What is a G4 light bulb
A G4 light bulb is a bi-pin base lamp that runs off a low-voltage power supply. “G4” is a base designation which means the base has two pins and the gap width between the pins (center to center) is 4 millimeters. The G4 light bulb finds its usage in a variety of applications where space is a premium. These bulbs are used in chandeliers, wall sconces, ceiling lights, under cabinet lights, decorative lights, landscape lights, and other light fixtures or lighting systems in which the low voltage (12V) power supply is readily available. G4 bi-pin base light bulbs are also the usual choice of light source for marine and RV applications. They’re used in cabin lights, dome lights, step lights, and other smaller sized lighting systems.
DC operation
G4 LED bulbs are long life, energy efficient replacements for halogen bulbs. Because LEDs run natively at 12V, the LED bulbs can be designed with much less complexity when compared with line voltage LED lamps. In line-voltage operated systems, the driver that converts the AC line voltage into a constant load voltage or a constant load current is often the bottleneck both in terms of efficiency and reliability.
Performance
A G4 LED bulb is basically an LED module because it doesn’t contain an LED driver. The “LED module” can have roughly 10 – 15 times the rated product life of the halogen bulbs (20000-30000 hours versus 2000 hours) and 7-10 times the luminous efficacy (90-120 versus 12-15 lm/W). The lifespan of a G4 LED bulb largely depends on its thermal management. Some products do not have an adequately dimensioned heat sink. Buildup of thermal energy within the LED bulb can accelerate the kinetics of temperature-induced degradation, leading to permanent lumen depreciation and color shift.
Light source
G4 LED bulbs typically use mid-power plastic LED packages as the light source. They can be assembled to resemble the emission pattern of a G4 halogen bulb or to provide a light-emitting surface in a disc shape. Some G4 LED products use a COB LED to produce an omni-directional beam of white light.
