re:difference between to amplify the signal and boost the energy level of signal?

Question

hi friends
i m confused beween to amplify and to increase the energy level of signal can any one explain me with example pls?

Answer 1

Amplification is a term widely used in the early days (1920's) of tube circuits. Triode tubes were commonally specified by their "amplication factor". For exampe when used in a typical circuit, a voltage change of 1 on the input (grid) would cause a change of 100 on the output (plate) and this was called a voltage amplification of 100. However just looking at the voltage changes is quite deceptive as to function, because it is the energy increase parameter that is the real work of the "amplifier". The modern terminology is to describe the "gain" of a circuit which is an accounting of the power level change without respect to voltage. The gain increase is expressed usually in dB, so an amplifier rated at 20 dB will increase the power by a factor of 100. For example this circuit will absorb 1 milliwatt from the source, and deliver 100 milliwatts to a load.

Answer 2

First off, energy is an instantaneous quantity. Amplifiers don't increase energy, they increase power. The distinction is subtle.

The basic way an amplifier works is by following the voltage -- that is, replicating the input voltage on the output -- while increasing the current. By the definition of power, P=VI, that increases the output power.