It was a valued export in Silk Road trading, but the manufacturing process was kept secret. During the Tang Dynasty (618-907) and the Song Dynasty (960-1279), varieties of paper were developed for different purposes.
April 7, 2015 Written by controlguru. Like the P-Only controller, the Proportional-Integral (PI) algorithm computes and transmits a controller output (CO) signal every sample time, T, to the final control element (e.g., valve, variable speed pump).
The signal then passes into the servo control or amplifier section. The servo control takes this. low power level signal and increases, or amplifies, the power up to appropriate levels to actually. result in movement of the servo motor/load.