共查询到19条相似文献,搜索用时 156 毫秒
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在电子电路中,矩形波、三角波、锯齿波统称为非正弦波,所设计的非正弦波信号发生器以矩形波发生电路为基础,在其输出端加积分运算电路及相应的辅助电路产生三角波或锯齿波信号,辅以外围电路设计,实现信号频率、幅值、占空比调节。在Multisim 10开发环境中搭建该电路并进行了验证分析,结果表明,电路达到了设计要求,实现了预期功能。 相似文献
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正弦信号发生器作为最基本的电子设备,广泛应用于航空航天控制、通信、电子测量、研究等等。本文介绍了基于FPGA技术,根据正弦信号移相原理,利用matlab/simlink/DSP Builder搭建移相正弦信号模型,采用直接数字频率合成技术(DDS),设计实现了一个频率、相位可控的正弦信号发生器。采用此方法设计的数控移相正弦信号发生器能够产生频率、相位均可数字式预置并可调节的正弦波信号,该数字移相信号发生器的频率、相位、幅度均可预置,分辨率高,精确可调,且可分别用作两路独立的信号发生器使用。采用这种方法设计可控移相信号发生器方便快捷,提高了开发效率,缩短研发周期,而且系统的调试方便,容易修改。 相似文献
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函数发生器作为一种多波形的信号源,可产生正弦波、三角波、方波、锯齿波,甚至于任意波形,是一种不可或缺的通用信号源。文章研究基于fpga的DDS函数发生器,从而设计出稳定性能好、频率的分辨率高和能输出多个波形信号发生器。 相似文献
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正弦波和非正弦波发生电路常作为信号源被广泛地应用于无线电通信以及自动测量和自动控制等系统中。通常把既能产生正弦波又能产生三角波、方波、锯齿波等非正弦输出信号的电路叫作函数信号发生器。在电子技术应用领域。要求信号源的温度、频率的稳定性都比较高。介绍的5G8038是一种性能稳定、精度较高的集成芯片。介绍了用5G8038设计多功能函数信号发生器的方法。 相似文献
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本文介绍用89C51单片机和DA转换器、分频电路构成能产生两路方波、三角波、梯形波、锯齿波、正弦波以及脉冲信号的一种新型信号发生器。该信号发生器的两路同步波形的频率可在零点几Hz到几万Hz的范围内变化。文中介绍了信号发生器的工作原理和软硬件的设计方法。 相似文献
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<正> 振荡器是一种能自动地将直流能量转换为一定波形的交变振荡信号的转换电路。它与放大器的主要区别在于,它无需外加激励信号,就能产生具有一定频率、一定波形和一定振幅的交流信号。 根据所产生的波形不同,振荡器可分为正弦波振荡器和非正弦波振荡器。前者产生正弦波,后者产生矩形波、三角波、锯齿波等。本讲只介绍正弦波振荡器。这是因为正弦波振荡器在无线电技术领域有着极为广泛的应用。在无线电发送设备中,正弦波振荡器可用来产生载波;在超外差接收机中,可用来构成本地振荡器;在各种定时系统中,可用作时间基准信号。在研制和调试各类电子设备时所需的信号源和各种测量仪器中,也大多包含有振荡器,例如高频信号发生器、音频信号发生器等等。总之,振荡器在电子测量、通信等系统中是必不可少的。 相似文献
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Salmon J. Liping Wang Noor N. Krieger A.W. 《Power Electronics, IEEE Transactions on》2007,22(5):1708-1718
A carrier-based unipolar pulsewidth modulation (PWM) current controller is described using a one-phase PWM rectifier bridge as a test circuit. The controller PWM signal generator uses a sawtooth carrier signal to obtain both synchronized PWM waveforms and a constant switching frequency. A current-error signal and an amplitude modulation depth signal are used to create the input reference signal to the PWM signal generator. The amplitude modulation depth signal is obtained from the PWM-cycle average of the PWM signal generator output signals. This internal feedback is illustrated using a second-order low pass Butterworth filter. With an appropriately designed low-pass filter, the current-error signal is forced to be centered on zero over a PWM cycle. The maximum peak-peak magnitude of the current-error signal is used as a design guideline for deciding an appropriate gain constant in the controller current feedback loop. The low pass filter design is examined to determine a suitable gain and 20-dB attenuation frequency to minimize the current-error signal. The steady-state and transient operation of the proposed current controller is compared with a proportional-integral controller and an average current-error controller. SPICE simulations and experimental results are used to demonstrate the characteristics of the controller. 相似文献
