Hi, I am introducing myself to logic circuits and I want to build a network of logic gates (CMOS) that have push buttons as inputs and LEDs as ouputs. At most there are 4 gates between a button and a LED. However, at the inputs of the 4th gate, which is a AND gate, I measure 4 V and 4 V, but the output I get is only 2 volts. I don't understand why. I use Vcc = 5 V. Maybe 4 V isn't considered a 1 and I need to boost the inputs to 5 V? If this is so, how can I do that? Thank you.