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发表于 2015-4-28 15:05:14
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你可以多试试看型号,比如台湾的亿光,国产的兰丰,诚强光电(CHQ)等等。不过国产的品控,一致性比较差。
还有不推荐HS0038虽然,虽然你说新出的是HS0038D,但是按照老外的脾气,是不会随便去大动其内部设计的。
因为这是个很古老的接收头,所以肯定没有用上最新的技术。
Vishay方面,现在主推的应该是TSOP34838(AGC2)/TSOP34438(AGC4),我推荐你选后者。
更具Vishay的文档和实际应用(只是感觉,没有很严谨),阳光下可用,只是灵敏度降低。
给你看官方的文档说明:
The primary performance characteristic to evaluate when choosing an infrared receiver is its ability to receive data signals and to suppress all other sources of noise. An infrared receiver may have the industry’s best transmission distance and lowest price but, if susceptible to noise, be a bad choice for design engineers. If it is susceptible to noise, repeated remote control unit command entries are required — noise from other light sources in the room is being received at the same time as the emitted data and corrupting the signal. This noise might include emissions from incandescent, halogen, neon, fluorescent and compact fluorescent lamps; liquid crystal and plasma displays; and sunlight.
IR receiver control circuits provide feedback of the received signal to the automatic gain control (AGC) circuitry. This reduces the gain of the amplifier in the presence of noise signals to ensure that no spurious pulses are received and keeps the gain high if data is being received. Ambient DC light sources, like incandescent and halogen lamps or sunlight, will cause the gain to be reduced. When turned on, an incandescent lamp may produce spurious pulses at the output of the infrared receiver until the AGC has settled the gain to a lower level. After this, the noise of the lamp will be filtered but at the cost of reducing the maximum receiving range.
Other than an effect on range, DC light sources will not corrupt data signals. AC signals are another story. While applying a 10W/m² DC signal, an AC signal that is 1000 times lower (1mW/m²) can still be received by the infrared receiver. Fluorescent lights and flat screen TV emissions are the most common AC noise sources affecting an infrared receiver. Figure 1 charts the relative IR receiver sensitivity of the TSOP34836 receiver along with the near infrared emission produced by a “warm” fluorescent light. This large optical noise at 1014 nm can be a corrupting source.
The AGC circuitry utilizes some inherent differences to distinguish data from noise. But because there are so many different possible noise sources and coding schemes, no single AGC algorithm can completely suppress all noise and pass encoded data signals. To solve this problem, Vishay has devel- oped four different AGC response algorithms based on coding schemes and ambient noise conditions. These AGC algorithms allow developers to choose the most appropriate receiver for their expected operating environment. For example, AGC1™ was developed for compatibility with any coding scheme in low noise environments and for data transmission up to 4 kbit/sec. AGC2™ was developed for typical remote control coding schemes with a reliable function in noisy environments, AGC3™ for the operation with fast coding schemes and bet- ter noise suppression and AGC4™ for best noise suppression including dimmed LCD backlighting and Plasma displays. In Figure 2, AGC1, AGC2, AGC3 and AGC4, common infrared data signals and common noise sources are graphed. Any signal below the curve will be received as a legitimate data signal by the receiver and passed to the output. Any signal above the curve will be filtered out as noise.
Each AGC type responds to noise at a different rate. Data and noise signals can be distinguished by the receiver according to the carrier frequency, burst length and maximum envelope duty cycle. The following figures demonstrate the affect that strongly modulated fluorescent light and plasma emissions have on a receiver that was not correctly chosen for its environment. Figure 3 shows an oscilloscope image of the receiver output (blue) when receiving the RC5 code, using a receiver with AGC1 without disturbing noise (red).
Figure 4 shows the AGC1 receiver output when the same RC5 signal is being received in the presence of a strongly modulated fluorescent light. Note that the transmitted signal is corrupted by spurious pulses. In this case the data signal would need to be sent again; repeated pressing of the remote control unit buttons.
Figure 5 shows the AGC1 receiver output when receiving the same RC5 code plus noise from the plasma television in which it is assembled. It would be nearly impossible to use the remote control unit given this level of noise being passed by the receiver.
