Safe traffic control system, method and apparatus

• US 20030146851A1
• Filed: 07/16/2002
• Published: 08/07/2003
• Est. Priority Date: 07/16/2002
• Status: Abandoned Application

• Current Assignee: Miguel S. Giacaman
• Original Assignee: Miguel S. Giacaman
• Inventors: Giacaman, Miguel S
• Application Number:
  US10/181,283
• Publication Number:
  US 20030146851A1
• Time in Patent Office: Days
• US Class Current: 340/907
• CPC Class Codes: G08G 1/095 Traffic lights

Abstract

The present invention demonstrates that light-emitting diodes (LEDs) have electrical characteristics that can be used to dramatically reduce the complexity and cost of the traffic signaling equipment needed to control the array of signals to give the right of way to the vehicles in a given intersection. This also enhances the energy saving features of LEDs by relocating the power source to the traffic signal control system and the electric conditioning devices to the signal position, increasing the energy efficiency of the whole intersection. One benefit is “intrinsic safety” based on a method for power distribution to the signals that does not allow failure modes that could cause accidents. The system ensures that simultaneous green or yellow signals on crossed streets are impossible even though the signals are connected to the same power lines, allowing also the use of a bus connection topology with a command driven control of the ON/OFF state for each individual light or signal. This “phase conflict prevention” is safer and simpler than the prior art and also eliminates the need of the independent monitoring equipment usually required to prevent such hazardous conditions. Also there is a large reduction in the number of wires resulting in even greater controller simplicity due to the ability of controlling a larger number of signals with a given number of electric conductors than in the prior art.

Claims

1. A traffic control system, comprising:

at least one pair of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) connected with opposite polarity orientation relative to one another;

a plurality of polarity switches (404, 405, 703, 704, 705), an output of a first one of said polarity switches (404, 405, 703, 704, 705) connected (310, 311, 712, 713, 714, 906, 909, 910, 919, 920, 921, 936, 937, 938, 939) to at least a first end of one pair of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945), and an output of a second one of said polarity switches (404, 405, 703, 704, 705) connected (310, 311, 712, 713, 714, 906, 909, 910, 919, 920, 921, 936, 937, 938, 939) to at least a second end of said one pair of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945).

2. The system of claim 1, wherein first and second members of said least one pair of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) are connected with said opposite polarity orientation relative to one another, in parallel with one another (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945).

3. The system of claim 1, further comprising:

a first bypass diode (1006) connected in parallel with, and in opposite polarity orientation relative to, a first member (203) of said at least one pair of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945); and

a second bypass diode (1007) connected in parallel with, and in opposite polarity orientation relative to, a second member (204) of said at least one pair of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945);

wherein;

said oppositely polarized parallel combination of said first member (203) with said first bypass diode (1006) is connected in series with said oppositely polarized parallel combination of said second member (204) with said second bypass diode (1007), such that said first (203) and second (204) members of said least one pair of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) are connected in said series with said opposite polarity orientation relative to one another.

4. The system of claim 1, further comprising:

at least one AC-to-DC power converter (301) converting an alternating current (107, 117) to a direct current (309, 312), and supplying said direct current (309, 312) as input to at least two of said polarity switches (404, 405, 703, 704, 705).

5. The system of claim 1, said plurality of polarity switches (404, 405, 703, 704, 705) comprising M polarity switches (404, 405, 703, 704, 705), and said at least one pair of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) comprising P=C(M,2) pairs of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945), further comprising:

M cables (310, 311, 712, 713, 714) each associated with and connected to the output of one of said M polarity switches (404, 405, 703, 704, 705), delivering a direct current from its associated polarity switch (404, 405, 703, 704, 705) to one end of M−

1 of said P=C(M,2) pairs of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945), each of said M−

1 pairs of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) connected at another end thereof to a different one of the remaining M−

1 cables, thereby delivering power in pairwise combination to said first ends and said second ends of P=C(M,2) said pairs of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945).

