JDM, it is helpful in that I can use it as a real example.
Here we go, fetch your reading glasses, a calculator, and a cup of coffee...
If you have two grips at a rated current of 1.6A each, battery voltage in the normal range, (let's say above 12.25V - I will determine a more specific cut-off threshold during testing) and controller set to 50%, then the peak current will be 1.6 * 2 = 3.2A, and the average current will be 1.6 * 2 * .5 = 1.6A, just like any other controller.
If the battery voltage drops down below the critical voltage then the duty cycle (which determines average current) applied to the grips will be reduced dynamically such that the average current will drop to the point that the average battery voltage stops falling, or until the pre-programmed minimum current is reached (say for the sake of argument that's 1A, but you'll get to program the actual value yourself.)
Now, if the controller is set to give 100% - or 1.6A to each grip - that's a total of 3.2A, both peak and average (peak and average are always the same at 100%). Again, if the battery voltage drops down to the cut-off threshold, the duty cycle will start to be reduced, this time more harshly until the battery voltage stops falling or until the minimum current is reached.
So it doesn't matter what the power setting is, the power will be reduced as the battery voltage drops so as to protect the remaining charge in the battery, while attempting to keep your hands warm.
The difference becomes even more significant when you add your electro-thermal jacket to the equation.
Let's say your jacket takes 1.8A. With both the jacket and the grips on at 100% the peak and average current (always the same at 100%) is 1.8 + 1.6 + 1.6 = 5A. If the battery voltage drops down to the "priority threshold" (which is always above the critical fold-back threshold, but let's say it's 12.8V) the controller will switch into the prioritized sequence mode. The calculated maximum available current (programmable, but let's say 3A) will be divided between the grips and the tunic by sequencing the current through each heater circuit in turn, and also by adjusting the duty cycle (percentage on time). First the grips will get current, then the tunic, then back to the grips. instantaneous current will be 3.2A for grips and 1.8A for the tunic, but the average current (the current that causes the voltage drop) will be 3A. As the battery voltage falls down to the critical threshold, the average current will then start to be reduced until the battery voltage stops dropping or until the minimum current is reached.
As you see, the controller is smart enough to search for the optimum compromise of desired heat level vs safe battery voltage.
Now you see that the controller is making changes based on battery voltage, it should be easy to see how it can make adjustments based on speed. A speed signal from the engine tells the controller how fast you are going, and the controller will - within the limits set by the battery voltage monitor, which always takes priority - adjust the average power to each heated item based on the change in speed from a nominal value. You could set the nominal speed at 40 MPH, and you could program the controller to reduce the power to all items (individually !!) by some value at 0 MPH, and increase it by a value at 70MPH. The tunic could go down to a minimum of 10% at standstill while the pants could shut off altogether. At 70MPH the tunic could go up to 100%, while the gloves could go up to 80%.
Finally, you can see how the same adjustments could be made based on temperature. I've already noticed how several people are sensitive to cold while others are Eskimos. You could have the tunic shut off altogether above 40F, the pants shut off above 35F, while the gloves could stay on right up to 50F if you so choose. At temperatures below 30F you could send the tunic to 100%, the gloves at 80, and the pants to 45%. Below 25F your boots come on at 65%.
Again, all this is limited by the battery voltage, which always has priority, for safety. As the battery voltage drops below the priority sequence threshold each item gets gets rationed power - always in proportion to the percentage demand.
You can clearly see that if we add more heated components- say gloves, pants, boots, and the same again for a passenger - then this automatic monitor and control system starts to make a lot of sense. Instead of twiddling around and arguing with the wife or girlfriend you set the priorities up front.
Of course you'll be able to make temporary changes on the fly: if your significant other/passenger gets cold and grumpy (not good if you want her to keep you warm once you get to the hotel), you will be able to temporarily "bump" the priority of any or all items on the passengers extension controller (which connects to - and is automatically incorporated into the control strategy of - the pilot's controller) to keep the dear lady warm and happy.
Again, while there is plenty of power all heated zones get whatever percentage they are set to; but under high load conditions the system automatically makes adjustments to adopt the best compromise between requested heat and safe battery voltage.
One advantage (specially for for the disbelievers!) is that your settings will never get "lost". The nominal setting you program into the system stays there despite the "bumps". Once you have the system set up to suit your physiology, meteorology, clothing, and riding style, it will always be there for you at a press of the starter.
There are a couple exciting little more little gimmicks, but I'll keep them to myself for now, so as not to give away the farm.
Lastly, let me say, with some concern, that I'm taking a HUGE risk on this commercial opportunity by sharing all these details. I hope I won't get gazumped by somebody getting to market before me. I'm gambling that by sharing details and getting feedback early, I will get a better product out the door for the good of the motorcycling community. I hope I'm not making a mistake. I will definitely be making a patent application on this device.
I hope this helps. Feel free to post more questions and make more suggestions.
Julian.
