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voltage values and provide constant current (Dias 2012; ABILUX 2017). However,
the fact that LEDs may operate at low voltages and currents means that they do not
require a reactor (as opposed to fluorescent lights); therefore, the circuits used to
switch LEDs on are simpler (Oliveira 2007; Dias 2012).
In the effort to develop products with better lighting output, high power values
are used in LEDs. Nevertheless, the heat generated in the process increases substantially, degrading phosphor, reducing brightness, affecting colour, and decreasing life
cycle and luminous efficiency of these products (Castro 2013; Jang et  al. 2014).
Compact LED fittings such as retrofit bulbs normally require a cooling device as a
means to transfer heat to the environment. This prevents overheating, maintaining
operation temperatures at ideal values. This cooling device is the largest element in
a LED fitting, and it usually is produced using aluminium or a ceramic material that
dissipates heat (Castro 2013; Gassmann et al. 2016).
Fig. 9.3 Types of LED
bulbs. (Source: ABILUX
2017)
E. C. A. dos Santos et al.