Abstract
Along with social progress and technological development, people's living standards and gradually improve the living requirements for different categories of product features and the requirements of increasingly high price, only suited to the needs of consumers living products can be approved. Thus the recording was also broadcast a new functional requirements, the need to adapt to innovation and development needs.HGT2212/HGT2222 broadcasting recorder is the pre-launch audio resource and the central controlling equipment of the emergency broadcasting system. The background music of HGT2212 is played by tape and the background music of HGT2222 is played by CD or MP3, both of them have an interface with the linkage device. The recorder uses the solid-state electronic recording mode for broadcasting and recording incidents. On the principles of ensuring a normal performance in case of emergency as well as focusing on ordinary broadcastings, this series of products are added a number of practical features, namely nice bell-sound entry, background incremental volume control and so on. Among them the most characteristic one is-- with two sets of power amplifiers this series of products can make an emergent broadcasting and a backgroud broadcasting at the same time, so that not only the command mission of evacuation in incident region can be achieved, but also a tranquil and peaceful atmosphere in non-accident areas can be mantained.In this thesis through the project development process, research and design of radio-CD players and recorders voice player of the circuit, and Second Road signal synthesis. According to the Fire Services and the functions of broadcasting technology can achieve a state of emergency in the voice alarm player, CD player stopped the coordination of work.
