I better provide more data for my original experiment:-
I used a 5V regulated supply, instead of directly using the 9V, for the
relay. From experiment, I found that my relay will close when the voltage
applied on the coil is 3.8V, the current flowing through the coil at that
moment is 82mA. If the voltage is up to 5V, the current is 98mA. So, nothing
wrong with your calculation, you just took it wrongly that I'm applying 9V
directly.

>Taking the original poster's 5V relay @ 80mA, the coil resistance should be
>62.5 Ohm. So, if we assume the wall-wart is operating at nominal voltage
>(eg
>9V) and the transistor saturation voltage is negligible, the coil current
>is
>9V/62.5Ohm = 144mA. That's close to twice the specified coil current.

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