Hello, I had a basic analog electronics course this summer. Now that I'm trying to design my own circuit with a bipolar junction transistor (both for fun and to prepare for the future), I'm finding I don't really understand how and why I have to follow certain procedures to get maximum output voltage swing. I don't understand why you have to consider the AC and DC loadlines' intersection to get the quiescent (Q) point of a transistor, for example of a bipolar junction transistor (BJT) amplifier. The DC loadline tells me how the collector current will look for a given collector-emitter voltage. It is a negatively linear relationship meaning if I increase the collector-emitter voltage, I get a proportional decrease in collector current. If I want a different result, I have to change the collector and/or emitter resistors. The AC loadline tells me my maximum possible output swing. Similarly, if I want a different characteristic, I need a different set of impedances or perhaps my input signal could be changed. Question: Why do I need the intersection to determine the Q point? Why can't I just use the DC loadline's middle to give me the quiescent (Q) point?