PURPOSE: To omit a frequency dividing circuit, by subjecting the main shaft of a revolution detector to gear reduction to lower the pulse rate of the pulse signal of the output signal.
CONSTITUTION: When a main shaft 3 is connected directly to a rotating material to be detected and is rotated, a photocoupler 7 outputs detection signals whose number corresponds to the number of slits formed on a slit plate 6 during one rotation of the main shaft 3. The signal detected by a code plate 14 fixed to a reduction rotation shaft 13 is transmitted to a pulse generating circuit mounted on a print substrate 18 through a brush 15 and a lead wire 17 and is shaped to square wave pulses and is outputted, The reduction gear ratio of the reduction mechanism consisting of a worm and a worm wheel is set to a proper value to drive directly a counter, which displays a running distance for a vehicle or the like without lowering the pulse rate by a frequency dividing circuit.
TANAKA YASUHIRO
SATOU MINORU
