航空开关知识和相关术语，switch，Microswitches，Relays

Switches

开关

Switches control the current flow in most aircraft electrical circuits. A switch is used to start, to stop, or to change the direction of the current flow in the circuit. The switch in each circuit must be able to carry the normal current of the circuit and must be insulated heavily enough for the voltage of the circuit.

开关控制着大多数飞机电路中的电流。开关用于启动、停止或改变电路中的电流方向。每个电路中的开关必须能够承载电路的正常电流，并且必须具有足够的绝缘性能以承受电路的电压。

An understanding of some basic definitions of the switch is necessary before any of the switch types are discussed. The number of poles, throws, and positions they have designates toggle switches, as well as some other type of switches.

在讨论任何类型的开关之前，必须理解一些基本的开关定义。它们的极、掷和位置指定了拨动开关以及某些其他类型的开关。

Pole: the switch’s movable blade or contactor. The number of poles is equal to the number of circuits, or paths for current flow, that can be completed through the switch at any one time.

极：开关的可移动触片或触点。极数等于电路数，即在任何时刻通过开关可以完成的电流通路数。

Throw:indicates the number of circuits, or paths for current, that it is possible to complete through the switch with each pole or contactor.

掷：表示通过开关与每个极或触点可完成的电路或电流通路的数量。

Positions:indicates the number of places at which the operating device (toggle, plunger, and so forth) will come to rest and at the same time open or close one or more circuits.

位置：表示操作装置（开关、柱塞等）在同时打开或关闭一个或多个电路时将停止的位置数量。

Toggle Switch

拨动开关

Single-Pole, Single-Throw (SPST)

单极单掷（SPST）

The single-pole, single-throw switch allows a connection between two contacts. One of two conditions will exist. Either the circuit is open in one position or closed in the other position. The schematic symbol for this switch is shown in Figure 10- 68.

单刀单掷开关允许两个触点之间建立连接。存在两种情况之一：电路在一个位置上是打开的，或者在另一个位置上是闭合的。该开关的原理图如图10- 68所示。

Single-Pole, Double-Throw (SPDT)

单刀双掷（SPDT）

The single-pole, double-throw switch is shown in Figure 10-69. With this switch, contact between one contact can be made between one contact and the other.

单刀双掷开关如图10-69所示。使用该开关时，可在一个触点之间形成另一个触点之间的接触。

Double-Pole, Single-Throw (DPST)

双刀单投（DPST）

The double-pole, single-throw switch connection can be made between one set of contacts and either of two other sets of contacts. The schematic symbol for this switch is shown in Figure 10-70.

双刀单掷开关的接线方式可以在一组触点和另外两组触点中的任意一组之间进行，该开关的原理图符号如图10-70所示。

Double-Pole, Double-Throw (DPDT)

双刀双掷（DPDT）

The schematic symbol for the double-pole, double-throw switch is shown in Figure 10-71. This type of switch makes a connection from one set of contacts to either of two other sets of contacts.

双刀双掷开关的原理图如图10-71所示。该类开关可将一组触点连接到另外两组触点中的任意一组。

A toggle switch that is spring-loaded to the OFF position and must be held in the ON position to complete the circuit is a momentary contact two-position switch.

弹簧加载到关闭位置的拨动开关，必须保持在打开位置才能完成电路，是瞬时接触式双位置开关。

One that will come to rest at either of two positions, opening the circuit in one position and closing it in another, is a two-position switch. A toggle switch that will come to rest at any one of three positions is a three-position switch.

一个将停在两个位置中的一个，打开电路在一个位置，闭合电路在另一个位置的开关是双位置开关。一个将停在三个位置中的任意一个的拨动开关是三位置开关。

A switch that stays open, except when it is held in the closed position, is a normally open switch (usually identified as NO). One that stays closed, except when it is held in the open position is a normally closed switch (NC). Both kinds are spring loaded to their normal position and will return to that position as soon as they are released. Locking toggles require the operator to pull out on the switch toggle before moving it in to another position. Once in the new position, the switch toggle is release back into a lock, which then prevents the switch from inadvertently being moved.

