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Old March 5th, 2015, 04:16 PM   #17
kalleh
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Name: Kalle
Location: Mountain View,CA
Join Date: Feb 2015

Motorcycle(s): Ninja 300, Duke 690

Posts: 33
Quote:
Originally Posted by Electronic M View Post
Air valve is operated by a 14-15 voltage, depending on your charging system. To calculate the current you'd use Ohm's law Current = voltage/resistance. Since we have the voltage and the resistance, we can calculate the current, 14v/220ohm =.064amp. Now to calculate power you'd need need to use voltage * current, that would be 14volts * .064amp = .896 watts. So the reason your resistor is getting hot is because its half the size it should be. You'd need at least 1 watt 220 ohm resistor.
Actually, the resistor is 22 Ohm so it's close to 10W

However, saw someone mentioning that measuring resistance over the valve is not representative because it's an inductive load - any input on if I could actually get away with a higher resistance to lower the current through it?
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