6. The system of claim 1, said plurality of polarity switches (404, 405, 703, 704, 705) comprising:

at least one polarity inverter selected from the polarity inverter group consisting of;

at least one non-inherently-polar polarity inverter (903, 940, 941) comprising a pair of said plurality of polarity switches (404, 405, 703, 704, 705); and

at least one inherently-polar polarity inverter (905, 907) comprising another pair of said plurality of polarity switches (404, 405, 703, 704, 705);

wherein;

an output of any said non-inherently-polar polarity inverter (903, 940, 941) is connected to an input of an electrical device selected from the electrical device group consisting of;

at least one of said pairs of inherently-polarized traffic signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945);

at least one non-polar traffic signal (118, 199, 1102);

at least one of said inherently-polar polarity inverters (905, 907);

at least one of said non-inherently-polar polarity inverters (903, 940, 941);

at least one of said polarity switches (404, 405, 703, 704, 705);

at least one local control switch (506, 508, 510, 512, 602);

at least one DC power switch (304, 305); and

at least one rectifier (509, 601); and

an output of any said inherently-polar polarity inverter (905, 907) is connected to an input of an electrical device selected from the electrical device group consisting of;

at least one of said pairs of inherently-polarized traffic signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945);

at least one non-polar traffic signal (118, 199, 1102);

at least one of said inherently-polar polarity inverters (905, 907);

at least one of said non-inherently-polar polarity inverters (903, 940, 941);

at least one of said polarity switches (404, 405, 703, 704, 705);

at least one local control switch (506, 508, 510, 512, 602);

at least one DC power switch (304, 305); and

at least one rectifier (509, 601).

7. The system of claim 6, at least one of said inherently-polar polarity inverters (905, 907) comprising a non-inherently-polar polarity inverter in combination with:

a safety diode (926, 928, 1103) between two inputs (910, 911, 912, 913) thereof, in parallel thereto, and with opposite polarity orientation relative to an intended polarity orientation of said inherently-polar polarity inverter (905, 907);

a main diode (904, 906, 1101) in series with one of said two inputs (910, 912) thereof, in polarity opposite to and upstream from said safety diode (926, 928, 1103); and

a current breaking device (927, 929, 1104) in series with the other one of said two inputs (911, 913) thereof, also upstream from said safety diode (926, 928, 1103);

thereby converting said non-inherently-polar polarity inverter to said at least one of said inherently-polar polarity inverters (905, 907).

8. The system of claim 1, at least one of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) comprising a non-inherently-polarized traffic control signal (118, 119, 1102) in combination with:

a safety diode (926, 928, 1103) between two inputs thereof, in parallel thereto, and with opposite polarity orientation relative to an intended polarity orientation of said traffic control signal (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945);

a main diode (904, 906, 1101) in series with one of said two inputs thereof, in polarity opposite to and upstream from said safety diode (926, 928, 1103); and

a current breaking device (927, 929, 1104) in series with the other one of said two inputs thereof, also upstream from said safety diode (926, 928, 1103);

thereby converting said non-inherently-polarized traffic control signal (118, 119, 1102) to said at least one of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945).

9. The system of claim 1, further comprising:

at least one local control switch (506, 508, 510, 512, 602) connected with one of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) in series combination (506, 508, 510, 512, 602), (203, 204, 511, 513);

wherein;

said first end of one pair of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) comprises a first end of said local control switch and traffic control signal series combination (506, 508, 510, 512, 602), (203, 204, 511, 513) and said second end of said one pair of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) comprises a second end of said local control switch and traffic control signal series combination (506, 508, 510, 512, 602), (203, 204, 511, 513).

10. The system of claim 1, further comprising at least one rectifier (509, 601), local control switch (510, 602), and inherently-polarized traffic control signal (511, 603) combination, wherein:

a first corner of said rectifier (509, 601) is connected to a direct current distribution (310) from said first one of said polarity switches (404, 405, 703, 704, 705);

a third corner of said rectifier (509, 601) opposite said first corner is connected to the direct current distribution (311) from said second one of said polarity switches (404, 405, 703, 704, 705);

said local control switch (510, 602) is connected in series with said inherently-polarized traffic control signal (511, 603) of said rectifier, local switch and signal combination;

a first end of the local control switch (510, 602) and traffic control signal (511, 603) series is connected to a second corner of said rectifier (509, 601); and

a second end of said local control switch (510, 602) and traffic control signal (511, 603) series is connected to a fourth corner of said rectifier (509, 601) opposite said second corner.

11. The system of claim 1, further comprising at least one rectifier (509, 601) connected across said outputs of said first and second ones of said polarity switches (404, 405, 703, 704, 705), to provide power independently of a polarity between said outputs.

