Absolute encoder of the multirotation type

摘要

The multirotation type absolute encoder has a power source voltage detecting circuit (13) to detect whether the power source voltage has reached a predetermined voltage value when the power source is turned on, and a control circuit (17) for first serially transmitting a signal indicative of the number of multirotations to an external controller when the power source voltage has reached a predetermined voltage or higher and, thereafter, for transmitting a signal indicating the absolute angle within one rotation by use of square wave signals of two phases having a phase difference of 90 DEG .