is also used to control the instrument to sample the voltage at the power supply output terminal at each second fitted potential and obtain the third sample value;

[0045] The host computer is also used to perform multi-segment fitting calculations based on the second fitted potential and the received third sample value to obtain the DA correction function, and send the DA correction function to the control module for storage. The control module corrects the output value of the DA chip through the DA correction function.

[0046] Compared with the prior art, the technical advantages of the present invention are as follows:

[0047] The voltage correction method provided by this invention includes correcting the feedback value of the AD chip used to collect the load terminal voltage in the load feedback circuit. During the sampling process of AD correction function calculation, a jump time avoidance algorithm is used to avoid using the jump voltage caused by the charging of the electrolytic capacitor at the power output terminal as the sampled value in the AD correction function calculation, thereby improving the accuracy of the AD correction function and thus improving the accuracy of the feedback value after the AD chip collects the load terminal voltage. The method also includes correcting the output value of the DA chip used to configure the power output terminal voltage in the load feedback circuit, thereby improving the accuracy of the DA chip output voltage. The improvement of the sampling feedback accuracy of the AD chip and the output accuracy of the DA chip helps to improve the accuracy of the no-load voltage and load voltage supply at the output terminal of the display device. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the implementation process of the voltage correction method in Embodiment 1 of the present invention;

[0049] Figure 2 This is a schematic diagram of the implementation process of the voltage correction method in Embodiment 2 of the present invention;

[0050] Figure 3 This is a schematic block diagram of the voltage correction device in Embodiment 3 of the present invention;

[0051] Figure 4 This is a schematic block diagram of the voltage correction device in Embodiment 4 of the present invention;

[0052] Figure 5 This is a measured waveform of voltage jumps displayed on an oscilloscope. Detailed Implementation

[0053] The present invention will now be described in detail with reference to the specific embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and any structural, methodological, or functional modifications made by those skilled in the art based on these embodiments are included within the scope of protection of the present invention.

[0054] It should be noted that this invention only relates to technical solutions for improving the sampling feedback accuracy of the AD chip and the output accuracy of the DA chip, and does not involve the calculation of the compensation voltage. Subsequently, the user of the display device calculates the voltage that needs to be compensated to the load (display screen) due to losses under the current connected load using a voltage compensation function. The purpose of this invention is to improve the accuracy of the calculated compensation voltage by increasing the sampling feedback accuracy of the AD chip, and to ensure that the compensation voltage can be accurately configured to the power output terminal by improving the output accuracy of the DA chip, thereby helping to improve the accuracy of the no-load voltage and load voltage supply at the output terminal of the display device.

[0055] Example 1

[0056] Please see Figure 1 A voltage correction method is applied to the load feedback circuit of a dot-screen device. By correcting the feedback value of the AD chip used to collect the load terminal voltage in the load feedback circuit, the sampling feedback accuracy of the AD chip is improved. By correcting the output value of the DA chip used to configure the power output terminal voltage in the load feedback circuit, the output voltage accuracy of the DA chip is improved.

[0057] The voltage correction method in this embodiment is implemented through the following process:

[0058] The first and second fitting potential ranges are defined based on the driving voltage distribution of common displays on the market. The defined ranges of the first and second fitting potential ranges can cover the driving voltage distribution range of common displays. For example, the driving voltage distribution of common displays is between 24-12V. In practical applications, the screen-clicking device may need to test any display with a driving voltage distribution between 24-12V. It is necessary to ensure that the driving voltage output by the screen-clicking device is accurate within this range. The fitting potential range is selected accordingly between 24-12V. The AD chip and DA chip are calibrated within the fitting potential range.

[0059] Since the outputs of the AD and DA chips change non-linearly within the fitted potential range, a multi-segment fitting method is used to correct them. In this process, the fitted potential range is divided into multiple sets of fitted potentials, further dividing it into segments. Theoretically, if the number of segments is sufficient, the outputs of the AD and DA chips within each segment can be considered linearly changing; that is, there is a linear correspondence between the ideal and actual output values ​​of the AD and DA chips. This linear correspondence can be represented by the correction function described below. By sampling the ideal and actual output values ​​of the AD and DA chips within each fitted potential segment and substituting them into the linear equation, the correction coefficient between the ideal and actual output values ​​within each fitted potential segment can be calculated, thus obtaining the correction function between the ideal and actual output values ​​of the AD and DA chips within each fitted potential segment. In practical applications, the feedback value of the AD chip and the output value of the DA chip can be corrected using the correction function within the corresponding voltage range.

