The siemens is the standard unit of electrical conductance. It is the inverse of resistance and is equal to one divided by resistance, or current divided by voltage. One siemens is equal to one ampere per volt. History of the Siemens The siemens was defined at an international conference in 1881, and is named after …
Trickle charging, also called float charging, is the replacement of charge lost through self-discharge. Trickle chargers work at a lower rate than quick chargers, and are used to keep a battery at full charge, not to charge it from empty. Some battery chargers use electronics to control both quick and trickle charge modes, allowing them …
Basic diodes are constructed from two semiconductor materials, germanium or silicon, to create a basic PN-junction. When two single diodes are connected to each other back-to-back, two PN-junctions that are connected in series are created. They share a common N or P terminal, which forms the basis of a BJT or Bipolar Junction Transistor. The …
Satellite radio refers to a number of subscription-based radio broadcasting programs that are available in the US, Europe, and elsewhere that are dependent on satellites to provide mobile users with constant radio access. While terrestrial-based FM radio stations only provide radio broadcasts to a specific area, usually confined to the city they are located in, …
An Internet repeater is a device that allows amateur radio operators to communicate with each other over the Internet, much like how VoIP software allows telephone operators to communicate with each other over the Internet. Internet repeaters should not be confused with wireless repeaters, which allow users to extend the range of a wireless network. …
Business band stands for a series of frequencies in the UHF and VHF two-way radio bands, which are exclusively reserved for businesses to communicate within limited ranges. Of course, not just anyone can use this bandwidth. Anyone that wants to use the business band must first receive a license from the Federal Communications Commission, also …
Radio-Frequency Identifier (RFID) technology has become really popular because of the various advantages it comes with. However, such as passports, national identity cards, credit cards etc have become a serious security concern. Two electrical engineering students (Ilan Kirschenbaum and Avishai Wool) from Tel Aviv University wrote a paper titled "How to Build a Low-Cost, …
A photoresistor is a light-dependent resistor which slowly loses its resistance when exposed to high levels of ultraviolet light. As a result, photoresistors convert light energy into electrical energy. Photoresistors are used in a wide variety of devices to detect the presence of light, control a device, or activate a system. They are usually dependent …
An attic antenna is one that is mounted inside of an attic in order to provide maximum range as well as protection from rain, snow, sun, wind, and animals. Attic antennas are rather common and provide quality reception for those who live in rural areas, away from most radio transmitters. While attic antennas do not …
DVB-RCS stands for Digital Video Broadcast – Return Channel Satellite. DVB-RCS is part of the DVB standards for satellite communication, DVB-S and DVB-S2. The purpose of DVB-RCS is to provide a return channel to enable Internet and other data services over satellite. ViaSat’s LinkStar system is one of the VSAT satellite broadband implementations which support …