Research And Design Of Three-in-one Industrial Alarm

Security products play an important role in people's lives and work.With the continuous development of security industry products,a variety of alarms have emerged at the historic moment,and are widely used in industrial,agricultural,transportation,medical and other industries of automation equipment,which can effectively prevent various accidents.The alarms currently on the market are classified into WS type,WA type and WV type 3 types of sound source type alarms.The combination of WS-type products 1s a switching power supply control chip+pulse power driver+single-chip microcomputer+pulse power amplifier;the combination of WA-type and WV-type products is a switching power control chip+pulse power driver+single-chip microcomputer+class D power amplifier.Product working voltage is divided into 12V,24V,48V and so on,so there are many types of products,which is not conducive to management and maintenance.Class-D power amplifiers designed with ASICs are expensive and complex circuits are not conducive to miniaturization.Based on the above reasons,a three-in-one industrial alarm with a wide voltage range based on the STC15W402AS microcontroller is proposed.First,using the ADC and CCP module of the STC15W402AS high-speed microcontroller,audio-modulated PWM signals are generated and transmitted to both ends of the BTL driver for driving.The LC filter simplifies the circuit.Secondly,in order to increase the working voltage range of the product,a push-pull converter based on KA3525A is designed to work in a wide voltage range of 10-30V.The variable voltage output by the converter is used as the working voltage of the BTL driver,and the output volume is adjusted by changing the working voltage.This way of adjusting the volume with low noise can obtain a good signal-to-noise ratio.Finally,a method of implementing various WS-type sound sources and control methods of WA-type and WV-type sound sources are proposed.The WS-type or WA-and WV-type sound sources are selected through a 1-position WS/WM selection switch,and the 3-position Group switch and 5-position sound source The combination of selection switches can provide different combinations of sound sources to meet different needs of users.The test results show that the class D amplifier using a combination of a high-speed microcontroller and a BTL driver meets the frequency response requirements of WA and WV sound sources with a sampling frequency of 8kHz.The designed three-in-one industrial alarm has a wide voltage range operation and circuit.Features of simple,high output power,and the integration of three sound sources in one product increase the versatility of the product,increase the scope of application of the product,reduce the volume,and save costs.