ZT372a-E ABB 控制显示面板 

ZT372a-E ABB 控制显示面板 

产品介绍：

ZT372a-E GJR2237800R1 具有高共模抑制比和洽的抗搅扰性。低通滤波器选用压控电压源型二阶低通滤波器。50Hz工频信号对外表肌电信号的收集有很大的影响，它的频率恰好在外表肌电信号能量集中的频段，且其幅度比外表肌电信号大1－3个量级，因而有必要除去。本设计中选用双T有源滤波器来滤除50Hz的工频信号

下面来分析或许引进工频搅扰的途径：1由空间辐射引进：空间的电磁场可以经过检测设备中的电极连线、印刷电路板上的连线、器材引脚或器材自身感应为相应频率成分的电流，成为噪声混入肌电信号。空间的电磁场或许来自于多种源，*致命的是电网辐射形成的工频搅扰。2由直流电源引进：检测设备中，为有源器材供电的直流电源一般都是由工频交流电源变压、整流、稳压而得到的。直流稳压电源不或许到达抱负的滤波作用。以纹波方式存在的工频（或其谐波）电流会经过电源引进到放大电路中。3由受试者身体引进：露出于空间电磁场中的受试者身体同样会感应电磁场而产生感应电流，受试者身体所感应的工频电流经过检测电极，与生物电信号一起加到放大器输入端，形成工频搅扰。

针对直流电源引进的工频搅扰，选用电池对有源器材进行供电。选用电池供电不只避免了整流稳压电源纹波所带来的工频搅扰问题，并且还消除了因漏电而导致受试者被电击伤的或许。由于电池的电压较低，用多节电池又会显得体积巨大，所以选用DC/DC模块来升压解决芯片的供电问题。

ZT372a-E ABB 控制显示面板 

Product Introduction:

The ZT372a-E GJR2237800R1 has a high common-mode rejection ratio and consistent disturbance resistance. Low-pass filter The voltage-controlled voltage source type second-order low-pass filter is selected. The 50Hz power frequency signal has a great impact on the collection of the external EMG signal, and its frequency is just in the frequency band where the energy of the external EMG signal is concentrated, and its amplitude is 1-3 orders larger than the external EMG signal, so it is necessary to remove. In this design, double T active filter is used to filter out 50Hz power frequency signal

The following ways to analyze the possible introduction of power frequency interference: 1 Introduced by space radiation: The electromagnetic field of space can be induced by the electrode connection in the detection device, the connection on the printed circuit board, the device pin or the device itself as the corresponding frequency component of the current, becoming noise mixed with the EMG signal. The electromagnetic field of space may come from a variety of sources, the most fatal is the power frequency interference caused by grid radiation. 2 Introduced by the DC power supply: In the detection equipment, the DC power supply for the active equipment is generally obtained by the power frequency AC power supply. Dc regulated power supply may not achieve the desired filtering function. The power frequency (or harmonic) current present in the form of a ripple is introduced through the power supply into the amplifier circuit. 3 Introduced by the subject's body: the subject's body exposed to the space electromagnetic field will also sense the electromagnetic field and generate an induced current. The power frequency current induced by the subject's body will pass through the detection electrode and be added to the amplifier input with the bioelectric signal to form power frequency interference.

In view of the power frequency interference introduced by DC power supply, the battery is used to power the active equipment. The choice of battery power supply not only avoids the problem of power frequency interference caused by the ripple of the rectifier voltage regulator power supply, but also eliminates the possibility of the subject being injured by electricity due to leakage. Due to the low voltage of the battery, the use of multiple batteries will appear huge, so the DC/DC module is used to boost the voltage to solve the power supply problem of the chip.