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本文介绍一种低频疲劳试验机的全晶体管化控制系统。试验机是油压加荷,以电液伺服阀作控制元件,对试样进行梯波、三角波、方波的应力、应变疲劳试验。系统的特点:波形给定装置是数字式的。在应力应变测量桥路中直接引入一个数字控制电阻。当它的阻值随着波形数码变化时,闭环伺服系统随时维持桥路的平衡,保证试样受相应波形的应力或应变。电阻应变式测量桥路本身就是闭环系统的比较环节,可采用交流放大器进行放大。保证了系统的低零漂。
This article describes a low-frequency fatigue testing machine full transistor control system. Testing machine is hydraulic loading, with electro-hydraulic servo valve as the control element, the specimen of the ladder, triangle wave, square wave stress, strain fatigue test. System Features: The waveform given device is digital. In the stress-strain measurement bridge directly into a digital control resistor. When its resistance changes with the digital waveform, closed-loop servo system to maintain the balance of the bridge at any time to ensure that the sample by the corresponding waveform stress or strain. Resistance strain gauge bridge itself is a comparative part of the closed-loop system can be used to amplify the AC amplifier. Ensure that the system of low zero drift.