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Essentially a 9 v power supply, a diode resistor and relay.

So the coil operates between .08w and .17w so to figure out the current needed at 9v, I say P/E=I or about .12w/9v = .016A. Then since the circuit is series, the amperage stays at .016 for everything. So to find the voltage drop of the 9v, I use resistance and current to find the voltage drop. The relay's resistance is 580 and the diodes resistance is 514. 580x.016= 9.28v and 514x.016 = 8.224v. So that can't be right. I'm pretty new but I'm really trying to understand. So could someone help me understand what I did wrong and what I should be doing to make this work? Any and all help is greaty appreciated, so Thanks so much in advance...