Hi, i just want a little help, i have just finish a pic based controller,
this is for Unipolar motors, with chopper, and microstepping (calculated in realtime for more precision or in contants 4-64 microsteping), change steps on the fly(bia the RX pin, not in schematic, so i deside to use a manager board), I have test this design in discrete components (48hrs continusly, with a fan, if not IRLZ44 gets hot... and the motor just a little) and it works wondelfull in every config, and i'd like to make it in SMT, and I have a little questions.
1 - how much does the IRLZ44 get hot, with a 3A paused (HOT!!! i Guess), and in a D2Pak?
2 - discrete is better than SMT for this kind of aplications?
3 - I'm a programmer not electronic, as you see the design is a little simple, can someone please help me to check posible design error in the electronic side, protections, noise etc.
4 - Does anyone know a method for sense the current other than checking the voltage passing thoung a Resistance??
5 - for PWM of microstepping which frecuency is adecuated 40Khz <- the one I use, 20 Khz <- half for a diferent cristral, or 7.8Khz <- to use the internal osillator, bye bye cristal.
This board is for 1 motor, I'm planning to have a Interfaz board with a pic to control everything, I dont know how g-codes works, but I was planning to used the serial conector or USB or a kind of interface to mach2, 3 or something like that, and pass a bunch of g-code to the pic proccess it and send every thing to N motor modules, instead of limit us with the parallel port, the same goes for the inputs, and is kind of cheap.
well is everything I will apreciate your help, I have send a rudimentary schematic, the PIC should be PIC16F88(is another 'cause i want the QFN 28 encapsulated to apper in the SMT image, and doesnt apper (wedge) , the 16f88 has a pin to pin compability and more with QFN pak ), the Power transistor is IRLZ44 (the same but for the D2pak), SV1 = Vref, Dir, Step, Sv2 and SV3 for motor and power conection (but planning to cominicate just for RX), the SMT image is just a "It should be like this".
Thanks Everyone.
PD i dont not much Eagle and where the hell are the components, resistences and conector i'd like,........ or I dont know their correct names