The connector ad E27 connection medium (called coarse fillet) represents the European standard together with the E14 connection, the latter called 'mignon' (small fillet). In the USA it is different: here the mains voltage is 110V (unlike 220-240 in Europe) and the standards are E26 (medium), E17 (intermediate) and E12 (candelabra).
Today for those who want to save on lighting costs there are LED bulbs, which can be found for sale with both con E27 connection both with E14 connection. The advantage of LED lamps is that, in addition to consuming less electricity, they last a lot of kind compared to traditional low consumption light bulbs.
Just to know, the 'E' that appears in the identification code of the bulb connections stands for 'Edison', Thomas Edison, the American inventor of the incandescent light bulb. In fact, it was he who developed the system of screw connectors for attaching the bulbs in 1909, which then became standard. The number following the 'E' instead indicates the diameter of the attachment in millimeters: E27 connection = Edison 27mm.
In fact Thomas Edison was a great entrepreneur as well as an inventor, very good at engineering and standardizing the processes related to his ideas. A little known thing is that in the invention of the incandescent lamp there was another who came before Edison, the German Heinrich Goebel, but it was the American who became famous because he was better able to spread and commercialize the discovery that opened the modern era .
Edison connections for lamps and IEC standards
Each type of attack corresponds to a standard assigned by the International Electrotechnical Commission (IEC standard) as in the table below.
- E5 5 mm - IEC 60061-1 (7004-25)
- E10 10 mm miniature - IEC 60061-1 (7004-22)
- E11 11 mm mini-candelabra - IEC 60061-1 (7004-6-1)
- E12 12 mm candelabra - IEC 60061-1 (7004-28)
- E14 14 mm small - IEC 60061-1 (7004-23)
- E17 17 mm intermediate Small - IEC 60061-1 (7004-26)
- E26 26-27 mm medium - IEC 60061-1 (7004-21A-2)
- E27 26-27 mm medium - IEC 60061-1 (7004-21)
- E39 39 mm giant
- E40 40 mm giant - IEC 60061-1 (7004-24)
As mentioned, the most common connector for light bulbs we have at home is the one with an E27 socket, or with an E14 socket (small thread).
A LED relamping, ie an intervention to replace traditional bulbs with others a LED technology, it can save you a lot of money. It also has the advantage that you can do it yourself, unless it is a large surgery.
An idea may be that of 'step-by-step' procedures by starting to replace a few bulbs and then, slowly, the entire lighting system. LED bulbs with E27 socket are also available online and can also be purchased one at a time. The ones on Amazon are valid in my opinion and the many positive customer reviews confirm this. You can buy them here:
From traditional teardrop bulbs:
Teardrop LED bulb E27 9.5W = 60W (60W warm white light)
LED drop bulb E27 6W = 40W (40W warm white light)
At spotlight type bulbs:
LED bulb E27 16W = 160W 1550 lumen (160W cold white light)
LED bulb E27 16W = 160W 1550 lumen (160W warm white light)
LED bulb E27 12W = 120W 900 lumen (120W cold white light)
LED bulb E27 12W = 120W 900 lumen (120W warm white light)