CN107066000B - A kind of logging instrument amplifier power supply self-adapting regulation method - Google Patents

Abstract

The invention discloses a kind of logging instrument amplifier power supply self-adapting regulation methods, by detecting transmitting signal amplitude size in real time, signal amplitude RMS-DC converter will be emitted into a DC voltage, it is sampled again by one 8 parallel port ADC sampling modules, parallel port output is realized after analog-to-digital conversion, the analog quantity for emitting signal amplitude size is converted into 8 binary digital quantities, is reacted on the output voltage values of Switching Power Supply.It is matched by rational circuit parameter, reject the nonlinearity erron of Switching Power Supply and power amplifier output, so that the variation of transmitting signal and the input voltage of power amplifier, that is the output voltage linear proportional relationship of Switching Power Supply, power amplifier is always worked in close to output state at full capacity, reduce power supply thermal losses, improve power amplification efficiency, also reduce system power dissipation.Meanwhile the present invention for power amplifier selection by Switching Power Supply can be powered or powered by overall system power automatically according to the size of transmitting signal.

Description

A Self-Adaptive Adjustment Method for Power Amplifier of Well Logging Tool

technical field

The invention belongs to the technical field of power amplifier energy saving and consumption reduction, and in particular relates to the design of a self-adaptive adjustment method for power amplifier power supply of a well logging instrument.

Background technique

At present, the power amplifier types of logging tools usually include Class A, Class B, Class AB, Class D, etc. Different types of power amplifiers have different advantages and disadvantages, and various power amplifiers have different related applications. Among them, class A power amplifier has the lowest efficiency, but has good linearity and simple design; class B power amplifier has higher efficiency than class A, but has more serious crossover distortion and poor linearity; class AB is between the two, and its efficiency is in the middle. The linearity is better than Class B; Class D power amplifier has the highest efficiency and good linearity, but due to device limitations (switching speed, leakage current, non-zero on-resistance, etc.) and design imperfections, the highest efficiency does not exceed 85%, and can only be applied to the amplification of low-frequency signals, so when the frequency of the transmitted signal is high, the class D power amplifier is not suitable.

The power amplifiers of traditional logging tools are basically powered by a constant voltage source. When the power output of the power amplifier reaches full load, that is, when the transmission current is the largest and the output signal is not distorted, the efficiency of the power amplifier is the highest. However, once the transmission amplitude is reduced, the output power will fall back. Backing off will lead to a decrease in the efficiency of the power amplifier, resulting in unnecessary power loss. As shown in Figure 1, when the transmission signal is S1, the power amplifier power supply is VS1, and the power amplifier output is at full load (because there is a certain tube voltage drop and start-up voltage in the power amplifier tube, the power amplifier power supply is one Vdrop larger than the output amplitude of the power amplifier), and the efficiency reaches The highest, the power loss is very small; when the transmission signal is reduced to S2, if the power amplifier power supply remains unchanged at VS1, then a considerable part of the power consumption of the system will be consumed in the form of heat loss of the power supply, so the efficiency of the power amplifier drops sharply. When the power amplifier power supply When converted to VS2, the output of the power amplifier is fully loaded, and the efficiency reaches the highest. Since logging instruments generally work in harsh high-temperature environments, after the electrical energy is converted into heat, the temperature will rise accordingly, which is extremely detrimental to the stability of the power amplifier circuit and the system itself.

Contents of the invention

The purpose of the present invention is to propose a self-adaptive adjustment method for the power amplifier of the well logging instrument in view of the shortcomings of the power amplifier of the traditional well logging instrument in the background technology, so that the power amplifier output of the well logging instrument is maintained at close to full load during the operation and debugging process output state to improve system efficiency and reduce power loss.

The technical solution of the present invention is: a method for self-adaptive adjustment of power amplifier power supply of logging instrument, comprising the following steps:

S1. Detect the effective value of the amplitude of the signal transmitted by the logging tool, and convert the transmitted signal from the effective value signal of the amplitude into a DC voltage signal;

S2. Perform analog-to-digital conversion on the filtered and rectified DC voltage signal, convert the DC voltage signal into an 8-bit binary digital signal H1, and output it to 8 parallel IO ports;

S3. Perform a NAND operation on the highest two bits of the digital signal H1, if the operation result is low level, enter step S4, otherwise enter step S5;

S4. Control the second MOS tube combination switch to be turned on, the first MOS tube combination switch to be turned off, the main power supply provides power input for the power amplifier, and the adjustment is completed;

S5. Control the first MOS tube combination switch to be turned on, the second MOS tube combination switch to be turned off, and the switching power supply provides power input for the power amplifier;

S6. Control the analog switch resistor network according to the digital signal H1, adjust the output voltage of the switch power supply, and the adjustment is completed.

