states is switches at 5V with 200mW.
I do not understand why sustained operation would cause damage?
The learning process is fun
I understand that the transistor is there to increase the current. However, due to my lack of knowledge, I do not understand why sustained operation would cause damage? Is it because of the current going through the coil that would damage the coil or something?
View it as this: the transistor isn't there to increase the current, the transistor is there to separate the circuit that drives the coil from the arduino pin (although in most places you see people saying that a transistor amplifies the signal, in most cases you can think of it as two circuits sharing a ground). Without the transistor, the current passing through the coil is the same as the current passing through the pin circuits inside the arduino chip, which can only tolerate low currents.