Transmission of digital data over an A.C. supply line

• US 6,476,709 B1
• Filed: 06/21/1999
• Issued: 11/05/2002
• Est. Priority Date: 06/22/1998
• Status: Expired due to Term

• Current Assignee: STMicroelectronics SA (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SA (STMicroelectronics NV)
• Inventors: Wuidart, Luc, Bardouillet, Michel
• Primary Examiner(s): POPE, DARYL C
• Application Number:
  US09/336,894
• Time in Patent Office: 1,233 Days
• Field of Search: 340/310.02, 340/310.01, 340/310.04, 340/825.22, 340/825.23
• US Class Current: 375/259
• CPC Class Codes: H04B 2203/5458 Monitor sensor; Alarm systems
• CPC Class Codes: H04B 3/542 the information being in digital form
• CPC Class Codes: H05B 47/185 via power line carrier transmission

Abstract

The present invention relates to a method of data transmission over an A.C. power supply line of a load to be cyclically powered, including organizing a switching of the A.C. supply voltage according to a coding of the data to be transmitted and outside cyclic load supply periods.

Claims

1. A method of transmitting data over an A.C. power supply line of a load having cyclic power supply periods, comprising acts of:

organizing a switching of an A.C. supply voltage according to a coding of the data to be transmitted outside the cyclic power supply periods of the load; and

using the A.C. supply voltage as an envelope of pulses having a higher frequency.

2. The method of claim 1, wherein a frequency of the A.C. power supply is relatively low with respect to a relatively high switching frequency for the data to be transmitted.

3. The method of claim 1, wherein the organizing of the switching of the A.C. supply voltage, occurs every other halfwave.

4. The method of claim 1, wherein the organizing the switching of the A.C. supply voltage occurs at each halfwave, during a decreasing portion of the halfwave.

5. A transmitter of digital data over an A.C. power supply line of a load having cyclic power supply periods, including:

a switching means adapted to interrupt the A.C. power supply line according to a coding of the digital data to be transmitted, that uses the A.C. supply signal as an envelope of pulses having a higher frequency; and

wherein the switching means is controlled outside the cyclic supply periods of the load.

6. The transmitter of claim 5, including a one-way conduction component in parallel with the switching means.

7. A receiver of digital data transmitted over an A.C. power supply line of a load having cyclic supply periods, the receiver including:

a means for extracting from a load supply voltage the digital data that was transmitted; and

wherein the data is formed by a switching, outside the cyclic supply periods of the load, of the A.C. supply voltage according to a predetermined coding.

8. The receiver of claim 7, including:

an associated capacitor adapted to provide an approximately D.C. voltage to a load supply circuit; and

a one-way conduction means adapted to isolating the capacitor from the means for extracting the digital data.

9. A transmitter of digital data over an A.C. power supply line of a load having cyclic power supply periods, including:

a switching circuit to switch an A.C. supply voltage according to a coding of the digital data to be transmitted; and

wherein the switching circuit switches the A.C. supply voltage outside the cyclic power supply periods of the load.

10. The transmitter of claim 9, wherein the switching circuit switches the A.C. supply voltage during every other halfwave.

11. The transmitter of claim 9, wherein the switching circuit switches the A.C. supply voltage each halfwave during a decreasing portion of the halfwave.

12. The transmitter of claim 9, wherein the A.C. supply voltage is used as an envelope for pulses having a higher frequency than a frequency of the A.C. supply signal.

13. The transmitter of claim 9, wherein a switching frequency of the A.C. supply voltage during periods of data transmission is higher than at least twice a frequency of the A.C. supply voltage.

14. The transmitter of claim 9, wherein the coding of the digital data to be transmitted is done according to an RS232-type transmission protocol.

15. A system for transmitting digital data over an A.C. power supply line of a load, including:

a switching circuit that, during a first period of an A.C. supply signal, allows the load to be supplied by the A.C. supply signal, and during a second period of the A.C. supply signal, switches the signal according to a coding of the digital data to be transmitted; and

a first element that supplies a D.C. voltage to the load during the second period of the supply signal.

16. The system of claim 15, wherein the first and second periods of the A.C. supply signal are alternate halfwaves of the A.C. supply signal.

17. The system of claim 15, wherein the first period of the A.C. supply signal corresponds to an increasing portion of a halfwave of the A.C. signal, and wherein the second period of the A.C. supply signal corresponds to a decreasing portion of a halfwave of the A.C signal.

18. The system of claim 15, wherein the first element that supplies a D.C. voltage to the load is a capacitor.

19. The system of claim 15, wherein the A.C. supply signal is used as an envelope signal for the digital data.

20. The system of claim 15, wherein a switching frequency of the A.C. supply signal is higher than at least twice a frequency of the A.C. signal.

21. The system of claim 15, wherein the coding of the digital data is done according to an RS232-type transmission protocol.

22. A receiver of digital data transmitted over an A.C. power supply line of a load having cyclic power supply periods, including:

a circuit that extracts the digital data that was transmitted from a load supply voltage; and

wherein the digital is formed by a switching of an A.C. supply voltage outside the cyclic power supply periods during which the A.C. supply voltage supplies the load.

23. The receiver of claim 22, further including:

a capacitor that provides a substantially D.C supply voltage to the load during periods when the A.C. supply voltage does not supply the load and is being switched to transmit the digital data; and

a one-way conduction element that isolates the capacitor from the circuit that extracts the digital data.