(6) To the timing system still in the absence of low-speed operation (that is, the phenomenon of emergence of reptiles) This is because the system of "zero drift" caused by. When the input signal is zero, the output voltage by the input amplification stage of the offset potentiometer decisions can be offset by adjusting the potential allows α = 90 °, at this time to zero output voltage rectification system, the electrical will not crawl. 

(7) With a given system can not run 

Should first check whether it is normal for the external control system, such as outside the normal control system, it may be given points, speed regulator, current regulator, such as caused by link failure. Shall be cut off main circuit power supply, only the control system to the electricity, not Add the given circumstances, the key points of each test (such as the current regulator, voltage regulator, etc.) of the potential. and then combined with a given, after the previous one by one to each of the key points to check the potential changes, that is, where to find fault. 

(8) Lack of control accuracy in the distributor for a given run-time external control often requires precision sufficient parking in order to work properly. If poor precision parking, you can adjust the speed of the appropriate regulator of the PI link, generally by reducing the the ratio of the integral part of efforts to get satisfactory results. 

(9) Reversible system oscillation 1) open-loop system in the state (the main circuit disconnect) the oscillation can be changed at this time given the previous inspection to the key points of the potential changes. If a given unchanged, but the potential is still a point of change, here is the crux of .2) system in the state when the closed-loop oscillation, in which case in order to ensure the safety of the electrical load should be replaced by the general resistance of the load, if there is no suitable resistance box which can be used in place of the two electric sub-series. inspection methods and similar open-loop, focusing on the link to check is: given points, level detection, operation control, such as the speed regulator. oscillations are often caused as a result of operational amplifiers, such as damage to electronic components , system parameters caused by improper, according to the specific circumstances, properly addressed.

1  一种节能的液压疲劳试验机

摘要：液压疲劳试验机结合了机械液压波轮和闭环控制系统已经完成了实验。对于电力和本机用水量约是伺服控制电液机的三分之一。这种控制系统的稳定性在0.5%的范围之内。实验结果鉴证了疲劳试验载荷下良好的稳定性。

简介：源[自-优尔^`论/文'网·www.youerw.com

现在已经建成了具有三个环节的机械液压机。它的稳定性在0.5个百分点范围内，电力消耗大约只有电动液压机的三分之一。

前言：

液压和谐振式疲劳试验机用于高负荷疲劳试验中，谐振式疲劳试验机用少量的电力就可以运行，但它不能在一个高阻尼条件下，或长冲程和高负荷疲劳试验中运行，而液压机可以在这些条件下运行。因此，液压疲劳试验机用于高负荷长冲程疲劳试验。这种类型的机器通常分为两类：一类是伺服控制电动液压机，另一种是机械液压波轮。伺服控制液压疲劳试验机具有闭环连续体系，并不断纠正了这个不同于负荷或伸长的命令信号。因此，伺服控制电液压机可运行在一个负载或在有限频率的条件下，来延长任意波形。也就是说，它不仅能产生正弦波形，也可以按照一个指令信号发生器产生任意波形。然而，这种类型的机器需要大量的电力和水去冷却油液，所以它无论是在建设还是在营运上成本都很高。如果实验室不具备足够大的电力供应系统，这种机器不能装备。另一方面，波轮液压机确实比伺服控制的电液冷却机节约电力和用水。不过，这台机器有一个开环控制系统。也就是说，只要在开始对负荷幅值进行设置，这个值将不会自动改变。此外，负载平均值保持在百分之五负载范围内，只能有一到两个油压开关，都是通过机械式波轮设备，带动气瓶阀开关的旋转的。这种开关控制系统不能维持在开始时设定的油的温度值。