How to Add Audio to VideoWritten by Ross MacIver
Digital media is everywhere you look. Music and video production have made it to grass roots level thanks to affordability and widespread use of powerful computers. Inexpensive digital video cameras are widely available, and older analog video cameras can be connected to a computer through a video card to download movies to computer for editing, storage, and distribution to friends and relatives over internet.It has become fairly easy to edit your own videos, and there are many software packages available aimed at amateur. The Windows operating system has its own video editing package called Windows Movie Maker that allows you to produce professional-looking videos. As you explore this exciting new world, you will inevitably come up with need to edit audio portion of your video file. The sound quality of most video cameras is not great, so you may want to process sound or replace it all together with music or voice-overs. It is very easy to separate audio from video. Free software packages that do this task include Windows Media Encoder from Microsoft (if you are working with WMV video files) and VirtualDub (if you are working with AVI files). Either of these programs (and many others) allow you to save audio portion of video file quickly and easily.
| | Successful Motor Protection FormulaeWritten by Thomas Yoon
As we have discussed before, all overload relays have one major limitation - because they operate on line current, they do not directly sense motor temperatures.However, with proper heater selection and careful attention to factors that affect heater performance, overload relay can work extremely well to protect motors. Some of these factors that need close attention are: Motor full load current Motor temperature rise rating Service factor Ambient temperature at motor and at protector Motor locked rotor current ratio Starting time Duty cycle Locked rotor endurance time. If attention is not given to these factors, overload relay will perform poorly. The other factor to be considered is maintenance. Below are some maintenance routines: Cleaning - The overload relays should be cleaned periodically. Dirt or dust created by operating conditions in plant tends to settle around moving parts in device and prevent it from operating properly. Tightening connections - Because most overload relays make use of current flowing through heater elements to sense overloaded conditions, it is important that electrical terminals are not loose. Loose electrical connections can create extra heat and cause false tripping of relays.
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