CN103389665A - Detection control device of high-power digital power amplifier - Google Patents

Abstract

The invention discloses a detection and control device for a high-power digital power amplifier. It includes a sampling board and a main control board. Through the Hall current sensor, resistor divider, voltage follower and Hall voltage sensor in the sampling board, the 10KV voltage and 1KA current are converted into 2V voltage signals; through the main control board The ARM9 processor and the peripheral connected voltage detection unit and current detection unit divide the 2V voltage signal, take the effective value and digital/analog conversion, and realize the detection of 10KV voltage and 1KA current; through the peripheral connection of the main control board ARM9 processor The temperature detection unit, LCD display unit, alarm unit and control unit realize temperature detection, LCD display, fault emergency control, gear control and power-on self-test control. The invention has the advantages of detecting and controlling a voltage within 10KV and a current within 1KA of a high-power digital power amplifier, and can be used in a high-power digital audio power amplification system.

Description

Detection and Control Device of High Power Digital Power Amplifier

technical field

The invention belongs to the technical field of electronic circuits, and in particular relates to a detection control circuit, which can be used in a high-power digital audio power amplification system.

Background technique

With the continuous development of science and technology, high-power digital power amplifiers play an important role in the fields of national defense and industry. In order to effectively detect and control the working state of the digital power amplifier, a detection and control device is installed on the digital power amplifier chassis, which can detect the working parameters of the digital power amplifier in real time, control the working state of the digital power amplifier, and detect various faults of the digital power amplifier. Call the police in time.

Currently, there are two ways to detect the most common digital power amplifiers. One is the mutual inductance detection method, and the other is the resistance voltage division detection method. in:

Mutual inductance detection method is generally used for high voltage and high current. The transformer is composed of mutually insulated main winding, auxiliary winding, iron core and frame. When the main winding flows different currents, the auxiliary winding can sense the corresponding If the voltage of the secondary winding is different, the voltage of the main winding can be calculated by measuring the voltage of the secondary winding. However, when the detection voltage is high, it is difficult to insulate the transformer, and the volume, quality and price of the mutual induction circuit are increased due to the insulation. , when the current is large, the magnetic flux density will be saturated, and the dynamic range is small.

The resistance voltage division detection method, after the high voltage is divided, the voltage before the voltage division can be calculated by measuring the voltage of the voltage division resistor, but when the detection voltage is high, the resistance voltage division detection method needs to design an electrical isolation circuit to measure safely .

In 2010, the China Patent Office published the patent "Multifunctional Digital Power Amplifier Detection and Control System" applied by Tianjin Xianwei Railway Electronic Equipment Co., Ltd., the authorized announcement number is CN201497905U, and the Chinese patent number (ZL) is: 200920220841.8. Although the system has the functions of detection, control and display, it can only be applied to low-power digital power amplifiers, and the lower-end 51 single-chip processor is used, and the processing capacity is limited.

To sum up, the current common digital power amplifier detection and control devices are difficult to meet the high-voltage and high-current requirements of high-power digital power amplifiers, and most of them use lower-end processors, which have low data processing, transmission and control capabilities.

Contents of the invention

The present invention aims at the deficiencies of existing digital power amplifier detection and control systems, and provides a detection and control device for high-power digital power amplifiers to improve data processing, transmission and control capabilities and meet the requirements of 10KV alternating voltage and 1KA alternating current. Power digital power amplifier needs high voltage and high current.

To achieve the above object, the present invention includes:

The sampling board is used to isolate the high voltage and large current output by the digital power amplifier system under test, convert it into a small voltage signal, and transmit it to the main control board; the main control board receives the sampling board signal, detects working parameters such as current and voltage, and controls the digital power amplifier The working status of the system;

It is characterized by:

The above sampling board includes a Hall current sensor, a resistor divider, a voltage follower and a Hall voltage sensor; the input end of the Hall current sensor is connected in series with the 1KA high current signal on the load of the system under test, and the output end is connected to the main The control board connection is used to convert the 1KA high current signal into a 2V small voltage signal; the resistor divider is connected in parallel with the 10KV high voltage on the load of the system under test, and the divided signal passes through the voltage follower and is connected to the Hall Voltage sensor, which isolates the 10KV high-voltage signal through the Hall voltage sensor, converts it into a 2V small voltage signal, and outputs it to the main control board;

