基于555定时器的湿度检测电路的设计与Multisim仿真

基于Multisim仿真软件,利用555定时器设计了湿度检测电路,用于电子技术实践教学。系统设计:1)利用HM1500湿度传感器采集湿度信息,转换为电压信号;2)利用555定时器设计压频转换电路,间接实现模/数转换;3)利用74LS161、74LS273等设计计数器测量锁存湿度值;4)利用数码管显示湿度值。Multisim软件仿真结果显示,本文设计电路准确稳定,转换精度高,线性度高,且成本低。该系统设计融合了模拟电子技术及数字电子技术课程基本教学内容,可作为实践项目用于教学。

基于Multisim的交通灯控制器设计与仿真

本文以Multisim仿真软件为平台设计了交通灯控制电路,对电路的相关参数进行调整,并进行仿真和理论分析。仿真结果表明,设计的电路达到了预期要求。

基于计数器的数字电子钟的设计

本设计是一个基于计数器的数字电子钟装置。该装置电路的主要组成部分是555定时器、分频器、计数器、译码器、显示器、校时电路。译码代替机械式传动,用LED显示器代替指针显示进而显示时间,减小了计时误差。这种表具有时、分、秒显示时间的功能,还可以进行时和分的校准,片选的灵活性好。这种用数字电路实现的电子钟与机械式时钟相比具有更高的准确性和直观性。

555电路在级联应用中的频率计算与设计

在电工电子实验教学中,发现555集成电路是比较基本的一款应用电路,他的更广泛应用之一是多级级联,在这一应用中的最初设计时的难点是振荡频率的计算。本文以一例实验电路的设计为例,介绍555定时集成电路的级联应用,给出了各级振荡频率的计算方法、时序波形和频率实测方法。

基于Multisim12的玩具控制器的设计和仿真

通过Multisim12实现玩具控制器的设计和仿真。软件采用数字集成器件,不需要编程。设计了玩具控制器的触摸开关电路、秒信号产生电路、计数和复位电路。

基于NE555的风扇阵风控制器的设计

电风扇在生活中使用十分广泛,电风扇持续吹风,会使人感觉不太舒服。本文基于NE555定时器实现电风扇间断工作产生阵风,不仅使人感到比较舒适、而且还省电。该控制系统还可以用于烤火器等电器的控制。

Development of OPTO-LDR coupled timer based voltage to frequency converter

This paper describes the development of a timer based voltage to frequency converter(V FC).Timer LM555is used in astable multivibrator mode with two OPTO-LDRs(light dependent resistors)in the circuitry.The frequency of timer output waveform which is measured using a digital storage oscillator(DSO)is almost linearly proportional to the applied input voltage.Hence we obtain a linear relationship between the frequency of timer output waveform and the input voltage.Because of its quasi-digital output,the main advantages of this developed converter are linear input-output relationship,small size,easy portabilityand high cost performance.In addition,the timer output waveform can be directly interfaced with personal computer or microprocessor/microcontroller for further processing of the input voltage signal without intervening any analog-to-digital converter(ADC).

Development of timer based on liquid level measurement system

This paper describes the design and development of the timer based on liquid level measurement system in which timer 555 is used in astable mode. The capacitor charging time i. e. the ON time pulse width of the timer output waveform which is measured using a digital storage oscillator （DSO）,is linearly proportional to the capacitance of a co-axial cylindrical capacitive transducer, and this capacitance once again linearly varies with the change in liquid level. Hence, we obtain a linear relationship between the liquid level and the capacitor charging time. The main advantages of this developed system are linear input-output relationship, small in size, easily portable, cost effective, and independent on the ambient temperature effect. The system can also be exploited to measure dielectric constant of liquid or solid in various process industries.

湿度测量仪表设计

本文介绍了采用电容式相对湿度传感器HS1101作为555定时器的充放电电容进行湿度测量的方案,并详细介绍了其硬件电路设计的过程。