12. The system of claim 1, further comprising:

at least one local control switch (512), inherently-polarized traffic control signal (513), and plurality of same-polarity-orientated diodes (514, 515) combination, wherein;

a first end of said local control switch (512) is connected directly (504) to a direct current distribution;

a second end of said local control switch (512) is connected in series to a first end of said inherently-polarized traffic control signal (513), which is polarity-oriented to enable current flow through said local control switch (513);

a second end of said inherently-polarized traffic control signal (513) is connected in same-polarity orientation series with said plurality of diodes (514, 515); and

said plurality of diodes (514, 515) are thereby connected to allow current flow through said inherently-polarized traffic control signal (513) and prevent a short circuit.

13. The system of claim 1, further comprising:

at least one inherently-polarized traffic control signal (513) in which at least one power input is connected to at least two outputs (310, 311) of at least one of said polarity switches (404, 405, 703, 704, 705) using diodes in series (514, 515) to allow current flow through said inherently-polarized traffic control signal (513) and prevent short circuiting said outputs (310, 311).

14. The system of claim 1, further comprising an AC prevention device (524) connected to the output of at least one of said polarity switches (404, 405, 703, 704, 705) to prevent the polarity of said polarity switches (404, 405, 703, 704, 705) from inverting at a frequency high enough to cause retinal persistence in a human eye.

15. The system of claim 1, further comprising:

at least one controller (302) controlling at least one of said polarity switches (404, 405, 703, 704, 705).

16. The system of claim 9, further comprising:

at least one controller (302) controlling at least one of said polarity switches (404, 405, 703, 704, 705) and at least one of said local control switches (506, 508, 510, 512, 602).

17. The system of claim 10, further comprising:

at least one controller (302) controlling at least one of said polarity switches (404, 405, 703, 704, 705) and at least one of said local control switches (510).

18. The system of claim 12, further comprising:

at least one controller (302) controlling at least one of said polarity switches (404, 405, 703, 704, 705) and at least one of said local control switches (512).

19. The system of claim 1, further comprising:

at least one controller (302) controlling at least one of said polarity switches (404, 405, 703, 704, 705); and

at least one monitoring system (303) monitoring at least one current characteristic selected from the current characteristic group consisting of;

value, voltage, polarity, sequencing and timing, of a direct current output of at least one of said polarity switches (404, 405, 703, 704, 705), and providing information (315) about said monitoring to at least one of said controllers (302).

20. The system of claim 1, wherein:

one member of given one of said pairs of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) signals a first roadway to allow traffic to pass;

the other, oppositely polarized member of said given one of said pairs of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) signals a second roadway in conflict with said first roadway to allow traffic to pass; and

it is thereby impossible to simultaneously signal both said first roadway and said second roadway to allow traffic to pass, resulting in intrinsically-safe traffic control of these conflicting roadways.

21. The system of claim 9, wherein:

one member of given one of said pairs of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) signals a first roadway to allow traffic to pass;

the other, oppositely polarized member of said given one of said pairs of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) signals a second roadway in conflict with said first roadway to allow traffic to pass;

at least one (506, 508) of said local control switches (506, 508, 510, 512, 602) is used to control as between the signal allowing traffic to pass being a “

proceed”

signal, and its being a “

proceed with caution”

signal;

it is thereby impossible to simultaneously signal both said first roadway and said second roadway to allow traffic to pass, resulting in intrinsically-safe traffic control of these conflicting roadways.

22. The system of claim 10, wherein said inherently-polarized traffic control signal (511, 603) of said combination is a “

stop”

signal.

23. The system of claim 12, wherein said inherently-polarized traffic control signal (513) of said combination is a “

stop”

signal.

24. The system of claim 1, further comprising at least one low dropout voltage diode (509, 514, 515, 601, 904, 906, 1006, 1007, 1101) in series combination with at least one high-current flow path thereof.

25. The system of claim 1, further comprising a local monitoring device (523) monitoring a state of at least one of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945).

26. The system of claim 25, wherein said local monitoring device (523) monitors said state of said at least one of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) by monitoring at least one current characteristic selected from the current characteristic group consisting of:

value, voltage, polarity, sequencing and timing, of a power input of said at least one of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) and provides information (522) about said monitoring to at least one local node (516, 517) and ultimately to at least one controller (302).