The above-mentioned main control board is centered on the ARM9 processor, and the periphery is connected with a voltage detection unit, a current detection unit, a temperature detection unit, a memory unit, an LCD liquid crystal display unit, a control unit, and an alarm unit; wherein: the voltage detection unit, the current The detection unit and the temperature detection unit are connected with the digital/analog converter ADC of the ARM9 processor for converting the analog voltage signals of voltage detection, current detection and temperature detection into digital signals; the memory unit is connected with the storage control of the ARM9 processor Connected to the controller to store the program and temporary data to ensure the normal operation of the program; the LCD liquid crystal display unit is connected to the LCD controller of the ARM9 processor to display detection parameters and alarm information; the control unit is common to the ARM9 processor The input/output port GPIO is connected to control the working state of the ARM9 processor and the system under test; the alarm unit is connected to the pulse width modulation port PWM of the ARM9 processor to indicate the working state and fault alarm of the ARM9 processor.

The detection and control device of the above-mentioned high-power digital power amplifier is characterized in that: the voltage follower includes an operational amplifier, an input resistor and a feedback resistor, and the positive input terminal of the operational amplifier is connected to a resistor divider through a series input resistor; The feedback resistor is connected between the inverting input terminal and the output terminal of the operational amplifier; the input resistor and the feedback resistor have the same resistance value, and are used to realize the 1:1 follow-up output of the resistor divider output voltage signal to the Hall voltage sensor.

The detection control device of the above-mentioned high-power digital power amplifier is characterized in that: the voltage detection unit includes a voltage divider, an effective value detection circuit and an amplifying circuit, and the voltage divider is switched to the 2V output by the Hall voltage sensor of the sampling board. The variable voltage signals are connected in parallel, and the divided voltage is 200mV alternating voltage, which is converted into a 100mV DC voltage signal by the effective value detection circuit, and then amplified into a 2V DC voltage signal by the amplifier circuit, and input to the digital/analog converter ADC of the AMR9 processor. It is used to convert the 2V analog alternating voltage signal output by the Hall voltage sensor of the sampling board into a digital signal.

The detection control device of the above-mentioned high-power digital power amplifier is characterized in that: the current detection unit includes a voltage divider, an effective value detection circuit and an amplification circuit; The variable voltage signals are connected in parallel, and the divided voltage is 200mV alternating voltage, which is converted into a 100mV DC voltage signal by the effective value detection circuit, and then amplified into a 2V DC voltage signal by the amplifier circuit, and input to the digital/analog converter ADC of the AMR9 processor. It is used to convert the 2V analog alternating voltage signal output by the Hall current sensor of the sampling board into a digital signal.

The detection and control device of the above-mentioned high-power digital power amplifier is characterized in that: the temperature detection unit includes a platinum thermal resistance, a temperature transmitter and a temperature follower; Connector connection, used to convert the temperature into 2V DC voltage signal, and input to the digital/analog converter ADC of the AMR9 processor through the temperature follower, and convert the temperature value of the chassis of the system under test into a digital signal.

The detection and control device of the above-mentioned high-power digital power amplifier is characterized in that: the memory unit includes a Norflash memory and an SDRAM memory, and the Norflash is used to store programs; the SDRAM is used to temporarily store data to ensure that the programs can run normally;

The detection control device of the above-mentioned high-power digital power amplifier is characterized in that: the control unit includes an ARM9 processor restart key, four gear switching keys, and a power-on self-test selection key; the restart key is processed with the ARM9 Connected to the RESET port of the reset device, the gear switching key and the power-on self-test selection key are connected to the GPIO of the input/output port of the ARM9 processor, and are used to control the working gear and power-on self-test of the system under test.

The detection and control device of the above-mentioned high-power digital power amplifier is characterized in that: the ARM9 processor of the system main control board is also provided with a power-on self-check module, which is used for self-check of the system under test, and its self-check mode is through power-on The self-inspection selection key selects power-on self-inspection or skip self-inspection, and the self-inspection module is connected with the processor serial port of the system under test through the ARM9 processor of the main control board to realize cooperative communication.

