LED Light Bulb

We have a brief introduction of LED signal module in last article. Now we are talking about more about the technical issues of LED signal module.

Many technical issues have been overcome since the initial implementation of LED traffic signals. The 2005 ITE specification addresses many of the early problems with LEDs. The following discusses the issues that have been addressed, as well as some issues that are still outstanding.

An LED module is a system of transformer; electrical characteristics of an LED module are component- and-design-dependent. The slow voltage decay can be interpreted by the signal monitor as two conflicting indications being energized simultaneously causing the monitor to place the signal into conflict flash. This condition has been addressed and corrected in the new specification.

A far worse condition than a signal monitor falsely placing a signal in conflict flash is a scenario that would warrant a conflict flash condition that is ignored or missed. There have been reports of malfunctioning LED modules that no longer emit light, which continue to present an electrical load to the conflict monitor, giving the monitor the appearance of normal operation. This potential problem has been identified. However, it must be realized that the only true test is observation of the presence or absence of adequate light output, which can only be inferred from LED electronics.