摘要 |
The coupling device comprises a transformer having a primary winding in series with a two-way switch controlled via an optocoupler and a three-position selector switch by a control circuit. In standby mode, the switch is connected to an oscillator defining a switching frequency (49 kHz) ensuring power supply of the control circuit, which circuit is able to detect the presence of a carrier on the transformer secondary winding. In receipt mode, the switch is closed and the control circuit analyzes the modulated information received on the transformer secondary winding. In transmission mode, the control circuit causes switching of the switch at the information modulation frequency (132 khz), performing both power supply of the control circuit and transmission of the information.
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