CN110596575A - A system and method for detecting characteristics of a triode amplifier circuit - Google Patents

Abstract

The invention relates to the technical field of circuit characteristic detection, in particular to a triode amplifying circuit characteristic detection system which comprises a controller, a signal generating unit, a tested amplifying circuit interface unit and a data acquisition unit, wherein the controller, the signal generating unit, the tested amplifying circuit interface unit and the data acquisition unit are sequentially connected in series to form a loop; the signal generating unit is controlled by the controller and sends a corresponding signal to the interface unit of the tested amplifying circuit; the interface unit of the tested triode amplifying circuit is used for being connected with the tested triode amplifying circuit and comprises an input interface and an output interface which are respectively connected with two ends of the tested triode amplifying circuit; the data acquisition unit is used for acquiring characteristic data of the triode amplifying circuit to be detected and transmitting the characteristic data to the controller for centralized processing. In addition, the related detection method is also provided, and multiple data detections are carried out on the triode amplifying circuit by changing parameters, so that the frequency amplitude characteristic of the triode amplifying circuit is obtained, and a frequency amplitude characteristic curve is displayed.

Description

A system and method for detecting characteristics of a triode amplifier circuit

technical field

The invention relates to the technical field of circuit characteristic detection, and more specifically, to a system and method for detecting the characteristics of a triode amplifier circuit.

Background technique

The triode amplifier circuit can convert small signals into large signal output without distortion when the triode is not saturated, and is widely used in signal processing circuits. Therefore, obtaining the working characteristics of the triode amplifier circuit and detecting the working state of the triode circuit is of great significance to the signal processing circuit. The invention is committed to providing a new triode amplifier circuit characteristic detection system and detection method.

Contents of the invention

In order to overcome the above-mentioned defects in the prior art, the present invention provides a triode amplifier circuit characteristic detection system and method, which is convenient for obtaining the working characteristics of the triode amplifier circuit, detecting the working state of the triode circuit, and visually displaying related characteristic curves.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

A triode amplifying circuit characteristic detection system, comprising a controller, a signal generating unit, an interface unit of the amplified circuit under test and a data acquisition unit sequentially connected in series to form a loop, the controller is used for issuing instructions, starting the signal generating unit, and analyzing the detected data Perform centralized processing; the signal generation unit is controlled by the controller, and sends a corresponding signal to the interface unit of the amplified circuit under test; the interface unit of the amplified circuit under test is used to connect to the amplified circuit of the triode under test, Measure the input interface and output interface at both ends of the triode amplifier circuit;

The data acquisition unit is used to collect the characteristic data of the triode amplifier circuit under test, and transmit it to the controller for centralized processing; the data acquisition unit includes an input side acquisition unit, an output side acquisition unit and an analog-to-digital converter, an input side acquisition unit, an output The side acquisition unit is respectively connected to the input interface and the output interface, both of which are connected in parallel, and are jointly connected to an analog-to-digital converter, and the analog-to-digital converter is bidirectionally connected to the controller.

Further, the signal generating unit includes a signal generator for generating a signal, an automatic gain amplifier for stably outputting the signal, and a follower amplifier for enhancing the signal, which are connected in sequence.

Further, the input-side acquisition unit includes a current sampling resistor, an instrument amplifier, and an input-side effective value detection module connected in sequence, the current sampling resistor is connected to the input interface, and the input-side effective value detection module is connected to the analog-to-digital converter.

Further, the output-side acquisition unit includes a switching module and an output-side effective value detection module connected in sequence, the switching module is connected to the output interface, and the output-side effective value detection module is connected to the analog-to-digital converter; the switching module is connected to the output side A first branch and a second branch connected in parallel are arranged between the effective value detection modules, and the first branch is provided with a load resistor.

Further, the switching module is a relay, which is used for switching between the first branch and the second branch. Generally, the switch module also includes an optocoupler.

Further, the effective value detection module at the input side and the effective value detection module at the output side are all effective value detection circuits.

Further, the controller is connected with a key input unit for command and parameter input. The key input unit is a waterproof key, which is connected with the controller to set the frequency, amplitude and waveform input of the signal generating unit, as well as test mode selection and start-stop input.

