I'm designing a stepper driver board and want to use the stepper library, which means I have a A+/- and B+/- output (4 pins), and not the input pins the L297 would use.
I want a current limiting circuit, and so I choose to use the L6506 and the L298. But I have some questions. First, the motor has 2 phases, is bipolar, 1A per phase, 8.6V, phase resistance 8.6ohm and a phase inductance of 18mH.
I found this citcuit for those chips:
Here are the datasheets: http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00000097.pdfhttp://www.sparkfun.com/datasheets/Robotics/L298_H_Bridge.pdf
The motor will be powered with 12V.
So here is the bunch of questions I have
1. There are two resistors which are called Rsense. They can be calculated using the formula Ipeak=Vref/Rsense. But what is Ipeak? In my case 1 or 2A? I think with the Ipeak = 2A, the resistor value would be 6ohms. And what is Vref? Does this have something to do with the two ref pins? I would be glad if someone could explain this part of the circuit to me.
2. There is a resistor between pins 16, 17 and GND. What size should it be?
3. There are 2 enable inputs on the L298. Do I understand this correct, I just have to tie them to 5V if I want the chip to work?
4. The L6506 has a enable input too. Same here?
5. Do i have to look for something special for the diodes? Or will 1N4004 do?
6. Watt rating of the resistors: the 22K wont have a large wattage drop, I guess 1/4W will do? So for the mysterious resistor without a name? The Rsense resistors will have a huge rating, I'll look for 30W resistors, right?
Thank you very much!