| 摘要 |
In the field of powerline carrier transmission and reception for remote control, a slave receiver counts cycles of carrier in a time window near to a zerocrossing of the power main. The receiver is implemented using discrete components (1,2,3) and a microprocessor. The discrete components form an input filter (1), a limiting preamplifier (2), a demodulator and noise filter (3) and means to detect the zerocrossing points (4). A capacitor is charged and discharged, depending upon the rate of occurence of carrier cycles to produce a binary signal dependent on the digital value present on the carrier. By measuring the length of time the binary signal is in one of its states in said time window, the microprocessor determines whether the signal resulted from noise or not.
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