So, I’m stuck. I’m trying to control LEDs using a decade counter that drives some transistors, but I just can’t seem to get it right. I need help!
What I’m trying to accomplish is a circuit that controls a set of LEDs in such a way that if you press a button, the counter would trigger the next output and illuminate the next LED in the sequence (of course through a transistor, since the chips themselves can’t directly drive heavier loads more than about 10mA). Here is the sequence I am going for:
Red, Green, Blue, RGB, Off.
Im using the transformer of a small digital alarm clock, and since I want to run both the clock and the LED circuit on one transformer, I need to keep the power consumption of the LED driver circuit as low as possible.
My theoretical idea was that by using a resettable decade counter, I could have one input and several outputs, which the counter would progress to the next output in the sequence when I pressed the button. I would use the secondary counter, controlled by the final output, to reset the counter and turn all LEDs off until the button is pressed again.
“You stupid fool, use a Raspberry Pi or an Arduino!” Well I would but I do not have one. Besides, I’d like to get more into logic circuits and the raw functionality of them.
I don’t have schematics that are useable. The two failed attempts to draw a schematic had the logic improperly wired, it wouldn’t work as I expected it to when I breadboarded the circuits.
The logic chips I have in my inventory that I could use are:
Ne555 (x2)
74LS74A
CD4094BE
MC14520 (that’s the decade counter I tried to use)
SN74196N (x2, and those are also decade counters)
74LS157N
MC14013B
HEF4053BP
SN74LS123N
I appreciate your help.