[0060] In practice, to facilitate operation and reduce computational load, the fitting potential range can be divided into several sub-fitting potential ranges based on the driving voltage distribution of various displays. Within each sub-fitting potential range, two points can be randomly selected to form multiple sets of fitting potentials, and then the correction function can be calculated.

[0061] For example, the driving voltage of common displays is distributed between 24-12V, with large displays having a driving voltage between 24-17V and small displays having a driving voltage between 17-12V. Two potentials can be randomly selected from the 24-17V and 17-12V ranges to form multiple sets of fitting potentials for voltage correction. Assuming we select 22V, 20V, 16V, and 14V, the correction function between 22-20V can be used as the correction function between 24-17V, and the correction function between 16-14V can be used as the correction function between 17-12V. When applying the technology, if the driving voltage of the display screen is between 24-17V, a correction function between 22-20V is used to correct the feedback value of the AD chip and the output value of the DA chip. If the driving voltage of the display screen is between 17-12V, a correction function between 16-14V is used to correct the feedback value of the AD chip and the output value of the DA chip. The correction functions between 24-22V, 20-17V, 17-16V, and 14-12V do not need to be calculated.

[0062] Please see Figure 5 , Figure 5 This is a measured waveform of voltage jumps displayed on an oscilloscope, with the horizontal axis representing time and the vertical axis representing voltage. To reduce noise and stabilize output, the power output of the display device includes electrolytic capacitors (for filtering and power supply). Based on the relationship between the capacitance and voltage of these electrolytic capacitors, voltage jumps occur when the fitted potential changes. During the sampling process for calculating the AD correction function, a jump time avoidance algorithm is used to prevent the voltage jumps caused by the charging of the electrolytic capacitors at the power output from being used as sampled values ​​in the AD correction function calculation, thus improving the accuracy of the AD correction function. Furthermore, during the DA chip calibration process, no-load calibration is used (no load is applied to the power output, i.e., no current is generated). Since the electrolytic capacitors do not undergo charging or discharging, they do not generate voltage jumps that affect the DA correction function calculation.

[0063] Using the selected 22V, 20V, 16V, and 14V as examples of the four sets of first fitting potentials, a voltage jump will occur when the first fitting potential is switched sequentially from 22V to 20V, from 20V to 16V, and from 16V to 14V.

[0064] This embodiment avoids collecting the switching voltage by pre-calculating the transition time at each switching and then delaying the sampling.

[0065] Specifically, the transition time avoidance algorithm includes: before correcting the feedback value of the AD chip used to collect the voltage at the power output terminal in the load feedback circuit, the correction host computer calculates the transition time and sends it to the control module for storage; when the first fitted potential switches, the control module controls the AD chip to sample after delaying the transition time; and the correction host computer controls the console table to sample after delaying the transition time.

[0066] The transition time t is calculated using the following formula derived from the charging characteristics of the electrolytic capacitor at the power output terminal of the touchscreen device:

[0067] t = RCLn[E / (EV) f )]

[0068] Where t is the transition time, C is the maximum capacitance of the electrolytic capacitor at the power supply output terminal, R is the internal resistance of the power supply, E is the initial value of the power supply output voltage, and V f It is the peak value of the voltage jump at the power supply output terminal, and Ln represents the natural logarithm.

[0069] It should be noted that R and C in each dot-screen device are constants, and E is the initial value of the power supply output voltage during each first fitting potential switch. The value of E is sampled by the instrument and sent to the calibration host computer. f It is the peak value of the voltage jump at the power supply output terminal during each first fitted potential switch, V f The values ​​are sampled by the oscilloscope and sent to the calibration host computer. The calibration host computer then uses each group of E and V values... f The jump time at each first fitted potential switch can be calculated from this value.