The detection control device of the above-mentioned high-power digital power amplifier is characterized in that: the main control board adopts the ARM9 processor of the ARM920T series, and the UART port of the processor is connected with the system under test for connecting with the system to communicate.

The detection and control device of the above-mentioned high-power digital power amplifier is characterized in that: the main control chip ARM9 processor of the main control board runs a multi-task embedded operating system μC/OS-II for detecting the output voltage of the system under test , output current, output power and operating temperature parameters.

Compared with the prior art, the present invention has the following advantages:

1. The present invention converts 10KV voltage and 1KA current into 2V voltage signal because the sampling board uses Hall current sensor, resistor divider, voltage follower and Hall voltage sensor, so it can detect high-power digital power amplifier 10KV voltage, 1KA High power output of current;

2. In the present invention, because the main control board adopts the ARM9 processor of the ARM920T series, it has strong computing power and improves the processing capacity of the detection data; at the same time, because the ARM9 processor is compatible with multiple communication methods, it can pass through the asynchronous transceiver The UART port communicates with the system under test, improving the ability to transmit test data; in addition, because the ARM9 processor is peripherally connected with multiple control buttons for gear switching keys and self-test selection keys, the control ability for test data is improved.

3. The present invention can detect in real time and display parameters such as the output voltage, output current, output power, operating temperature of the system under test due to running the multitasking embedded operating system μC/OS-II on the ARM9 processor; Since the ARM9 processor has a power-on self-test module, it can realize the power-on self-test of the system under test.

Description of drawings

Fig. 1 is a block diagram of the overall structure of the present invention;

Fig. 2 is ARM9 processor connection relationship block diagram among the present invention;

Fig. 3 is the circuit structural diagram of sampling plate voltage follower of the present invention;

Fig. 4 is the circuit structure diagram of the main control board voltage detection unit of the present invention;

Fig. 5 is a circuit structure diagram of the current detection unit of the main control board of the present invention.

Detailed ways

Below in conjunction with accompanying drawing, embodiment of the present invention is described in further detail:

Referring to FIG. 1 , the detection and control device of a high-power digital power amplifier provided by the present invention includes a sampling board 1 and a main control board 2 .

The sampling board 1 is used to convert the 10KV voltage and 1KA current signal output by the load into a 2V voltage signal; it includes a Hall current sensor 11, a resistor divider 12, a voltage follower 13 and a Hall voltage sensor 14; the Hall current The input terminal of the sensor 11 is connected in series with the load of the system under test, and the output terminal is connected with the main control board 2; the resistor divider 12 is connected in parallel with the load of the system under test, and the divided signal is connected to the Hall voltage sensor 14 through the voltage follower 13 .

The main control board 2 is used to receive the current detection signal output by the Hall current sensor 11 of the sampling board and the voltage detection signal output by the Hall voltage sensor 14; the main control board is centered on the ARM9 processor, and a voltage detection unit is connected to the periphery 21. Current detection unit 22, temperature detection unit 23, memory unit 24, LCD display unit 25, control unit 26, alarm unit 27; wherein:

The voltage detection unit 21, the current detection unit 22 and the temperature detection unit 23 are all connected to the digital/analog converter ADC port of the ARM9 processor, and are used to convert the analog voltage signals of voltage detection, current detection and temperature detection into digital signals;

Memory unit 24, used for storing programs and temporary data, is connected with the storage controller of ARM9 processor;

LCD display unit 25 is connected with the LCD controller of ARM9 processor;

The control unit 26 is used to control the working state of the ARM9 processor and the system under test, and is connected with the ARM9 processor input/output port GPIO;

Alarm unit 27, used to indicate the operating state and fault alarm of the ARM9 processor, is connected with the pulse width modulation PWM port of the ARM9 processor;

The above-mentioned unit circuits connected with the ARM9 processor have a structure as described in Figure 2, wherein:

The voltage detection unit 21 is mainly composed of a voltage divider 211 , an effective value detection circuit 212 and an amplifier circuit 213 electrically connected. Its circuit structure is shown in FIG. 4 , but it is not limited to this structure.

