(Edited text 15:53--05/1-2017)
I got these two steppers for my home project, and thought that I just needed a H-bridge and then I am good, until I found that either I am misunderstanding these ratings, or I have a special stepping engine. Stepper It has data 3.3V and 3A. and it is a 4 wired Bipolar
The idea was to have an arduino with 4 sensors that would make a "scan" every 1 or 2. hour. Then the arduino shuld tell 1 step motor to turn left/right and another motor to go up/down, so the sun panels would get most out of the sun.
So, looked at WWW to get some ideas on what chip to use, and most recommended the L293D and then i got stuck. then i wrote a post in here and now im super confused hehe.. (so i edited this text to clarify my thoughts and what is my end goal, and how)
I have a 12V battery as a supply! But I just step that down.
The L293D, or SN754410, require 5V or more, or have less then 3A current. (the steppers was 3.3V 3A)
Q. Am I misunderstanding something, or am I just blind?
Q. Can any help me design a schematic for my own bridge for driving 2 steppers, if there really ain't any out there in the world?
A. I wont just buy one of them already done prints (example). I just need the chip, or help designing my own bridge, that can drive 2 steppers 3.3V 3A
Answer
The L298 H-bridge can handle 4A DC total if using both channels in constant operation. Your stepper will use 3A intermittently on each channel, which the device should be able to handle according to the datasheet. If you are using a programmable microcontroller such as an Arduino, you can also reduce the stepping frequency to reduce the current through the H-bridge chip. You should also attach a heat sink to the chip. Note that you need to add ultra fast recovery diodes (or just fast recovery) to reduce back-EMF.
As for the power issues, I recommend using voltage regulators, such as the L7805 or equivalent with filter capacitors for your 5V and 3.3V.
Here is a link to an instructable which shows you how to make your own stepper driver to use with arduino: http://www.instructables.com/id/DIY-Arduino-Motor-Shield-L298N-Chip-2-4-Amps-/
If you would rather not use a microcontroller, here is a tutorial for building a stepper driver circuit that uses a 555 timer circuit instead:
http://circuitdigest.com/electronic-circuits/stepper-motor-driver
Edit: You can't control the current through a stepper by adjusting the frequency. A Chopper drive is what you need, and it can be run at several times the rated voltage of the stepper (See bottom of the linked page):
https://learn.adafruit.com/all-about-stepper-motors/matching-the-driver-to-the-stepper
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