| 摘要 |
PROBLEM TO BE SOLVED: To send and receive power supply and measurement signals with a simple circuit configuration. SOLUTION: A remote measuring apparatus comprises a coil 16 provided at a transmission section 1; and a coil 38 provided at a reception section 3 that is separated spatially from the coil 16 and is electromagnetically coupled to the coil 16. A transistor 13 is operated by a pulse signal Sa outputted from a microcomputer 11 according to the measurement signal of a sensor 2, and changes the coupling impedance of the coils 16, 38. A pulse oscillator 31 gives a high-frequency pulse signal to the coil 38. A high-frequency pulse signal generated in the coil 16 by electromagnetic induction is rectified and smoothed by a rectification circuit 14 and a three-terminal regulator 12, and is supplied to the microcomputer 11 as an operating power supply. A rectification circuit 33 of the reception section 3, a low-pass filter circuit 34, a comparison circuit 36, and the like detect a pulse signal Sa according to the measurement signal from the high-frequency pulse signal of the coil 38, where a crest value is changed according to a change in the coupling impedance for sending to the microcomputer 32. COPYRIGHT: (C)2005,JPO&NCIPI |
