What controls the gate in a transistor?
inside a microchip, transistor gates are usually driven by other transistors but they could also be driven by transistors directly or directly connected to other elements such as resistors and capacitors. the transistors (gates) connected to the input pins are left to the user. they could be driven by transistors of another chip or be connected to the power supply or to the earth or to a signal generator.
fets work on microchips like switches – think about on-off devices . the gate is the button that toggles between the two states (on and off). in a fet that is done by adjusting a voltage at two levels.
a follow up to your question is: what can I do with the switches? turns out that these two states refer to bits, zeros and those that are at the base of digital electronics.
With these switches, you can create assemblies that respond to logical tables. If you do not know what a logical table is, do a Boolean algebra search. Logical tables have corresponding inputs and outputs of).
you can now think of an input control as any signal that will trigger such an arrangement of transistors. These signals may be analog in nature, but they are usually packaged in a digitized format (again tables of zeros and ones). these signals will then cascade through transistors which, in a higher abstraction layer, will convert zeros and zeros until the signal reaches the output. switches.
looking at a fundamental level of implementation is what happens – the input signals provided by yourself or by the environment trigger the on-off behavior of these transistors. this will happen even in super-complex machines – like the computer.