一个开关，除保持在闭合位置外，始终处于断开状态，称为常开开关（通常标识为NO)。一个开关，除保持在断开位置外，始终处于闭合状态，称为常闭开关（NC）。这两种开关都采用弹簧复位设计(两种弹簧都处于正常位置)，一旦释放就会自动复位。锁定开关要求操作员在将其移至另一个位置之前，先将开关拉出。进入新位置后，开关拨杆被释放回锁中，从而防止开关意外移动。

Pushbutton Switches

按钮开关

Pushbutton switches have one stationary contact and one movable contact. The movable contact is attached to the pushbutton. The pushbutton is either an insulator itself or is insulated from the contact. This switch is spring loaded and designed for momentary contact.

按钮开关有一个固定触点和一个可移动触点。可移动触点附着在按钮上。按钮本身是绝缘体，或者与触点绝缘。这种开关由弹簧加载，并设计为瞬时接触。

Microswitches

微动开关

A microswitch will open or close a circuit with a very small movement of the tripping device (1/16 inch or less). This is what gives the switch its name, since micro means small.

微动开关通过触发装置的微小移动(1/16英寸或更小）来打开或闭合电路。这就是开关得名的原因，因为“micro”意为“小”。

Microswitches are usually pushbutton switches. They are used primarily as limit switches to provide automatic control of landing gears, actuator motors, and the like. The diagram in Figure 10-72 shows a normally closed microswitch in crosssection and illustrates how these switches operate. When the operating plunger is pressed in, the spring and the movable contact are pushed, opening the contacts and the circuit.

微型开关通常采用按钮式设计，主要作为限位开关使用，用于自动控制起落架、作动器电机等设备。图10-72的剖面示意图展示了常闭型微型开关的工作原理：当操作柱塞被按下时，弹簧与动触点受压，从而断开触点并切断电路。

Rotary Selector Switches

旋转式选择开关

A rotary selector switch takes the place of several switches. When the knob of the switch is rotated, the switch opens one circuit and closes another. Ignition switches and voltmeter selector switches are typical examples of this kind of switch. [Figure 10-73]

旋转式选择开关可代替多个开关。当旋钮转动时，该开关断开一个电路并闭合另一个电路。点火开关和电压表选择开关是这种类型的典型例子。[图10-73]

Lighted Pushbutton Switches

带照明的按钮开关

Another more common switch found in today’s aircraft is the lighted pushbutton switch. This type of switch takes the form of a 5/8-inch to 1-inch cube with incandescent or LED lights to indicate the function of the switch. Switch designs come in a number of configurations; the two most common are the alternate action and momentary action and will usually have a two-pole or four-pole switch body. Other less common switch actions are the alternate and momentary holding coil configurations. The less known holding or latching coil switch bodies are designed to have a magnetic coil inside the switch body that is energized through two contacts in the base of the switch. When the coil is energized and the switch is pressed, the switch contacts will remain latched until power is removed from the coil. This type of design allows for some degree of remote control over the switch body. Figure 10-71 illustrates a schematic representation of this switch design.

如今飞机上另一种常见的开关是带指示灯的按钮开关。这种开关通常呈5/8英寸至1英寸的立方体形状，通过白炽灯或LED灯显示功能状态。开关设计有多种配置方式，其中最常见的两种是交替动作型和瞬时动作型，通常采用双极或四极结构。其他少见的开关类型包括交替保持线圈和瞬时保持线圈结构。较为少见的保持或锁定线圈开关内部装有磁性线圈，通过开关底座的两个触点通电。当线圈通电且按下开关时，触点会保持锁定状态直至断电。这种设计允许对开关进行一定程度的远程控制。图10-71展示了该开关设计的原理示意图。

The display optics of the lighted pushbutton switch provide the crew with a clear message that is visible under a wide range of lighting conditions with very high luminance and wide viewing angles. While some displays are simply a transparent screen that is backlit by an incandescent light, the higher quality and more reliable switches are available in sunlight readable displays and night vision (NVIS) versions. Due to the sunlight environment of the cockpit, displays utilizing standard lighting techniques will “washout” when viewed in direct sunlight. Sunlight readable displays are designed to minimize this effect.

