Actually both amplifies the input voltage. A step up transformer amplifies the input voltage and a transistor also amplifies. So what is the differece????
Easy. A transistor is a semi conductor that can essentially function as an on-ff switch. On certain configurations, you can use a transistor circuit with the right driving voltages to function as an amplifier/ Where as a transformer, is an active lumped circuit element which composed of wound coils, and ferromagnetic elements as a core which steps up or down the voltage of an electrical current by mutual induction. The principles behind both are VERY different, both in function, understanding and operation. Hope I helped some :)
A transformer does not , strictly speaking, amplify the voltage A a wire wound / laminate iron core transformer changes the voltage in relation to the turns ratio of the primary and secondary windings. ThE supply must change voltage either as ALTERNATING CURRENT or rapidly pulsed ( on off) Direct current e.g 100 ( In put - primary) turns to 1000 ( out put secondary) turns will give a 1:10 change in voltage ( and inverse change in current) in the above example 20 volts in gives 200 volts out in the above example Amplification, as carried out by the use of a TRANSISTOR like a mechanical valve. The higher voltage is always there in the circuit but is controlled by sending a signal to the transistor ( base) which turns on the flow of the higher voltage on and off ( up or down) Imagine a water pipe carrying high pressure water . The pipe has a valve to control the high pressure supply but, that valve is so sensitive just a small amount of low pressure can make it turn on and off . that is how a transistor operates It AMPLIFIES the small signal , by acting as a valve for the already present higher volage
A transformer is passive, to simplify it changes the voltage either up or down as a ratio of the number of windings on each side. Transistors can be used many ways. To amplify a voltage the transistor itself does not change the voltage but acts as a sort of valve. The higher voltage is actually supplied to it and it opens the valve to allow the higher voltage to pass .
