Patent ID: 7847486

Claim:
A lighting system comprising: an array ( 100 ) of at least one light-emitting solid-state element, and a voltage source ( 10 ) that energizes the array, array state circuitry ( 125 ; Q 2 , R 2 ), electrically connected in series with the array ( 100 ) and sensing at least one state of the array; secondary circuitry ( 127 ; R 1 , Q 1 ; 200 , 201 , 202 ; 200 , R 4 , Q 1 ; 126 , 127 ) connected in parallel with the array ( 100 ); a switching component (Q 1 ; Q 1 , Q 3 ; 202 ) adjusting the current passing through the secondary circuitry in accordance with the sensed state of the array such that current through the array is maintained substantially constant; a load, included in the secondary circuitry, through which passes overflow current shunted from the array by the array state circuitry and the switching component; an excess current shunt path connected in parallel with the array and the secondary circuitry; excess current shunt circuitry that senses current flowing in the secondary circuitry and that shunts current in the secondary circuitry in excess of an excess current threshold to the excess current shunt path, whereby overflow current above a first threshold for the array ( 100 ) is shunted away from the array and excess current above a second threshold is shunted from the secondary circuitry to the excess current shunt circuitry; in which the array, the secondary circuitry, and the excess current shunt circuitry are in separate parallel, but switched electrical paths.