户外LED照明

High brightness LEDs are now being used in many different lighting applications such as outdoor display boards, traffic signals, street or tunnel lighting, airport runway lighting, etc.

LED lighting offers many advantages, including extreme long life and high efficiency, though outdoor LED lighting applications require special attention to protection due to environmental conditions and the added sensitivities on LED circuits. The engineers who design lighting products must be concerned with reliability, especially in applications where maintenance is difficult and where the failure of LED strings could jeopardize safety.

The loss of one LED can result in the loss of the entire LED lighting string. One of the major causes of an electrical open in an LED is thermo-mechanical stress on the wire bonds. Other causes of LED open circuits are electrostatic discharge (ESD) events or surges induced by nearby lightning events.

Open LED protection is designed as an electronic shunt which provides a current bypass in the case of an open circuit caused by a single LED failure.