| 摘要 |
PURPOSE:To enable the receiving side to check the state of transmission at all times in wireless transmission of signals for which the time of occurrence cannot be specified by transmitting a check signal group from a transmitter to a receiver at a fixed period. CONSTITUTION:A pulse generating circuit 10 for check signal transmission control generates square wave pulses of less than 50% duty ratio repeatedly, and a check signal generating circuit 9 generates signals of specified frequency within the limit of 0.1-20KHz continuously. Further, a high frequency crystal oscillating circuit 1 oscillates a specified frequency within the limit of 4-20MHz. When there is no transmission output signal from a sensor circuit 8, pulses for check signal transmission control are putputted from an NAND gate circuit 6 and sent to the receiving side. On the other hand, when a transmission output signal is outputted from the sensor circuit 8, a sensor output signal in which a check signal is formed is outputted and sent to the receiving side. |