The beneficial effects of the present invention are: the present invention adopts the form of self-adaptive adjustment of the power supply, automatically adjusts the input power of the power amplifier in real time according to the size of the signal transmitted by the logging instrument, ensures that the output of the power amplifier is in a state close to full load, reduces power consumption, reduces The power consumption of the system is reduced, and the efficiency of the power amplifier is improved. At the same time, the present invention does not need the main controller MCU and program software, and is fully automatically adjusted by the circuit itself, and has certain real-time performance. Through reasonable parameter matching and calculation, the non-linear error of the switching power supply and the power amplifier is eliminated, and finally the size of the transmitted signal is matched with the input voltage of the power amplifier, that is, the output voltage of the switching power supply.

Further, the analog switch resistor network in step S5 includes an analog switch and 8 resistors in series, the analog switch includes 8 channel switches, each channel switch is connected in parallel to a resistor, and is connected in series with other 7 resistors at the same time; The channel switch is turned on at low level and turned off at high level; the resistance is in a binary progressive relationship, that is, the resistance of the latter stage is twice the size of the resistance of the previous stage; the analog switch and 8 resistors together form an adjustable resistance Internet Rs.

The beneficial effect of the above further scheme is: the 8 parallel IO ports of the 8-bit parallel port ADC sampling module control the size of the resistance network Rs, the resistance network output resistance range is 0-255K, and the 8-bit binary digital signal H1 can be expressed as a resistance Network Rs, their values are equal, that is, H1=Rs, which is proportional to the effective value of the transmitted signal amplitude, so that the transmitted signal amplitude can be completely corresponding to the output adjustment control word of the switching power supply.

Further, the analog switch resistor network in step S5 also includes a resistor R1 connected in series with the resistor network Rs, and the resistor network Rs and the resistor R1 together form the feedback resistor Rhs output by the switching power supply, which is used to adjust the switching power supply together with the voltage dividing resistor Rls The output voltage.

The beneficial effect of the above further scheme is: the function of the resistor R1 is to eliminate the nonlinear error, because the output of the switching power supply and the output of the power amplifier have certain nonlinear factors with the amplitude of the transmitted signal, and through reasonable parameter matching, it can be made Non-linear factors are eliminated.

Further, the relationship between the output voltage Vout of the switching power supply and the digital signal H1 in step S5 is:

H1×K1+Vdrop=Vout (3)

In the formula, K1 represents the linear coefficient, and Vdrop represents the voltage drop between the output voltage Vout of the switching power supply and the amplitude Vpp of the transmitted signal.

The beneficial effect of the above-mentioned further scheme is: since Vdrop is a fixed value, K1 can be deduced and offset by the formula, and does not participate in the calculation, and the size of the digital signal H1 is in an absolute proportional linear relationship with the effective value Vpp of the transmitted signal amplitude, and finally the output of the switching power supply The size of the voltage is determined by the effective value Vpp of the transmitted signal amplitude, which is convenient for adjustment.

Description of drawings

Figure 1 is a schematic diagram of the power consumption of traditional logging tools with different transmission signal output amplitudes and power amplifier input power sources.

Fig. 2 is a structural block diagram of a self-adaptive adjustment device for a power amplifier of a logging tool provided by Embodiment 1 of the present invention.

FIG. 3 is a schematic block diagram of effective value detection and analog-to-digital conversion provided by Embodiment 1 of the present invention.

FIG. 4 is a circuit diagram of an analog switch resistor network provided by Embodiment 1 of the present invention.

FIG. 5 is a circuit diagram of a combined MOS transistor switch for controlling power supply input switching provided by Embodiment 1 of the present invention.

Fig. 6 is a flow chart of a method for self-adaptive adjustment of power amplifier power supply of a logging tool provided by Embodiment 2 of the present invention.

FIG. 7 is a structural diagram of a switching power supply circuit provided by Embodiment 2 of the present invention.