Further, the controller is also connected with a liquid crystal display unit for displaying output results. The liquid crystal display unit is an OLED liquid crystal display.

The present invention also provides a method for detecting the characteristics of a triode amplifier circuit, based on the above-mentioned system for detecting the characteristics of a transistor amplifier circuit, including but not limited to the following steps:

S1 connects both ends of the triode amplifier circuit under test to the input interface and output interface respectively;

S2 uses the key input unit to input relevant frequency, amplitude, waveform data and start commands to the controller;

The S3 controller issues instructions to start the signal generating unit, and instructs the signal generating unit to generate corresponding frequency, amplitude, and waveform;

The S4 signal generator sends out the waveform signal, and the automatic gain amplifier outputs the waveform signal with a fixed amplitude and stability, and follows the amplifier to strengthen the driving ability of the waveform signal, generates an AC voltage source Us to the input interface, and then connects the triode amplifier circuit under test;

In the acquisition unit on the input side of S5, the voltage signal Ursi of the current sampling resistor Rsi is amplified by the instrument amplifier, and the relevant data is transmitted to the effective value detection module on the input side, and the controller obtains the data in the effective value detection module on the input side through an analog-to-digital converter , the input resistance Ri, input voltage Ui and input current Ii of the triode amplifier circuit under test are calculated by the following formula,

Ii=Ursi/Rsi,

Ui=Us-Ursi,

Ri = Ui/Ii;

In the acquisition unit on the output side of S6, the switch module is switched to the first branch, and the relevant data is transmitted to the effective value detection module on the input side, and the controller obtains the data load resistance R _L , Load resistance voltage U _L ; the switching module switches to the second branch, the controller obtains the output voltage U _O of the triode amplifier circuit through the analog-to-digital converter, and divides by the following formula to calculate the output resistance R _O of the triode amplifier circuit under test,

I _c ×R _O =U _O ,

I _c ×(R _O //R _L )=U _L ;

The S7 controller outputs the frequency f, the input resistance Ri of the triode amplifier circuit, the output resistance R _O of the triode amplifier circuit and the amplification gain Au of the triode amplifier circuit to the liquid crystal display unit for display, where the calculation formula of Au is A _U = U _O / U _i ;

S8 changes the input data so that the controller changes the frequency f of the signal generating unit in steps of 1kHz, repeats S3-S7 to obtain the amplification gain Au of the triode amplifier circuit corresponding to the frequency f, and takes the maximum amplitude of 0.707 as the threshold value to obtain the measured triode Amplify the frequency-amplitude characteristic of the circuit, and output and display the frequency-amplitude characteristic curve on the liquid crystal display unit.

Compared with the prior art, the beneficial effect of the present invention is: the present invention specifically includes components such as a controller, a signal generating unit, an input side acquisition unit, an output side acquisition unit, etc., by changing parameters, the triode amplifier circuit performs multiple data Detection, so as to obtain the frequency-amplitude characteristic of the triode amplifier circuit, and display the frequency-amplitude characteristic curve.

Description of drawings

Fig. 1 is the overall connection diagram 1 of the present invention.

Fig. 2 is the overall connection diagram 2 of the present invention.

Among them, 1 controller, 2 signal generating unit, 3 tested amplifier circuit interface unit, 4 data acquisition unit, 5 key input unit, 6 liquid crystal display unit, 7 tested triode amplifier circuit, 21 signal generator, 22 automatic gain amplifier , 23 follower amplifier, 31 input interface, 32 output interface, 41 analog-to-digital converter, 42 current sampling resistor, 43 instrumentation amplifier, 44 input side effective value detection module, 45 switching module, 46 output side effective value detection module, 47 load resistance.

Detailed ways

The accompanying drawings are for illustrative purposes only, and should not be construed as limitations on this patent; in order to better illustrate this embodiment, certain components in the accompanying drawings will be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art It is understandable that some well-known structures and descriptions thereof may be omitted in the drawings. The positional relationship described in the drawings is for illustrative purposes only, and should not be construed as a limitation on this patent.

