The Study On Multi-channel Test System Of Pyroelectric Infrared Detector

With the development of intelligence in the fields of consumer electronics,security,fire protection and public health for civilian use,pyroelectric infrared detectors with detection functions have been widely used.Pyroelectric infrared detectors are the research hotspots of uncooled infrared detectors.They have the characteristics of easy production,low cost,and simple operation.The demand for the production of pyroelectric detectors has increased sharply.The detection efficiency of the product,the demand for a multi-channel pyroelectric infrared detector test system came into being.Firstlly,the hardware circuit of 96 channel pyroelectric infrared detector test system is designed.The hardware part mainly includes five modules: control module,filter module,channel switching module,sampling module,and communication module.This system selects DSPIC33 EP series 16-bit single-chip microcomputer as the control center to execute the instructions sent by the PC.The channel switching module selects 96 signal channels through six groups of multi-channel analog switches CD4067 B.The function of the filter module is to filter the signal obtained after channel switching and amplify the target signal.In order to avoid signal sudden changes caused by channel switching,each sensor test path is equipped with a separate filter module.The sampling module mainly uses the ADS1278 A/D converter to collect noise signals and perform analog-to-digital conversion.The communication module is mainly for the exchange of control commands and data information between the upper computer and the lower computer.It can be connected to the computer through the RS232 bus to the USB port.After the hardware device is powered on,the single-chip microcomputer runs immediately after resetting,performs self-checking,receives the PC command word for verification,and executes the task after it is correct.The sampling circuit collects the amplified signal after filtering,and then sends the single-chip microcomputer to the host computer.Secondly,according to the hardware part and the function you need to implement,the human-computer interaction software program is designed,which is realized by using the integrated development environment visual studio and Win Form of C #.The main functions of the host computer are: the input of the parameter,control the lower computer acquisition signal and determine,display,and store the test results.The host machine includes the communication control section and the form display section and the parameter setting portion.The entire software section passes the start test signal to the next machine via the RS232 bus communication,and receives the data packet transferred by the lower computer,and the host computer software in the PC analyzes the validity of the noise data,and visually displays whether the detector is connected normally,the noise stability time and the noise stability value in the display window.Finally,through the verification test,comparison test and the actual use in the factory,the equipment is convenient,the connection between the test system and the detector is stable,the measured noise stability time meets the standard,and the noise stability value index data is stable.The testing speed of this system can be up to 1600 per hour,which provides an efficient method for the qualified testing of pyroelectric infrared detector products.