FIG. 8 is a graph showing the relationship between the output voltage of the switching power supply and the 8-bit binary digital quantity H1 provided by Embodiment 2 of the present invention.

FIG. 9 is a graph showing the comparison of power consumption between the self-adaptive power amplifier power adjustment method and the constant power supply method provided by Embodiment 2 of the present invention.

Explanation of reference numerals: 1-total power supply, 2-first MOS tube combination switch, 3-second MOS tube combination switch, 4-RMS amplitude detector, 5-low-pass filter, 6-8-bit parallel port ADC sampling module , 7-NAND operation module, 8-analog switch resistor network 9-switching power supply, 10-power amplifier.

Detailed ways

Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be understood that the implementations shown and described in the drawings are only exemplary, intended to explain the principle and spirit of the present invention, rather than limit the scope of the present invention.

In order to make the technical solution of the present invention more clear and complete, before introducing the self-adaptive adjustment method of the power amplifier power supply of the logging instrument provided by the present invention, firstly, a pair of embodiments of the self-adaptive adjustment method of the power amplifier power supply of the well logging instrument will be introduced in detail. :

Embodiment one:

The embodiment of the present invention provides a self-adaptive adjustment device for the power amplifier power supply of the logging instrument, as shown in Figure 2, comprising:

General power supply 1, used to provide power input for the entire adjustment device.

The first MOS transistor combination switch 2 controls whether the main power supply 1 provides power input for the switching power supply 9 by turning on/off.

The second MOS tube combination switch 3 controls whether the main power supply 1 directly provides power input for the power amplifier 10 of the logging tool by turning on/off.

The RMS amplitude detector 4 is used to detect the effective value of the amplitude of the signal transmitted by the logging tool, and convert the transmitted signal from the effective value signal of the amplitude into a DC voltage signal.

The low-pass filter 5 is used for filtering and rectifying the DC voltage signal.

The 8-bit parallel port ADC sampling module 6 is used for performing analog-to-digital conversion on the DC voltage signal, converting the DC voltage signal into an 8-bit binary digital signal H1, and outputting it to 8 parallel IO ports.

The NAND operation module 7 is used to perform a NAND operation on the highest two bits of the digital signal H1, and control the on/off of the first MOS transistor combination switch 2 and the second MOS transistor combination switch 3 according to the operation result.

The analog switch resistor network 8 is used to adjust the output voltage of the switch power supply 9 according to the magnitude of the digital signal H1.

The switching power supply 9 is used to provide adaptive power input for the power amplifier 10 of the logging tool under the control of the analog switching resistor network 8 .

The input end of the RMS amplitude detector 4 is connected to the transmission signal of the logging tool, the RMS amplitude detector 4, the low-pass filter 5, the 8-bit parallel port ADC sampling module 6, the analog switch resistance network 8, the switching power supply 9 and the logging tool The power amplifiers 10 are connected in sequence. The input terminals of the AND-N operation module 7 are connected to the 8 parallel IO ports of the 8-bit parallel port ADC sampling module 6, and the output terminals are respectively connected to the input terminals of the first MOS tube combination switch 2 and the input terminals of the second MOS tube combination switch 3 The total power supply 1 is connected to the switching power supply 9 through the first MOS tube combination switch 2, and is connected to the power amplifier 10 of the logging tool through the second MOS tube combination switch 3.

In the embodiment of the present invention, the power amplifier 10 of the logging tool is a single power amplifier. If it is a positive and negative power amplifier, it is necessary to add a switching power supply as a negative power supply, and the design is consistent in other respects.

As shown in Figure 3, the transmission signal is output to the RMS amplitude detector 4 after filtering and conditioning, and the effective value of the waveform is converted into a DC voltage output. The value is converted into a digital signal H1 and output to 8 parallel IO ports. The ADC sampling rate is provided by an external sampling clock CLK, which is 20-100Msps in the embodiment of the present invention. The reference reference voltage VREF is obtained by outputting a special voltage reference source through resistance division. The specific value of VREF needs to be determined after parameter matching and debugging. The 8 parallel IO ports control the size of the analog switch resistor network 8.