Example

As shown in Figure 1-2, this embodiment provides a triode amplifying circuit characteristic detection system, including a controller 1, a signal generating unit 2, an interface unit 3 of the amplifying circuit under test and a data acquisition unit 4 sequentially connected in series to form a loop.

Among them, the controller 1 is a triode amplifier circuit characteristic detection controller, which is used for issuing instructions, starting the signal generating unit 2, and performing centralized processing on the detection data. And controller 1 is connected with key input unit 5 and liquid crystal display unit 6 separately, and key input unit 5 waterproof keys, is connected with controller 1, carries out the input setting of frequency, amplitude, wave form of signal generation unit 2, and test pattern The input of selection and start-stop; the liquid crystal display unit 6 is an OLED liquid crystal display, which is used to display the output detection result.

In addition, the signal generating unit 2 is controlled by the controller 1 and sends corresponding signals to the interface unit 3 of the amplified circuit under test. The signal generating unit 2 includes a signal generator 21 for generating a signal, an automatic gain amplifier 22 for stabilizing the output of the signal, and a follower amplifier 23 for enhancing the signal, which are connected in sequence. Specifically, the signal generator 21 includes an AD9851 function signal generation chip, a second-order passive low-pass RC filter circuit, and the automatic gain amplifier 22 includes a linear variable gain amplifier chip VCA821, a current feedback amplifier chip ad811, and a voltage feedback amplifier chip opa820 , the follower amplifier 23 includes a voltage feedback amplifier chip AD848.

Further, the tested amplifying circuit interface unit 3 is used to connect to the tested triode amplifying circuit 7 , and includes an input interface 31 and an output interface 32 respectively connected to two ends of the tested triode amplifying circuit 7 .

Furthermore, the data collection unit 4 is used to collect characteristic data of the triode amplifier circuit 7 under test, and transmit them to the controller 1 for centralized processing. In this embodiment, the data acquisition unit 4 includes an input-side acquisition unit, an output-side acquisition unit, and an analog-to-digital converter 41. The input-side acquisition unit and the output-side acquisition unit are connected to the input interface 31 and the output interface 32 respectively, and the two are connected to each other. Parallel connection, and common access to the analog-to-digital converter 41, the analog-to-digital converter 41 and the controller 1 bidirectional signal connection, specifically, the analog-to-digital converter 41 includes a 24-bit digital-to-analog conversion chip ADS1256, a 2.5V reference voltage source chip ref192.

Wherein, the input side acquisition unit includes a current sampling resistor 42 (Rsi), an instrument amplifier 43 and an input side effective value detection module 44 connected in sequence, the current sampling resistor 42 is connected to the input interface 31, and the input side effective value detection module 44 is connected to the mold digital converter 41. Wherein, the instrument amplifier 43 includes an AD623 instrument amplifier chip.

In addition, the output-side acquisition unit includes a switching module 45 and an output-side effective value detection module 46 connected in sequence, the switching module 45 is connected to the output interface 32, the output-side effective value detection module 46 is connected to the analog-to-digital converter 41, further, the switching A first branch and a second branch connected in parallel between the module 45 and the effective value detection module 46 on the output side are respectively marked as N1 and N2 . The first branch N1 is provided with a load resistor 47 . Specifically, the switching module 45 includes an Omron miniature relay G6S-2 and a pc817 optocoupler, which are mainly used for switching between the first branch and the second branch.

Specifically, the input-side RMS detection module 44 and the output-side RMS detection module 46 are RMS detection circuits, including a true RMS conversion chip AD637 and a precision low-noise amplifier chip AD8655.

