无线遥控器怎样工作外文及翻译.doc

附录 A 外文文献及翻译 How Remote Controls Work by Julia Laytonfrom: /remote-control.htm Introduction to How Remote Controls Work The worlds first remote controls were radio-frequency devices that directed German naval vessels to crash into Allied boats during WWI. In WWII, remote controls detonated bombs for the first time. The end of the great wars left scientists with a brilliant technology and nowhere to apply it. Sixty years later, some of us spend an hour looking for the remote before we remember there are buttons on the TV.In this article, well examine the infrared technology used in most home theaters, look at the difference between IR and RF remotes, find out the difference between a universal and a learning remote and check out some of the other high-tech features you can find on remotes today, like PC connectivity, RF extenders and macro commands.Infrared Remote Controls: The Process Pushing a button on a remote control sets in motion a series of events that causes the controlled device to carry out a command. The process works something like this: 1. You push the volume up button on your remote control, causing it to touch the contact beneath it and complete the volume up circuit on the circuit board. The integrated circuit detects this. 2.The integrated circuit sends the binary volume up command to the LED at the front of the remote. 3.The LED sends out a series of light pulses that corresponds to the binary volume up command. One example of remote-control codes is the Sony Control-S protocol, which is used for Sony TVs and includes the following 7-bit binary commands:Button 1 2 3 4 Channel up Channel down Power on Power off Volume up Volume down Source: ARRLWebCode 000 0000 000 0001 000 0010 000 0011 001 0000 001 0001 001 0101 010 1111 001 0010 001 0011The remote signal includes more than the command for volume up, though. It carries several chunks of information to the receiving device, including: ?a start command ?the command code for volume up ?th