27. The system of claim 1, further comprising:

at least one controller (302) controlling at least one of said polarity switches (404, 405, 703, 704, 705) connected to an output of at least one AC-to-DC power converter (301) and to an input of at least one of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945).

28. The system of claim 1, further comprising:

at least one controller (302) controlling at least one of said polarity switches (404, 405, 703, 704, 705) connected to an output of at least one AC-to-DC power converter (301) and to an input of at least one of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945); and

at least one monitoring system (303) monitoring at least one current characteristic selected from the current characteristic group consisting of;

value, voltage, polarity, sequencing and timing, of a direct current output of at least one of said polarity switches (404, 405, 703, 704, 705), and providing information (315) about said monitoring to at least one of said controllers (302).

29. The system of claim 1, further comprising at least one battery and battery charger (316) connected to outputs of at least one AC-to-DC power converter (301).

30. The system of claim 1, further comprising at least one in-line communication device (604, 605, 606) modulating and demodulating an AC waveform over DC power lines (309, 312) of said system to control at least one local control switch (506, 508, 510, 512, 602) of said system.

31. A traffic control system, comprising:

at least one AC-to-DC power converter (301) converting an alternating current (107, 117) to a direct current (309, 312), and supplying said direct current (309, 312) to power a plurality of traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945).

32. The system of claim 31, further comprising:

at least one controller (302) controlling at least one switch (304, 305) connected to an output of said AC-to-DC power converter (301) and to an input of at least one of said traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945).

33. The system of claim 31, further comprising:

at least one controller (302) controlling at least one switch (304, 305) connected to an output of said AC-to-DC power converter (301) and to an input of at least one of said traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945); and

at least one monitoring system (303) monitoring at least one current characteristic selected from the current characteristic group consisting of;

value, voltage, polarity, sequencing and timing, of a direct current output of at least one of said switches (304, 305), and providing information (315) about said monitoring to at least one of said controllers (302).

34. The system of claim 31, further comprising at least one battery and battery charger (316) connected to outputs of at least one of said AC-to-DC power converters (301).

35. The system of claim 31, further comprising at least one in-line communication device (604, 605, 606) modulating and demodulating an AC waveform over power lines (309, 312) of said system to control at least one local control switch (506, 508,) of said system.

36. The system of claim 31, further comprising at least one local control switch (506, 508) connected with one of said traffic control signals (203, 204) in series combination.

37. The system of claim 31, further comprising at least one controller (302) controlling at least one local control switch (506, 508) of said system.

38. A method of interconnecting traffic control signals to control traffic, comprising the steps of:

connecting at least one pair of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) with opposite polarity orientation relative to one another;

connecting (310, 311, 712, 713, 714, 906, 909, 910, 919, 920, 921, 936, 937, 938, 939) an output of a first one of a plurality of polarity switches (404, 405, 703, 704, 705) to at least a first end of one pair of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945); and

connecting (310, 311, 712, 713, 714, 906, 909, 910, 919, 920, 921, 936, 937, 938, 939) an output of a second one of said polarity switches (404, 405, 703, 704, 705) to at least a second end of said one pair of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945).

39. The method of claim 38, further comprising the step of:

connecting first and second members of said least one pair of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) with said opposite polarity orientation relative to one another, in parallel with one another (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945).

40. The method of claim 38, further comprising the steps of:

connecting a first bypass diode (1006) in parallel with, and in opposite polarity orientation relative to, a first member (203) of said at least one pair of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945); and

connecting a second bypass diode (1007) in parallel with, and in opposite polarity orientation relative to, a second member (204) of said at least one pair of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945); and

connecting said oppositely polarized parallel combination of said first member (203) with said first bypass diode (1006) in series with said oppositely polarized parallel combination of said second member (204) with said second bypass diode (1007), such that said first (203) and second (204) members of said least one pair of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) are connected in said series with said opposite polarity orientation relative to one another.

41. The method of claim 38, further comprising the steps of:

converting an alternating current (107, 117) to a direct current (309, 312) using at least one AC-to-DC power converter (301); and

supplying said direct current (309, 312) as input to at least two of said polarity switches (404, 405, 703, 704, 705).

