Screw Cap

The Edison screw fitting is a system of light bulb connectors, developed by Thomas Edison and licensed starting in 1909 under the Mazda trademark. Most have a right-hand threading, so that it goes in when turned clockwise and comes out when turned counterclockwise, like a hardware screw. There are rare instances where these are reversed to deter theft, so that they cannot be used in other light fixtures. Screw bases suffer from two disadvantages. Firstly, the metal screw itself forms one of the contacts for the circuit. If the lighting system is not correctly wired, the metal screw can become energized, presenting an electric shock hazard to anyone attempting to change the bulb. Secondly, if the bulb unscrews in the socket for any reason, it can lose contact with the center contact and stop working until it is screwed-in tighter. This is not always a disadvantage, however: it provides a method for turning a single bulb off without using a wall or fixture switch, with appropriate precautions against the high heat of the bulb.


Product Image Item Name+ Price
LTES27-5 Watt

LTES27-5 Watt

Aluminum with Glass cover Φ60115mm 220-240V AC 5.0W 140 lighting angle 80 3528smd Epistar 1023mil 15-18Lm 270-300Lm 40W 6000K 40000 suitable...


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LTES27-5 Watt Sensor

LTES27-5 Watt Sensor

Item Type: Incandescent Bulbs Brand Name: RITA Luminous Flux: 460 Wattage: 5 Application: Indoor,Outdoor Certification: CE,RoHS Base Type: E27...


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LTPAR20-60SMD

LTPAR20-60SMD

Base: ES27 Wattage: 4 W Beam degree: 120 Voltage: 240v Colour: day white Lumen: 6500K, 280Lm Dimensions: 65mm x 85mm Lifespan: 50000hrs It can...


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LTPAR30-40SMD

LTPAR30-40SMD

Base: ES27 Wattage: 7.5 W Beam degree: 120 Voltage: 240v Colour: day white Lumen: 6500K, 550Lm Dimensions: 94mm x 88mm Lifespan: 50000hrs It can...


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LTPAR38-70SMD

LTPAR38-70SMD

Base: ES27 Wattage: 15 W Beam degree: 120 Voltage: 240v Colour: day white Lifespan: 50000hrs It can replace the incandescent, halogen and compact...


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