An LED-based light system includes a primary light source and at least one
redundant light source. The primary light source is activated by itself
and the performance of the light source is measured to determine whether
nor not to drive the redundant light source. The redundant light source
is activated when the performance measurements indicate that a
performance characteristic is not being met by the primary light source
alone. The first light system can be activated in combination with the
redundant light source once the decision is made to activate the
redundant light source.