Keyboard resistance measuring method with high efficiency

Abstract

The invention relates to the technical field of keyboard resistance measurement, and discloses a high-efficiency keyboard resistance measurement method, which comprises the following steps of: starting up and initializing an impedance measurement box; closing an impedance detection channel, and adjusting a current limiter until the maximum amplifier is minimized, so that the impedance measurement box is in a standby state; when the keyboard measurement function is started, a detection channel between the impedance measurement box and the keyboard is opened; whether the current value is too small or not is measured, and if the measured current value is too small, the current limiter is reduced; and measuring whether the amplification factor of the amplifier is too small, and increasing the amplification factor when the amplification factor is too small. The 5V power supply is arranged between every two pins of the keyboard, the current probe and the amplifier are connected to the negative electrode of the power supply, and the output signal of the amplifier is fed back to the control circuit for resistance calculation, so that the calculated resistance can be quickly fed back to a computer end for recording, and the efficiency of keyboard resistance measurement is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of keyboard resistance measurement, and in particular to a keyboard resistance measurement method with high efficiency. Background Art

[0002] A keyboard is a device for inputting commands and data to operate a computer device. It also refers to a set of function keys that are arranged to operate a machine or device (such as a typewriter or computer keyboard). Measuring the resistance of a keyboard is usually done to check the health of the keyboard circuit, detect the contact of a switch, or debug the circuit.

[0003] The existing patent discloses an ARM-based keyboard resistance detection system and method for detecting the contact resistance of a finished computer keyboard (publication number CN101833040A), where the keyboard to be tested is connected to an array switch, and the array switch is respectively connected to a constant current source, a voltage comparator, an amplifier, and an ARM chip; each column of switches in the array switch is composed of a KI switch and a KV switch, the KI switch is connected to a constant current source, and the KV switch is respectively connected to an amplifier and a voltage comparator, and a constant current scan is performed on the keyboard to be tested through the array switch, and the voltage comparator judges the output of the constant current source. In the technology disclosed in the patent, when measuring the resistance of keyboards of different models, the keyboard resistance will be different due to the different keyboard materials, and it is difficult to ensure the accuracy and efficiency of the measurement without changing the test range of the keyboard. Summary of the invention

[0004] The main technical problem solved by the present invention is to provide a keyboard resistance measurement method with high efficiency, which solves the problems in the above-mentioned background technology.

[0005] To solve the above technical problems, according to one aspect of the present invention, more specifically, a keyboard resistance measurement method with high efficiency comprises the following steps:

[0006] S1. Initialize the impedance measurement box;

[0007] S2, close the impedance detection channel, adjust the current limiter to maximize the amplifier and minimize the impedance measurement box to be in standby mode;

[0008] S3, when the keyboard measurement function is started, the detection channel between the impedance measurement box and the keyboard is opened;

[0009] S4, measure whether the current value is too small, if the measured current value is too small, reduce the current limiter;

[0010] S5, measuring whether the amplification factor of the amplifier is too small, if the amplification factor is too small, increasing the amplification factor, and repeating step S3;

[0011] S6. When the amplification factor of the amplifier is normal, the impedance value of the keyboard is calculated, and the calculated impedance value is stored and transmitted to the measuring computer.

[0012] Furthermore, in the step S3, after the horizontal 50 PIN pins and the vertical 50 PIN pins of the keyboard are connected to the wiring socket of the impedance measurement box through wires, the detection channel between the impedance measurement box and the keyboard is opened.

[0013] Furthermore, in step S5, the range of the measured current is changed by switching the amplification factor of the amplifier.

[0014] Furthermore, in step S5, whether the amplification factor is too small is determined based on whether the degree of the current exceeds one fifth of the measuring range.

[0015] Furthermore, in step S6, the impedance value of the keyboard is calculated by the ARM control circuit.

[0016] Furthermore, in step S6, the impedance value of the keyboard is calculated by arbitrarily combining any two of the 50PIN pins on the keyboard and connecting them to the positive and negative poles of a 5V power supply respectively, and then measuring the current on the negative pole of the 5V power supply.