The current detection unit 22 is mainly composed of a voltage divider 221, an effective value detection circuit 222 and an amplifying circuit 223 electrically connected, and its circuit structure is shown in Figure 5, but it is not limited to this structure;

The temperature detection unit 23 includes a platinum thermal resistance 231, a temperature transmitter 232 and a temperature follower 233; the platinum thermal resistance 231 is located in the chassis of the system under test and is connected to the temperature transmitter 232 for converting the temperature signal into a DC voltage signal, and input to the digital/analog converter ADC of the AMR9 processor through the temperature follower 233, the temperature value of the chassis of the system under test is converted into a digital signal;

Memory unit 24, for storing program and temporary data, it comprises Norflash memory 241 and SDRAM memory 242, all links to each other with the storage controller of ARM9 processor;

Control unit 26, it comprises an ARM9 processor restart key 261, four gear switching keys 262, a power-on self-test selection key 263; This restart key 261 is connected with ARM9 processor restart RESET port; This gear switching key 262 and the power-on self-test selection key 263 are all connected to the ARM9 processor input/output port GPIO;

The alarm unit 27, which includes an LED indicator light and a buzzer, is all connected to the pulse width modulation PWM port of the ARM9 processor.

Referring to Fig. 3, the voltage follower 13 of described sampling plate 1 comprises operational amplifier U1, input resistance R1 and feedback resistance R2; Resistor R2 is connected across the inverting input terminal and output terminal of operational amplifier U1, and the resistance value of input resistor R1 and feedback resistor R2 is the same, which is used to realize the 1:1 output voltage signal of resistor divider 12 to follow and output to Hall Voltage sensor 14.

放大后的直流电压信号输入到AMR9处理器的数/模转化器ADC。With reference to Fig. 4, described voltage detection unit 21, its voltage divider 211 is connected with sampling plate Hall voltage sensor 14 output ends, after the voltage division by resistance R3, R4, input to effective value detection circuit 212 through current-limiting resistance R5, The DC signal output by the effective value detection circuit 212 passes through the RC filter circuit composed of the resistor R6 and the capacitor C1, and then is input to the amplifier circuit 213 for amplification, and the amplification factor K1 is set by the resistors R7 and R8, wherein

The amplified DC voltage signal is input to the digital/analog converter ADC of the AMR9 processor.

放大后的直流电压信号输入到AMR9处理器的数/模转化器ADC。Referring to Fig. 5, the current detection unit 22, its voltage divider 221 is connected to the output terminal of the Hall current sensor 11 of the sampling board, after the voltage is divided by the resistors R9 and R10, it is input to the effective value detection circuit 222 through the current limiting resistor R11, The DC signal output by the RMS detection circuit 222 passes through the RC filter circuit composed of the resistor R12 and the capacitor C2, and then is input to the amplifier circuit 223 for amplification, and the amplification factor K2 is set by R13 and R14, wherein

The amplified DC voltage signal is input to the digital/analog converter ADC of the AMR9 processor.

The working principle of the present invention is as follows:

First, detect the current and voltage of the high-power digital power amplifier. The current detection process is that the Hall current sensor 11 of the sampling board 1 converts the 1KA alternating current output by the load into a 2V alternating voltage signal and inputs it to the current detection unit 22 of the main control board 2, and the voltage divider of the current detection unit 22 After the 221 divides the 2V alternating voltage signal into a 200mV alternating voltage, it is converted into a 100mV DC voltage signal by the effective value detection circuit 222, and then amplified into a 2V DC voltage signal by the amplifier circuit 223, and input to the digital/analog signal of the AMR9 processor. The converter ADC is converted into a digital signal, which is processed by the AMR9 processor and controls the LCD liquid crystal 25 to display the current value of the system under test;

The voltage detection process is to convert the 10KV alternating voltage output by the load into a 2V alternating voltage signal and input it to the main control board 2 through the resistor divider 12, voltage follower 13 and Hall voltage sensor 14 of the sampling board 1. The voltage detection unit 21, the voltage divider 211 of the voltage detection unit 21 divides the 2V alternating voltage signal into a 200mV alternating voltage, which is converted into a 100mV DC voltage signal by the effective value detection circuit 212, and then amplified to 2V by the amplifier circuit 213 The DC voltage signal is input to the digital/analog converter ADC of the AMR9 processor and converted into a digital signal, which is processed by the AMR9 processor to control the LCD liquid crystal 25 to display the voltage value of the system under test.

