Linear Tech on how to power LEDs and protect them

LEDs are not a “heater” like an incandescent bulb, which is essentially a resistor, they are essentially a diode. As such, they need a fairly tightly regulated current and voltage, which is generally provided by an LED driver circuit. However, this circuit is susceptible to open or short circuit conditions – so care must be taken during the design process to protect against potential occurrences. Also, high temperatures negatively impact an LEDs useful light output, so care must be taken when designing both their driver circuit and its housing.