CA1052280A - Transmitting over power lines - Google Patents
Transmitting over power linesInfo
- Publication number
- CA1052280A CA1052280A CA239,097A CA239097A CA1052280A CA 1052280 A CA1052280 A CA 1052280A CA 239097 A CA239097 A CA 239097A CA 1052280 A CA1052280 A CA 1052280A
- Authority
- CA
- Canada
- Prior art keywords
- power lines
- switching means
- input
- gate
- switching
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
- H04B3/54—Systems for transmission via power distribution lines
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B2203/00—Indexing scheme relating to line transmission systems
- H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
- H04B2203/5404—Methods of transmitting or receiving signals via power distribution lines
- H04B2203/5416—Methods of transmitting or receiving signals via power distribution lines by adding signals to the wave form of the power source
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B2203/00—Indexing scheme relating to line transmission systems
- H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
- H04B2203/5462—Systems for power line communications
- H04B2203/5483—Systems for power line communications using coupling circuits
Abstract
TRANSMITTING OVER POWER LINES
Abstract of the Disclosure A transponder transmitter for transmitting over power lines includes a rectifier circuit that rectifies the power at power line frequency to provide a unipolar potential having ripple at twice the power line frequency. A circuit receives a drive signal from a modulator for interrupting the unipolar potential at a rate corresponding to the carrier frequency of the modulating signal. Circuitry, including a triac couples the interrupted unipolar potential to the power lines.
Abstract of the Disclosure A transponder transmitter for transmitting over power lines includes a rectifier circuit that rectifies the power at power line frequency to provide a unipolar potential having ripple at twice the power line frequency. A circuit receives a drive signal from a modulator for interrupting the unipolar potential at a rate corresponding to the carrier frequency of the modulating signal. Circuitry, including a triac couples the interrupted unipolar potential to the power lines.
Description
:` Background of the Invention ; The present invention relates in general to trans-mitting and more particularly concerns novel apparatus and techniques for transmitting over power lines. The invention is especially useful for transmitting digital data over power lines.
~l~h~ invell~ioll is cllaract~rize~ by r~liability, relatively good `~ efficiency and is relatively inexpensive and easy to fabricate . while being operative over a relatively broad range of fre-;.~
~; quencies.
It is an important object of the invention to provide a transmitter for transmitting over power lines.
:y It is another object of the invention to achieve one or more of the preceding objects with a transmitter that re-.~,- . .
celves ltS energizing potentials from a power line and uses ; ripple thus derived to help est~ablish synchronism between the -, transmitted signal and the power line frequency.
s~`
.. ,~ --1--,, ~ . .
:. ' ,.,~
r.
',~
~;' ~' ;,.
!~r ,,~
.,'"~'~; .
" ' ,,''~''~
:' `''.' " 7f :'''`'''^
:`: lOS;~Z80 It is another object of the invention to achieve one or more of the preceding objects with circuitry that is reli-able and relatively efficient.
It is a further object of the invention to achieve one or more of the preceding objects with a transmitter that may operate over a wide range of frequencies without tuning.
1i~ SUMMARY OF THE INVENTION
:i According to the invention, there is a source of a unipolar potential derived from electrical power and having ;
ripple at twice the power line frequency, means for interrupt-ing the unipolar potential at a rate corresponding to a car-, ~ .
rier frequency, and means for coupling the interrupted uni- ~
polar potential to the power lines to provide a carrier signal `
on the power lines. Preferably, the means for interrupting ; comprises transistor switching means coupled to the unipolar ; potential source and rendered alternatively conductive and ;
non-conductive at a rate corresponding to the carrier frequency ; established by a modulating signal applied at a modulating in-~ put. The means for coupling the interrupted unipolar potential ;~ 20 to the power lines typically comprises a triac.
More particularly, there is provided apparatus for ;~
transmitting over power lines comprising:
a source of a unipolar potential derived from .~
,~ electrical power on said power lines, a source of a modulating signal of carrier frequency ' for interrup~ng said unipolar potential at a rate corresponding to said carrier frequency, ~ and means for coupling the interrupted unipolar ; potential to said power lines to provide a carrier signal of said carrier frequency on said power lines, .,', . ~ . .
~ -2-;~, . .:
:.
`--lOS;~280 . . .
said means for coupling comprising gated semi-conductor switching means having gate electrode means and input . and output electrode means in series with one of said power i~';~'l' lines, gate resistive means connected between said input and .~ gate electrode means, gate capacitive means connected between said gate -:: electrode means and the other of said power lines, ., .