As shown in Figure 4, the analog switch resistor network 8 includes an analog switch and 8 series resistors (R2-R9), the analog switch includes 8 channel switches (CH1-CH8), and each channel switch is connected in parallel with a resistor ( For example, CH1 is connected in parallel with R2), and connected in series with the other 7 resistors. Each channel switch is turned on at low level and turned off at high level. The size of the resistance is in a binary progressive relationship, that is, the resistance of the latter stage is twice the size of the resistance of the previous stage; the analog switch and 8 resistors together form an adjustable resistance network Rs. The output resistance range of the resistor network is 0-255K, and the 8-bit binary digital quantity H1 can also be expressed as a resistor network Rs, and their values are equal, that is, H1=Rs, which is proportional to the effective value of the transmitted signal amplitude.

The analog switch resistor network 8 should also include a resistor R1 connected in series with the resistor network Rs. The resistor network Rs and the resistor R1 together constitute the feedback resistor Rhs output by the switch power supply 9 for adjusting the output voltage Vout of the switch power supply. The function of R1 is to eliminate the nonlinear error, because the output of the switching power supply 9 and the output of the power amplifier 10 have certain nonlinear factors with the transmitted signal amplitude, and the nonlinear factors can be eliminated through reasonable parameter matching.

As shown in Figure 5, since there is a voltage drop of about 0.6V between the input and output of the switching power supply 9, and the switching power supply 9 also has the problem of conversion efficiency, when the input power of the power amplifier is greater than about 31.4V, if the switching power supply conversion is also enabled It seems inappropriate, so the power amplifier power supply can directly adopt the total power supply 1 input, and the switching power supply 9 is turned off. The first MOS tube combination switch 2 and the second MOS tube combination switch 3 jointly control whether the input power of the power amplifier is provided by the switching power supply 9 or the main power supply 1 .

The highest two digits (D6, D7) of the binary digital quantity H1 control the on/off of the first MOS tube combination switch 2 and the second MOS tube combination switch 3 after the non-operation operation, then the 8-bit binary digital signal H1 is 192 (converted into binary and can be expressed as 1100 0000), as the control word for switching the input power of the power amplifier, the threshold voltage for switching the input power of the power amplifier at this moment can be set to 31V. When the highest two bits (D6, D7) of the digital signal H1 are at high level at the same time, that is, the digital signal H1≥192, and the input power supply voltage required by the power amplifier is ≥31V, the output result of D6, D7 and non-calculation is low level, At this time, the second MOS tube combination switch 3 is turned on, and the first MOS tube combination switch 2 is turned off, and the power supply 1 provides power input for the power amplifier 10; otherwise, the first MOS tube combination switch 2 is turned on, and the second MOS tube combination switch 3 is turned off, and the switching power supply 9 provides power input for the power amplifier 10. The combined switches of the two MOS transistors will not be turned on at the same time at any time, which effectively avoids the possible risk of the switches being turned on at the same time.

Similarly, the power input switching control word can also be set to 128, that is, 1000 0000, then only the highest bit D7 is used to control the combined switch of two MOS tubes. But because of the reduction of the number of digits, the precision of the dynamic adjustment output of the switching power supply 9 is reduced, and the scale level is reduced to 128. Therefore, the embodiment of the present invention adopts the output control after the NAND operation of the upper two digits, which improves the output accuracy of the power supply and does not Increased hardware difficulty.

Similarly, the threshold voltage of switching power amplifier input power can also be set to other voltage values less than 32V, and the specific size can be freely set according to system needs.

Embodiment two:

The embodiment of the present invention provides a method for self-adaptive adjustment of the power amplifier power supply of the logging instrument, as shown in FIG. 6 , comprising the following steps:

S1. Detect the effective value of the amplitude of the signal transmitted by the logging tool, and convert the transmitted signal from the effective value signal of the amplitude into a DC voltage signal.

S2. Perform analog-to-digital conversion on the filtered and rectified DC voltage signal, convert the DC voltage signal into an 8-bit binary digital signal H1, and output it to 8 parallel IO ports.

S3. Perform a NAND operation on the highest two bits of the digital signal H1. If the operation result is low level, proceed to step S4, otherwise proceed to step S5.

S4. Control the second MOS tube combination switch to be turned on, and the first MOS tube combination switch to be turned off, the main power supply provides power input for the power amplifier, and the adjustment is completed.

S5. Control the first MOS tube combination switch to be turned on, the second MOS tube combination switch to be turned off, and the switching power supply provides power input for the power amplifier;

S6. Control the analog switch resistor network according to the digital signal H1, adjust the output voltage of the switch power supply, and the adjustment is completed.

