An LED array switching apparatus, comprising: a plurality of LED segments (D1 to Dn) connected in series, each LED segment having a forward voltage; a voltage supply coupled to the plurality of LED segments; a plurality of constant current sources (G1 to Gn), coupled to outputs of LED segments (D1 to Dn), respectively, each of the constant current sources being configured to switch between a current regulating state and an open state such that as the voltage of the voltage supply increases, LED segments are switched on and lit to form a higher forward voltage LED string, and as the voltage of the voltage supply decreases, segments are switched off and removed from the LED string starting with the most recently lit segment; further characterised by comprising: a toggle switcher that has an output that toggles between a first output and a second output complementary to the first output; a first switch coupled to the first output of the toggle switcher; a second switch coupled to the second output of the toggle switcher and to the plurality of constant current sources; and a plurality of second constant current sources (GT1 to GTn) coupled to outputs of LED segments (Dn to D1), respectively, and to the first switch, wherein when the first output of the toggle switcher is active, the first switch becomes closed and the second constant current sources are disabled and the constant current sources are active, and when the second output of the toggle switcher is active, the second switch is closed and the constant current sources are disabled and the second constant current sources are active. a plurality of LED segments (D1 to Dn) connected in series, each LED segment having a forward voltage; a voltage supply coupled to the plurality of LED segments; a plurality of constant current sources (G1 to Gn), coupled to outputs of LED segments (D1 to Dn), respectively, each of the constant current sources being configured to switch between a current regulating state and an open state such that as the voltage of the voltage supply increases, LED segments are switched on and lit to form a higher forward voltage LED string, and as the voltage of the voltage supply decreases, segments are switched off and removed from the LED string starting with the most recently lit segment; further characterised by comprising: a toggle switcher that has an output that toggles between a first output and a second output complementary to the first output; a first switch coupled to the first output of the toggle switcher; a second switch coupled to the second output of the toggle switcher and to the plurality of constant current sources; and a plurality of second constant current sources (GT1 to GTn) coupled to outputs of LED segments (Dn to D1), respectively, and to the first switch, wherein when the first output of the toggle switcher is active, the first switch becomes closed and the second constant current sources are disabled and the constant current sources are active, and when the second output of the toggle switcher is active, the second switch is closed and the constant current sources are disabled and the second constant current sources are active. a toggle switcher that has an output that toggles between a first output and a second output complementary to the first output; a first switch coupled to the first output of the toggle switcher; a second switch coupled to the second output of the toggle switcher and to the plurality of constant current sources; and a plurality of second constant current sources (GT1 to GTn) coupled to outputs of LED segments (Dn to D1), respectively, and to the first switch, wherein when the first output of the toggle switcher is active, the first switch becomes closed and the second constant current sources are disabled and the constant current sources are active, and when the second output of the toggle switcher is active, the second switch is closed and the constant current sources are disabled and the second constant current sources are active.