General Knowledge Questions on Technology

The IEEE (Institute of Electrical and Electronics Engineers) was formed in 1963 by the merger of the Institute of Radio Engineers (IRE, founded 1912) and the American Institute of Electrical Engineers (AIEE, founded 1884).

On December 12, 1901, a radio transmission received by Guglielmo Marconi resulted in the first transmission of a transatlantic wireless signal (Morse Code) from Poldhu, Cornwall, to St. John’s, Newfoundland.

SPICE (Simulation Program with Integrated Circuit Emphasis) was introduced in May 1972 by the University of Berkeley, California.

Some authorities are recommending TV’s, VCR’s and Stereo’s be connected to power strips with switches and turned off when not in use to save energy. Your remote will not work until power is switched back on.

It’s commonly used for MP3 players, computer BIOS code and “thumb” drives. Originally developed in Japan by Toshiba, it has become quite popular for products requiring non-volatile erasable memory. Flash devices have a limited number of erase cycles (typically 10,000 to 1,000,000 cycles) so they’re not as good a choice for applications in which the data changes constantly. However, since it has no moving parts (unlike a hard disk) it is an excellent choice for storing the operating code for small personal electronics like PDAs, cell phones, digital cameras, and the data in items like MP3 players

JVC (Japan Victor Corporation) and Matsushita (Panasonic) developed the VHS format to compete with Sony which developed the Beta format as the first home video cassette recorder. VHS originally stood for Vertical Helical Scan, but now means Video Home System.

It is a method of controlling the speed of an AC induction motor, whereby speed, current and torque can all be accurately controlled

The HF band is based on frequencies 3 to 30 Mhz. AM radio stations are in the HF band but normally are stated in kilohertz.

A collection of atoms or molecules that can be excited to a higher energy state is called an active medium. Before lasing can occur, the active media is “pumped”. The process of raising the atoms in the active media from a lower energy state to a higher state is like pumping water up from a well.

A given signal’s second harmonic is twice the given signal’s fundamental frequency. Harmonics are generated when there are non-linearities in an amplifier (there are always non-linearities). The worse the non-linearities, the more harmonics. A signal at 27.5 MHz (approximate frequency for US citizen’s band) would have a second harmonic at 55.0 MHz (on US channel 2!). Can you see why there might be problems? A CB operator might do well to place a low-pass filter on his radio.

“Noise figure” is one critical parameter for determining the “quality” of a low-noise, small-signal, amplifier, and perhaps more importantly, the sensitivity of the overall receiver system. It is especially important for VHF (very high frequency) – and higher frequency – designs where most of the undesired “noise” (noise that masks or overpowers the desired signals) is generated internal to the electronics itself. In HF (high frequency) applications, atmospheric noise plays a much larger role in determining overall useful sensitivity, so a circuit’s “noise figure” is less important.

CDs reproduce 44,100 samples per second. Which has a maximum frequency reproduction of 22,050 Hz, or just a hair past the upper limit of human hearing. In this way CDs can theoretically reproduce any frequency in the human hearing range.

Phil Zimmermann created the first version of PGP encryption in 1991. Pretty Good Privacy (PGP) is a data encryption and decryption computer program that provides cryptographic privacy and authentication for data communication. PGP is often used for signing, encrypting and decrypting texts, E-mails, files, directories and whole disk partitions to increase the security of e-mail communications.

The word “laser” is actually an acronym for light amplification by stimulated emission of radiation. Atoms or molecules of the active medium that have been excited to a higher energy level are stimulated by a passing photon to relax to a lower energy level and emit a photon that is indistinguishable from the passing photon, thereby increasing the number of photons like the incident one.

Extension cords can be a tripping hazard, and can be easily damaged, causing an unsafe situation. There are many ways of safely getting power to each work place, where wiring is protected and concealed.

An uninterruptable power supply (UPS) is a backup power supply, such as a battery, that provides emergency power in the event that power is lost from the main supply.

Neon lighting runs at a high voltage, typically above 1000 Volts. A fireman’s switch protects a fireman from receiving a shock when a water jet is sprayed onto the installation. The switches are red, and mounted in a conspicuous position. (This is specified by IEE Regulations (Europe), SANS (South Africa), UK Electricity regulations and many Asian countries. I am unable to confirm other countries’ requirements, so feel free to let me know.)

PAL and SECAM are standards used in other countries. RGB stands for red, green, and blue – the colors of light used to create an image in a color tv set and is often used as a format name for computer monitors

This voltage often remains in storage even if the set is unplugged. Although the voltage is very high it has very low power but it can be dangerous because your body jumps if brought in contact.

The flyback is usually connected to the system that pulls the electron beam across the screen in one direction to ‘paint’ a line of the image and then returns in the other direction much faster.

Useful in tuning and filtering circuits, it blocks DC while passing AC. How much charge a capacitor can store is its capacitance, measured in farads.nn

Amplitude modulation was the first type to be used in radio. It works well with HF and morse code.

The terminals of FETs are called gate, drain and source. You might be more familiar with bipolar junction transistors (BJTs), which have terminals called base, collector and emitter. FETs were conceptualized first, but BJTs were easier to produce and so developed sooner.

The first laser was a solid state laser. Solid state refers to any solid material like a glass rod. Diode lasers are very common because they are used to read compact disks and digital video disks in computers, CD players, and DVD players. Before diode lasers, the most common type of laser may have been the helium-neon laser, in which the active medium is a combination of the two gasses helium and neon.

UPS stands for Uninterruptible Power Supply. Examples of equipment that may require a UPS supply are computers, fire detection systems, hospital operating theatre equipment and escape route lighting.

According to many stories surrounding the origin of the compact disc, 74 minutes was settled on because it would comfortably contain all of Beethoven’s 9th symphony on one disc. Although some stories reference a specific Sony higher-up who claimed this as his favorite piece of music, stories differ. All that’s known for sure is that Sony insisted on this and won out over Phillips’ original 60 minute proposal.

Spontaneous emission is what you see with most “glow in the dark” toys. You excite the toy by exposing it to bright light, then the toy glows in the dark by spontaneously emitting photons as the excited atoms relax back down to their normal state.

About the same as as the most popular light bulb size.

Electricity is voltage and current. Voltage is electrical pressure, and current is the flow of charged particles. The difference between alternating current (AC) and direct current (DC) is that the electrons in an AC circuit regularly reverse their direction. In a DC circuit electrons always flow in the same direction.

On April 6, 1914, Hiram Percy Maxim proposed the formation of the American Radio Relay League.

The term EMF, or Electromotive Force, its use now in decline, is attributed to Italian physicist Alessandro Volta (1745-1827). Today we generally use the term “voltage” – can you guess why we call it that?

Amplitude modulation was the first type to be used in radio. It works well with HF and morse code.

RF is radio frequency. IF is intermediate frequency used inside the TV for processing. AF is audio frequency. SAP is second audio program which may have another language or other soundtrack as an option to the main soundtrack.

The transformer is used to transform a medium voltage supply to a low voltage supply, e.g. from 11 000 V to 400 V. A transformer is rated in kVA, kilo-Volt-Amps, which is a measurement of electrical power.

Theodore Maiman built the first working laser using a ruby rod while working at Hughes Research Laboratories in Malibu, California. It lased for the first time on May 16, 1960.

A chip found in alomst every microprocessor

Novell (based in Provo, UT) created NetWare which is still one of the most used PC networking systems in the world.