To filter these noise signals, a receiver with a higher AGC level is required. For the fluorescent light and plasma displays, moving from AGC1 to AGC2 would likely solve the problem. For devices with dimmed LCD backlighting, it is recommended that an AGC4 receiver be used.
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Google的机器翻译:
最主要的特性来评价时,选择一个红外线接收器是它能够接收数据信号,并抑制噪声的所有其他来源的能力。红外接收器可能具有业界最佳的传输距离,最低的价格,但如果容易受到噪音,是设计工程师一个不错的选择。如果它易受噪声,反复遥控单元命令条目是必需的 - 是在同一时间作为发射数据被接收到在房间其他光源的噪声和破坏信号。这种噪声可能包括从白炽灯,卤素灯,霓虹灯,荧光灯和紧凑型荧光灯的排放;液晶和等离子体显示器;和阳光。
IR接收器的控制电路提供所接收的信号到自动增益控制(AGC)电路的反馈。这减少了在噪声信号的存在的放大器的增益,以确保没有虚假脉冲被接收,并保持高如果正在接收的数据的增益。环境直流光源,如白炽灯和卤素灯或阳光下,将导致增益降低。开机后,白炽灯可以在红外接收器的输出端产生虚假的脉冲,直到AGC已落户的增益,以一个较低的水平。在此之后,该灯的噪声将被过滤,但在减少了最大接收范围的成本。
除了对范围内的效果,DC光源不会破坏数据信号。 AC信号是另一个故事。同时施加10W /平方米DC信号,AC信号是低1000倍(1毫瓦/平方米)仍然可以由红外线接收器接收。荧光灯和平面电视的排放量是影响一个红外接收器的最常用的交流噪声源。图1的图表的TSOP34836接收机以及由一个“暖”荧光所产生的近红外发射的相对IR接收器的灵敏度。在1014 nm的这家大型光学噪声可能是一个腐败的源头。
该AGC电路采用了一些固有的分歧,从噪音区分开来的数据。但是因为有这么多不同的可能的噪声源和编码方案,没有一个AGC算法可以完全抑制所有的噪声,并通过编码的数据信号。为了解决这个问题,威世开发出来四个不同的AGC响应根据编码方案和环境噪声的条件的算法。这些AGC算法使开发人员能够选择最合适的接收器,其预计的经营环境。例如,AGC1™被用于与在低噪声环境中的任何编码方案的相容性和用于数据传输多达4千比特/秒的开发。 AGC2™是为典型的远程控制编码方案,在嘈杂的环境中的可靠功能发达,AGC3™用于快速编码方案和更好的噪声抑制和AGC4™操作以获得最佳的噪声抑制包括调暗LCD背光和等离子显示器。在图2中,AGC1,AGC2,AGC3和AGC4,通用红外数据信号,并共同噪声源作图。该曲线以下的任何信号将被接收作为由接收一个合法的数据信号,并传递到输出。曲线以上的任何信号将被过滤掉噪音。
每个AGC类型响应噪音以不同的速率。数据信号和噪声信号可以由接收器根据载波频率,突发长度和最大包络占空比来区分。下面的附图显示出影响强烈调制荧光灯和等离子体排放,对为没有正确地选择对于其环境的接收机。图3示出了当接收到的RC5码,使用具有AGC1的接收机,而不会干扰噪声(红色)的接收器输出(蓝色)的示波器图像。
图4示出了当正被接收在强调制荧光的存在相同RC5信号AGC1接收机输出。需要注意的是所发射的信号是由伪脉冲损坏。在这种情况下,数据信号需要被重新发送;反复按压遥控器的按钮。
图5示出当接收到从等离子电视,其中它被组装在相同的RC5码加噪声的AGC1接收机输出。这将是几乎不可能使用给定的噪声的这一级被传递由接收机的遥控单元。
过滤这些噪声信号,具有较高水平的AGC的接收器是必需的。对于荧光灯和等离子体显示器,从AGC1移动到AGC2可能会解决这个问题。用于与调暗的LCD背光设备,则建议一种AGC4接收机中使用。
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