. output transistor switching means connected to said input electrode means for selectively exchanging current with said gate capacitive means through said gate resistive means, ~' input capacitive means coupled to said output transis-tor switching means for carrying a potential for slowly switch-ing the latter amplifying means on, first and second input switching means responsive to ?;,,;~
said modulatin~ signal coupled to said input capacitive means , and rendered conductive during alternating contiguous time . intervals at said carrier signal frequency for alternately charging and discharging said input capacitive means and thereby :-- .
. 20 slowly switching on and switching off said transistor switching means whereby said gated semiconductor switching means delivers to said power line a slowly rising and falling current provided ~ -by said transistor switching means. ;
:.: Numerous other features, objects and advantages of the '~.;-:
`` invention will become apparent from the following specification l . .,.i i when read in connection with the accompanying drawing, the single ~, ~ figure of which is:
BRIEF DESCRIPTION OF THE DRAWING
A schematic circuit diagram of an exemplary embodi-"' 30 ment of the invention.
` . -2a-.::
-, l~S~Z~10 ,,~ Detailed Description of Preferred Embodiments With reference now to the drawing, there is shown an exemplary embodiment of a transponder transmitter. Transformer ~; 500 which is a Stancor P-8605, steps down the 120V, 60-Hz power ~` line voltage from electric service entrance 24 and 24'. The ~' :
~; reduced voltage is rectified by diodes 501 and 502, which are Motorola MR751, and filtered by capacitor 503. Transistors 504 and 505, which are 2N2222A, are normally turned off by the modulator signals on lines 136 and 136', via resistors 506 and ~; 10 507, respectively. When input terminals 136 and 136' receive .:
a modulating signal, transistors 504 and 505 are switched 180 degrees out of phase. When transistor 504 is switched on, current flows through resistors 508 and 509, charging capacitor . :
~' 510, thereby slowly switching on transistor 511, which is a ,.,, ~
i 2N2905, whose collector current is limited by resistor 523, ~' and transistor 512, which is a 2N6111 whose emitter current is limited by resistor 513. This raises the voltage on line 525 to that on line 526, thereby charging capacitor 528 '`, through resistor 527. The voltage drop across resistor 527 , ;-.
i 20 causes triac 529 to conduct. When the modulating signal on ;: l;
,~i line 136 switches off transistor 504, capacitor 510 discharges through resistor 508, slowly switching off transistors 511 and 512, while diode 514, which is a Motorola MR751, clips the ~:,;,, - , ' spike created by the inductance of electric service entrance 24 .,.,., :
and a distribution transformer. When transistor 505 is switched on by the modulating signal on line 136', transistors 515, , ~ .
which is a 2N2905, is switched on via resistors 516 and 517.
.
Current then flows through resistor 518, charging capacitor 519, thereby slowly turning on transistor 520~which is a 2N6386, ,:
..
.
:: .
.
.
lOS;~Z~
whose emitter current is limited by resistor 524. This lowers the voltage on line 525 to that on line 24', the service en-trance neutral, thereby discharging capacitor 528 through resistor 527. The voltage drop across resistor 527 causes triac 529 to conduct. When the modulating signal on line 136 switches off transistor 505, capacitor 519 discharges through resistor 521, slowly switching off transistor 520, while diode 522, which is a Motorola MR751, clips the spike created by the inductance of electric service entrance 24 and the distri-bution transformer. The voltage transitions on line 525 arecoupled to the electric service entrance, lines 24 and 24', by coupling capacitor 109.
The circuitry just described comprises a source of unipolar potential on line 526 derived from the electrical power and having ripple at the power line frequency. The transistor circuitry comprises means for interrupting the unipolar po-tential at a rate corresponding to the carrier frequency in , response to the means for modulating applied to the bases of transistors 504 and 505 to interrupt the unipolar potential at a rate corresponding to the carrier frequency. The triac 529 comprises means for coupling the interruped unipolar potential to the power lines to provide a carrier signal on the power lines.
There has been described novel apparatus and techni-ques for effectively communicating over power lines with numer-ous advantages and features described above. It is apparent that those skilled in the art may now make numerous uses and modifications of and departures from the specific embodiments described herein without departing from the inventive concepts.
Consequently, the invention is to be construed as embracing each and every novel feature and novel combination of features present in or possessed by the apparatus and techniques herein disclosed and limited solely by the spirit and scope of the appended claims.
~l~h~ invell~ioll is cllaract~rize~ by r~liability, relatively good `~ efficiency and is relatively inexpensive and easy to fabricate . while being operative over a relatively broad range of fre-;.~
~; quencies.
