低频数字式相位测量仪

文档编号:CK137   文档字数:11601,页数:31 附外文翻译

摘  要

 本设计实现了一个低频相位测量系统，包括相位测量仪、数字式移相信号发生器和移相网络三部分。
 移相网络主要是由RC移相电路和LM324运放电路组成，将被测信号送入移相网络，经RC移相、LM324隔离放大，产生两路信号，一路为基准信号经过波形转换，另一路为移相后的信号。分别经过波形转换、整形、二分频送给相位测量模块及频率测量模块。
 相位差测量仪主要是由锁相环PLL（Phase Lock Loop）产生360倍频基准信号和移相网络的基准信号与待测信号进行异或后的信号作为显示器的闸门电路和控制信号。
 频率测量模块主要是用计数法测量频率的，它是有某个已知标准时间间隔Ts内，测出被测信号重复出现的次数N，然后计算出频率f=N/Ts。
 显示电路模块主要是由计数器、锁存器、译码器和数码管组成。
 对于低频相位的测量，用传统的模拟指针式仪表显然不能够满足所需的精度要求，随着电子技术以及微机技术的发展，数字式仪表因其高精度的测量分辨率以及高度的智能化、直观化的特点得到越来越广泛的应用。同频率正弦信号间的相位差测量在电工技术、工业自动化、智能控制及通讯、电子等许多领域都有着广泛的应用，如电工领域中的电机功角测试，介质材料损耗角的确定等。因此，相位差测量技术有着广泛的实用价值。

关键词：相位测量；频率测量；低频；PLL

Abstract

 This design has realized a low-frequency phase measuring system, including three parts: phase measuring apparatus, digital phase excursion signal generator and phase excursion network.
 Phase-shifting network mainly by the RC phase shifter circuit and LM324 op amp circuit, will the measured signal into the phase-shifting network, by the RC phase shifter, LM324 enlarge isolation, resulting in two signals, all the way through wave-based signal conversion, another way for the phase-shifted signal. Waveform, respectively, after conversion, shaping ,second sub-frequency to the phase measurement and frequency measurement module.
 Phase difference measurement is the main phase-locked loop PLL (Phase Lock Loop) frequency reference signal 360 generated and phase-shifting network of reference signal varies with the test signal or after the display of the signal as the gate circuit and control signals.
 Frequency measurement module is measured by counting the frequency, which is a known time interval Ts, the measured signal to detect the number of repeated N, and then calculated the frequency of f = N / Ts.
 Display circuit modules mainly by the counter, latch, decoder and digital tubes.
 For low-frequency phase measurements, using traditional analog pointer instrument is clearly not able to meet the required accuracy, with the electronic technology and computer technology, digital high-precision measurement instrumentation for its resolution and a high degree of intelligence, visual characteristics of a wide range of applications has been increasing. Sinusoidal signal with frequency between the phase difference measurement in electrical technology, industrial automation, intelligent control and communications, electronics and many other fields have a wide range of applications, such as electricians in the field of electric power angle test, dielectric materials, such as the determination of loss angle. Therefore, the phase measurement techniques have a wide range of practical value. 
Keywords：Phase Measurement；Frequency Measurement；Low- Frequency ；PLL

目录
摘要
Abstract 
目录
1  前 言…...  1
2  总体方案设计 2
2.1设计要求 2
2.2方案比较 3
2.2.1相位测量方案 3
2.2.2 移相网络方案 4
2.2.3显示界面方案 5
2.2.4 总体设计方案 5
3 系统设计 6
3.1总体框图 6
3.2相位测量部分 6
3.2.1波形转换、整形放大 8
3.2.2锁相环倍频 9
3.2.3闸门电路 11
3.2.4控制门 11
3.2.5计数器 11
3.2.6锁存器 11
3.2.7  显示译码器与数码管 12
3.3频率测量部分 12
3.3.1数字频率计的基本原理 12
3.3.2系统框图 12
3.4 移相网络 14
4 系统设计细节化 16
4.1  LM324运放电路 16
4.2相位锁定环路 PLL 17
4.3放大整形电路 18
4.4  1秒的时基信号发生器 18
4.5计数、译码、显示部分 19
4.6电源电路的设计 19
5 系统措施分析 21
5.1改善稳压器工作稳定性和瞬变响应的措施 21
5.2 确保不毁坏器件的措施 21
5.3稳压器输入电压值的确定 22
6  总 结 23
致 谢 24
参考文献 25
附件 26

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