Design And Key Technology Study Of High Power Loudspeaker Test System

Taking into account the drawbacks of the traditional loudspeaker test system(such as low power test accuracy,low monitoring performance parameter,single audio test signal type,small test power range and external audio power amplifier with low monitoring degree etc)and the new requirements of loudspeaker test system put forward by electro-acoustic enterprises,this study targetedly designed a high-power loudspeaker test system.The system not only meets the power test requirements of large loudspeaker,but also meets the power test requirements of medium and small loudspeaker.The system can real-timely monitor and record some parameters which includes electrical parameters,power parameters,resonant frequency and impedance curve,etc,when it carries out long-term maximum power test,short-term maximum power test and custom power test,etc.The hardware of this system consists of the high-power loudspeaker tester and the external audio amplifier.The hardware-circuit design of the high-power loudspeaker tester plays a connected role in the whole system.The front is connected to the sound card and the computer.The back is connected to the external audio power amplifier.It is mainly used to realize the selection of the test signal type,the adjustment of the signal amplitude,the generation of the instrument calibration signal,the acquisition of the test voltage and current,the drive of the status indicator and the USB communication,etc.The hardware-circuit design of the external audio power amplifier mainly completes the power amplification of the audio signal in the whole system.At the same time,the audio power amplifier can collect the voltage of input and output,collect the temperature of power amplifier chip,drive the status indicator,overcurrent protection relay and USB,etc.The main control chip of the two instruments use a same kind of chip which is 32-bit microprocessor stm32f103v8t6.The software design of the system includes the lower computer programming of the high-power loudspeaker tester and the upper and lower computer programming of the external audio power amplifier.The lower computer programming environment use the Keil MDK.The connection of the upper and lower computer communication is established by transplanting the USB driver library function and configuring the standard descriptor.The lower computer receives operation instructions sent by upper computer through the USB receiving interrupt.At the same,the lower computer analysis and judges the operation instruction type,and then calls the interface function of each function module to complete the chip driver and realize the hardware circuit function.The upper computer monitoring software which real-timely monitors and displays some parameters which includes input and output voltage,radiator temperature of audio power amplifier,etc.Finally,in the process of testing the whole system with the System PC Software,it is found that the system not only realizes the preset functions,but also can operate stably and reliably.Figures: 71,Tables: 7,References: 54...