Before step S1, the necessary parameter calculation and formula derivation should be carried out (whether the system can operate normally, the parameters of the circuit must first be determined, and the next steps can only be performed after the determination). Circuit parameter matching mainly has 3 parameters that need to be calculated (VREF, R1, Rls), and these 3 parameters are required. First, the size of the voltage drop Vdrop must be determined. In the embodiment of the present invention, Vdrop is 3.2V; secondly, it is necessary to determine the switching power amplifier For the threshold voltage of the input power supply, the value of the binary control word in the embodiment of the present invention is 192 (decimal notation), and the value of the threshold voltage is 31V.

The derivation process of calculation formula in the embodiment of the present invention is as follows:

Let the output voltage of the switching power supply be Vout, as shown in Figure 7, then:

Vout＝(Rhs+Rls)×0.8÷Rls (1)

In the formula, Rhs represents the feedback resistance of the switching power supply output, and Rhs=Rs+R1, and Rls represents the voltage dividing resistor, which is used to adjust the output power of the switching power supply together with Rhs, so:

Vout＝(Rs+R1+Rls)×0.8÷Rls (2)

In the formula, Rs represents the size of the adjustable resistor network, and R1 represents the size of the resistance used to eliminate nonlinear errors. In the embodiment of the present invention, R1=16.5K.

At the same time, the switching power supply output Vout is one Vdrop higher than the transmission signal amplitude Vpp. According to different power amplifier types, Vdrop is generally about 3V. The embodiment of the present invention leaves a little room for choosing 3.2V to facilitate subsequent parameter calculations. . The transmitted signal amplitude Vpp is proportional to the 8-bit binary digital signal H1 output after ADC conversion, then the formula can be expressed as:

H1×K1+Vdrop=Vout (3)

In the formula, K1 represents the linear coefficient, which can be offset in the subsequent formula derivation and does not participate in the calculation.

Simultaneous formula (2) (3) can get:

H1×K1+Vdrop＝(Rs+R1+Rls)×0.8÷Rls (4)

After tidying up we get:

H1×K1＝Rs×0.8÷Rls+{(R1+Rls)×0.8÷Rls-Vdrop} (5)

Since Vdrop=3.2V, H1=Rs, when H1=0, then:

(R1+Rls)×0.8÷Rls-Vdrop＝0 (6)

Therefore:

R1＝(Vdrop-0.8)×Rls÷0.8 (7)

After simplification:

R1＝3×Rls (8)

Similarly, substitute formula (6) into formula (4) to simplify:

H1×K1＝0.8×Rs÷Rls (9)

Simultaneous formula (3) (9) can also be obtained:

0.8×Rs÷Rls+Vdrop＝Vout (10)

According to the relationship between the critical value voltage input by the switching power amplifier and the binary digital quantity H1, it can be obtained by the formula (2):

(R1+192)×0.8÷Rls+0.8＝31 (11)

Similarly, substitute formula (8) into formula (11) to simplify:

Rls=5.525 (12)

In order to consider the convenience of resistance value selection, the final value of Rls is 5.5K, then R1 is 16.5K.

Keep the power amplifier power supply at 31V voltage input, adjust the transmission signal to be in the maximum state without distortion, and the effective value Vpp of the transmission signal amplitude is about 27.8V. At this moment, if the 8-bit binary digital value H1 converted by the ADC is 192, It needs to be realized by adjusting the reference reference voltage VREF of the ADC. When the value of VREF is determined, it can be obtained by dividing the voltage by two resistors from the output of the precision voltage source. Finally, in the automatic conversion process of the circuit, the effective value of the transmitted signal amplitude Vpp corresponds to the 8-bit binary digital quantity H1, and the size of Rs is equal to H1, and the two are absolutely proportional to the effective value of the transmitted signal amplitude Vpp.

