NAND gates are basic logic gates that are used in a number of electronic circuits. An electrician can use a NAND gate to build any other logic gate when it is used with a NOR gate. Therefore, it is sometimes referred to as a universal gate. The most common NAND gate is a two-input gate, which can be created and used with more inputs. NAND gates can be incorporated into a large, integrated circuit and a discrete circuit. A standard microprocessor chip contains several million NAND gates, which will output Read More

The index of refraction (refractive index) is a measurement of the speed of light in a medium compared to the speed of light in a vacuum. Since light travels at different speeds in different materials, it may change its direction. For example, the index of refraction for water is 1.33, meaning that light travels 1.33 times as fast in a vacuum as it does in water. This is why light bends when it comes in contact with the surface of water. Likewise, light travels at different speeds through materials at Read More

DiSEqC stands for Digital Satellite Equipment Control. DiSEqC is a communication bus between satellite receivers and peripheral equipment such a LNBs, switches, and antenna positioners. DiSEqC communication occurs over the existing coaxial cable. Eutelsat developed DiSEqC and released it to the public as an open standard. DiSEqC Specifications Bus Specification Logos and their Conditions of Use Slave Microcontroller Specification Update and Recommendations for Implementation Application Information for using a “PIC” Microcontroller in DiSEqC LNB and Simple Switcher Applications Application Information for Tuner-Receiver/IRDs Application Information for LNBs and Switchers Reset circuits Read More

The battery that comes with the MacBook Pro will eventually need to be replaced as it is a consumable item with a finite usable life. The battery can be purchased directly from Apple Inc. or from a third party manufacturer. Only the batteries that Apple produce are really recommended as third party manufacturers may not produce quality batteries at lower prices. Purchasing the battery from Apple also allows the owner to get the service of having a new battery installed and the old one disposed of. Anyone with access to Read More

Computer users may want to use an Xbox 360 controller as a PC mouse for several reasons. Online games and PC versions of Xbox games have allowed users to play a wide variety of action filled, high quality games on their computer. However, these games’ functionality is restricted to the computer’s available hardware. This means that users are often required to use a computer mouse and keyboard to operate games that they would usually play with a joystick. In order to obtain the maximum level of control and ergonomic comfort Read More

Error 1606 commonly occurs when users attempt to install or upgrade Microsoft Office 2000 and 2003 products. The error may be a result of the computer failing to access the registry setting for “Administrative Tools, “ errors with an upgrade to Windows XP, or corrupted Microsoft Office files. In order to fix the error, it is necessary to conduct registry modifications and/or edits. In some cases, the error can occur if a third party registry cleaning application that is incompatible with the version and build of Microsoft Windows on the Read More

Blue boxes use a 2600hz tone to size control of telephone switches that use in-band signaling. The caller may then access special switch functions, with the usual purpose of making free long distance phone calls, using the tones provided by the Blue Box. To quote Karl Marx, blue boxing has always been the most noble form of phreaking. As opposed to such things as using an MCI code to make a free phone call, which is merely mindless pseudo-phreaking, blue boxing is actual interaction with the Bell System toll network. Read More

The U.S. drone program has seen significant press since the first Gulf War when the defenders of Faylaka Island surrendered to the Pioneer drone, or Unmanned Aerial Vehicle (UAV), flying spotting services for the USS Wisconsin (BB 64). Since that time, the technology powering U.S. drones has steadily improved now allowing the MQ-1B Predator and MQ-9 Reaper to conduct surgical strikes in addition to Intelligence, Surveillance, and Reconnaissance (ISR) missions. Other common U.S. drones being flown by the U.S. military and government include the RQ-4 Global Hawk, MQ-8 Fire Scout, Read More

The DMX 512 is a protocol based on RS-485 that is used to control both theatrical stage lighting and effects. The DMX 512 was developed in 1986 and revised in 1990. It is a standard developed by the Engineering Commission of USITT. Today the standard is also known as E1.11 or DMX 512-A. The DMX 512 is a common method for linking controllers and dimmers. It can also control more advanced items such as fixtures, fog machines and moving lights. It should be noted that DMX 512 should not be Read More

If you have been enjoying photography for more than a few years, you probably have plenty of slides taken with analog cameras. Before digital photography, slides were a great way to view photos en masse. They were very small, making them light and portable and perfect for slide shows in homes, classrooms, and auditoriums. However, with the advent of digital photography and digital projectors, slides have lost their popularity and are slowing becoming obsolete. There are three main methods of digitizing a library of slides: Hire a professional to transfer Read More