Today's society, the rhythm of people's lives greatly accelerated when a timer to remind people to do the original plan good things , not because of a busy and forget the losses . Digital preset timer circuit to a digital circuit timing preset time to time by the sound regularly reminded of preset timer . It mainly consists of the 555 timer and two decimal count / divider CD4017 composition . It uses the 555 timer with two diodes, two fixed value resistors and a capacitor to control the timing time ; decimal counter / divider CD4017 output termination diode to expand the scope of the regulation of the timing circuit .Design schematics, and then proceed to the simulation, Multisim is an EDA software tools for electronic circuit simulation and design , belong to Electronics, the workbench ( referred to as EWB) software version of the series . EWB simulation software is a powerful circuit design software, which provides designers with a variety of components and instrumentation . Multisim retain the the EWB original advantages on the basis of greatly expanded the number of circuit elements in the component library , and enhance the software simulation testing and analysis capabilities can be realized Spice simulation of analog / digital circuit design and simulation of VHDL / Verilog RF circuit simulation .The design using Multisim software must first master the use of software , designed circuit and then ported to Multisim circuit debugging and emulation , simulation results show that : the design is feasible .
望采纳~
不懂欢迎追问~虽然是谷歌翻译的，还是谢谢了！