It is an important object of the invention to provide a transmitter for transmitting over power lines.
:y It is another object of the invention to achieve one or more of the preceding objects with a transmitter that re-.~,- . .
celves ltS energizing potentials from a power line and uses ; ripple thus derived to help est~ablish synchronism between the -, transmitted signal and the power line frequency.
s~`
.. ,~ --1--,, ~ . .
:. ' ,.,~
r.
',~
~;' ~' ;,.
!~r ,,~
.,'"~'~; .
" ' ,,''~''~
:' `''.' " 7f :'''`'''^
:`: lOS;~Z80 It is another object of the invention to achieve one or more of the preceding objects with circuitry that is reli-able and relatively efficient.
It is a further object of the invention to achieve one or more of the preceding objects with a transmitter that may operate over a wide range of frequencies without tuning.
1i~ SUMMARY OF THE INVENTION
:i According to the invention, there is a source of a unipolar potential derived from electrical power and having ;
ripple at twice the power line frequency, means for interrupt-ing the unipolar potential at a rate corresponding to a car-, ~ .
rier frequency, and means for coupling the interrupted uni- ~
polar potential to the power lines to provide a carrier signal `
on the power lines. Preferably, the means for interrupting ; comprises transistor switching means coupled to the unipolar ; potential source and rendered alternatively conductive and ;
non-conductive at a rate corresponding to the carrier frequency ; established by a modulating signal applied at a modulating in-~ put. The means for coupling the interrupted unipolar potential ;~ 20 to the power lines typically comprises a triac.
More particularly, there is provided apparatus for ;~
transmitting over power lines comprising:
a source of a unipolar potential derived from .~
,~ electrical power on said power lines, a source of a modulating signal of carrier frequency ' for interrup~ng said unipolar potential at a rate corresponding to said carrier frequency, ~ and means for coupling the interrupted unipolar ; potential to said power lines to provide a carrier signal of said carrier frequency on said power lines, .,', . ~ . .
~ -2-;~, . .:
:.
`--lOS;~280 . . .
said means for coupling comprising gated semi-conductor switching means having gate electrode means and input . and output electrode means in series with one of said power i~';~'l' lines, gate resistive means connected between said input and .~ gate electrode means, gate capacitive means connected between said gate -:: electrode means and the other of said power lines, ., .
. output transistor switching means connected to said input electrode means for selectively exchanging current with said gate capacitive means through said gate resistive means, ~' input capacitive means coupled to said output transis-tor switching means for carrying a potential for slowly switch-ing the latter amplifying means on, first and second input switching means responsive to ?;,,;~
said modulatin~ signal coupled to said input capacitive means , and rendered conductive during alternating contiguous time . intervals at said carrier signal frequency for alternately charging and discharging said input capacitive means and thereby :-- .
. 20 slowly switching on and switching off said transistor switching means whereby said gated semiconductor switching means delivers to said power line a slowly rising and falling current provided ~ -by said transistor switching means. ;
:.: Numerous other features, objects and advantages of the '~.;-:
`` invention will become apparent from the following specification l . .,.i i when read in connection with the accompanying drawing, the single ~, ~ figure of which is:
BRIEF DESCRIPTION OF THE DRAWING
A schematic circuit diagram of an exemplary embodi-"' 30 ment of the invention.
` . -2a-.::
-, l~S~Z~10 ,,~ Detailed Description of Preferred Embodiments With reference now to the drawing, there is shown an exemplary embodiment of a transponder transmitter. Transformer ~; 500 which is a Stancor P-8605, steps down the 120V, 60-Hz power ~` line voltage from electric service entrance 24 and 24'. The ~' :
~; reduced voltage is rectified by diodes 501 and 502, which are Motorola MR751, and filtered by capacitor 503. Transistors 504 and 505, which are 2N2222A, are normally turned off by the modulator signals on lines 136 and 136', via resistors 506 and ~; 10 507, respectively. When input terminals 136 and 136' receive .:
a modulating signal, transistors 504 and 505 are switched 180 degrees out of phase. When transistor 504 is switched on, current flows through resistors 508 and 509, charging capacitor . :
~' 510, thereby slowly switching on transistor 511, which is a ,.,, ~
i 2N2905, whose collector current is limited by resistor 523, ~' and transistor 512, which is a 2N6111 whose emitter current is limited by resistor 513. This raises the voltage on line 525 to that on line 526, thereby charging capacitor 528 '`, through resistor 527. The voltage drop across resistor 527 , ;-.
i 20 causes triac 529 to conduct. When the modulating signal on ;: l;
,~i line 136 switches off transistor 504, capacitor 510 discharges through resistor 508, slowly switching off transistors 511 and 512, while diode 514, which is a Motorola MR751, clips the ~:,;,, - , ' spike created by the inductance of electric service entrance 24 .,.,., :
and a distribution transformer. When transistor 505 is switched on by the modulating signal on line 136', transistors 515, , ~ .
which is a 2N2905, is switched on via resistors 516 and 517.
