红外遥控人的眼睛能看到的可见光按波长从长到短排列，依次为红、橙、黄、绿、青、蓝、紫。
其中红光的波长范围为0.62-0.76um；紫光的波长范围为0.38-0.46um。
比紫光波长还短的光叫紫外线，比红光波长还长的光叫红外线。
红外线遥控就是利用波长为0.76-1.5um之间的近红外线来传送控制信号的。
常用的红外遥控系统一般分发射和接收两个部分。
发射部分的主要元件为红外发光二极管。
它实际上是一只特殊的发光二极管；由于其内部材料不同于普通发光二极管，因而在其两端施加一定电压时，它便发出的是红外线而不是可见光。
目前大量的使用的红外发光二极管发出的红外线波长为940nm左右，外形与普通φ5发光二极管相同，只是颜色不同。
红外发光二极管一般有黑色、深蓝、透明三种颜色。
判断红外发光二极管好坏的办法与判断普通二极管一样；用万用表电阻挡量一下红外发光二极管的正、反向电阻即可。
红外发光二极管的发光效率要用专门的仪器才能精确测定，而业余条件下只能用拉锯法来粗略判判定。
接收部分的红外接收管是一种光敏二极管。
在实际应用中要给红外接收二极管加反向偏压，它才能正常工作，亦即红外接收二极管在电路中应用时是反向运用，这样才能获得较高的灵敏度。
红外发光二极管一般有圆形和方形两种。
由于红外发光二极管的发射功率一般都较小（100mW左右），所以红外接收二极管接收到的信号比较微弱，因此就要增加高增益放大电路。
前些年常用Μpc1373H、CX20106A等红外接收专用放大集成电路。
最近几年不论是业余制作还是正式产品，大多都采用成品红外接收头。
成品红外接收头的封装大致有两种：一种采用铁皮屏蔽；一种是塑料封装。
均有三只引脚，即电源正（VDD）、电源负（GND）和数据输出（VO或OUT）。
红外接收头的引脚排列因型号不同而不尽相同，可参考厂家的使用说明。
成品红外接收头的优点是不需要复杂的调试和外壳屏蔽，使用起来如同一只三极管，非常方便。
但在使用时注意成品红外接收头的载波频率。
红外遥控常用的载波频率为38kHz这是由发射端所使用的455kHz晶振来决定的。
在发射端要对晶振进行整数分频，分频系数一般取12，所以455kHz÷12≈37.9kHz≈38kHz。
也有一些遥控系统采用36 kHz、40 kHz、56 kHz等，一般由发射端晶振的振荡频率来决定。
红外遥控的特点是不影响周边环境的、不干扰其他电器设备。
由于其无法穿透墙壁，故不同房间的家用电器可使用通用的遥控器而不会产生相互干扰；电路调试简单，只要按给定电路连接无误，一般不需任何调试即可投入工作；编解码容易，可进行多路遥控。
由于各生产厂家生产了大量红外遥控专用集成电路，需要时按图索骥即可。
因此，现在红外遥控在家用电器、室内近距离（小于10米）遥控中得到了广泛的应用。
多路控制的红外遥控系统，多路控制的红外发射部分一般有许多按键，代表不同的控制功能。
当发射端按下某一按键时，相应的在接收端有不同的输出状态。
接收端的输出状态大致可分为脉冲、电平、自锁、互锁、数据五种形式。
“脉冲”输出是当按发射端按键时，接收端对应输出端输出一个“有效脉冲”，宽度一般在100ms左右。
“电平”输出是指发射端按下键时，接收端对应输出端输出“有效电平”，发射端松开键时，接收端“有效电平”消失。
此处的“有效脉冲”和“有效电平”，可能是高、也可能是低，取决于相应输出脚的静态状况，如静态时为低，则“高”为有效；如静态时为高，则“低”为有效。
大多数情况下“高”为有效。
“自锁”输出是指发射端每按一次某一个键，接收端对应输出端改变一次状态，即原来为高电平变为低电平，原来为低电平变为高电平。
此种输出适合用作电源开关、静音控制等。
有时亦称这种输出形式为“反相”。
“互锁”输出是指多个输出互相清除，在同一时间内只有一个输出有效。
电视机的选台就属此种情况，其它如调光、调速、音响的输入选择等。
“数据”输出是指把一些发射键编上号码，利用接收端的几个输出形成一个二进制数，来代表不同的按键输入。
一般情况下，接收端除了几位数据输出外，还应有一位“数据有效”输出端，以便后级适时地来取数据。
这种输出形式一般用于与单片机或微机接口。
除以上输出形式外，还有“锁存”和“暂存”两种形式。
所谓“锁存”输出是指对发射端每次发的信号，接收端对应输出予以“储存”，直至收到新的信号为止；“暂存”输出与上述介绍的“电平”输出类似。
英文原稿来自：百度文库Infrared remote controlPeople’s eyes can see the visible wavelength from long to short according to the arrangement, in order to red, orange, yellow, green, green, blue, violet. One of the red wavelengths for 0.62-0.7 6 muon m, Purple is 0.38 wavelength range- muon m. Purple is shorter than the wavelength of ligh t called ultraviolet ray ,red wavelengths of light is longer than that of infrared light. Infrared remot e control is to use wavelength for 0.76- 1.5 muon m between the near infrared to transfer control si gnal.Commonly used infrared remote control system of general points transmit and receive two pa rts. The main component part for the launch of infrared light emitting diode. It is actually a special light emitting diode, due to its internal material differs from ordinary light emitting diode, resultin g in its ends on certain voltage, it is a rather infrared light. Use of infrared light emitting diode the infrared wavelengths, for 940nm appearance and ordinary, just the same light emitting diode five d ifferent colors. Infrared light emitting diode generally have black and blue, transparent three colors . Judgement of infrared light emitting diode and judgment method, using a multimeter to ordinary diode electric block measure of infrared light emitting diode, reverse resistance. The infrared light emitting diode luminescence efficiency to use special instrument to measure precise, and use only spare conditions to pull away from roughly judgement. Receiving part of infrared receiving tube is a photosensitive diode.In actual application of ir receiving diode to reverse bias, it can work normally, the infrared receiving circuit application in diode is used to reverse, higher sensitivity. Infrared receiving diode usually have two round and rectangular. Due to the power ofinfrared light emitting diode(or less commonly 100mW),so ir receiving diode received signal s is weak, so will increase high-gain ones. The amplifier circuit.In common