Patent ID: 7394296

Claim:
A method for automatically offsetting linear deviation of V/F converter, comprising following steps: a) setting up a standard V/F transfer function and a standard frequency down function, both standard functions having a corresponding relationship between (V 1 , F 1 ), (V 0 , F 0 ) and (F 1 , K 1 ), (F 0 , K 0 ); b) inputting a first voltage V 1 , thus a real first frequency F 1 ′ being obtained; c) inputting a second voltage V 0 , thus a real second frequency F 0 ′ being obtained; d) comparing above two corresponding value sets, namely, F 1 ′ with F 1 , and F 0 ′ with F 0 ; e) in step d, if any corresponding values are different, namely, F 1 ≠F 1 ′ or F 0 ≠F 0 ′, frequency down values K 1 and K 0 are set correspondingly to F 1 ′ and F 0 ′ respectively; f) according to two coordinate points (F 1 ′, K 1 ) and (F 0 ′, K 0 ), calculating an offset frequency down function, figure of which is a straight line passing through said two coordinate points in a Cartesian coordinate.