Now I'll start trashing my baby for every ones enjoyment
Per discoveries in PUMA, there are many circuits here that should/could be updated. These include the RPM input circuit, MAP's, injector grounds, the "current sense" feature on the injectors should be replaced with a purchased chip ACS714, the injector LED should have a schottky to prevent reverse conductivity, ignition circuit should better match Ravage, and the fuse thing should go away.I don't plan to update this any time soon, as I'm quite busy. However I can offer help if there is a branch, or what ever, of this board. Basically I can help in 10 to 15 minute windows of time. Here's a little more each of the above notes.
RPM, The op-amp circuit is probably OK, but the LM chip isn't good. It should be a MAX9926, same as schematic found here https://github.com/jharvey/Cinch_enclos ... mplate.pdf See page 4.
MAP's, These should also be modeled after PUMA, as they allow a BOSH sensor and MPX sensor(s). See page 44 of 56 here http://puma.freeems.org/docs/Puma_spin1_schematic.pdf
Injectors, The BOM calls for an older hard to obtain chip. That chip can be updated to the VNB10N07 or equiv. There are versions of that chip that can do some 20 or 30 amps. I'd recommend the larger ones as they will have less resistant heating, however the 10 amp chip should be fairly cool as well. I had an experimental current sense circuit in there, however that can be purchased these days with this ACS714, so it should be updated. Also it's grounding isn't ideal, so we should address that. I'd like to see them isolated via optocoupler, however if it's only highZ and 6 cyls, you can probably get by with one fat wire. So it's likely easier to just limit the design scope to highZ only. If one want's lowZ, they can use JBperf's external box.
Ignition, Follow Ravage instead of what I did here. Look at page 7 found here https://github.com/dvisser/Ravage/blob/ ... Ravage.pdf
Fuse thing, The intent was that if you shorted something, and if the traces were designed to handle the same current, the failed trace would happen who knows where. So I put in these mock up fuses, such that if you did bugger it, the trace between the fuse pads would be the thinnest and would be the location of a failure. Then you could replace it with a real fuse instead of having to do some kind of misc jumper. In reality, the device should be fused up stream, and this could lead to bad practice, as the fusing should happen closer to the bat. Also fuse theory is more complicated than that, and if this thinner trace were to burn, you would likely have to rework some chips any how. So it probably should go, but eh, it's there so I guess it can stay.
Power supply, Oh yeah, I feel there is a power issue with this linear design, but Fred feels linear(s) are fine. As long as the current is low, the vregs should be fine, but I believe the current is more than what Fred has measured on a couple builds. I believe he simply hasn't seen the right combo of components to see the max current draws. So I might recommend the switching supply from PUMA, it bumps from Vbat down to 6V, then the linear takes it from there, such that they don't make more heat than required.
Oh yeah, also the digi protects and AN protects are buggered, but footprint wise should be OK. The 10k's on the digi protects are to high, they can be dropped down around 1k to 1.6k total resistance. Once that happens the filter caps can be adjusted. Not a huge deal, the footprints on the PCB are the same, but the values that go there should change.
An how, that a quick rough up of my baby.
A feature note done there, but might be nice, would be to add the USB chip from Ravage as well. I think when the RPM shrinks, you'll have room for that under the TA card. So if it can fit, it might be nice to add it.