.
Current then flows through resistor 518, charging capacitor 519, thereby slowly turning on transistor 520~which is a 2N6386, ,:
..
.
:: .
.
.
lOS;~Z~
whose emitter current is limited by resistor 524. This lowers the voltage on line 525 to that on line 24', the service en-trance neutral, thereby discharging capacitor 528 through resistor 527. The voltage drop across resistor 527 causes triac 529 to conduct. When the modulating signal on line 136 switches off transistor 505, capacitor 519 discharges through resistor 521, slowly switching off transistor 520, while diode 522, which is a Motorola MR751, clips the spike created by the inductance of electric service entrance 24 and the distri-bution transformer. The voltage transitions on line 525 arecoupled to the electric service entrance, lines 24 and 24', by coupling capacitor 109.
The circuitry just described comprises a source of unipolar potential on line 526 derived from the electrical power and having ripple at the power line frequency. The transistor circuitry comprises means for interrupting the unipolar po-tential at a rate corresponding to the carrier frequency in , response to the means for modulating applied to the bases of transistors 504 and 505 to interrupt the unipolar potential at a rate corresponding to the carrier frequency. The triac 529 comprises means for coupling the interruped unipolar potential to the power lines to provide a carrier signal on the power lines.
There has been described novel apparatus and techni-ques for effectively communicating over power lines with numer-ous advantages and features described above. It is apparent that those skilled in the art may now make numerous uses and modifications of and departures from the specific embodiments described herein without departing from the inventive concepts.
Consequently, the invention is to be construed as embracing each and every novel feature and novel combination of features present in or possessed by the apparatus and techniques herein disclosed and limited solely by the spirit and scope of the appended claims.
Claims (4)
1. Apparatus for transmitting over power lines comprising:
a source of a unipolar potential derived from electrical power on said power lines, a source of a modulating signal of carrier frequency for interrupting said unipolar potential at a rate corresponding to said carrier frequency, and means for coupling the interrupted unipolar potential to said power lines to provide a carrier signal of said carrier frequency on said power lines, said means for coupling comprising gated semi-conductor switching means having gate electrode means and input and output electrode means in series with one of said power lines, gate resistive means connected between said input and gate electrode means, gate capacitive means connected between said gate electrode means and the other of said power lines, output transistor switching means connected to .
said input electrode means for selectively exchanging current with said gate capacitive means through said gate resistive means, input capacitive means coupled to said output :
transistor switching means for carrying a potential for slowly switching the latter amplifying means on, first and second input switching means responsive to said modulating signal coupled to said input capacitive means and rendered conductive during alternating contiguous time intervals at said carrier signal frequency for alternately charging and discharging said input capacitive means and thereby slowly switching on and switching off said transistor switching means whereby said gated semiconductor switching means delivers to said power line a slowly rising and falling current provided by said transistor switching means.
a source of a unipolar potential derived from electrical power on said power lines, a source of a modulating signal of carrier frequency for interrupting said unipolar potential at a rate corresponding to said carrier frequency, and means for coupling the interrupted unipolar potential to said power lines to provide a carrier signal of said carrier frequency on said power lines, said means for coupling comprising gated semi-conductor switching means having gate electrode means and input and output electrode means in series with one of said power lines, gate resistive means connected between said input and gate electrode means, gate capacitive means connected between said gate electrode means and the other of said power lines, output transistor switching means connected to .
said input electrode means for selectively exchanging current with said gate capacitive means through said gate resistive means, input capacitive means coupled to said output :
transistor switching means for carrying a potential for slowly switching the latter amplifying means on, first and second input switching means responsive to said modulating signal coupled to said input capacitive means and rendered conductive during alternating contiguous time intervals at said carrier signal frequency for alternately charging and discharging said input capacitive means and thereby slowly switching on and switching off said transistor switching means whereby said gated semiconductor switching means delivers to said power line a slowly rising and falling current provided by said transistor switching means.
2. Apparatus for transmitting over power lines in accordance with claim 1 and further comprising a unilaterally conducting device connected across said output transistor switching means for clipping the spike created on said power lines in response to a sudden change in current when said gated semiconductor switching means changes conductive state.
