This is such a problem on these dam boards. My 2 cents...

Dave, stop bad mouthing Sal's ideas and build your own mouse trap if you think it is better, do so on a different thread, speak positively about yours without badmouthing other's designs, and let the crucible of competition amongst friends (aren't we all Porsche nuts out here?) hone both designs.

Sal, Totally appreciate your efforts. Please keep them up. You obviously have done a TON of work on this, and think you have the best path forward. Take it with confidence, feel good that you tried once or twice to enlighten Dave as to your opinion as to why things are better your way, and realize it is clear that you will never convince him (he has his own ideas). So I would politely stop engaging with Dave in this thread as there is no more value in it to other than to get dragged into an internet pissing contest, continue on your path, bring it "to market" and enjoy the ride.

There are just some people out here who will never be convinced that someone else's opinion is right if it differs with their own (wonders of the Internet, every stayed at a Holiday Inn Express last night out here). Those same people often do not exchange different ideas in a positive and supportive manner, nor do they understand when to let the other person take their own path. Likewise, there are some people who always want to try to convince others that their idea is right, not to to be derogatory or superior, but to simply spread the love and benefit of all of their hard work. Those same people often never realize when it is time to just stop responding to the a person who won't let it go because their minds are clearly closed, and move on with their own plans. We are not deciding the fate of the human race here....we are all enjoying a HOBBY!

My 2 cents, and you paid nothing for it, so take it for what it is worth.

Very good advice, I'm done with Dave!
I'll just move on and ask he start another thread for his idea as he does not care to participate in this thread.

It's kind of sad for folks who behave like him because he actually did bring fourth some useful information worth considering. But at the expense of attacking other decent designs. I'm sure his idea will also work I encourage him to design it and compete if he so desires.

Thanks for the kind words.
He really does not bother me, I have thick skin. Takes a lot to get to me.

Sal, I have been on the receiving end of this kind of thing recently.

There are lots of 'talkers' out there, but you (like me) are a 'doer'.

Talkers very rarely put forward real world experience or put their necks in the line. Doers, on the other hand, try stuff out, test, fail, remedy, test, and ultimately succeed through tenacity. Talkers are very guarded whereas doers are open and share their successes and failures.

In many cases it is irrelevant how the design is implemented if it can be proven to work reliably through testing. Often, this actually results in new understanding which is of benefit to all.

The attitude of the talker is a complete 'blocker' to any kind of discovery and is the exact opposite to the mind set of the entrepreneur.

Pretty much ALL new science and technology is discovered through people trying stuff that no one else thought to try. Remember when the iPad launched? It was neither a PC, nor a mobile device, I mean, who would buy such a thing? You can't even replace the batteries! It would be the biggest tech flop in history according to the talkers' first reviews.

Keep on doing!

Right, so why haven't you used a cheaper design (?) with a one transistor inverter
and one module? Have you figured out how that might be done with just four resistors
a NPN and a module? Or based on your logic; 1 regulator, 1 PNP transistor, 4 resistors
& 1 module. In either case you only need one module. You should be able to easily
modify your two module design to use only one module with some thought.

Sal deserves considerable credit here for working on something that has a very small market segment. He isn't going to get rich on making this signal "decoder" and nor does he want to. He does this in his spare time and, on top of the time he spends vetting this thing, he chooses to spend the time to thoughtfully share his work for others to see & critique. All that takes time, for which I think he deserves some respect.

I don't think the Dave who continues to be somewhat condescending and borderline insulting is really a Dave. I think he's someone else who's participated in very many past electronic discussions, who has also done a great job of behaving this same way. Anyone else agree?

His purposely incomplete answers do have a familiar ring to them.



I read and re-read Sal's original post and for the life of me, i can't find the part where he solicited advice regarding how to build his splitter.

OK, so back to the task at hand.

Last night I spent a few hours in the garage with a scope figuring out the exact current requirements for the circuit, not the theoretical from the specs but the actual measured current with the PNP circuit running in car.

Turns out that the 124 Ignition module is not and can not be exactly as I assumed. It's not just a basic hi-powered darlington! It can't be just a darlington, here's why:
The actual current flowing via that trigger signal is only 60ua (0.00006Amps)! And that's with both modules firing! This means 1 BIM pulls just 30ua! The 124 modules are very high impedance input devices and must have some sort of front end buffer device built in. I have the Bosch spec book for the BIM 200 series ignitors but these 124 modules must be different. I've looked everywhere for the 124 specs, can't find them, if someone knows where to get them or has the specs please share.

I'm still sticking with my PNP design but I think you could also even get away with a TTL chip. I'm amazed how little current they need to turn on.

