AC-sourced LED Light Fixtures (LED Light "Bulbs")
Figure 1 is also the block diagram for a typical LED AC light fixture but some of the protection elements would not be used. LED lighting fixtures have all of the same operational circuits as their larger and much more expensive industrial counterparts, but the threats and motivation for circuit protection are quite different.
LED light fixtures are sold with minimal warranties and compete largely on price. Therefore, the pressure is on the designer to drive out costs, and circuit protection is usually an easy place to cut corners because it isn't essential to the function of the light bulb. Fire safety requirements can sometimes be met by using a thin circuit board trace as a "poor man's fuse". This may meet the safety tests where components are shorted or opened, but they will not interrupt overload conditions caused by leaking electrolytic capacitors on the input stage. The resulting failure modes are scary with smoke and bad smell as a real possibility. The use of an actual fuse is the only real solution.
As in the industrial lighting solution, an MOV on the input is a must, as the voltage withstand margins on the electronic components are much smaller on these price competitive goods. Space constraints and budget issues will likely drive the selection to a much smaller MOV device. A smaller MOV will not protect as well, but no protection at all can lead to early failures at the first lightning storm. After investing in an LED lighting fixture, consumers will likely switch preferences to another brand if they have a bad initial experience.