I am a newbie electrical engineering hobbyist who is trying to get four 28BYJ-48 stepper motors to turn for a split flap display project. I managed to get each motor working perfectly well individually but when I tried all four together the motors did not have enough torque to turn the flaps. I do not have a multimeter available to me so I require some intelligence in figuring out the problem.
My question is: why are my motors not receiving enough power? Each motor requires 12V to run, I don't know the amperage required and it seems this info is hard to get. Rough estimations online seem to suggest about 250 mA is required per motor but nobody seems sure
Here is the schematic below, I'm using an arduino&ULN203 Driver board to run the steppers I apologize if it is terrible but please know that I am trying my hardest:
If an addition knowledge is needed please do not hesitate to ask for it. Many thanks -KWC
Slightly tidied up schematic by @Transistor.