Patent ID: 8596408

Claim:
A torque sensor comprising: a plurality of torque signal detection sections detecting a torque signal, the torque signal depending on a torque and having a value between a first lower limit and a first upper limit; at least one monitoring signal detection section detecting a monitoring signal, the monitoring signal being a signal for determining abnormality of the torque signal and having a value between the first lower limit and the first upper limit; a limiting section changing the torque signal to a second lower limit when the torque signal is equal to or less than the second lower limit that is greater than the first lower limit, the limiting section changing the torque signal to a second upper limit when the torque signal is equal to or greater than the second upper limit that is less than the first upper limit; an abnormality determination section determining whether abnormality has occurred in the torque signal based on the torque signal and the monitoring signal; and an output section transmitting an output signal corresponding to the torque signal of each of the torque signal detection sections, wherein when abnormality has not occurred in the torque signal, the output section transmits, as the output signal, a normal signal that is a value based on the torque signal and is between the second lower limit and the second upper limit, and when abnormality has occurred in the torque signal, the output section transmits, as the output signal, a first fault notification signal that is a value between the first lower limit and the second lower limit or a second fault notification signal that is a value between the first upper limit and the second upper limit.