[0070] The specific process by which the transition time t is obtained based on the charging characteristics of the electrolytic capacitor at the power output terminal of the touch screen device is as follows:

[0071] Let V0 be the initial voltage value across the electrolytic capacitor, V u The termination voltage value for fully charging the electrolytic capacitor, V t Let C be the voltage across the electrolytic capacitor at any time t1. t Let V be the voltage value at any given time. t The capacitance value of the electrolytic capacitor can be determined based on V. t The parameters of the electrolytic capacitor were calculated.

[0072] V t =V0+(V u -V0)×[1-exp(-t1 / RC t )]

[0073] If a battery with voltage E charges an electrolytic capacitor with an initial value of 0 through a resistor R, then V0 = 0, and the charging limit is V. u =E, therefore, at any time t1, the voltage across the electrolytic capacitor is:

[0074] V t =E×[1-exp(-t1 / RC] t )]

[0075] When V t equals V fOnce the transition ends, the formula for calculating the transition time can be derived:

[0076] t=RC t Ln[E / (EV f )]

[0077] Based on the relationship between an electrolytic capacitor and its voltage (power supply output voltage), it can be seen that the smaller the voltage across the electrolytic capacitor, the larger its capacitance. Furthermore, due to voltage fluctuations, V... t During the process of change, the corresponding voltage value V at any given time t The capacitance value C of the lower electrolytic capacitor t It is also subject to change, C t The value is difficult to obtain, so C is... t Let C be the maximum capacitance value of the electrolytic capacitor at the power output terminal. The calculated value of t will be greater than C. t The t value calculated by substituting it into the formula, and the sampled after the delay, can be used to avoid the voltage jumps during each switching.

[0078] After the jump time corresponding to the first fitted potential is calculated, the DA chip calibration and AD chip calibration are performed sequentially.

[0079] First, the DA chip is calibrated.

[0080] Turn on the touch screen device and ensure it is in an unloaded state (no load is applied to the power output terminal, i.e., no current is generated). Connect the meter to the power output terminal.

[0081] The host computer provides multiple sets of second fitting potentials to the control module. The second fitting potentials are voltage signals ordered in ascending or descending order. The control module controls the DA chip to configure the power output voltage according to the second fitting potentials.

[0082] The host computer control panel samples the voltage at the power output terminal at each second fitted potential to obtain the third sample value;

[0083] The host computer performs multi-segment fitting calculations based on the second fitted potential and the received third sample value to obtain the DA correction function, and sends the DA correction function to the control module for storage. The control module corrects the output value of the DA chip through the DA correction function.

[0084] The DA correction function obtained by the host computer through multi-segment fitting calculation based on the second fitted potential and the received third sample value is as follows:

[0085] V DA =aV2+b

[0086] Among them, V DAV1 is the ideal output voltage at the power supply output terminal, V2 is the actual output voltage at the power supply output terminal, and a and b are correction coefficients.

[0087] By using at least two sets of second fitted potentials as V DA The third sampled value under the same second fitting potential is used as V2 and substituted into the DA correction function to calculate the correction coefficients a and b.

[0088] It should be noted that when the DA chip is operating ideally, the voltage output from the power supply terminal should be equal to the second fitting potential configured by the host computer. Therefore, the second fitting potential is used as V. DA The third sample value measured by the meter connected to the power output terminal is the actual output voltage of the power output terminal under the corresponding second fitted potential. Because the fitted potential range is divided into multiple small segments (the interval between two sets of second fitted potentials is one small segment) by multiple sets of second fitted potentials, the actual output voltage of the power output terminal can be considered to change linearly according to the second fitted potential (ideal output voltage) in each small segment. Therefore, the linear equation shown by the DA correction function can reflect the linear correspondence between the actual output voltage and the ideal output voltage of the power output terminal. Using the two sets of second fitted potentials as V... DA The third sampled value under the same second fitting potential is used as V2 and substituted into the DA correction function to solve the system of equations. The correction coefficients a and b can then be calculated, which determines the DA correction function corresponding to the second fitting potential segment.

