I am like just getting into electronic's, so I am really dumb when it comes to components. Would it be possible to maybe post the part numbers that you would actually look for, say from Digi-Key? I started to ordering some things from Digi-Key and I think I actually got some of it correct. But man I got this one component, it was like supper small. Oh it looked like an IC, but was it small. So if you could please help a dumby I would be greatful.
tach,
I haven't done anything that discrete for MANY years! Scratched my head for awhile, but think I've got a high level understanding. I can't see a reason it wouldn't work.
On your 3 axis boards, 3 questions:
1. Did you mean for the current limiting resistors for the LED's to be 1K?
2. Hmm, the IRLZ44 has a 1 to 2 v gate threshold, maybe we had a typo somewhere in the translation, the schematic I had IRFZ44 which is 2 to 4, thats what we've been missing?
3. What about putting a 120K resistor from VDD to the base of the logic probe for a bit of glow in an open state?
If you concur with any of the above, how about updating your eagle files and reporting them. I'll incorporate into a parts list and document.
You might double check the parts listed at the bottom of my webpage as a second set of eyes.
Can someone look at this board and give an opinion
Í saw this project at least a year ago, but now that i have some interest i ask if someone with some experience could look at this and give an opinion about it...
it's a controller for a foam cutter designed in a spannish forum...
I don't read spanish, but looking at the board layout, it uses 4 18F84 PIC controllers and IRF540's to drive the motors. Very clean layout, current limit resistors not much space. Needs external 5vdc, besides motor power. You would have to be able to program the PIC's. Two relays on board, driven by a 7438N in conjuntion with a 555 timer. Very comparable to the 3 axis board tach has done in terms of drive. Other than that, I'm not much help. Sorry
Here's the the 3 axis layout with the new logic probe and the Mosfet part numbers.
I rearanged the bias for the open glow to work with a range of transistor beta, it will work properly for a range of 100 - 500 with the led current doubling from open to high. Since the glow of the open circuit logic probe can act as a power indicator i removed the power led.
Methinks the original design Mosfet specification could have been a typo but most likely it was just a marginal design.
The schmit trigger in the chopper converter works by positive feedback through the coupled emitters.
The pic 4 axis board seems a bit like over kill using 4 pics when one bigger one would do. Babelfish tells me it reduces the current by chopping when there has been no movement on a axis for a while. The maximum voltage is 50 volts with the Mosfets given - which like the choice given in the original unipolar design are marginal in terms of gate drive in this circuit.
Gary
Most of Phils links worked for me - there were a couple which didn't. Your super small ic sounds like a surface mount part. You need a "DIP" (Dual Inline Pins) Package. Have you got your Mosfets yet? I'm now recommending a diferent type to the original. If you already have them don't worry the original ones will still work ok.
3 Axis board bill of materials attached with digikey part numbers.
The IRLZ44 seems to come in 60 and 55 volt versions i have given the 60 volt version digikey number.
Tach,
Absolutely outstanding! The board looks great! I'll try to complile some documentation and get it posted. What about making your chopper a a 3axis piggyback board to go with this?
Phil the doc's are good but i see you miirored the copper layout for toner transfer you need it unmirrored looking from the component side of the board.
I'm going to get some parts this weekend and test out the chopper converter.
Tach,
I'm confused, which image are you referring to? The one in the pdf document can't be used for pcb mfg, it's not sized. I just put it there for reference. (I should state that, though) On the website is both mirrored and unmirrored at 600 dpi that are acurate.
tach,
No your Good! I wondered when I included the image in the pdf document if it would be confusing. It gave me an idea, so I changed the pdf document. Double check me on the images, I feel like crud this morning. I think I need to figure a way to post toner transfer image in pdf format that is accurate.
I got the 3 way board and the converter board etched and drilled earlier today - might get some components in tommorow.
I once made a eprom programmer using a copper layout from a pdf file, it was all going good until i tried to fit the 28 pin socket and i realised the board was 4 percent too small!
It was ok for the smaller bits but i ended up having to use a wire wrap socket up in the air with pins tapering in down towards the board. That said a pdf (should) be accurate scale wise providing you are carefull not to rescale to fit papersize etc. Perhaps if you include a ruler next to the layout it would make it easy to check.