This embodiment also provides a method for detecting the characteristics of a triode amplifier circuit, based on the above-mentioned system for detecting the characteristics of a transistor amplifier circuit, including but not limited to the following steps:

S1 connects the two ends of the triode amplifier circuit 7 under test to the input interface 31 and the output interface 32 respectively;

S2 uses the key input unit 5 to input relevant frequency, amplitude, waveform data and start commands to the controller 1;

S3 controller 1 issues an instruction, starts the signal generating unit 2, and instructs the signal generating unit 2 to generate corresponding frequency, amplitude, and waveform;

S4 The signal generator 21 sends out the waveform signal, and the automatic gain amplifier 22 outputs the waveform signal with a fixed amplitude and stable value, and follows the amplifier 23 to strengthen the drive capability of the waveform signal, generates an AC voltage source Us to the input interface 31, and then connects the tested triode amplifier circuit 7 ;

In the S5 input side acquisition unit, the voltage signal Ursi of the current sampling resistor 42 (Rsi) is amplified by the instrument amplifier 43, and the relevant data is sent to the input side effective value detection module 44, and the controller 1 obtains the input side through the analog-to-digital converter 41. The data in the effective value detection module 44 is calculated by the following formula to obtain the input resistance Ri, the input voltage Ui and the input current Ii of the triode amplifier circuit 7 under test,

Ii=Ursi/Rsi,

Ui=Us-Ursi,

Ri = Ui/Ii;

S6 In the output side acquisition unit, the switching module 45 is switched to the first branch, and the relevant data is transmitted to the input side effective value detection module 44, and the controller 1 obtains the data in the output side effective value detection module 46 through the analog-to-digital converter 41 Load resistance 47R _L , load resistance 47 voltage U _L ; the switch module 45 switches to the second branch, the controller 1 obtains the output voltage U _O of the triode amplifying circuit through the analog-to-digital converter 41, and divides by the following formula to calculate the measured triode The output resistance R _O of the amplifying circuit 7,

I _c ×R _O =U _O ,

I _c ×(R _O //R _L )=U _L ;

S7 controller 1 outputs the frequency f, the input resistance Ri of the triode amplifier circuit, the output resistance R _O of the triode amplifier circuit and the amplification gain Au of the triode amplifier circuit to the liquid crystal display unit 6 for display, wherein the calculation formula of Au is A _U = U _O / U _i ;

S8 changes the input data, so that the controller 1 changes the frequency f of the signal generating unit 2 in steps of 1 kHz, repeats S3-S7, and obtains the amplification gain Au of the triode amplifier circuit corresponding to the frequency f, and takes the maximum amplitude of 0.707 as the threshold value to obtain the amplified Measure the frequency-amplitude characteristic of the triode amplifying circuit 7, and output and display the frequency-amplitude characteristic curve on the liquid crystal display unit 6.

Apparently, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, rather than limiting the implementation of the present invention. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. All modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the claims of the present invention.

Claims (9)

