LED driver circuits

A method for coordinating light emission from a plurality of warning light assemblies, each of said warning light assemblies comprising at least one light emitter and a driver circuit for applying a pattern of electrical energy to the at least one light emitter to produce a warning light signal, said method comprising:

• sensing an electrical potential of a synchronization line to which each of the driver circuits are connected, the synchronization line having applied thereto a first potential corresponding to an absence of a synchronization signal from one of the driver circuits or a second potential corresponding to the presence of a synchronization signal from one of the driver circuits, said sensing performed by a first electrical circuit in each driver circuit;
• generating a synchronization input to a controller in each said driver circuit corresponding to the presence of said second potential, said synchronization input generated by said first electrical circuit and occurring substantially contemporaneously with a change of the electrical potential of said synchronization line from said first potential to said second potential;
• generating a synchronization output corresponding to commencement of application of the pattern of electrical energy to the at least one light emitter, said synchronization output generated by the controller in each driver circuit;
• and
• applying said second potential to the synchronization line, said applying performed by said first electrical circuit in each driver circuit and triggered by and substantially contemporaneously with the generation of said synchronization output,
• commencing application of the pattern of electrical energy to the at least one light emitter from the driver circuit of each warning light assembly, said commencing triggered by the generation of said synchronization input if said synchronization input has been generated prior to generation of said synchronization output by the controller of said driver circuit.

A driver circuit for energizing a light emitter, said driver circuit comprising:

• an energizing circuit responsive to a first input to energize the light emitter;
• a controller connected and programmed to;
• monitor the state of a synchronization input to the controller;
• provide said first input to said energizing circuit in a predetermined pattern, initiation of said pattern alternatively controlled by the controller or by a change of state of said synchronization input;
• and
• produce a synchronization output indicating initiation of said pattern by said controller;
• and
• a synchronization circuit electrically connected to a synchronization line, said synchronization circuit responsive to a change in the electrical potential present on the synchronization line from a first electrical potential to a second electrical potential to provide said synchronization input to the controller and responsive to said synchronization output from the controller to apply said second electrical potential to said synchronization line,
• wherein initiation of said pattern is triggered by the change of electrical potential on the synchronization line if said synchronization input is present before the controller produces said synchronization output and initiation of said pattern is triggered by the controller if said synchronization input is not present before the controller produces said synchronization output.