Just one quick simple question, with a self-biasing transistor circuit, why when putting in a square wave input would you get an inverted output response?
When the base goes positive, the transistor turns on. That means currrent flows to ground and the collector has minimum voltage on it. When the base is grounded, the transistor is "off" and the voltage at the collector can't get through the transistor. Therefore, the voltage at the collector is "high"...whatever the supply voltage is.