带照明功能的按钮开关显示屏能为机组人员提供清晰的信息显示，无论在何种光照条件下都能呈现高亮度和宽视角。虽然有些显示屏只是由白炽灯背光的透明屏幕，但更优质可靠的开关设备可选配阳光可读显示屏和夜视（NVIS）版本。由于驾驶舱处于阳光直射环境，采用标准照明技术的显示屏在强光下会出现“画面褪色”现象。阳光可读显示屏的设计正是为了最大限度减少这种视觉干扰。

Lighted pushbutton switches can also be used in applications where a switch is not required and the optics are only for indications. This type of an indicator is commonly called an annunciator.

带照明的按钮开关也可用于不需要开关且光学装置仅用于指示的应用场合。这种类型的指示器通常称为指示器。

DIP Switches

DIP开关

The acronym “DIP” switch is defined as Dual In-Line Parallel switch in reference to the physical layout. DIP switches are commonly found in card cages, and line replaceable units (LRU) are used in most cases to adjust gains, control configurations, and so forth. Each one of the switches is generally an SPST slide or rocker switch. The technician may find this switch in packages ranging in size from DIP2 through DIP32. Some of the more common sizes are DIP4 and DIP8.

“DIP”开关的全称是双列直插式开关，这个名称源自其物理布局结构。这类开关常见于电路板中，通常通过航线可更换部件（LRU）来调节增益、控制配置等参数。每个开关本质上都是单刀双掷（SPST）滑动开关或拨动开关。技术人员会发现这类开关的封装规格从DIP2到DIP32不等，其中较为常见的规格包括DIP4和DIP8。

Switch Guards

开关防护装置

Switch guards are covers that protect a switch from unintended operation. Prior to the operation of the switch, the guard is usually lifted. Switch guards are commonly found on systems such as fire suppression and override logics for various systems.

开关防护装置是保护开关免受意外操作的护罩。在操作开关之前，通常会将防护装置抬起。开关防护装置常见于各种系统的灭火系统和超控逻辑中。

Relays

继电器

A relay is simply an electromechanical switch where a small amount of current can control a large amount of current. Figure 10-74 illustrates the basic relay in both schematic and pictorial format. When a voltage is applied to the coil of the relay, the electromagnet will be energized due to the current. When energized, an electromagnetic field will pull the common (C) or arm of the relay down. When the arm or common is pulled down, the circuit between the arm and the normally closed (NC) contacts is opened and the circuit between the arm and the normally open (NO) contacts are closed. When the energizing voltage is removed, the spring will return the arm contacts back to the normally closed (NC) contacts. The relay usually has two connections for the coil. The (+) side is designated as X1 and the ground-side of the coil is designated as X2.

继电器本质上是一种机电开关装置，其工作原理是通过小电流控制大电流。图10-74以原理图和示意图形式展示了基础继电器结构。当向线圈通电时，电磁铁因电流作用而产生磁能。通电时产生的电磁场会将继电器的公共端(C)或衔铁（臂）向下拉拽。衔铁或公共端（C）下压后，衔铁（臂）与常闭触点（NC）的电路断开，同时与常开触点（NO）的电路闭合。当电源断开后，弹簧会将衔铁（臂）触点复位至常闭位置。继电器通常设有两个线圈接点：线圈的（+）侧标记为X1，接地侧标记为X2。

相关文章，可点击查看