Synchronization/reference pulse-based powerline pulse position modulated communication system

A powerline pulse position modulated communication system comprising:

• a transmitter, first and second connections for connecting said transmitter to an AC powerline, said transmitter having a zero voltage crossing detector connected to said connections, said transmitter having a circuit for producing a pulse;
• a signal source connected to said circuit to actuate said transmitter circuit so as to produce a reference pulse in the powerline at reference pulse position which is in one of a plurality of signal time positions relative to the zero crossing time and said signal source being actuated to produce a plurality of subsequent data pulses in one of said plurality of signal time positions away from zero crossing and within about 1000 microseconds of zero crossing prior to subsequent powerline zero crossings, said subsequent pulses being in selected signal time positions referenced to and following said reference pulse;
• and
• a receiver having first and second connections for connecting to the same AC powerline, a zero voltage crossing detector in said receiver connected to said first and second connections and a circuit responsive to a reference pulse so that subsequent pulses following the reference pulse in one of the signal time positions can be detected as a function of the time after the reference pulse.

A powerline pulse position modulated communication receiver comprising:

• first and second connections for connecting to an AC powerline;
• a digital control integrated circuit;
• a filter circuit coupled to said first and second connections for filtering out power voltages and passing signal pulses, said digital control integrated circuit being connected to said filter circuit to receive signal a message composed of at least one synchronization/reference pulse followed by one or more data pulses passed by said filter circuit;
• and
• a zero voltage crossing detector circuit coupled to said first and second connections and to said digital control integrated circuit, said digital control integrated circuit being programmed to compare the timing of the data pulses to the timing of said synchronization/reference pulse to determine at which one of a plurality of signal timing positions the data pulse is in relative to said synchronization/reference pulse position, said digital control integrated circuit deriving an encoded digital data number from the position of said data pulse being located in said one of said plurality of possible said timing positions relative to said synchronization/reference pulse position.

A powerline pulse communication apparatus comprising:

• a transmitting controller and a receiving controller, said transmitting controller and said receiving controller each having connections for connecting to an alternating current powerline;
• said transmitting controller having a zero voltage crossing detector circuit with connections for connecting to the alternating current powerline, said transmitting controller having a digital control integrated circuit therein, said zero voltage crossing detector circuit having an output connected to said digital control integrated circuit;
• a command input connected to said digital control integrated circuit so that when said command input is actuated said digital control integrated circuit emits a trigger signal;
• a serially connected switch and capacitor having connections for coupling to the alternating current power supply so that, when said switch is actuated, said capacitor is charged by the alternating current power supply, said switch being connected to receive at least one trigger signal from said digital control integrated circuit, said digital control integrated circuit being programmed so that the synchronization/reference pulse trigger signal is within a predetermined time period referenced to a prior zero crossing so that said capacitor is discharged and the synchronization/reference pulse is added to the powerline within said predetermined time period near to but spaced from a zero crossing time;
• said digital control integrated circuit being programmed so that the one or more data pulse trigger signals are produced within a predetermined time period so that said capacitor is discharged and at least one data pulse is added to the powerline within one of a plurality of time positions within said predetermined time period referenced to said prior synchronization/reference time position.

A powerline pulse position modulated communication system comprising:

• a transmitter, first and second connections on said transmitter for connecting to an AC powerline, a zero voltage crossing detector connected to said connection, a circuit in said transmitter for producing a pulse to said connections for producing a pulse in the powerline, said circuit receiving zero voltage crossing information from said zero voltage crossing detector and creating at least one synchronization/reference pulse in the powerline in a quiet zone window which is positioned in a predetermined quiet time period near to zero voltage crossing but not at the zero crossing time, followed by at least one data pulse time referenced to said synchronization/reference pulse;
• and
• a receiver having first and second connections for connecting to the same AC powerline, a zero voltage crossing detector in said receiver and a circuit in said receiver connected to said first and second connections and to said zero voltage crossing detector, said circuit being conditioned by the zero voltage crossing detector to receive at least one synchronization/reference pulse from said transmitter through the powerline said synchronization/reference being positioned in a predetermined quiet time period near to zero voltage crossing but not at the zero crossing time;
• said circuit being conditioned to receive subsequent data pulses from the powerline within the quiet zone which is positioned in a predetermined quiet time period near to zero voltage crossing but not at the zero crossing time;
• said subsequent data pulses being located at positions which are referenced to said synchronization/reference pulse position and not to the subsequent zero crossing times.

A powerline pulse position modulated communication method for remotely controlling a load, comprising the steps of:

• providing a transmitting controller for connection to the powerline;
• sensing zero voltage crossing in the powerline;
• sensing a load control command and causing the discharging of a capacitor across the powerline and causing the transmission of a reference pulse related to the zero crossing sensing and the load control command;
• causing the discharging of a capacitor across the powerline for causing transmission of a series of actuating data pulses related to the position of the reference pulse and the load control command;
• sensing at a receiving controller the zero voltage crossing, sensing the reference pulse, sensing the data pulses and determining in which signal timing positions the data pulses are located as compared to position that the reference pulse occurred;
• and
• actuating the load depending upon in which signal timing positions the data pulses occurred.