A voltage signal conditioning circuit for automatic control terminal, which is characterized in that the circuit consists of a voltage transformer, sampling and amplifying circuit, A / D acquisition circuit, single chip processing circuit, D / A / I conversion circuit, V conversion circuit, reference circuit, the circuit of the specific connection are as follows: in transformer T1 primary side series resistance R21, transformer secondary side parallel bidirectional transient suppression diode CR1 and sampling resistor R1, the secondary side is connected with the ground, side non grounding terminal through the resistance R2 access amplifier U5BMXL1013 negative input, at the same time through pins output resistance R3 U5B access terminal and the U6PIC16F73 MCU 2, reference voltage 5Vref by the divider resistor R4 connected to the terminal through the resistance and positive input U5B R5; in the MCU reset pin 1 reset chip U8X5043 pins 7, provide a low level reset signal, at the same time through a pull-up resistor R6 in power VCC, 1, 4, 5 legs, 6 legs, 3 ground, 8 power supply pins U6PIC16F73 microcontroller VCC; the 5 is connected with a reference voltage 5Vref, pins 8 ground pins, 9, 10 and two Y1 crystal capacitors C4, C5 formed the oscillation circuit 20 is connected to the power pins VCC, 19 ground pins, pins 19, 20 parallel capacitor C6, 14 and 16 respectively by pins on pull resistance R10, R11 in power VCC tube, 12 legs, 13, 14 and 16 are respectively connected with the D / A conversion chip U7 13, 8 7, 6; D / A pins conversion chip U7 14 power VCC tube, 1 leg grounding, leg 1, 14 parallel capacitor C7, voltage reference 5Vref resistor in series, R9 to R8, which is connected to the D / A pins point conversion chip U7 2, 3. 4, 5; D / A pins conversion chip U7 12 series resistor R12, potentiometer W6, resistor R22 and capacitor C9, voltage reference 5Vref series resistor potentiometer WZ, R13 composed of a zeroing circuit to the potentiometer W6 and the resistance R22 of the connection point, the negative input end and by U9A the resistor R14 is connected to the operational amplifier U9A output, positive input ground U9A, 15V R24, R22 series by reducing resistance to ground, R24, R22 and 15V respectively provide connection point voltage to U9A, the output of the U9A negative input resistance R15 is connected to U9B through and through resistor R17, parallel capacitor C8, and resistor R9 series and then connected with the output end of the U9B U9B, the output end of the resistor R20 is connected with a current of 4 ~ 20mA output current. The output end of the 4 ~ 20mA series resistor R18, R16 grounding resistance R18, R16 connection point is connected with the input of U9B.
【技术实现步骤摘要】
本技术涉及一种调理电路,特别是指一种用于工业过程自动化控制终端设备中,用以将现场提供的交流电压信号调理成标准信号的电压信号调理电路,以供模拟量输入电路进行采集,随时监测现场控制设备供电电压的起伏,从而保证设备的正常运转,特别适合于石化、给排水、电力、冶金等领域的工业过程自动化控制终端设备测量交流电压信号,将电压信号转换为4~20mA电流信号传给模拟量输入电路,完成电流信号的测量和显示。
技术介绍
目前,在我国应用于工业自动化领域控制设备中将输入的单项电压信号调理成标准信号的电路,由于电路设计简单,在设计时也没有考虑降低现场干扰信号对电路的作用和破坏,造成单项电压转换信号误差大、输出不稳定、测量数据不准确,给整个自动化控制系统造成极大影响,另外,不能根据现场实际情况进行调零、调满度,给实际操作带来很大不便。
技术实现思路
本技术的目的在于避免上述现有技术中的不足之处而提出的一种用于自动化控制终端的电压信号调理电路,它可以同时将一路交流电压信号(0-500VAC),转换成标准的4-20mA直流电流信号,不仅测量精度高,更适于根据实际情况进行调节,方便了实际操作。本技术的目的可以通过以下措施来达到一种用于自动化控制终端的电压信号调理电路,该电路由电压互感采样、放大、升压电路、A/D采集电路、单片机处理电路、D/A转换电路、V/I转换电路、基准电路组成,其电路的具体连接如下 在互感器T1原边串联电阻R21,互感器副边并联双向瞬变抑制二极管CR1和采样电阻R1,副边一端接地,副边非接地端通过电阻R2接入放大器U5B MXL1013负输入端,同时通过电阻R3接入U5B ...
【技术保护点】
【技术特征摘要】
【专利技术属性】
技术研发人员:俞凌,庄贵林,
申请(专利权)人:北京安控科技发展有限公司,
类型:实用新型
国别省市:
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