IEC Protection Classes for Electric Appliances

IEC protection classes differentiate protective-earth connection requirements for devices.

Class 0 - non-earthed product, illegal for sale in UK.
Class 1 - connected to "earth" by an earth conductor.
Class 2 - double-insulated, labelled with square inside a square

A-weighted Decibels (dbA ratings)

A-weighted decibels, abbreviated dBA or dBa, measures loudness of sounds whereby the decibel level of sounds at low frequencies are reduced, since the human ear is less sensitive to those sounds (below 1000Hz). It is often used to describe the loudness of fans e.g . microprocessor cooling fans or bathroom extractor fans. 25 dBA is a human whisper in a quiet room.

FB Keys

FB keys are Fire Brigade keys. They are used for areas where the fire brigade or other service personnel may need to get access to: communal areas, cupboards and access points.

What is an IP Code?

IP Code refers to the Ingress Protection Rating of some device, regarding the degree of protection against intrusion of solid objects. It is meant to offer a higher degree of precision to terms such as "waterproof". The IP rating consists of two digits: the first refers to penetration by solid particles and the second by liquids. A second digit of 4 means the device is protected against splashing water, but not against water jets, and certainly not powerful water jets. It certainly can't be immersed (to any depth). The relevant standards body is the IEC (International Electrotechnical Commission).

US Mains electricity

US electricity is 120V and 60Hz. A travel adaptor is a minimum requirement to use appliances bought overseas for 220V systems, provided the expected voltage range is 100-240V.

For some appliances, a step-up voltage converter may be required (to bring 110V up to 220V).

HDMI

HDMI is the High-definition multimedia interface, designed as a digital replacement for analog video standards. Production of consumer products using HDMI started in late 2003. The companies that founded HDMI were Matsushita, Hitachi, Sony, amongst others.

The latest version of the spec is HDMI 1.3. It has support for Deep Color (48 bit vs. the "normal" 24 bit). "Normal" 24 bit color means 16.7 million colors, but 48 bit color means 281 trillion colors.

HDMI together with DVI use TMDS (Transition-minimized differential signaling), a technology for high-speed serial data transmission. TMDS was developed by Californian company Silicon Image, which trades on NASDAQ.

Wall Plugs

Wall plugs help to give a firm hold in solid materials, through which you can drive a screw.