Types of light bulbs
By
Terry Rawkins
Copyright © 2020
I
Light Bulbs
The familiar light bulb has been with us for over 100 years and is now changing both it's looks and the technology that make it work.
1 Physical outline
The traditional light bulb type is known as the A-series light bulb. For example an A60 bulb which is 60 mm wide at its widest point and approximately 110 mm in length.
2 Base or Cap type
The base, the part that you fit into the light fitting is changing, it's now smaller and easier to produce than the old type.
The original A-series light bulbs in the UK would have been of the older bayonet twist type base known as BC
for bayonet cap or sometimes B22. There is also a small bayonet SBC or B15
Bayonet Cap
Edison Screw
Some A60 light bulbs in the UK have an E27 type base. The E27 or Edison Screw ES indicates a screw connection of size 27 mm
Small Edison Screw
A smaller size base is also available, the E14 or Small Edison Screw SES which has a 14 mm threaded base.
GU10 Base
Popular spotlight fittings typically use a GU10 turn-and-lock base.
So they cannot be accidentally interchanged with low-voltage lamps the GU10 is distinguished from the lower-voltage MR lamps by the U-shaped ceramic base.
The GU10 is a 2-pin bayonet like base with 10 mm distance between pins.
Lamps with a GU10 base can be used anywhere in the home, from the bathroom to workspaces where you want a little extra focus. As with the older, less efficient Halogen GU10, the LED GU10 features two pins at the base, which means in most cases they can be retrofitted into existing halogen fixtures.
There are adaptors / converters that enable you to use a GU10 bulb in a BC or ES light fitting.
3 Lighting technology
The modern incandescent light bulb, with a coiled filament of tungsten, was first patented in 1906, it had been developed from the carbon filament lamp introduced in C 1880.
Less than 3% of the input energy is converted into usable light.
Incandescent bulbs are being phased out in many countries due to their low energy efficiency.
Halogen lamps
Halogen lamps, which are usually much smaller and operate at a higher temperature than a standard incandescent lamp of similar power and operating life are used in certain applications. Halogen lamps produces light with higher luminous efficacy and colour temperature.
Halogen lamps should not be touched with bare hands, oily fingerprints can create local hotspots which can damage the glass bulb.
LED
An LED lamp or LED light bulb is an electric light for use in light fixtures that produces light using one or more Light Emitting Diodes.
LED lamps have a lifespan many times longer (15 times) than equivalent incandescent lamps, and are significantly more efficient than most fluorescent lamps.
Similar to incandescent lamps (and unlike most fluorescent lamps), LEDs come to full brightness immediately with no warm-up delay.
Frequent switching on and off does not reduce life expectancy. Light output decreases gradually over the lifetime of the LED
Of the three types of lamp mentioned here the LED lamps are perhaps 6 times more efficient than the old incandescent bulbs. Because of this the older types are now being phased out in many jurisdictions .
Reference material
https://en.wikipedia.org/wiki/A-series_light_bulb
https://en.wikipedia.org/wiki/Edison_screw#Types
https://en.wikipedia.org/wiki/Bi-pin_lamp_base
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28 December 2020