"switch on and off" - connect and disconnect. Link line, lines or cables as you prefer that link two or more components....
Ok i have two stepper motors each have four lines connected to the Arduino, due to the way the code works they can only rotate separately unless the corresponding lines to each stepper motor are linked together thus they act as one and turn at the same rate, so i currently have the first stepper motor running of pins 4,5,6,7 and stepper motor two 8,9,10,11 so they can work separately to turn and such then i need them linked so they work in perfect sync.
To link the stepper motors I also have a set of jumpers from the first stepper motor cables to the second stepper motor cables and a 4 way dip switch so when i flick the switch, if i run either stepper motor they both run. But i want to be able to use a digital output to a electrical component to switch off each of these four four cables that link each stepper cable to each other, instead of the dip switch, i don't want to use a relay they are to big and to power hungry, i was hoping for some kind of circuit using transistors which have in my draw "NPN transistors" but i can go to the store if in need something else, the steppers are 12v