There's a technique used on older bikes. Run the heaters off AC, directly off the alternator coils.. Put a series inductor. As the RPM increases and the frequency increases, the inductor has greater impedance. When you do the math, you might find that the inductor is physically too big for your liking, but it's worth a calculation. YMMV. mike
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Expanding upon John's comments (with which I concur), the PWM generating circuit you have can probably be simply modified to alter the duty cycle in the appropriate direction as the supply changes. Showing your circuit, (perhaps with the help of the tool at
What puzzles me is why, if your controller controls temperature, is it sensitive to supply voltage at all? That may be due to a simple design oversight which can be spotted readily once you show the circuit. Alternatively, it will allow others to discern which parts could be powered by a low power regulator to fix the problem, rather than regulating the power circuit.
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-- You don\'t need regulated 12.5V. If you want to keep the grip heaters at a constant temperature you need to make that temperature happen with the lowest system voltage you\'ve got and then use your PWM circuit to keep them from getting hotter as your system voltage increases.
I have built a very simple PWM controller to control the temperature of the grip heaters on a ATV. Uses a 4093 with a transistor, 2 diodes, 2 caps, 1 resistor and a pot.Circuit is powered by the battery and works ok but the temperature increases or decreases slightly with the RPM of the motor and the output of the alternator. My question is what is the easiest way to have regulated 12.50 volt to power the circuit? The alternator will output 15 volt max. and the circuit handles 3 amps. max.. Thanks in advance, BobG.
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