Hi Bill;
Yeah, probably similar 'cause I use your schematics as reference all the time! The regulator and caps came straight from the ICD2 schematic (I had a 0.33uF cap on the input side, as can be seen above -- which I changed to a 100uF).
I always say I'm not a hardware guy, but I am learning -- and it's from guys like you -- thanks!
I will have a look at your Mongoose design.
blueroomelectronics said:
I don't see the logic supply of the SN754410 connected in the schematic.
Sorry, just want to make sure I understand you -- are you referring to Vcc1 (5VDC) supply? If so, they are hidden pins and connect when transferred to ARES. That is what C7 is for -- C6 is for the PIC.
As for using a 12V stepper -- I don't understand why? The reason I chose a 3VDC stepper was because I could run it at 12VDC (which is the voltage that I have to work with -- I don't have the luxury of designing a 48VDC power source -- I have to work with what the machine offers) and limit the current to get speed and torque (I'll have to show you a video of what it does -- attached is an image though). Well, that, and it was readily available at Sayal! Again, I am a noob, so correct me if I am wrong, but you'll get nowhere near the same speed / torque from a 12VDC stepper, supplied at 12VDC.
As a final note, the stepper itself is not causing the brownout -- it is a DC motor (regular motor) that turns on to start the cutting wheel of the key machine. My 12VDC source is being supplied from the same source as this motor.
So, according to your comments, I should be concentrating on a larger cap on the OUTPUT side of the regulator, which feeds the logic. Do you know of any good explanations on caps? I keep reading on them, but I keep getting explanations on how they are made and how they work (which I understand) -- I just don't understand how to pick sizes -- how much "reserve" any particular cap will provide, etc.
Oh, and for those interested -- here's the process I used to create the PCB -->
https://www.electro-tech-online.com/threads/my-first-home-made-pcb.33911/.