Patent ID: 7265654

Claim:
A powerline pulse position modulated communication transmitter comprising: first and second connections for connecting to an AC powerline; a first chargeable capacitor and a first switch in series with said first capacitor coupled to said first and second connections for connection in parallel to the AC powerline; a second chargeable capacitor and a second switch in series with said second capacitor coupled to said first and second connections for connection in parallel to the AC powerline; a digital control integrated circuit; a zero voltage crossing detector circuit coupled to at least one of said first and second AC powerline connections and to said digital control integrated circuit; said digital control integrated circuit being coupled to said first switch in series with said first capacitor to actuate said first switch to charge said first capacitor in a first half cycle and to also discharge said capacitor in a second half cycle following said first half cycle, said first and second half cycles being of opposite polarity, said discharge occurring in one of a predetermined number of a plurality of signal time positions; said digital control integrated circuit being coupled to said second switch in series with said second capacitor to actuate said second switch to charge said second capacitor in a first half cycle and to also discharge said capacitor in a second half cycle following said first half cycle, said first and second half cycles being of opposite polarity, said discharge occurring in one of a predetermined number of a plurality of signal time positions; said digital control integrated circuit controlling said first switch and controlling said second switch to discharge said first capacitor and discharge said second capacitor to occur on alternating half cycles of opposite polarity.