I am in a mecatronics class at my school. Our first project is to build a clock. Our teacher suggested we use stepper motors. I have currently constructed three h bridges to drive three different steppers from the arduino. They are constructed of pnp and npn transistors, 2.2 resistors, and some catch diodes for the excess current. At one point I had one of my stepper going forward perfectly, but now it goes three steps, then pauses before continuing, and I did not write that into my program. Why is it pausing? Is is skipping a step?
How are you powering the h-bridge (please don't say "9v battery")?
Which motor? which transistors? What's the circuit?
I am powering it with arduinos usb input 12v adapter for final product. 2 of the motors run fine with the usb power but the third one is slow and won't run on the h bridge or directly into the adruino. I can tell for the little pulse I get from it that it is not going forward when running that same program as the other two that work on the h bridges. The schematic I am using is based off of this one
with some modifications:
- All the transistors are in a row instead of in an H shape.
- Each pair of inputs on either side of the h bridge are connected so I only have to provide two inputs
- Each breadboard has two h bridges in order to control one stepper.
Hope this helps
I don't see how you can connect inputs in that circuit at all - the high-side transistors need to be driven low, the low-side driven high, so they cannot be commoned.
That circuit cannot be run at 12V as is, the Arduino cannot produce 12V output signals.
I did some research and found that arduino can. The circuit is connected to the 5v power pin. And you have two different transistors on each side of the hi bridge( a row of them in my case). That means that you can connect two of them and not matter what the input is, only one will be open. Then you put in the opposite high or low pin for the other set of transistors. Then it will reverse the voltage.