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This paper presents a direct digital synthesizer (DDS) with no ROM that still produces square waves with low spurious signals. The main features are the interpolation of the analog-converted accumulator contents and the extraction of timing at the points where the interpolated signal is identical to a continuous sawtooth waveform. Experimental results confirm successful frequency synthesizer operation. The output frequency is determined by the frequency control word, and spurious signals present in the accumulator contents are greatly reduced 相似文献
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During a sustained muscle contraction, the amplitude of electromyographic (EMG) signals increases and the spectrum of the EMG signal shifts toward lower frequencies. These effects are due to muscular fatigue and can cause problems in the control of myoelectric prostheses and in the estimation of contraction level from the EMG signal. It has been well known that the fatigue effects can be explained by the conduction velocity changes during the fatigue process and by the idea that the conduction velocity is linearly proportional to the median frequency of EMG signals. Hence the fatigue process can be monitored by measuring the median frequency. A fatigue compensation preprocessor has been developed. It uses the widely accepted power spectrum density model of EMG signals that contains the conduction velocity as a measure of fatigue. It was verified that the preprocessor scales down the amplitude of the fatigued EMG signal and decompresses the spectrum. Hence, the preprocessor eliminates the increase in amplitude and the shift in frequency and enables consistent EMG signals to be used to control prostheses 相似文献
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用超声波传送语音信号的实现 总被引:1,自引:1,他引:0
简要说明了幅度调制原理,单边带信号的产生方法,介绍利用相移法产生单边带信号的原理,设计出一种用超声波传送语音信号的单边带幅度调制电路.若需大功率推动负载,则将输出的单边带幅度调制信号送到满足超声波频响要求的功率放大器来实现. 相似文献
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基于AT89C51的信号发生器的设计 总被引:1,自引:1,他引:0
为了设计一款结构简单、性能优良的信号发生器,采用了AT89C51单片机为控制核心。在Proteus下仿真可以产生正弦波、方波、三角波、锯齿波,而且可以方便地设定输出信号的频率及幅度,得到的输出波形失真度低,频谱纯度高。 相似文献
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Generation and transmission of millimeter-wave data-modulated optical signals using an optical injection phase-lock loop 总被引:1,自引:0,他引:1
Generation and transmission of millimeter-wave data-modulated optical signals is presented using an optical injection phase-lock loop (OIPLL). Millimeter-wave signal generation is demonstrated with wide locking range, 30-GHz low phase noise level, -93 dBc/Hz, and a wide frequency tuning range, 4-60 GHz generation demonstrated using optical injection locking only, verified by using OIPLL in the 26-40 GHz range. The OIPLL is also used to transmit error-free 140-Mb/s amplitude shift keying and 68-Mb/s differential phase-shift keying (DPSK) modulated millimeter-wave signals over up to 65 km of uncompensated standard singlemode fiber. The DPSK system uses reference frequency modulation, eliminating the need for optical amplification. 相似文献
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直接数字频率合成器的教学实验 总被引:2,自引:0,他引:2
本文介绍一个电子系统设计实验-直接数字频率合成(DDS)信号源的设计与实现。该信号源可输出一定频率范围的正弦波、方波和三角波信号,输出频率可通过键盘进行预置,输出信号的类型和频率由LED数码管显示。实验采用单片机完成波形的相位、幅度值计算,波形数据存储在RAM中;用CPLD进行相位累加,并提供与单片机和数码管、RAM及内部累加器的接口和控制,由RAM读出的波形数据通过DAC芯片转换为模拟量,最后经一个模拟滤波器,对输出波形进行平滑。 相似文献