电压检测与显示电路设计

Design of Voltage Detection and Display Circuit

目前的电压检测技术主要有模拟电路检测和数字电路检测两大类。前者速度快且功耗低,后者精度高且效果好。结合模拟电路和数字电路的优点,设计了由放大模块、比较器模块、译码器模块、显示模块以及电源模块组成的电压检测与显示电路。该电路由变压器降压、全波整流以及串联稳压电路提供+5 V的直流电源,调节RP2模拟被测电压的变化,通过由LM324运放组成的一级同相放大器后送给电压比较器电路,三级电压比较器的基准电压分别为1 V、2 V以及3 V,最后将电压比较器的输出送给由74LS138组成的译码器驱动发光二极管显示。采用模拟电路与数字电路相互配合的控制模式,通过模拟电路的高速特性和数字电路的准确特性,设计出了一款带有LED二极管显示的电压表。

At present,the voltage detection technology mainly includes analog circuit detection and digital circuit detection.The former has high speed and low power consumption,while the latter has high precision and good effect.Combining the advantages of analog circuit and digital circuit,this paper designs a voltage detection and display circuit composed of amplifier module,comparator module,decoder module,display module and power module.This circuit provides+5 V DC power supply by transformer step-down,full wave rectification and series voltage stabilizing circuit.Adjust RP2 to simulate the change of measured voltage,and send it to the voltage comparator circuit composed of LM324 through the in-phase amplifier.The reference voltage of three-stage voltage comparator is 1 V,2 V and 3 V.The output of the voltage comparator is sent to the decoder composed of 74LS138,which drives the LED display.The system adopts the control mode of analog circuit and digital circuit,through the high-speed characteristics of analog circuit and the accurate characteristics of digital circuit,a voltmeter with LED diode display is finally designed.