比值调节和加、减、乘、除运算在自控工程的设计过程中是经常遇到的。在 DDZ-Ⅱ系列仪表中实现上述的调节和运算一般可采用运算单元。但是,对于某些控制系统则可以利用电动调节器输入端的电阻进行加、减、乘、除运算,且可简化系统的结构。 Ratio adjustment and add, subtract, multiply and divide operations in the design of self-control project is often encountered. In the DDZ-Ⅱ series of instruments to achieve the above-mentioned adjustment and operation can generally use the computing unit. However, for some control systems, the resistance at the input of the motor regulator can be used to add, subtract, multiply and divide and simplify the structure of the system.