Patent ID: 8447542

Claim:
A method of measuring the electric power of a universal electric motor connected to an electric power mains by a switch; said electric power mains supplying said motor with a substantially sinusoidal alternating voltage (V(t)); at half-periods of said voltage (V(t)), said switch being turned on at a first instant (ton) and turned off at a second instant (toff), which are established as a function of a current (I(t)) to be supplied to said motor; said method comprising the steps of: sampling the current (I(t)) supplied to said motor, at at least a third instant (tin) between said first and said second instants, to determine a corresponding sampled current value (Ic); estimating a fitting current time pattern (f(t)) having a zero current value at said first (ton) and said second (toff) instants, and a current value (I(tin)) equal to said sampled current value (Ic) at said at least a third instant (tin); calculating a measure of electric power on the basis of the estimated said fitting current time pattern (f(t)).