Grinch - thanks for the enthusiasm. I'll post notes on this project as I go.
datsaxman - thanks for the input. Ain't no laughin' at riding 3400 miles in four days; that's 850 miles a day
So as I try to characterize your riding (as distinct from 2fast's riding) it seems you're often (well, most recently, at least) on the highway at more or less constant speed for long periods. With little variation in conditions it would make sense you don't need much in the way of dynamic adjustment. The engine is rarely at low RPM, so your alternator is churning out enough power to satisfy the needs of your jacket. Is it the sleeved or sleeveless variety, may I ask? If you're cold even with the jacket at max, I wonder if you're simply underheated? An intelligent controller can't help you in that case - it can't add more heat than the maximum available (actually there's a way around that too, but I'm not up for designing an inverter voltage booster just yet!).
Here's my own "test profile". Let me know what you think...
It's mid October, a pleasant, sunny afternoon around 60 F in northern Illinois - Chicago, say. I am going to ride the six hour journey to Minneapolis, where I live, close enough. I leave around 5:30 PM in bright, warm sunshine. By the time I'm half way home it's 8:30 PM and the sun has set; solar heating is long gone. I've been riding for three hours, and I stop for dinner with three more hours to go. As it's only October there's still plenty of moisture in the cool Midwest air, so the dew falls throughout the rest of the evening, maybe even a bit of fog, and it is now cold and damp and I'm not even at the stateline. This is not pleasant on a bike if one is only 175lbs. In the past I'd have had to change clothes half way - add a lining, sweater, balaclava, etc - for the rest of the ride.
I have electric hand grips, but they are not enough for long periods in the cold: I can't grip the handlebars to conduct sufficient heat through my gloves for six hours at a time, and I get cold fingertips. I want electric gloves. My legs get cold too, after four hours, so a little heat (not much) in the legs would be nice.
Finally, the last leg of my trip includes several traffic light stops around 1 AM. I would anticipate that if a system is keeping me warm at 75, then it's going to overheat me at a red light.
I'm hoping that I can put my electric gear on at the start and be done with it. If I have a controller that is properly sensitive to ambient air temperature and is set up for my physiology, I don't have to keep twiddling with the heat as it gets colder, and hopefully I don't have to stop to add more layers.
So the controller would - assuming one's gear is capable of putting out enough heat in the first place - modulate the heat based on three factors: 1) your basic heat setting, 2) the air temperature, and 3) your speed. You would be able to set the compensation level for both those factors. I would anticipate that the jacket heat would have to increase more than the pants or gloves based on speed, and they would all go up and down as a function of temperature.
I agree that setting rider preference is still going to be necessary. My hope is that continual manual adjustment under changing conditions can be reduced, on the premise that when your gear matters most, you'd like not to have to worry about it.
Keep the opinions coming, guys...