[0089] The correction coefficients corresponding to the second fitted potential of each segment are calculated, that is, the DA correction functions corresponding to the second fitted potential of each segment are calculated and sent to the control module for storage. When performing voltage compensation later, the corresponding DA correction function can be called to perform DA correction.

[0090] Then, AD chip calibration is performed.

[0091] Turn on the touch screen device to put it under load (add a simulated load to the power output terminal; the simulated load is used to simulate the display screen with various driving voltages), and connect the meter to both ends of the simulated load.

[0092] The host computer provides multiple sets of first fitted potentials to the analog load, and the first fitted potentials are voltage signals in descending order.

[0093] It should be noted that when the host computer provides the first fitted potential to the analog load, it performs DA correction on the first fitted potential through the corresponding DA correction function (making the actual voltage at the voltage output terminal closer to the first fitted potential), and then configures the voltage at the power output terminal through the DA chip, and then outputs it to the analog load.

[0094] The control module controls the AD chip to sample the voltage of the analog load terminal at each first fitting potential to obtain the first sample value. When the first fitting potential switches, the AD chip is controlled to sample after a corresponding jump time to avoid the AD chip using the jump voltage caused by the charging of the electrolytic capacitor at the power output terminal as the first sample value.

[0095] The host computer control panel samples the voltage of the simulated load terminal at each first fitting potential to obtain the second sampling value. When the first fitting potential is switched, the control panel samples after a corresponding jump time delay to avoid the control panel using the jump voltage caused by charging the electrolytic capacitor at the power output terminal as the second sampling value.

[0096] The host computer performs multi-segment fitting calculations based on the received first and second sampled values ​​to obtain the AD correction function, and sends the AD correction function to the control module for storage. The control module then corrects the feedback value of the AD chip using the AD correction function.

[0097] The AD correction function obtained by the host computer through multi-segment fitting calculation based on the received first and second sample values ​​is as follows:

[0098] V1 = cV AD +dd

[0099] Where V1 is the ideal feedback value of the AD chip, V AD The actual feedback value of the AD chip is represented by c and d, which are correction coefficients.

[0100] By using at least two sets of first sampled values ​​as V AD The correction coefficients c and d are calculated by substituting the second sampled value under the same first fitting potential into the AD correction function as V1.

[0101] When the AD chip is operating ideally, its actual feedback value should equal the voltage of the analog load. Therefore, the second sampled value collected by the meter directly connected to the analog load is taken as the ideal feedback value of the AD chip. Because the fitting potential range is divided into multiple segments (a segment between two sets of first fitting potentials) by multiple sets of first fitting potentials, the actual feedback value of the AD chip can be considered to change linearly according to the load voltage (ideal feedback value) in each segment. Therefore, the linear equation shown by the AD correction function reflects the linear correspondence between the ideal and actual feedback values ​​of the AD chip. The two sets of first sampled values ​​are taken as V... AD The second sampled value under the same first fitting potential is used as V1 and substituted into the AD correction function to solve the system of equations, and the correction coefficients c and d are calculated, which determines the AD correction function corresponding to the first fitting potential of this segment.

[0102] The correction coefficients corresponding to the first fitted potential of each segment are calculated, that is, the AD correction functions corresponding to the first fitted potential of each segment are calculated and sent to the control module for storage. When AD sampling is performed later, the corresponding AD correction functions are called to perform AD correction, and the AD-corrected voltage values ​​are fed back to participate in the compensation voltage calculation.

[0103] Example 2

[0104] Please see Figure 2 The difference between this embodiment and embodiment 1 is that the jump time avoidance algorithm is different, but the rest are the same.

[0105] The transition time avoidance algorithm used in this embodiment does not require calculating specific transition time values. Instead, it filters sampled values ​​by sorting and selecting the median value after multiple samplings.

[0106] The transition time avoidance algorithm in this embodiment includes: when the first fitted potential switches, controlling the AD chip and the platform meter to perform multiple samplings, and sorting the first and second sampled values ​​obtained from the multiple samplings in order of size, and selecting the middle sampled value to output to the calibration host computer.

[0107] For example, when the first fitted potential is switched, the AD chip and the stage meter are controlled to perform 11 samplings respectively, and the first and second sampled values ​​obtained from the 11 samplings are sorted in order of size. The first and second sampled values ​​ranked 6th are selected and output to the calibration host computer.