Secondly, the power of the high-power digital power amplifier is detected, that is, the product of the voltage detection value and the current detection value is calculated by the AMR9 processor, and the power detection value is obtained, and displayed by the LCD liquid crystal 25 .

Again, the temperature of the high-power digital power amplifier is detected. The temperature detection process is to connect the temperature transmitter 231 through the platinum thermal resistance 231 located in the chassis of the system under test, convert the temperature signal into a 2V DC voltage signal, and input it to the digital/analog conversion of the AMR9 processor through the temperature follower 233 Converter ADC into digital signal, processed by AMR9 processor, controls LCD liquid crystal 25 to display the temperature value of the system under test;

Finally, the fault alarm, gear switching and power-on self-test selection control are carried out for the high-power digital power amplifier. in:

Fault alarm is to compare the detected voltage value, current value, power value and temperature value with the preset threshold value of the system through the ARM9 processor, when the voltage detection value, current detection value, power detection value and temperature detection value When any detection value exceeds the threshold value, the ARM9 processor controls the LED indicator light and the buzzer to alarm, and at the same time sends the alarm signal to the processor of the system under test through the UART port of the UART;

The gear switching is to select the working gear through the gear switching key 262 connected with the ARM9 processor. After the ARM9 processor detects the gear switching signal, it will be displayed by the LCD liquid crystal 25, and the gear switching signal will be displayed on the UART port of the universal asynchronous transceiver. sent to the processor of the system under test;

The power-on self-test is to select the power-on self-test or skip the self-test through the power-on self-test selection key 263 connected to the ARM9 processor, and the ARM9 processor UART port and the processor of the system under test cooperate to complete the communication Power-on self-test and display by LCD liquid crystal 25 .

The above description is only a specific example of the present invention, and does not constitute any limitation to the present invention. Obviously, for those skilled in the art, after understanding the content and principle of the present invention, it is possible to make various modifications and changes in form and details without departing from the principle and structure of the present invention, such as the sampling plate 1 The voltage follower circuit 13, the voltage detection circuit 21 and the current detection circuit 22 of the main control board can all be realized by other circuits, but these modifications and changes based on the idea of the present invention are still within the protection scope of the claims of the present invention.

Claims (10)

