Switching Elements 切换元件（开关元件）

天狼晓月

Switching Elements 切换元件（开关元件）


        A switching element implements the switching function defined by the switch configuration. For use in a switching system, the element must be electrically controllable, and should approximate an ideal switch. (See Section 1 for discussion of an ideal switch and switch configurations.) These two criteria remove many types of switching elements from consideration, even some electrically controllable switches.
        切换元件执行开关配置定义的切换功能。位率能够用于切换系统，元件必需是可电气控制的，并且宜接近于理想的开关。（参见第1章关于理解开关和开关配置的讨论）。这两个条件就排除了许多切换元件，哪怕是电气可控的开关。
        For example, a transistor is a controllable switch, but it is directional between the collector and emitter, and it has interactive control between the base and emitter.Both of these considerations make the transistor a poor choice for a signal switching element.

        例如，晶体管是可控的开关，但它在集电极和发射极之间是定向的，并且在基极和发射极之间是配合控制的。这两个条件都使得晶体管是非常差的信号切换元件。
        Figure 2-1 shows the schematic representations for four major types of electrically controllable switching elements. Table 2-1 compares the basic parameters of the four types. As can be seen from the table, the relay family of switching elements offers the best overall performance at a reasonable cost.

        图 2-1所示为4种主要的电气控制切换元件的示意图。表 2-1为这4种切换元件的基本参数对照表。从图中可以看出，继电器作为切换元件以合理的成本提供了最佳的总体性能。

图2‑1Figure 2-1. Switching elements

图2-1 切换元素

       表2‑1Table 2-1. Switching Element Parameters

       表2-1 切换原件参数

*For a complete off-on-off cycle.

* 完整的“关－开－关”周期