Bicolor LED Driver Circuit
5Circuit to drive a two-pin bicolor LED from a 5/12 volt computer power supply, using two 5V logic signals.
This circuit is part of a bigger project of mine, and I used Paul Falstad's Circuit Simulator to develop this element of the circuit.
The circuit uses two PNP transistors, four NPN transistors, six 10kΩ resistors, one 330Ω resistor, and one 220Ω resistor to drive a single bicolor LED lamp that has two pins and the color is dependent on polarity.
To simulate this circuit yourself, launch the Circuit Simulator at falstad.com/circuit/ and go to File, Inport. Copy and paste the following lines into the text box and click Import:
$ 1 4.9999999999999996E-6 10.20027730826997 55 12.0 50
L 144 256 48 256 0 0 false 5.0 0.0
L 144 336 48 336 0 1 false 5.0 0.0
162 544 128 544 240 1 2.1024259 1.0 0.0 0.0
162 560 240 560 128 1 2.1024259 0.0 1.0 0.0
w 544 128 560 128 0
w 544 240 560 240 0
R 496 112 496 48 0 0 40.0 12.0 0.0 0.0 0.5
R 624 128 624 64 0 0 40.0 5.0 0.0 0.0 0.5
w 560 128 624 128 0
t 464 128 496 128 0 -1 8.690361101209332 -0.13397187968894642 100.0
x 64 247 125 253 0 24 5/12V
x 57 329 133 335 0 24 Enable
r 496 144 496 240 0 330.0
r 544 240 544 320 0 220.0
t 512 336 544 336 0 1 0.5619633649063693 0.6429975285234808 100.0
g 544 352 544 384 0
t 480 384 512 384 0 1 -0.6429975280234808 4.999999997986E-10 100.0
g 512 400 512 416 0
r 512 336 400 336 0 10000.0
r 480 384 368 384 0 10000.0
w 512 368 512 336 0
w 368 384 368 256 0
w 496 240 544 240 0
t 384 144 416 144 0 1 -11.854280257521852 0.01174786119528432 100.0
r 416 128 464 128 0 10000.0
g 416 160 416 192 0
w 400 336 320 336 0
w 320 336 320 144 0
r 320 144 384 144 0 10000.0
t 352 192 384 192 0 1 0.5717044088004759 0.5834522699957603 100.0
r 352 192 224 192 0 10000.0
t 192 176 224 176 0 -1 -0.5718044766954256 -0.5824184731642621 100.0
R 224 160 224 112 0 0 40.0 5.0 0.0 0.0 0.5
r 192 176 144 176 0 10000.0
w 144 176 144 256 0
w 368 256 144 256 0
w 320 336 144 336 0
g 384 208 384 224 0
w 384 176 384 144 0