[0017] Furthermore, according to Ohm's law, the resistance of the keyboard under 5V voltage can be calculated, so:

[0018]

[0019] In the formula, R 实际 It represents the actual resistance between the two combined PIN pins on the keyboard, U represents the power supply voltage between the two PIN pins, I represents the current at the negative pole of the power supply measured by the current probe, and R0 represents the sum of the switch resistance and the line resistance.

[0020] Furthermore, in step S4, when judging whether the measured current value is too small, if the measured current value is too small, the current limiter is reduced. It is necessary to determine whether the measured current value is too small based on the absolute value of the difference between the pulse current started by the keyboard and the short-circuit current, the current change when the keyboard circuit is heated by 0.3°C, and the absolute value of the difference between the continuous current and the rated current. There are:

[0021]

[0022] In the formula, c represents the proportional coefficient for judging whether the measured current value is too small. When c is less than 68%, it indicates whether the measured current value is too small; a represents the absolute value of the difference between the pulse current started by the keyboard and the short-circuit current; m represents the current change when the keyboard circuit is heated by 0.3°C; i represents the absolute value of the difference between the continuous current and the rated current.

[0023] Beneficial effects:

[0024] 1. The present invention inserts a 5V power supply between two pins of the keyboard, connects a current probe and an amplifier to the negative pole of the power supply, and feeds back the output signal of the amplifier to the control circuit for resistance calculation. In this way, the calculated resistance can be quickly fed back to the computer for recording, thereby improving the efficiency of keyboard resistance measurement.

[0025] 2. The present invention connects an amplifier to the end of the current probe and can change the measurement range by changing the amplification factor of the amplifier. This design enables the impedance measurement box to be adapted to more types of keyboards. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is the principle diagram of the measuring box in the present invention;

[0027] Figure 2 This is a schematic diagram of keyboard measurement wiring of the present invention;

[0028] Figure 3 is a flow chart of the present invention;

[0029] Figure 4 This is a pin diagram of the keyboard of the present invention;

[0030] Figure 5 It is a schematic diagram of the present invention. DETAILED DESCRIPTION

[0031] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Example 1

[0033] like Figure 1-5 As shown, according to one aspect of the present invention, a keyboard resistance measurement method with high efficiency is provided, comprising the following steps:

[0034] Step 1: Initialize the impedance measurement box.

[0035] Step 2: Close the impedance detection channel, adjust the current limiter to maximize the amplifier and minimize the impedance measurement box to be in standby mode;

[0036] Step 3: When the keyboard measurement function is started, the detection channel between the impedance measurement box and the keyboard is opened. After connecting the horizontal 50PIN pins and the vertical 50PIN pins of the keyboard to the impedance measurement box wiring socket through wires, the detection channel between the impedance measurement box and the keyboard is opened.

[0037] Step 4: Measure whether the current value is too small. If the measured current value is too small, reduce the current limiter;

[0038] Step 5: Check whether the amplification factor of the measuring amplifier is too small. If it is too small, increase the amplification factor and repeat step 3. The range of the measured current can be changed by switching the amplification factor of the amplifier.

[0039] Whether the magnification is too small is determined by whether the current reading exceeds one fifth of the range. When the current reading exceeds one fifth of the range, it indicates that the magnification is normal. When the current reading does not exceed one fifth of the range, it indicates that the magnification is too small.

[0040] Step 6: When the amplifier's amplification factor is normal, the impedance value of the keyboard is calculated, and the calculated impedance value is stored and transmitted to the measurement computer. The impedance value of the keyboard is calculated through the ARM control circuit.

[0041] Example 2

[0042] like Figure 1 , 2 As shown in Figure 4, the impedance value of the keyboard is calculated by connecting any two of the 50PIN pins on the keyboard to the positive and negative poles of the 5V power supply, and then measuring the current on the negative pole of the 5V power supply. According to Ohm's law, the resistance of the keyboard in a 5V voltage environment can be calculated, so:

[0043]

[0044] In the formula, R 实际 It represents the actual resistance between the two combined PIN pins on the keyboard, U represents the power supply voltage between the two PIN pins, I represents the current at the negative pole of the power supply measured by the current probe, and R0 represents the sum of the switch resistance and the line resistance.

