| 摘要 |
PURPOSE:To measure an unbalance vector by chopping two DC signals having an optional level with mutually 90 deg. out-of-phase rectangular wave signals in synchronization with a key groove detection signal and adding the chopped signals together, and obtaining a key groove compensation signal. CONSTITUTION:Outputs of oscillation sensors 1L and 1R arranged on both right and left measurement surfaces of a body W to be tested and the signal of a photosensor 2 which detects a mark added at a reference position (0 deg.) are inputted to a dynamic balance measuring circuit 3. Further, a key groove K is detected by a proximity switch 4 and a rectangular wave forming circuit 5 outputs a 0 deg. and a 90 deg. pulse to open and close switches of two component synthesizing circuits 6 and 7, chopping two kinds of DC input signals. Then, the outputs are inputted to address 8 and 9 and added to output signals of sensors 1R and 1L, whose outputs are inputted to a measuring circuit 3. Then, variable resistors VR1 and VR4 are adjusted to obtain the key groove compensation signal. |