[0108] Example 3

[0109] Please see Figure 3 A voltage correction device is applied to the load feedback circuit of a dot-screen device. By correcting the feedback value of the AD chip used to collect the load terminal voltage in the load feedback circuit, the sampling feedback accuracy of the AD chip is improved. By correcting the output value of the DA chip used to configure the power output terminal voltage in the load feedback circuit, the output voltage accuracy of the DA chip is improved.

[0110] The voltage correction device includes a correction host computer, a control module, a table, and an oscilloscope to run a transition time avoidance algorithm.

[0111] The calibration host computer is an intelligent calibration terminal that is external to the dot-screen device, such as a PC;

[0112] A table meter is a measuring instrument that is externally installed on a dot-screen device, such as a multimeter with communication functions;

[0113] The oscilloscope is an external device for display screens and has communication capabilities;

[0114] The control module is a built-in module of the touch screen device, such as a microcontroller.

[0115] The communication connection between the host computer and the control module is corrected so that the control module can control the DA chip to configure the voltage at the power output terminal.

[0116] When running the transition time avoidance algorithm, the transition time is calculated first. When calculating the transition time, the acquisition terminals of the instrument panel and oscilloscope are connected to the power output terminal, and the feedback terminal is connected to the calibration host computer.

[0117] When calculating the transition time, the calibration host computer configures the first fitted potential at the power output terminal, the instrument panel feeds back the initial value E of the power output terminal voltage to the calibration host computer, and the oscilloscope feeds back the transition peak value V of the power output terminal voltage to the calibration host computer. f The host computer calibrates based on the E and V values ​​of each group. f The jump time t is calculated for each first fitted potential switch.

[0118] The transition time t is calculated using the following formula derived from the charging characteristics of the electrolytic capacitor at the power output terminal of the touchscreen device:

[0119] t = RCLn[E / (EV) f )]

[0120] Where t is the transition time, C is the maximum capacitance of the electrolytic capacitor at the power supply output terminal, R is the internal resistance of the power supply, E is the initial value of the power supply output voltage, and V f It is the peak value of the voltage jump at the power supply output terminal.

[0121] The calibration host computer sends the calculated transition time to the control module for storage. During the AD calibration process, when the first fitted potential switches, the control module controls the AD chip to sample after a corresponding transition time delay, and the calibration host computer controls the console meter to sample after a corresponding transition time delay.

[0122] The voltage correction device is also used to correct the output value of the DA chip used to configure the power output voltage in the load feedback circuit.

[0123] When calibrating the output value of the DA chip, the calibration host computer controls the DA chip to configure a second fitting potential to the unloaded power output terminal through the control module. The stage meter is connected to the power output terminal to collect a third sample value representing the actual output voltage of the power output terminal under the control of the calibration host computer, and feeds the third sample value back to the calibration host computer.

[0124] The host computer performs multi-segment fitting calculations based on the second fitted potential stored in its own memory and the received third sample value to obtain the DA correction function, and sends the DA correction function to the control module for storage, so that the control module can correct the output value of the DA chip through the DA correction function.

[0125] The voltage correction device is also used to correct the feedback value of the AD chip in the load feedback circuit of the dot-screen device, wherein the AD chip is used to collect the load terminal voltage of the dot-screen device.

[0126] When correcting the feedback value of the AD chip, the host computer provides a first fitted potential to the analog load. Specifically, the host computer sends the first fitted potential to the control module, which performs DA correction on the first fitted potential using the corresponding DA correction function, configures the power output voltage through the DA chip, and then outputs it to the analog load.

[0127] The meter is connected to the load end to collect a second sample value representing the ideal feedback value of the AD chip, and feeds the second sample value back to the calibration host computer. The AD chip is also connected to the load end to collect a first sample value representing the actual feedback value of the AD chip, and feeds the first sample value back to the calibration host computer through the control module.

[0128] During the process of obtaining the first and second sampled values.

