From what little info I can gather and without knowing the intricate details some of you have at your disposal, it looks like it gets varying amounts of voltage from the stator coil based on RPM. We know the alternator is good (I will still be testing it anyway) or we wouldn’t be getting any charge at all.
Not to be anal about this. But, every part has a function. Both stator and rotor are part of the alternator. Both are needed to make power in this system. The stator make power based on the amount of magnetic lines of flux that cross it's windings. The rotor makes the magnetic field in a specific pattern of North/ South orientations. The revolutions move these patterns, so the stator windings see changing lines of flux crossing the stator windings. Both the magnitude and the frequency of these flux crossings, determine the output of the stator voltage peaks and frequency intervals, which the rectifier converts to DC and the battery itself smooths out the ripples.
You do NOT know if Kit's alternator is good. The stator probably is. But, the only test data I have in hand says the rotor is highly suspect. The rotor, which is part of the alternator, has yet to be proven. Therefore, you can not make the statement that the alternator is good. And, before you cry "Semantics", be aware that there are no variables in electrical physics that contain semantics. (At least not at the level we are talking about regarding SOHC4s where supercoolers aren't part of the operating environment.)
Now we have DC voltage, but it’s probably a little bouncy so it seems they put in capacitors to smooth it out a little more.
The battery itself provides the output ripple smoothing. It behaves similar to capacitors in this regard. (It is actually an impedance calculation which involves capacitance, inductance and resistive elements and interacts with the frequency component of the line level applied.)
As you guys have stated, the regulator system puts out an approx max of 14.5v so we don’t fry the battery.
While there are different types of regulators. The SOHC4 system doesn't work this way. The rectifier portion delivers voltage/power to the battery. The regulator only provides power to the >>alternator rotor or magnetic field generator<< based upon the battery's needs. The alternator puts out power at a level corresponding to its RPM and the regulator's distribution of battery power to the alternator's magnetic field generator.
It looks like a zener diode is in there, in series with a resistor. (for overflow voltage? probably helps it not melt so easily too.) The load (battery) is in parallel with the zener diode. Being in parallel, that is how it "probes" to see if it is low, I assume? For a zener, (stepping into the way, way, way back machine in my brain now) we need to reach it’s breakover voltage for it to conduct. Anything over it's max is routed over to the resistor to handle. As the input voltage changes, the output voltage should, as long as it’s above the breakover for the zener, remain pretty even.
While I have seen regulators that work in fashion you describe. (Dumping excess power into a heat sink.) The SOHC4 regulator does not. It throttles back the alternator only when the battery might be damaged by overcharge. In all other cases, the alternator puts out all it is capable of making at the RPM it is spinning.
My big thing is… why do we have to rev these things up to 4-5,000 to get charging? If the alternator is cranking out what I think it is, then why aren't we using it? Is there a way set it up where you can start charging at an output voltage from the alternator at just above idle speed? I need to see what the output voltage is at that speed compared to a higher rev to answer that one for myself.
These questions likely arise from your misunderstanding of how the SOHC4 regulator/alternator actually functions.
You have to rev the alternator because its output is not constant or linear with RPM. It has a peak output graph that looks similar to an engine power output curve. The engine makes no power at zero RPM, neither does the alternator. The engine makes minimal power at idle. So, does the Alternator. REV it up and you get more power from both, and each has it's limit or peak on the curve.
BTW, we have just found a local guy who makes his R/Rs to do just that. It utilizes more of the spectrum. That’s all I was saying. If you need more detail, it will have to wait until I’m done checking the entire system again. I didn't get to study what he's doing differently and, as I said before, I don't have a detailed schematic on the current system to reference. I'm going by the meager drawings that are in the manual Kit has and what I've picked up through osmosis during her build.
The zener diode based regulator shunts excess power from the generating device. This type of regulator is more common with generators that have a permanent magnet instead of an controllable electromagnet like what is found on the SOHC4. The only operating regime where the SOHC4 alternator makes excess power is when the battery is overcharging, and the system is at fault.
Cheers,