This is why it's so important to test, test and then retest calculations! Do not assume anything.

The entire PNP circuit draws 17ma total load for all components.

I'm very surprised by this very low 30ua trigger, at this current level it makes the input more influenced by hi-freq noise. My guess is that bad spark cables could really cause issues in the 964 cars. But it is what it is and obviously it works in the 964, the trigger line from the DME to the modules does run in a shielded cable in the 964 harness. I also use a shielded cable from my circuit to the BIMs but not from the DME to the circuit since I'm using the factory 3.2L harness it does not shield the line from DME pin 1 to the coil. But my design also runs 15ma (0.015A) through that line, i wanted that level of current purposely.

For those interested I also used a simple DC current clamp on the 12v feed line to both coils just to see what they draw on average here's what I saw:
@ idle of 920RPMs they draw about 2.5AMPs
@ 2500RPMs they draw about 3.2AMPs
the draw just goes up as RPMs go up as it should.

Each BIM clamps current at about 8AMPs should you saturate the coil. This means that 2 coils saturated (should never happen) would be clamped at 16AMPs. You need a minimum of a 20Amp 12v feed to supply both these coils safely. This is why I added the relay in my design, I did not want an extra 16amps via the ignition switch.

I for one love your product....just wish I hadn't he 3 fuse for the rear. ;)

I also want to give credit and thanks to Rick and Ingo who have helped me think through the design and shared ideas as well as specs on the 964 and the 3.2L DME ignition driver. Guys like these are great to have! This solution was not just mine, I did build the prototype and did the testing but those guys are a huge help!

Thanks

I follow this because i am fascinated by such tech. Sal and i have spoken quite a bit in the past (my understanding is rudimentary in comparison) and his ideas operate on a different level... And he has many great ideas, many of which i am watching for to come to fruition. I support what he does.

And if you think you have a better/different answer, man the fu@$ up and post it here. Stop with the "if you were smart enough to find the correct values" crap, and figure it out yourself and post the proposed solution in detail. Don't be narcissistic about it. Easy to criticise, hard to build. And if two solutions did arrive on the market... I know which solution I would pass on. There are many ways to skin a cat, but i dont want to be dealing with a jerk for customer service.

"super sal"
 

TWO THUMBS WAY UP FOR SAL!!!

Gerry

Way to go Sal - I enjoy reading your posts, and I always learn something from you.
I side with the folks here who appreciate the time it takes to actually implement a design idea, and I consider condescension as just baiting.

I have the circuit now on printed circuit board, it's tinny at only 1" round board, slightly larger than a US Quarter.

After more thought and discussions with Rick we feel that the 7805 5 volt regulator should remain in the design. It provides an extra level of isolation from the automotive charging and electrical system.

I'll post some more pictures soon.

Here's the circuit board. Next, it will be sealed into that black can:
http://forums.pelicanparts.com/uploa...1454530490.jpg
The terminal strip is part of the solution, it will be how the circuit wires up to the existing car harness. That strip will be mounted onto the existing tin for the rear fuses. You will then just wire up 4 wires to the strip.
- Constant Power from rear fuses
- Switched Power from stock coil's '+' (black wire)
- Ground from main ground screw on intake runner #1
- Trigger signal from stock coil's '-' (green wire)

More pics will follow.

+10... Totally agree, ridiculous.

Sal, I for one appreciate the meticulous approach to your designs and posting the development process for us to follow.

So are we to conclude that you have now done what was described in this post?

If that's the case, then the special circuit board, the terminal strip, and one module will be cheaper
than the cost of two modules and a few resistors, right? So then these special custom parts would
cost less than $50 - $75, given that a module is about $100.

For the others in this thread, I was never out to build a CHEAP solution. I was designing a solution with decent noise isolation and simplicity to the end user. I don't think most folks care how difficult or complicated the circuit I designed is but they will care about how easy it is to install and how well it works. That was my goal and it's been accomplished.

Next up is final wiring into the engine bay and then some more testing.

Hey Sal, cool and way to go.


BTW, it's becoming painful to see this negatron Loren aka Dave chiming in every step of the way. There are 5 moderators - let's get a petition together to them and vote him off the island again ! It's been done before.

@Loren: nobody cares for your attitude here, how hard is that to understand, huh - either change or go and spew your crap elsewhere, PLEASE

I've just read through this solution by Sal.
All I can say is - WAY to go. Thanks for sharing your electronic knowledge with us mortals.
You and Inchmitz are fabulous. ...are you sure you two are not rocket scientist - :)

Nicely done!

If you provide a complete, finished product, we would be interested in buying them from you since we still have a demand for Motronic splitters on Carrera cars.