| 摘要 |
PURPOSE:To know the communication state in a home bus system through sounding by a simple method by fitting a sounding body and a driving device for the sounding body to the output or input of the transmitting device of a communication controller. CONSTITUTION:When a communication packet is transmitted, the output termi nal of a microprocessor 1 varies between a high and a low level repeatedly to turn on and off the collector of a transistor (TR) 8, whose collector current is flowed intermittently to the primary winding of a pulse transformer 9 to output a signal to an information transmitting medium. At this time, when the collector of the TR 8 is turned on, the base current of a TR 16 flows through a resistance 18, so a current flows to the collector of the TR 16 to charge the sounding body 18 electrostatically. Further, when the collector of the TR 8 is turned off, on the other hand, the collector of the TR 16 is also turned off to discharge the sounding body 17 through a resistance 19 electrostatically. Therefore, a rectangular wave voltage corresponding to trans mitted data is applied to the sounding body 17 during communication packet transmission and the sounding body 17 sounds.
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