| 摘要 |
A solid state light apparatus ideally suited for use in traffic control signals having a Self Diagnostic/Predictive Failure Analysis (SD/PFA) function facilitating a real time status of the signal as well as prediction of failure years in advance of the actual failure. Unlike incandescent signals, all LED based signals degrade over time until they are no longer in DOT light output specs. Current state of the art solid state signals must be periodically monitored to see if the light output is in spec. This is done by having DOT or contracted personnel ascend in a bucket truck and place a light meter on the signal typically on an annual basis. A signal system with SD/PFA coupled with a modem or RF link provides real time data, without the use of a bucket truck on the status of the signal. The system also provides data which allows the determination via an algorithm of when the signal will go below light output specs in the future. |
