Attached is a revised schematic of my stepper driver circuit. I have previously prototyped a very similar circuit and it is working. However, I plan to go straight to PCB without another prototype and would appreciate it being checked again by someone other than me. The changes I have made are as follows.
I changed the voltage regulator from a LM317 to an LM78L05. I am confidant of the .33uF and .1uF ceramics, but what about the 10uf electrolytic on the output? Is that large enough?
Are diodes D1 and D2 needed? My objectives are to protect the regulator from reverse polarity on the input and from any counter EMF from the step motor. (I don't know if step motors have this potential.)
I added a connector to bring Input 3 from the PICAXE, +5V, and GND out of the board. I don't know what I am going to do with it, but it seemed prudent. (I might need an external interrupt for the PICAXE.)
Any other comments are welcome. Because this is a PICAXE circuit, I am also going to post the schematic there.
Thanks.
I changed the voltage regulator from a LM317 to an LM78L05. I am confidant of the .33uF and .1uF ceramics, but what about the 10uf electrolytic on the output? Is that large enough?
Are diodes D1 and D2 needed? My objectives are to protect the regulator from reverse polarity on the input and from any counter EMF from the step motor. (I don't know if step motors have this potential.)
I added a connector to bring Input 3 from the PICAXE, +5V, and GND out of the board. I don't know what I am going to do with it, but it seemed prudent. (I might need an external interrupt for the PICAXE.)
Any other comments are welcome. Because this is a PICAXE circuit, I am also going to post the schematic there.
Thanks.
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