Hi All,
I've been going through and building all of the various logic gates using transistors, to help learn, and now I'm trying to do something a little different. I'd like to have and LED on until both signals are active (like a NAND), but to also turn on another LED simultaneously (for this example, let's say "off" is Red, and "On" is green.
I built the attached circuit (as well as a few others) and I'm able to get both to turn on, but can't get that elusive "Red off, Green on" working. I also tried driving another NPN with the output of the AND gate, and couldn't get that to work either, the Red stayed on, and the Green never came on.
I'm happy to build the schematics for the other circuits I tried, but I feel the attached gives a good idea of what I'm looking for.
P.S. I know I could build separate circuits, but this is supposed to end up miniaturized, so I'm trying to keep it simple. I'm also trying to get better at being clever with my circuits, instead of just brute force building everything.
Thanks so much!
P.P.S. I did look all over this forum, and Google, which led to trying other circuits, but I couldn't get this guy to work.
Edit: VCC and signal lines are both 9v.
I've been going through and building all of the various logic gates using transistors, to help learn, and now I'm trying to do something a little different. I'd like to have and LED on until both signals are active (like a NAND), but to also turn on another LED simultaneously (for this example, let's say "off" is Red, and "On" is green.
I built the attached circuit (as well as a few others) and I'm able to get both to turn on, but can't get that elusive "Red off, Green on" working. I also tried driving another NPN with the output of the AND gate, and couldn't get that to work either, the Red stayed on, and the Green never came on.
I'm happy to build the schematics for the other circuits I tried, but I feel the attached gives a good idea of what I'm looking for.
P.S. I know I could build separate circuits, but this is supposed to end up miniaturized, so I'm trying to keep it simple. I'm also trying to get better at being clever with my circuits, instead of just brute force building everything.
Thanks so much!
P.P.S. I did look all over this forum, and Google, which led to trying other circuits, but I couldn't get this guy to work.
Edit: VCC and signal lines are both 9v.