The power supply of this series of torque signal couplers is provided by a set of toroidal transformers on the standard strain bridge torque sensor. The induced voltage is rectified on the shaft. The voltage regulator circuit converts it into a high-stability DC voltage. This voltage is not only supplied to the strain bridge of the standard strain bridge torque sensor as a bridge voltage, but also supplied to the circuit on the shaft as a working voltage. The mV level torque signal detected by the strain bridge is amplified by a high-precision instrumentation amplifier to a KmV level strong signal, and then converted into a square wave signal proportional to the torsional strain through a V/F converter. Through the wireless transmitter on the shaft, it is transmitted to the wireless receiver outside the shaft non-contact. After demodulation, it is restored to a digital signal with the same frequency as the square wave converted by V/F. The phase difference is less than 1μS, can generally be ignored. This series of torque sensors can work for a long time because of the transformer induction power supply. It is widely used in torque monitoring of motors, generators, reducers and diesel engines. Since the output square wave frequency signal is high level, the anti-interference ability is strong. It can be directly sent to the computer or PLC for processing without A/D conversion, which is very convenient to use. If you need to measure the speed, as long as the special speed sensor and its speed wheel are installed inside the torque signal coupler of this series, the speed signal of 60 square waves per revolution can be measured.