42. The method of claim 38, said plurality of polarity switches (404, 405, 703, 704, 705) comprising M polarity switches (404, 405, 703, 704, 705), and said at least one pair of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) comprising P=C(M,2) pairs of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945), further comprising the steps of:

delivering a direct current from its associated polarity switch (404, 405, 703, 704, 705) to one end of M−

1 of said P=C(M,2) pairs of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) using M cables (310, 311, 712, 713, 714) each associated with and connected to the output of one of said M polarity switches (404, 405, 703, 704, 705), by connecting each of said M−

1 pairs of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) at another end thereof to a different one of the remaining M−

1 cables, thereby delivering power in pairwise combination to said first ends and said second ends of P=C(M,2) said pairs of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945).

43. The method of claim 38, said plurality of polarity switches (404, 405, 703, 704, 705) comprising at least one polarity inverter selected from the polarity inverter group consisting of:

at least one non-inherently-polar polarity inverter (903, 940, 941) comprising a pair of said plurality of polarity switches (404, 405, 703, 704, 705); and

at least one inherently-polar polarity inverter (905, 907) comprising another pair of said plurality of polarity switches (404, 405, 703, 704, 705);

comprising the further steps of;

connecting an output of any said non-inherently-polar polarity inverter (903, 940, 941) to an input of an electrical device selected from the electrical device group consisting of;

at least one of said pairs of inherently-polarized traffic signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945);

at least one non-polar traffic signal (118, 199, 1102);

at least one of said inherently-polar polarity inverters (905, 907);

at least one of said non-inherently-polar polarity inverters (903, 940, 941);

at least one of said polarity switches (404, 405, 703, 704, 705);

at least one local control switch (506, 508, 510, 512, 602);

at least one DC power switch (304, 305); and

at least one rectifier (509, 601); and

connecting an output of any said inherently-polar polarity inverter (905, 907) to an input of an electrical device selected from the electrical device group consisting of;

at least one of said pairs of inherently-polarized traffic signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945);

at least one non-polar traffic signal (118, 199, 1102);

at least one of said inherently-polar polarity inverters (905, 907);

at least one of said non-inherently-polar polarity inverters (903, 940, 941);

at least one of said polarity switches (404, 405, 703, 704, 705);

at least one local control switch (506, 508, 510, 512, 602);

at least one DC power switch (304, 305); and

at least one rectifier (509, 601).

44. The method of claim 43, further comprising the step of converting at least one of said non-inherently-polar polarity inverters to a said inherently-polar polarity inverter (905, 907) by:

connecting a safety diode (1103) between two inputs (910, 911, 912, 913) of said at least one of said non-inherently-polar polarity inverters, in parallel thereto, and with opposite polarity orientation relative to an intended polarity orientation of said inherently-polar polarity inverter (905, 907);

connecting a main diode (1101) in series with one of said two inputs (910, 911, 912, 913) thereof, in polarity opposite to and upstream from said safety diode (1103); and

connecting a current breaking device (1104) in series with the other one of said two inputs (910, 911, 912, 913) thereof, also upstream from said safety diode (1103).

45. The method of claim 38, further comprising the step of converting at least one non-inherently-polarized traffic control signal (118, 119, 1102) to at least one of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) by:

connecting a safety diode (1103) between two inputs of said at least one non-inherently-polarized traffic control signal (118, 119, 1102), in parallel thereto, and with opposite polarity orientation relative to an intended polarity orientation of said traffic control signal (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945);

connecting a main diode (1101) in series with one of said two inputs thereof, in polarity opposite to and upstream from said safety diode (1103); and

connecting a current breaking device (1104) in series with the other one of said two inputs thereof, also upstream from said safety diode (1103).

46. The method of claim 38, further comprising the step of:

connecting at least one local control switch (506, 508, 510, 512, 602) with one of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) in series combination (506, 508, 510, 512, 602), (203, 204, 511, 513);

wherein;

said first end of one pair of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) comprises a first end of said local control switch and traffic control signal series combination (506, 508, 510, 512, 602), (203, 204, 511, 513) and said second end of said one pair of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) comprises a second end of said local control switch and traffic control signal series combination (506, 508, 510, 512, 602), (203, 204, 511, 513).

