1. A method for managing power consumption in an apparatus having a plurality of separately-powered components for performing by command a plurality of operations each consuming a quantity of energy, said apparatus having a plurality of operating modes each corresponding to one of a plurality of predetermined power apportionment among said separately-powered components, said method comprising the steps of: (a) responsive to a command for one or more said operations, selecting a full operating mode corresponding apportionment of full operating power to all said separately-powered components; (b) creating a first signal E(t) representing the total consumption of said energy by said apparatus as a function of time; (c) creating a second signal E(t) representing the attenuated time average of said first signal E(t) such that ##EQU2## wherein .alpha. and .beta. are positive numbers; (d) comparing said second signal E(t) with a plurality of energy consumption threshold profiles and combining the results to create a mode selection signal; (e) selecting one of said operating modes responsive to said mode selection signal; and (f) repeatedly performing said steps (b) through (f) until receiving said command for one or more said operations.