Yeah, I wouldn't go too big either. Isn't the second trigger a 5V one?

One thing to keep in mind, sometimes large caps are slow, really good filters will typically have a small cap floating on top of a big one. Take apart the power supply in your PC, you'll see this all over the place. One kills high freq, one gives you some current for the bigger dips.

 

Cool.

I was just thinking about adding a cap, maybe at least 1000µF to the 12V to stabilize the voltage. When I turn my headlights (HIDs) I think the amps needed to power the ballast are to the point on where my MS actually misses/resets when I turn my headlights on. Although, I never really had that problem when I was running on parallel MSI

 

That's cool. Next time I have the PNP in my hands, I'll replace the 10k with a 2k I also have, and put the 10k at the power supply for the coils.

 

I have a big cap for the stereo, though the better/modern/gel batteries don't seem to have as many issues. It's a full farad. :-)

Remember, way too much capacitance, and it'll turn on slow. :-)

My HID's have never given me any trouble, they are 55W ones, too. Who knows. I think the answer is there's likely as much as you need, look at grounds if anything.

 

Dont know really. It wont power off the low-beam light. Could it be my ballast? I could try a different, more solid ground I suppose.

 

I saw an occasional reset when I turned my HIDs off on my last car.
These cheap chinese made HID kits are pretty crappy. (I'm not hating on them, I put them in my cars too)

 

Won't power off the low beam? A good ground, and power, is important. My friend is fond of making his connections to the alternator. :-)

Ballasts DO go bad, so it's a possibility. But my install went super easy, the only issue is the high beam light doesn't come on in the dash (I think it doesn't draw enough current).

Basically, it's powered off a separate power line, and just gets a *signal* from the headlight lines.

 

LS2 truck coils: Set dwell at 4.5ms for wasted spark or 5.5ms for sequential.
Scope verified.

 

This thread helped me out a lot when I got around to building mine. Thanks.

 

Great to hear. Does that mean that you're up and running?

 

After ~600 miles since the battery was disconnected, my only MIL was P1170 A/F Feedback Control. Totally reasonable since I had a quick tune and no EGO feedback at all.

I finally got my wideband controller installed and after an ordeal or two, it's WORKING, outputting realistic values on the analog out and it's communicating with my XD-16 gauge.

Now that the MS is receiving feedback, I turned on EGO corrections again. After 2 short drives, my MIL shut itself off. When I plugged in the OBD scanner, the code is still listed as pending. But this is huge progress. Now that I can watch my A/F I saw that there are some light load spots on the map that are in the 13:1 range. A little more street tuning should straighten it all out.

 

I have it built but my serial to usb cable sucks. My friends letting me borrow his this weekend. Should be running soon.

 

Are there any DIYPNPs out there that have the alternator circuit built into the prototype area? Not a custom PCB--just components and jumper wires. I'm afraid of how my autistic interpretation of the schematic might turn out, having never seen a photo of a circuit built there yet.

 

My alternator circuit was built on a little proto board, but when/if some free time rolls around, I'll give reconstructing it in the proto area a shot.

I don't think that the alt reg circuit has been a big deal, as it seems that people are just replacing the alternators with internally regulated ones.

 

Maybe I'll give it an experimental shot then. Going to Radio Shack today. Does this shopping list look ok?

Transistors:
2 X PN2907A

Resistors:
2 X 3KΩ 1/8W
1 X 1KΩ
1 X 30KΩ 1/8W
1 X 330Ω 1/8W
1 X 3.3KΩ
1 X 1MΩ 1/8W
1 X 22KΩ 1/8W
1 X 48.7 KΩ 1%
1 X 10 KΩ 1%

Capacitors:
1 X 22nF 50V
1 X 1nF 50V
1 X 100 uF 25V

Adjustable Shunt Regulators:
1 X TL431 2%

 

I wasn't able to find the exact parts in the schematic, and that circuit never worked for me with the replacement parts I was able to get, so I swapped in an internally regulated alternator from an RX-7 (FD).

Jim

 

Shopping list is correct.
I've built the circuit 4 times now. Last one I did is for Todd (thirdgen). They all work fine, but I'm sticking to what's in the circuit. The transistors are difficult to find indeed.

I never built a DIYPNP but it's not difficult to build the circuit the proto of the V3 board. The proto are of the DIYPNP board looks different with its 2 rows of inter-connected pads, but it shouldn't be too hard to do.

 

Be careful with the proto area at the DIYPNP the 3 hole of each row are connected with traces...That is how I blew my first circuit.

I used a little proto board for the second attempt which is working.



The little board left of the PWM converter board.

 

Mine looked like that, except we hot glued the new proto board in edge-ways so the mainboard's proto area would still be useful if needed.

 

Where did you get them? Farnell doesn't have them, and if they don't, I don't know who does.

Jim