Similarly, machines can be overloaded too. Those that were designed for a particular system are often pushed to their limits when new requirements emerge.

Just like final straw that breaks camel's back, electrical machines too, can reach their breaking point. If there is no vacation for them, they will burn.

Fuses and circuit breakers are designed to stop current in a circuit before any damage can occur - create a vacation or a break for them.

A circuit breaker is one of ways to prevent motors (or other electrical machines) from burning due to overloading. All electrical motors produce heat when running. At time of a fault, this heat builds up at a much higher rate than it can be dissipated. This can result in damaged equipment, fire or even explosion.

The electrical protective device like circuit breaker is designed to de-energize circuit before this heat level becomes dangerous.

There are basically 2 means of activating a break - thermally (heat) or magnetically.

Thermal circuit breakers make use of bimetallic strips that will bend due to different expansion rates of each of metals in strip. The bending of strip will move a tripping mechanism latch that will then open up contacts of circuit breaker.

However, there’s no doubt the industry sees HD video as a consumer format and prices will come down over next couple of years. This Sony HD camcorder is just start of what is sure to be an avalanche of HD camcorders from electronics companies over next few months.

So, does this mean we can all look forward to shooting Hollywood-quality home movies in future? Not quite. Although its true that some Hollywood fetaures, such as George Lucas’ ‘Star Wars: Attack of Clones’ are being shot in high definition video, its not same high definition as is shot and recorded by these camcorders.

If you look again at that Sony quote, you’ll see important label, 1080i. If you’re familiar with HDTV, you’ll know that 1080 refers to 1080 lines of vertical resolution and ‘i’ means video is interlaced. 1080i is one of two most common HDTV formats, other being 720p (720 lines, progressive scan).