Geostationary satellites are located exactly above the earth’s equator and revolve around the earth in a circular orbit. Their revolving speed and direction (west to east) are exactly same as that of the earth, which makes it look stationary from the earth’s surface. The exact altitude of these satellites above the equator is approximately 36,000 …
A fractal antenna is a diamond-shaped antenna that maximizes the total amount of material within a given amount of space that transmits or receives electromagnetic waves. Fractal antennas do this by making each section of the antenna its own separate dipole. Because of this design, fractal antennas operate at many different frequencies and wavebands, allowing …
A capacitor is used to store energy so that it can provide power to any kind of electrical appliance when it is needed. Over time, though, the capacitor does begin to wear out and when this happens, its effectiveness in powering the appliance can diminish. Therefore, conducting a simple test on the capacitor can provide …
Satellite images are taken by reconnaissance satellites that orbit the Earth at a relatively low altitude, between 300 to 600 miles (or 480 to 970 km). As the majority of today's satellites are custom made in order to accommodate particular needs of the designer, there is no standard on which photo imagery is based on …
A rheostat is an electrical component that has an adjustable resistance. It is a type of potentiometer that has two terminals instead of three. The two main types of rheostat are the rotary and slider. The symbol for a rheostat is a resistor symbol with an arrow diagonally across it. Rheostats are used in many …
Pulse Width Modulation, abbreviated as PWM, is a method of transmitting information on a series of pulses. The data that is being transmitted is encoded on the width of these pulses to control the amount of power being sent to a load. In other words, pulse width modulation is a modulation technique for generating variable …
Four digit security codes protect Kenwood car stereos from theft. If a thief steals a Kenwood car stereo, he/she will not be able to use the stereo until the secret four digit security code is entered. Unfortunately, many legitimate owners are also locked out of their Kenwood car stereos due to these security codes. This …
In the modern world of data and information, computer systems need circuits that are able to process and transfer that information. Because of this, a great deal of resources and innovation go into creating more advanced circuitry in order to increase data transfer rates and make computer systems smaller. This article will demonstrate how integrated …
Some materials have the ability to produce electricity when subjected to mechanical stress. This is called the piezoelectric effect. This stress can be caused by hitting or twisting the material just enough to deform its crystal lattice without fracturing it. The effect also works in the opposite way, with the material deforming slightly when a …
Capacitive reactance is a term used to describe an effect in capacitors that causes the capacitor’s resistance to change depending on changes in the electric field passing through it. Capacitive reactance is similar to resistance in that it can allow or block varying amounts of voltage in a circuit, but is different because it is …