@twinturbo
No need to apologize for anything. We just disagree on something, that’s all. If I had to do that, I’d be apologizing 24/7.
Understand I don’t want to belabor this but here’s what I think:
(sorry, this is a bit wordy but don’t know any other way to convey this. Just move along if you don’t like reading)
I know how engineer think because I’m one of them. Engineers sometimes use a particular technology for technology’s sake. We don’t just like doing that - we love doing that. That’s what we talk about meeting over lunch: what sort of new stuff we were able to fudge into a design. It puts a bounce in our steps.
But sometimes it is better to step back and wonder whether you’re actually improving things or whether you are busy redesigning the wheel.
That has actually been part of my job for quite a while now: keep an eye on designs to make sure things don’t jump the shark.
Even in its simplest form, an alternator is a control system. A control system basically measures, decides where it needs to be and corrects accordingly.
In the simplest form, an alternator adjusts for the rise and fall in current required. It has worked well because everything is localized to one piece under the hood.If you apply a new load to it, it may sag a little very briefly but quickly adjusts to 14.5 V.
If you don’t see your 14.5 volt when it is running, you check the belt, check you connections and, if those are good, throw the thing out and get a new one. Takes 10 minutes.
Simple.
This new alternator is driven by a computer that knows when it needs more or less current and adjusts accordingly.
I can possibly see the one advantage of saving gas. Not sure how much gas actually saves but that may possibly be the one advantage over the classic alternator.
I can also see various problems where you have and alternator controlled by a computer:
There are inherent problems involved sending mixed signals between an alternator and controller. The alternator generates a fair bit of high frequency ‘noise’ (called back EMF) that you, as a designer, would need to mitigate because digital circuits don’t deal with that very well. They can do that but it add complexity because you have to filter, maybe be careful what these wires run parallel to, possibly shield them, etc. Those long wires make for very nice antennas.
Along with that, you have several embedded processors running, doing different things, all at various speed, etc. We all agree this stuff is complex. After all, we all have OBD2 readers and we agree that it takes some investigating to get down to what’s really wrong. We never ever blindly believe the code it throws without some probing around, right?
Well, that’s problem 1. It is complex.
None of these computers are in their own sandbox as they talk to each other. In this case, if you turn your stereo on, the system should know to crank the alternator up just a little more, possibly keeping track of how much the radio is drawing, etc.
The more components you use to do something, statistically the higher the chances get in terms of failure. Designers call this MTBF. Since you have more components, you will need to use better components and better procedures to get the same long term reliability of old school alternators.
Sure, this can be all be made to work but it translates into complexity.
And what have we accomplished: to have a subsystem anticipate someone turning something on or off?
An old ELD did the same thing and was just a simple analog circuit, very few components, simple to troubleshoot and has a very high mean time between failures. A regulator inside the alternator is also pretty reliable and does good job. Most of the time, alternators fail because diodes blow out.
No doubt those very same diodes will still blow out on the new alternators. What problem did we solve?
Problem 2. Statistically these new alternators can’t be as reliable as the old method.
Another problem is that you’re using another normally unrelated part of the system to make this thing work right, that Power Train Controller.
That’s all fine and dandy but what if that PTC or Alternator breaks? All of the sudden you don’t know whether your alternator died or whether your PTC bought the farm. Could it be because the system has falsely detected that you’re not drawing a lot of current and it has throttled the alternator back?
Point in case: the OP clearly had an issue determining whether the alternator was at fault. That’s why he was here, asking questions. In fact, we mentioned that there was a chance it was the expensive PTC. It wasn’t as clearcut as just using a regular alternator, where you measure the voltage, see it isn’t 14.5 volt while running and just replace it. That takes five minutes.
Instead, you’re almost forced to try to swap it out for a known good alternator or go to the dealer and have them check it out for you.
I don’t think that makes our life easier, does it?
Problem 3: Did it really solve any real issue?
That’s why I think they over thought this problem.
A designer has to remember that the system is only as good as its weakest part. If it is interdependent, if one part fail, the entire system likely fails if the components are dependent on each other.
This is why humans have 32 teeth in our mouth and not just two very large ones - one on the top and one on the bottom. If one breaks, you have 31 left and you can still eat.
It is good to contain damage locally. That’s a design engineering tenet.
That’s why having an alternator with a simple regulator and ELD is a good idea.
That’s also why having a fuse that is tied in line with lights is a good idea and a micro controller detecting a short that shuts the line off is a really bad one.
The wheel: another great idea .
I believe to just leave well enough alone already. if it works well, you don’t mess with it.
How did we get here?
Engineers love to throw new stuff into designs because it makes life interesting. That’s how design engineers think. Believe it.
Most of the time that’s very good because you stumble into questions that have never been asked and figure out some new way of doing things.
Sometimes it is just putting the buggy in front of the horse. Nothing more.
Sure, it is a new approach but is it truly better to have a horse push a buggy?
The horse will likely disagree but they don’t talk much.
Things will always get through the cracks. What matters is how the situation is handled afterward. Some businesses will immediately own up to it and do whateever is necessary to correct it. Others may do a cost/benefit analysis and do something short of that or even nothing. A guy I work with has a good saying. “Everybody makes mistakes. What matters is when you come parachuting into the customers parking lot to make it right. That they remember.”