Optimum Design

Optimum design for a number of different LED configurations and average battery voltages is given in the following table. The last column gives the resistance values needed in the circuit for the approach chosen. Graph F1, F1a , F2, F3, F3a, F3b, F3c, F3d, F4, F4a, F4b are available.

Graph	Circuit Name	Type Driver	# of Cells	Battery Voltage	# of LEDs	R ohms
F1	1S-1P-6W-20	6 W-20 X-mass bulbs	4-AA	4.8	1	53.0
F1	1S-1P-CC15	Const current 15 ma	4-AA	4.8	1	82.0
F1	1S-1P-R160	Series Resistor	4-AA	4.8	1	160.0
F2	2S-1P-6-W-20	6 W-20 X-mass bulbs	8-AA	9.6	2	53.0
F2	2S-1P-CC15	Const current 16 ma	8-AA	9.6	2	82.0
F2	2S-1P-R320	Series Resistor	8-AA	9.6	2	320.0
F3	3S-1P-10W-20	10 W-20 X-mass bulbs	6 Lead	12.5	3	85.7
F3	3S-1P-CC15	Const current 15 ma	6-Lead	12.5	3	82.0
F3	3S-1P-R270	Series Resistor	6-Lead	12.5	3	270.0
F3a	3S-2P-12-D-35	12 D-35 X-mass bulbs	6-Lead	12.5	6	76.0
F3a	3S-2P-2-W-20	2 W-20 X-mass bulbs	6-Lead	12.5	6	18.4
F3a	3S-2P-3-W-20	3 W-20 X-mass bulbs	6-Lead	12.5	6	25.7
F3a	3S-2P-CC20	Const current 20 ma	6-Lead	12.5	6	62.0
F3a	3S-2P-CC30	Const current 30 ma	6-Lead	12.5	6	41.4
F3a	3S-2P-R130	Series R=130	6-Lead	12.5	6	130.0
F3b	3S-4P-3-D-35	3 D-35 X-mass bulbs	6-Lead	12.5	12	17.8
F3b	3S-4P-4-T-50	4 T-50 X-mass bulbs	6-Lead	12.5	12	11.0
F3b	3S-4P-CC40	Const current 40 ma	6-Lead	12.5	12	31.0
F3b	3S-4P-CC60	Const current 60 ma	6-Lead	12.5	12	21.0
F3b	3S-4P-R67	Series Resistor	6-Lead	12.5	12	67.3
F3c	3S-6P-4-W-35	4 W-35 X-mass bulbs	6-Lead	12.5	18	16.0
F3c	3S-6P-5-W-50W	5 W-50w X-mass bulbs	6-Lead	12.5	18	8.7
F3c	3S-6P-CC60	Const current 60 ma	6-Lead	12.5	18	20.5
F3c	3S-6P-CC90	Const current 90 ma	6-Lead	12.5	18	13.7
F3c	3S-6P-R44.7	Series Resistor	6-Lead	12.5	18	44.7
F3d	3S-7P-3-W-35	3 W-35 X-mass bulbs	6-Lead	12.5	21	7.2
F3d	3S-7P-4-W-35	4 W-35 X-mass bulbs	6-Lead	12.5	21	12.6
F3d	3S-7P-CC84	Const current 84	6-Lead	12.5	21	15.2
F3d	3S-7P-R39.9	Series Resistor	6-Lead	12.5	21	39.9
F4	4S-1P-3W-20	3 W-20 X-mass bulbs	6-Lead	12.5	4	24.3
F4	4S-1P-4W-20	4 W-20 X-mass bulbs	6-Lead	12.5	4	33.7
F4	4S-1P-5W-20	5 W-20 X-mass bulbs	6-Lead	12.5	4	44.7
F4	4S-1P-CC14	Const current 15 ma	6-Lead	12.5	4	82.0
F4	4S-1P-R110	Series Resistor	6-Lead	12.5	4	110.0
F4a	4S-2P-1-W-20	1 W-20 X-mass bulbs	6-Lead	12.5	8	8.1
F4a	4S-2P-4-G-50	4 G-50 X-mass bulbs	6-Lead	12.5	8	17.2
F4a	4S-2P-8-G-50	8 G-50 X-mass bulbs	6-Lead	12.5	8	31.0
F4a	4S-2P-CC30	Const current 15 ma	6-Lead	12.5	8	41.0
F4a	4S-2P-R56	Series Resistor	6-Lead	12.5	8	56.0
F4b	4S-4P-2-D-35	2 D-35 X-mass bulbs	6-Lead	12.5	16	33.0
F4b	4S-4P-2-G-50	2 G-50 X-mass bulbs	6-Lead	12.5	16	7.5
F4b	4S-4P-2-T-50	2 T-50 X-mass bulbs	6-Lead	12.5	16	5.3
F4b	4S-4P-3-T-50	3 T-50 X-mass bulbs	6-Lead	12.5	16	8.0
F4b	4S-4P-R40	Series Resistor	6-Lead	12.5	16	40.0

4S-4P in the above table stands for 4 LEDs are connected in Series and there are 4 parallel connected sets of the 4 series LEDs. This results in a total of 16 LEDs. 2-W-20 stands for a quantity of 2 of the W-20 type X-mass tree bulbs. W stands for Wal-Mart and 20 is the number of bulbs in the original string.

Offered by Mike.