POWER TRANSMITTING DEVICE AND WAVEFORM MONITORING CIRCUIT USED IN SAME

摘要

PROBLEM TO BE SOLVED: To prevent a waveform monitoring signal of negative voltage from being inputted to a waveform detection circuit.SOLUTION: A power transmission system includes a power transmitting device having a primary side coil and a power receiving device having a secondary side coil. The primary side coil and the secondary side coil are electromagnetically coupled with each other and alternating-current power transmitted from the power transmitting device is thereby received by the power receiving device. The power transmitting device includes: a waveform monitoring circuit which detects potential at one end of the primary side coil and outputs the waveform monitoring signal formed by limiting the detected potential to a potential not less than ground potential; a waveform detection circuit which detects waveform changes in the waveform monitoring signal inputted from the waveform monitoring circuit; and a data detection circuit which detects data transmitted according to load changes by a load modulating unit in the power receiving device on the basis of the results of waveform change detection detected by the waveform detection circuit.