G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
G01P1/00—Details of instruments
G01P1/07—Indicating devices, e.g. for remote indication
G01P1/08—Arrangements of scales, pointers, lamps or acoustic indicators, e.g. in automobile speedometers
G01P1/10—Arrangements of scales, pointers, lamps or acoustic indicators, e.g. in automobile speedometers for indicating predetermined speeds
G01P1/106—Arrangements of scales, pointers, lamps or acoustic indicators, e.g. in automobile speedometers for indicating predetermined speeds by comparing the time duration between two impulses with a reference time
G—PHYSICS
G01—MEASURING; TESTING
G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
G01P3/42—Devices characterised by the use of electric or magnetic means
G01P3/44—Devices characterised by the use of electric or magnetic means for measuring angular speed
G01P3/48—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage
G01P3/4802—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage by using electronic circuits in general