1. A detection and control device for a high-power digital power amplifier, comprising: The sampling board (1) is used to isolate the high voltage and high current output by the digital power amplifier system under test, convert it into a small voltage signal, and transmit it to the main control board; The main control board (2) receives the sampling board signal, detects working parameters such as current and voltage, and controls the working status of the digital power amplifier system; It is characterized by: The sampling board (1) includes a Hall current sensor (11), a resistor divider (12), a voltage follower (13) and a Hall voltage sensor (14); the Hall current sensor, its input terminal It is connected in series with the 1KA high current signal on the load of the system under test, and the output terminal is connected to the main control board, which is used to convert the 1KA high current signal into a small voltage signal of 2V; The voltage is connected in parallel, and the signal after voltage division is connected to the Hall voltage sensor through the voltage follower, and the 10KV high voltage signal is isolated and converted into a 2V small voltage signal through the Hall voltage sensor, and then output to the main control board; The main control board (2) is centered on an ARM9 processor, and is connected with a voltage detection unit (21), a current detection unit (22), a temperature detection unit (23), a memory unit (24), and an LCD liquid crystal Display unit (25), control unit (26), alarm unit (27); where: The voltage detection unit, the current detection unit and the temperature detection unit are connected with the digital/analog converter ADC of the ARM9 processor, and are used to convert the analog voltage signals of voltage detection, current detection and temperature detection into digital signals; The memory unit is connected to the memory controller of the ARM9 processor, used to store programs and temporary data, to ensure the normal operation of the program; LCD liquid crystal display unit, connected with the LCD controller of the ARM9 processor, used to display detection parameters and alarm information;  The control unit is connected with the general-purpose input/output port GPIO of the ARM9 processor, and is used to control the working state of the ARM9 processor and the system under test; The alarm unit is connected with the pulse width modulation port PWM of the ARM9 processor, and is used to indicate the working status and fault alarm of the ARM9 processor. the 2. The detection and control device of high-power digital power amplifier according to claim 1, characterized in that: the voltage follower (13) includes an operational amplifier (131), an input resistor (132) and a feedback resistor (133 ), the positive input terminal of the operational amplifier (131) is connected to the resistor divider (12) through a series input resistor (132); the feedback resistor (133) is connected across the negative input terminal of the operational amplifier (131) and the output between the terminals; the input resistance (132) and the feedback resistance (133) have the same resistance value, and are used to realize the 1:1 follow-up of the output voltage signal of the resistance divider (12) and output to the Hall voltage sensor (14). the 3. The detection and control device of high-power digital power amplifier according to claim 1, characterized in that: the voltage detection unit (21) includes a voltage divider (211), an effective value detection circuit (212) and an amplifier circuit (213), the voltage divider (211) is connected in parallel with the 2V alternating voltage signal output by the Hall voltage sensor (14) of the sampling board, and the divided voltage is 200mV alternating voltage, which is converted into 100mV by the effective value detection circuit (212) The DC voltage signal is amplified into a 2V DC voltage signal by the amplifier circuit (213), and input to the digital/analog converter ADC of the AMR9 processor, which is used to convert the 2V analog alternating voltage output by the sampling board Hall voltage sensor (14) The signal is converted into a digital signal. the 4. The detection and control device of high-power digital power amplifier according to claim 1, characterized in that: the current detection unit (22) includes a voltage divider (221), an effective value detection circuit (222) and an amplifier circuit (223); the voltage divider (221) is connected in parallel with the 2V alternating voltage signal output by the Hall current sensor (11) of the sampling board, and the divided voltage is 200mV alternating voltage, which is converted into 100mV by the effective value detection circuit (222) After the DC voltage signal is amplified into a 2V DC voltage signal by the amplifier circuit (223), it is input to the digital/analog converter ADC of the AMR9 processor, and is used to convert the 2V analog alternating signal output by the sampling board Hall current sensor (11) The voltage signal is converted into a digital signal. the 5. The detection and control device of high-power digital power amplifier according to claim 1, characterized in that: the temperature detection unit (23) includes a platinum thermal resistance (231), a temperature transmitter (232) and a temperature follower device (233); the platinum thermal resistance (231) is located in the chassis of the system under test, and is connected with the temperature transmitter (231), used to convert the temperature into a 2V DC voltage signal, and input it to the temperature follower (233) The digital/analog converter ADC of the AMR9 processor converts the temperature value of the chassis of the system under test into a digital signal. the 6. The detection and control device of high-power digital power amplifier according to claim 1, characterized in that: the memory unit (24) includes Norflash memory (241) and SDRAM memory (242), and Norflash (241) uses for storing programs; SDRAM (242) is used for temporarily storing data to ensure that programs can run normally. the 7. The detection and control device of high-power digital power amplifier according to claim 1, characterized in that: the control unit (26) includes an ARM9 processor restart key (261), four gear switching keys ( 262), a power-on self-test selection key (263); the restart key (261) is connected to the ARM9 processor restart RESET port, and the gear switching key (262) and the power-on self-test selection key (263) are all connected to the ARM9 The processor input/output port GPIO is connected to control the working gear and power-on self-test of the system under test. 8. The detection and control device of high-power digital power amplifier according to claim 1 or 2, characterized in that: the ARM9 processor of the system main control board (2) is also provided with a power-on self-test module (27), used For self-testing of the system under test, the self-testing method is selected through the power-on self-testing selection key (263) or skipping self-testing, and the self-testing module (27) communicates with the ARM9 processor on the main control board. The processor of the system under test is connected to the serial port to realize cooperative communication. the 9. The detection and control device of high-power digital power amplifier according to claim 1, characterized in that: the main control board (2) adopts the ARM9 processor of the ARM920T series, and the universal asynchronous transceiver UART of the processor The port is connected to the system under test and is used for communicating with the system under test. the 10. The detection and control device of high-power digital power amplifier according to claim 1, characterized in that: the main control chip ARM9 processor of the main control board (2) runs a multi-task embedded operating system μC/OS- II, used to detect multiple parameters of output voltage, output current, output power and operating temperature of the system under test. the

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