3. Apparatus for communicating over power lines in accordance with claim 1 and further comprising, a second output transistor switching means, and a second input capacitive means connected to said input electrode means for selectively exchanging current with said gate capacitive means through said gate resistive means coupled to said second output transistor switching means for carrying a potential for slowly switching the latter switching means on.
4. Apparatus for communicating over power lines in accordance with claim 3 and further comprising first and second unilaterally conducting devices connected across respective ones of said first and second output transistor switching means for clipping spikes in response to sudden changes in current in response to said gated semiconductor switching means changing conducting state.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US55135675A | 1975-02-20 | 1975-02-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1052280A true CA1052280A (en) | 1979-04-10 |
Family
ID=24200933
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA239,097A Expired CA1052280A (en) | 1975-02-20 | 1975-11-06 | Transmitting over power lines |
Country Status (15)
| Country | Link |
|---|---|
| JP (1) | JPS51101411A (en) |
| AR (1) | AR204804A1 (en) |
| BE (1) | BE836830A (en) |
| BR (1) | BR7601036A (en) |
| CA (1) | CA1052280A (en) |
| CH (1) | CH600709A5 (en) |
| DE (1) | DE2545344B2 (en) |
| ES (1) | ES441952A1 (en) |
| FR (1) | FR2301979A1 (en) |
| GB (1) | GB1528369A (en) |
| IL (1) | IL48210A (en) |
| IN (1) | IN143965B (en) |
| IT (1) | IT1052793B (en) |
| NL (1) | NL7601689A (en) |
| SE (1) | SE403421B (en) |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB662655A (en) * | 1949-02-04 | 1951-12-12 | Nl Standard Electric Maatsscha | Improvements in or relating to signalling systems employing d.c. impulses over and a.c. supply line |
| US3652876A (en) * | 1970-04-30 | 1972-03-28 | Quasar Microsystems Inc | Data transmission system, utilizing ac line frequency as clock |
| CH540607A (en) * | 1971-07-01 | 1973-08-15 | Zellweger Uster Ag | Method and device for signal generation and application of the method |
| JPS5326653B2 (en) * | 1973-06-14 | 1978-08-03 |
-
1975
- 1975-01-01 AR AR261387A patent/AR204804A1/en active
- 1975-09-30 IL IL48210A patent/IL48210A/en unknown
- 1975-10-09 DE DE19752545344 patent/DE2545344B2/en not_active Withdrawn
- 1975-10-21 ES ES441952A patent/ES441952A1/en not_active Expired
- 1975-11-06 CA CA239,097A patent/CA1052280A/en not_active Expired
- 1975-11-11 IN IN2153/CAL/75A patent/IN143965B/en unknown
- 1975-11-11 SE SE7512634A patent/SE403421B/en unknown
- 1975-12-10 IT IT52617/75A patent/IT1052793B/en active
- 1975-12-12 GB GB51056/75A patent/GB1528369A/en not_active Expired
- 1975-12-16 FR FR7538550A patent/FR2301979A1/en active Granted
- 1975-12-18 BE BE162904A patent/BE836830A/en unknown
- 1975-12-22 CH CH1662775A patent/CH600709A5/xx not_active IP Right Cessation
-
1976
- 1976-01-26 JP JP51007413A patent/JPS51101411A/en active Pending
- 1976-02-19 NL NL7601689A patent/NL7601689A/en not_active Application Discontinuation
- 1976-02-19 BR BR7601036A patent/BR7601036A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| DE2545344A1 (en) | 1976-08-26 |
| GB1528369A (en) | 1978-10-11 |
| IL48210A0 (en) | 1975-11-25 |
| SE7512634L (en) | 1976-08-23 |
| BR7601036A (en) | 1976-09-14 |
| IL48210A (en) | 1977-12-30 |
| JPS51101411A (en) | 1976-09-07 |
| NL7601689A (en) | 1976-08-24 |
| IT1052793B (en) | 1981-07-20 |
| BE836830A (en) | 1976-06-18 |
| FR2301979A1 (en) | 1976-09-17 |
| AR204804A1 (en) | 1976-02-27 |
| AU8528575A (en) | 1977-04-07 |
| CH600709A5 (en) | 1978-06-30 |
| FR2301979B1 (en) | 1978-05-12 |
| DE2545344B2 (en) | 1977-03-24 |
| SE403421B (en) | 1978-08-14 |
| ES441952A1 (en) | 1977-03-16 |
| IN143965B (en) | 1978-03-04 |
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