CX20106A,etcPC1373H muon infrared receiving special amplifier circuit. In rec ent years both amateur or formal products, mostly using infrared receiving head finished. The hea d of infrared receiving product packages generally has two kinds: one kind USES sheet shielding, A kind of plastic packaging. There are three pin, namely the power is(VDD),power negative (GN D)and data output(VO or OUT).Infrared receiving head foot arrangement for types varied, manufa cturer’s instructions. Finished the advantages of infrared receiving head is not in need of sophisticated debugging and shell screen, use rise as a transistor, very convenient. But when used in the inf rared receiving attention finished first carrier frequency.Infrared remote common carrier frequency for 38kHz, this is transmitted by using 455kHz Ta oZhen to decide. At the launch of crystals were integer frequency, frequency coefficients, so com monly 12, so 455kHz/12 hundredth kHz 38kHz hundredth 379000. Some remote control system a dopts 36kHz, 56kHz,etc, general 40kHz launched by the crystals of oscillation frequency to decide .Infrared remote characteristic is not influence the surrounding environment and does not inter fere with other electric equipment. Due to its cannot penetrate walls, so the room can use common household appliance of remote control without mutual interference, Circuit testing is simple, as lo ng as given circuit connection, generally does not need any commissioning can work, Decoding ea sily, can undertake multiple remote control. Because each manufacturer produces a great deal of in frared remote application-specific integrated circuit, when need press diagram suo ji. Therefore, th e infrared remote now in household appliances, indoor close(less than 10 meters)in the remote con trol is widely used.Multiple infrared remote control system of infrared emission control buttons, there are many parts general representative of different control function. When pressed a button, correspondingly in the receiver with different output.Receiving the output state can be roughly divided into pulse, level, self-locking an interlock, data five forms. “The pulse output is according to launch” when the button, the receiver output ter minals output corresponding “effective”, a pulse width 100ms in general. “Level” refers to the out put launch press button, the receiver output corresponding output level, effective transmit to loose n the receiver level disappears. This “effective pulse” and “effective”, may be of high level is low, and may also depend on the output corresponding static state, such as feet for low, static high for e ffective, As for the static, “low” high effective. In most cases, “high” for effective. “since the lock ” refers to launch the output of each time you press the button, a receiver output corresponding cha nge, namely originally a state for high level into a low level, originally for low level into high leve l. The output power switch and mute as control etc. Sometimes also called the output form for “in vert”.“The interlock” refers to multiple outputs each output, at the same time only one output, Th e TV sets of this case is selected, the other is like the light and sound input speed, etc.“Data” refers to launch the output some key, use a few output form a binary number, to repr esent different keystroke.Normally, the receiver except a few data output, but also a “valid” output data, so the timely t o collect data. This output form with single-chip microcomputer or are commonly used interface. I n addition to the above output form outside, still have a “latch” and “temporary” two forms. The s o-called “latch” refers to launch the output signal of each hair, the receiver output corresponding, new store until you receive signals. “Temporary” output and the introduction of “level” output is si milar。