A wide variety of protective devices can be considered for the power supply and LED driver. The circuit in Fig. 1 is an example that illustrates switch mode power supply (SMPS) protection in an LED street-lighting system. In this circuit, the AC fuse provides basic fire protection against major system failures that could cause an overcurrent condition but must be able to tolerate between 3kA to upwards of 6kA surges without opening. The DC fuse is for fast acting overcurrent protection in the event of a downstream component failure in the DC-to-DC converter or LED driver circuit.
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