The invention relates to a powder feed apparatus of a powder spraycoating equipment, containing a dense phase powder pump fitted with at least one feed chamber, preferably two feed chambers, alternatingly discharging coating powder, each feed chamber having one powder intake valve at a powder intake to aspirate coating powder during a suction stage and one powder outlet valve at a powder outlet to discharge coating powder during a discharge stage; further control valves to operate the dense phase powder pump; further an electric control unit containing at least one computer controlling the dense phase powder pump by means of said control valves, characterized in that a dependence mode of the total open time (ttotal) of the powder intake valves is stored in the control unit and defines the dependence of the total open time (ttotal) on an adjustable nominal value (mp) adjusted by a powder adjusting element at the control unit and relating to the rate of powder to be conveyed to be conveyed by the dense phase powder pump, further defining a response delay time (tdelay) and an apparatus constant (C).