1. A triode amplifying circuit characteristic detection system is characterized in that: comprise the controller (1), signal generation unit (2), measured amplifying circuit interface unit (3) and data acquisition unit (4) that form loop successively in series , The controller (1) is used for issuing instructions, starting the signal generating unit (2), and performing centralized processing on the detection data; The signal generating unit (2) is controlled by the controller (1), and sends a corresponding signal to the interface unit (3) of the amplified circuit under test; The tested amplifying circuit interface unit (3) is used to access the tested triode amplifying circuit (7), including an input interface (31) and an output interface (32) respectively connected to both ends of the tested triode amplifying circuit (7). ; The data acquisition unit (4) is used to collect the characteristic data of the triode amplifier circuit (7) under test, and transmits to the controller (1) for centralized processing; the data acquisition unit (4) includes an input side acquisition unit and an output side acquisition unit and the analog-to-digital converter (41), the input-side acquisition unit and the output-side acquisition unit are connected to the input interface (31) and the output interface (32) respectively, the two are connected in parallel with each other, and are connected to the analog-to-digital converter (41 ), the analog-to-digital converter (41) is connected with the controller (1) bidirectional signal. 2. A kind of triode amplifying circuit characteristic detection system according to claim 1, is characterized in that: described signal generation unit (2) comprises the signal generator (21) that is used to generate signal that is connected in sequence, is used to make signal An automatic gain amplifier (22) for stable output and a follower amplifier (23) for boosting the signal. 3. a kind of triode amplifying circuit characteristic detection system according to claim 2, is characterized in that: described input side acquisition unit comprises the current sampling resistance (42), instrument amplifier (43) and input side RMS detection that are connected successively The module (44), the current sampling resistor (42) is connected to the input interface (31), and the effective value detection module (44) at the input side is connected to the analog-to-digital converter (41). 4. a kind of triode amplifying circuit characteristic detection system according to claim 3, is characterized in that: described output side acquisition unit comprises the switch module (45) that connects successively and output side RMS detection module (46), switch module (45) is connected to the output interface (32), and the output side effective value detection module (46) is connected to the analog-to-digital converter (41); There are a first branch and a second branch connected in parallel, and the first branch is provided with a load resistor (47). 5. A triode amplifier circuit characteristic detection system according to claim 4, characterized in that: the switching module (45) is a relay, which is used to switch between the first branch and the second branch. 6. A triode amplifier circuit characteristic detection system according to claim 5, characterized in that: the input-side effective value detection module (44) and the output-side effective value detection module (46) are both effective value detection circuits. 7. A triode amplifier circuit characteristic detection system according to claim 6, characterized in that: said controller (1) is connected with a key input unit (5) for command and parameter input. 8. A triode amplifier circuit characteristic detection system according to claim 7, characterized in that: said controller (1) is also connected with a liquid crystal display unit (6) for displaying output results. 9. A method for detecting the characteristics of a triode amplifier circuit, based on the system for detecting the characteristics of a triode amplifier circuit according to claim 8, characterized in that it includes but is not limited to the following steps: S1 connects the two ends of the triode amplifier circuit (7) under test to the input interface (31) and the output interface (32); S2 uses the key input unit (5) to input relevant frequency, amplitude, waveform data and start commands to the controller (1); The S3 controller (1) issues instructions to start the signal generating unit (2), and instructs the signal generating unit (2) to generate corresponding frequency, amplitude, and waveform; The S4 signal generator (21) sends out the waveform signal, the automatic gain amplifier (22) outputs the waveform signal with a fixed amplitude and stability, and the follower amplifier (23) strengthens the drive capability of the waveform signal to generate an AC voltage source Us to the input interface (31), And then connect the tested triode amplifying circuit (7); In the acquisition unit on the input side of S5, the voltage signal Ursi of the current sampling resistor (42) Rsi is amplified by the instrument amplifier (43), and the relevant data is transmitted to the effective value detection module (44) on the input side, and the controller (1) passes the modulus The converter (41) obtains the data in the effective value detection module (44) at the input side, and calculates the input resistance Ri, the input voltage Ui and the input current Ii of the triode amplifier circuit (7) under test through the following formula, Ii=Ursi/Rsi, Ui=Us-Ursi, Ri = Ui/Ii; In the S6 output side acquisition unit, the switching module (45) is switched to the first branch, and the relevant data is sent to the input side effective value detection module (44), and the controller (1) obtains the output side through the analog-to-digital converter (41). The data load resistance (47) R _L in the effective value detection module (46), the load resistance (47) voltage U _L ; the switching module (45) switches to the second branch, and the controller (1) passes the analog-to-digital converter ( 41) Obtain the output voltage U _O of the triode amplifying circuit, divide by the following formula, and calculate the output resistance R _O of the triode amplifying circuit (7) under test, I _c ×R _O =U _O , I _c ×(R _O //R _L )=U _L ; The S7 controller (1) outputs frequency f, the input resistance Ri of the triode amplifying circuit, the output resistance R _O of the triode amplifying circuit and the amplification gain Au of the triode amplifying circuit to the liquid crystal display unit (6) for display, wherein the calculation formula of Au is: A _U =U _O /U _i ; S8 changes the input data, so that the controller (1) changes the frequency f of the signal generating unit (2) in steps of 1kHz, repeats S3-S7, and obtains the amplification gain Au of the triode amplifier circuit corresponding to the frequency f, with a maximum amplitude of 0.707 The threshold value is used to obtain the frequency-amplitude characteristic of the triode amplifier circuit (7) under test, and output and display the frequency-amplitude characteristic curve on the liquid crystal display unit (6).