[0129] The control module controls the AD chip to sample the voltage of the analog load terminal at each first fitting potential to obtain the first sample value. When the first fitting potential is switched, the AD chip is controlled to sample after a delay of the jump time to avoid the AD chip using the jump voltage caused by the charging of the electrolytic capacitor at the power output terminal as the first sample value.

[0130] The calibration host computer control panel samples the voltage of the simulated load terminal at each first fitting potential to obtain the second sample value. When the first fitting potential is switched, the control panel samples after a delay of the jump time to avoid the control panel using the jump voltage caused by the charging of the electrolytic capacitor at the power output terminal as the second sample value.

[0131] The correction host computer performs multi-segment fitting calculations based on the received first and second sample values ​​to obtain the AD correction function, and sends the AD correction function to the control module for storage, so that the control module can correct the feedback value of the AD chip through the AD correction function.

[0132] Example 4

[0133] Please see Figure 4 The difference between this embodiment and embodiment 3 is that the jump time avoidance algorithm of the voltage correction device is different, while the rest are the same.

[0134] In this embodiment, the voltage correction device's transition time avoidance algorithm does not need to calculate specific transition time values. Instead, it filters sampled values ​​by sorting and taking the median value after multiple samplings.

[0135] Since there is no need to calculate the transition time in this embodiment, the oscilloscope is omitted. The software stored in the control module and the calibration host computer performs multiple sampling, sorting and filtering of the first sample value and the second sample value.

[0136] Specifically, when the first fitted potential is switched, the AD chip and the stage meter are controlled to perform multiple samplings, and the first and second sampled values ​​obtained from the multiple samplings are sorted in order of size, and the sampled value in the middle is selected and output to the calibration host computer.

[0137] For example, when the first fitted potential is switched, the AD chip and the stage meter are controlled to perform 11 samplings respectively, and the first and second sampled values ​​obtained from the 11 samplings are sorted in order of size. The first and second sampled values ​​ranked 6th are selected and output to the calibration host computer.

[0138] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A voltage correction method applied to the load feedback circuit of a dot-screen device, characterized in that, include: The feedback value of the AD chip used to acquire the load terminal voltage in the load feedback circuit is corrected. The correction of the feedback value of the AD chip used to acquire the load terminal voltage in the load feedback circuit specifically includes: The host computer provides multiple sets of first fitted potentials to the analog load terminal, and the first fitted potentials are voltage signals in descending order; The control module controls the AD chip to sample the voltage of the analog load terminal at each first fitting potential to obtain the first sampled value. When the first fitting potential switches, the AD chip is controlled to sample by a jump time avoidance algorithm to avoid the AD chip using the jump voltage caused by the charging of the electrolytic capacitor at the power output terminal as the first sampled value. When the calibration host computer provides the first fitting potential to the analog load terminal, it performs DA correction on the first fitting potential through the DA correction function, configures the voltage of the power output terminal through the DA chip, and then outputs it to the analog load terminal. The calibration host computer controls the meter to sample the voltage at the simulated load terminal under each first fitting potential, obtain the second sample value, and control the meter to sample when the first fitting potential switches, so as to avoid the meter using the jump voltage caused by the charging of the electrolytic capacitor at the power output terminal as the second sample value. The host computer performs multi-segment fitting calculations based on the received first and second sampled values ​​to obtain the AD correction function, and sends the AD correction function to the control module for storage. The control module then corrects the feedback value of the AD chip using the AD correction function. The jump time avoidance algorithm includes, when the first fitting potential switches, controlling the AD chip and the stage meter to perform multiple samplings, and sorting the first and second sampled values ​​obtained from the multiple samplings in order of size, and selecting the middle sampled value to output to the correction host computer; Before correcting the feedback value of the AD chip used to acquire the load terminal voltage in the load feedback circuit, the output value of the DA chip used to configure the power output terminal voltage in the load feedback circuit is also corrected.

2. The voltage correction method according to claim 1, characterized in that, The AD correction function obtained by the host computer through multi-segment fitting calculation based on the received first and second sample values ​​is as follows: ； Where V1 is the ideal feedback value of the AD chip, VAD is the actual feedback value of the AD chip, and c and d are correction coefficients; The correction coefficients c and d are calculated by substituting at least two sets of first sampled values ​​as VAD and the second sampled values ​​under the same first fitted potential as V1 into the AD correction function.