As shown in FIG. 8, it is a curve diagram of the corresponding relationship between the switching power supply output Vout and the 8-bit binary digital quantity H1. The resistance network controlled by the 8 parallel IO ports output by the 8-bit parallel port ADC sampling module has 256 scale levels (11111111-00000000). The calculated voltage Vout output by the switching power supply ranges from 3.34V to 40.29V, and the output accuracy or linear coefficient K1 is 0.8/5.5=0.1454545V, and this accuracy fully meets the requirements of the power amplifier power supply of logging tools. Since the total power supply of the logging tool is generally powered by a 32V power supply, the upper limit of the output of the switching power supply should be less than 31.4V. At the same time, the output amplitude of the transmitting signal should not be too small, which will lead to a decrease in the final measurement accuracy. The lower limit of the power supply of the power amplifier should be above 6V, so In the embodiment of the present invention, the effective region of the output voltage Vout of the switching power supply is between 6-31V.

Similarly, when the total power supply of the logging tool is not 32V, but other voltages such as 24V, 36V, and 48V, the patented method is also applicable, and only need to recalculate the circuit parameters according to the derivation formula (11), other steps are not Change.

As shown in Figure 9, it is a power consumption comparison curve between the self-adaptive adjustment method of the power amplifier and the constant power supply mode. It can be seen from the power consumption comparison curve that when the output amplitude of the power amplifier is too small, the self-adaptive power supply of the power amplifier provided by the embodiment of the present invention can be used. The adjustment method can greatly reduce the power consumption of the power amplifier, improve the system efficiency, and reduce the risk of the thermal effect of the system. When the output amplitude of the power amplifier becomes larger and larger, the power consumption curves of the two gradually approach.

Those skilled in the art will appreciate that the embodiments described here are to help readers understand the principles of the present invention, and it should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical revelations disclosed in the present invention without departing from the essence of the present invention, and these modifications and combinations are still within the protection scope of the present invention.

Claims (6)

1. a kind of logging instrument amplifier power supply self-adapting regulation method, which is characterized in that include the following steps：

The amplitude virtual value of S1, detection logging instrument transmitting signal, and will transmitting signal by the effective value signal of amplitude to be converted into DC straight Flow voltage signal；

S2, analog-to-digital conversion is carried out to DC d. c. voltage signals, DC d. c. voltage signals is converted into 8 bit binary number signals H1 is exported to 8 parallel I/O ports；

S3, two progress NAND operations of highest to digital signal H1, enter step S4, otherwise if operation result is low level Enter step S5；

S4, control the second metal-oxide-semiconductor stacked switch conducting, the shutdown of the first metal-oxide-semiconductor stacked switch provide power supply by general supply for power amplifier Input, adjustment terminate；

S5, control the first metal-oxide-semiconductor stacked switch conducting, the shutdown of the second metal-oxide-semiconductor stacked switch provide electricity by Switching Power Supply for power amplifier Source inputs；

S6, analog switch resistor network, the output voltage size of regulating switch power supply, adjustment knot are controlled according to digital signal H1 Beam；

Analog switch resistor network includes an analog switch in the step S6 and the resistance of 8 series connection, the simulation are opened Pass includes 8 channel switch, and each channel switch correspondence is parallel to a resistance, while connect with other 7 resistance；Institute It states analog switch and 8 resistance collectively forms an adjustable resistor network Rs.

2. logging instrument amplifier power supply self-adapting regulation method according to claim 1, which is characterized in that in the step S2 DC d. c. voltage signals are carried out to further include before analog-to-digital conversion, rectification processing is filtered to DC d. c. voltage signals.

3. logging instrument amplifier power supply self-adapting regulation method according to claim 1, which is characterized in that each channel Low level conducting is switched, high level disconnects.

4. logging instrument amplifier power supply self-adapting regulation method according to claim 1, which is characterized in that the resistance sizes In binary system progressive relationship, i.e., rear stage resistance is twice of previous stage resistance sizes.

5. logging instrument amplifier power supply self-adapting regulation method according to claim 1, which is characterized in that in the step S6 Analog switch resistor network further includes the resistance R1 to connect with resistor network Rs, and the resistor network Rs and resistance R1 is collectively formed The feedback resistance Rhs of Switching Power Supply output, for the output voltage of the regulating switch power supply together with divider resistance Rls.

6. logging instrument amplifier power supply self-adapting regulation method according to claim 1, which is characterized in that in the step S6 The output voltage Vout and the relationship of digital signal H1 of Switching Power Supply be：

H1 × K1+Vdrop=Vout (3)

K1 represents linear coefficient in formula, and Vdrop represents switch power source output voltage Vout and emits the pressure between signal amplitude Vpp Drop.