[0045] Example 3

[0046] When judging whether the measured current value is too small, if the measured current value is too small, the current limiter is reduced. It is necessary to determine whether the measured current value is too small based on the absolute value of the difference between the pulse current started by the keyboard and the short-circuit current, the current change when the keyboard circuit is heated by 0.3℃, and the absolute value of the difference between the continuous current and the rated current. There are:

[0047]

[0048] In the formula, c represents the proportional coefficient for judging whether the measured current value is too small. When c is less than 68%, it indicates whether the measured current value is too small; a represents the absolute value of the difference between the pulse current and the short-circuit current when the keyboard is started; m represents the current change when the keyboard circuit is heated by 0.3℃; i represents the absolute value of the difference between the continuous current and the rated current. By measuring the absolute value of the difference between the pulse current and the short-circuit current when the keyboard is started, the current change when the keyboard circuit is heated by 0.3℃, and the absolute value of the difference between the continuous current and the rated current, it is possible to effectively evaluate whether the current is abnormal in a temperature-increasing environment where the keyboard is used for a long time, and in a water-infiltrated short-circuit environment.

[0049] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A keyboard resistance measurement method with high efficiency, characterized in that: The following steps are involved: S1. Initialize the impedance measurement box; S2, close the impedance detection channel, adjust the current limiter to maximize the amplifier and minimize the impedance measurement box to be in standby mode; S3, when the keyboard measurement function is started, the detection channel between the impedance measurement box and the keyboard is opened; S4, measure whether the current value is too small, if the measured current value is too small, reduce the current limiter; S5, measuring whether the amplification factor of the amplifier is too small, if the amplification factor is too small, increasing the amplification factor, and repeating step S3; S6. When the amplification factor of the amplifier is normal, the impedance value of the keyboard is calculated, and the calculated impedance value is stored and transmitted to the measuring computer.

2. The keyboard resistance measuring method with high efficiency according to claim 1, characterized in that: In the step S3, after the horizontal 50 PIN pins and the vertical 50 PIN pins of the keyboard are connected to the wiring socket of the impedance measurement box through wires, the detection channel between the impedance measurement box and the keyboard is opened.

3. The keyboard resistance measuring method with high efficiency according to claim 1, characterized in that: In step S5, the range of the measured current is changed by switching the gain of the amplifier.

4. The keyboard resistance measuring method with high efficiency according to claim 1, characterized in that: In step S5, whether the amplification factor is too small is determined based on whether the degree of the current exceeds one fifth of the range.

5. The keyboard resistance measuring method with high efficiency according to claim 1, characterized in that: In step S6, the impedance value of the keyboard is calculated by the ARM control circuit.

6. The keyboard resistance measuring method with high efficiency according to claim 1, characterized in that: In step S6, the impedance value of the keyboard is calculated by arbitrarily combining any two of the 50 PIN pins on the keyboard and connecting them to the positive and negative electrodes of a 5V power supply respectively, and then measuring the current on the negative electrode of the 5V power supply.

7. The keyboard resistance measuring method with high efficiency according to claim 6, characterized in that: According to Ohm's law, the resistance of the keyboard under 5V voltage can be calculated, so: In the formula, R 实际 It represents the actual resistance between the two combined PIN pins on the keyboard, U represents the power supply voltage between the two PIN pins, I represents the current at the negative pole of the power supply measured by the current probe, and R0 represents the sum of the switch resistance and the line resistance.

8. The keyboard resistance measuring method with high efficiency according to claim 1, characterized in that: In step S4, when judging whether the measured current value is too small, if the measured current value is too small, the current limiter is reduced. It is necessary to determine whether the measured current value is too small based on the absolute value of the difference between the pulse current started by the keyboard and the short-circuit current, the current change when the keyboard circuit is heated by 0.3°C, and the absolute value of the difference between the continuous current and the rated current. In the formula, c represents the proportional coefficient for judging whether the measured current value is too small. When c is less than 68%, it indicates whether the measured current value is too small; a represents the absolute value of the difference between the pulse current started by the keyboard and the short-circuit current; m represents the current change when the keyboard circuit is heated by 0.3°C; i represents the absolute value of the difference between the continuous current and the rated current.

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