3. The voltage correction method according to claim 1, characterized in that, The correction of the output value of the DA chip used to configure the power output voltage in the load feedback circuit specifically includes: The host computer provides multiple sets of second fitting potentials to the control module. The second fitting potentials are voltage signals ordered in ascending or descending order. The control module controls the DA chip to configure the power output voltage according to the second fitting potentials. The host computer control panel samples the voltage at the power output terminal at each second fitted potential to obtain the third sample value; The host computer performs multi-segment fitting calculations based on the second fitted potential and the received third sample value to obtain the DA correction function, and sends the DA correction function to the control module for storage. The control module corrects the output value of the DA chip through the DA correction function.

4. The voltage correction method according to claim 3, characterized in that, The DA correction function obtained by the host computer through multi-segment fitting calculation based on the second fitted potential and the received third sample value is as follows: ； Where VDA is the ideal output voltage of the power supply output terminal, V2 is the actual output voltage of the power supply output terminal, and a and b are correction coefficients; The correction coefficients a and b are calculated by substituting at least two sets of second fitted potentials as VDA and the third sampled value under the same second fitted potential as V2 into the DA correction function.

5. A voltage correction device, characterized in that, The voltage correction device is used to correct the feedback value of the AD chip in the load feedback circuit of the screen display device. The AD chip is used to collect the load terminal voltage of the screen display device. The voltage correction device includes a correction host computer, a control module, and a table. The voltage correction device is used to correct the feedback value of the AD chip in the load feedback circuit of the touch screen device, specifically including: The calibration host computer is used to provide multiple sets of first fitting potentials to the analog load terminal. The first fitting potentials are voltage signals in descending order. When the calibration host computer provides the first fitting potentials to the analog load terminal, it performs DA correction on the first fitting potentials through the DA correction function, configures the power output voltage through the DA chip, and then outputs it to the analog load terminal. The control module is used to control the AD chip to sample the voltage of the analog load terminal at each first fitting potential, obtain the first sample value, and control the AD chip to sample through the jump time avoidance algorithm when the first fitting potential is switched, so as to avoid the AD chip using the jump voltage caused by the charging of the electrolytic capacitor at the power output terminal as the first sample value. The calibration host computer is also used to control the instrument to sample the voltage of the simulated load terminal under each first fitting potential, obtain the second sampling value, and control the instrument to sample through the jump time avoidance algorithm when the first fitting potential is switched, so as to avoid the instrument using the jump voltage caused by the charging of the electrolytic capacitor at the power output terminal as the second sampling value. The correction host computer is also used to perform multi-segment fitting calculations based on the received first and second sample values ​​to obtain the AD correction function, and send the AD correction function to the control module for storage. The control module corrects the feedback value of the AD chip through the AD correction function. The voltage correction device is also used to run a jump time avoidance algorithm; The jump time avoidance algorithm includes, when the first fitting potential switches, controlling the AD chip and the stage meter to perform multiple samplings, and sorting the first and second sampled values ​​obtained from the multiple samplings in order of size, and selecting the middle sampled value to output to the correction host computer; Before the voltage correction device corrects the feedback value of the AD chip in the load feedback circuit of the screen display device, the voltage correction device is also used to correct the output value of the DA chip used to configure the power output voltage in the load feedback circuit.

6. The voltage correction device according to claim 5, characterized in that, The voltage correction device is also used to correct the output value of the DA chip used to configure the power supply output voltage in the load feedback circuit, specifically including: The calibration host computer is also used to provide multiple sets of second fitting potentials to the control module. The second fitting potentials are voltage signals ordered in ascending or descending order. The control module controls the DA chip to configure the power output voltage according to the second fitting potentials. The calibration host computer is also used to control the instrument to sample the voltage at the power supply output terminal at each second fitted potential and obtain the third sample value; The host computer is also used to perform multi-segment fitting calculations based on the second fitted potential and the received third sample value to obtain the DA correction function, and send the DA correction function to the control module for storage. The control module corrects the output value of the DA chip through the DA correction function.

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