47. The method of claim 38, further comprising the steps of:

connecting a first corner of a rectifier (509, 601) to a direct current distribution (310) from said first one of said polarity switches (404, 405, 703, 704, 705);

connecting a third corner of said rectifier (509, 601) opposite said first corner to the direct current distribution (311) from said second one of said polarity switches (404, 405, 703, 704, 705);

connecting a local control switch (510, 602) in series with an inherently-polarized traffic control signal (511, 603) of a combination of said rectifier (509, 601), said local control switch (510, 602) and said inherently-polarized traffic control signal (511, 603);

connecting a first end of the local control switch (510, 602) and traffic control signal (511, 603) series to a second corner of said rectifier (509, 601); and

connecting a second end of said local control switch (510, 602) and traffic control signal (511, 603) series to a fourth corner of said rectifier (509, 601) opposite said second corner.

48. The method of claim 38, further comprising the step of:

connecting at least one rectifier (509, 601) across said outputs of said first and second ones of said polarity switches (404, 405, 703, 704, 705), to provide power independently of a polarity between said outputs.

49. The method of claim 38, further comprising the steps of:

connecting a first end of a local control switch (512) directly (504) to a direct current distribution;

connecting a second end of said local control switch (512) in series to a first end of an inherently-polarized traffic control signal (513), which is polarity-oriented to enable current flow through said local control switch (513); and

connecting a second end of said inherently-polarized traffic control signal (513) in same-polarity orientation series with a plurality of same-polarity-orientated diodes (514, 515);

wherein;

said plurality of diodes (514, 515) are connected to allow current flow through said inherently-polarized traffic control signal (513) and prevent a short circuit.

50. The method of claim 38, further comprising the step of:

connecting at least one power input of at least one inherently-polarized traffic control signal (513) to at least two outputs (310, 311) of at least one of said polarity switches (404, 405, 703, 704, 705) using diodes in series (514, 515) to allow current flow through said inherently-polarized traffic control signal (513) and prevent short circuiting said outputs (310, 311).

51. The method of claim 38, further comprising the step of:

connecting an AC prevention device (524) the output of at least one of said polarity switches (404, 405, 703, 704, 705) to prevent the polarity of said polarity switches (404, 405, 703, 704, 705) from inverting at a frequency high enough to cause retinal persistence in a human eye.

52. The method of claim 38, further comprising the step of:

controlling at least one of said polarity switches (404, 405, 703, 704, 705) using at least one controller (302).

53. The method of claim 46, further comprising the step of:

controlling at least one of said polarity switches (404, 405, 703, 704, 705) and at least one of said local control switches (506, 508, 510, 512, 602) using at least one controller (302).

54. The method of claim 47, further comprising the step of:

controlling at least one of said polarity switches (404, 405, 703, 704, 705) and at least one of said local control switches (510) using at least one controller (302).

55. The method of claim 49, further comprising the step of:

controlling at least one of said polarity switches (404, 405, 703, 704, 705) and at least one of said local control switches (512) using at least one controller (302).

56. The method of claim 38, further comprising the steps of:

controlling at least one of said polarity switches (404, 405, 703, 704, 705) using at least one controller (302); and

monitoring at least one current characteristic selected from the current characteristic group consisting of;

value, voltage, polarity, sequencing and timing, of a direct current output of at least one of said polarity switches (404, 405, 703, 704, 705), using at least one monitoring system (303); and

providing information (315) about said monitoring to at least one of said controllers (302).

57. The method of claim 38, further comprising the steps of:

signaling a first roadway to allow traffic to pass, using one member of given one of said pairs of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945);

signaling a second roadway in conflict with said first roadway to allow traffic to pass using the other, oppositely polarized member of said given one of said pairs of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945);

wherein;

it is thereby impossible to simultaneously signal both said first roadway and said second roadway to allow traffic to pass, resulting in intrinsically-safe traffic control of these conflicting roadways.

58. The method of claim 46, further comprising the steps of:

signaling a first roadway to allow traffic to pass using one member of given one of said pairs of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945);

signaling a second roadway in conflict with said first roadway to allow traffic to pass using the other, oppositely polarized member of said given one of said pairs of inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945); and

controlling as between the signal allowing traffic to pass being a “

proceed”

signal, and its being a “

proceed with caution”

signal, using at least one (506, 508) of said local control switches (506, 508, 510, 512, 602);

wherein;

it is thereby impossible to simultaneously signal both said first roadway and said second roadway to allow traffic to pass, resulting in intrinsically-safe traffic control of these conflicting roadways.

59. The method of claim 47, wherein said inherently-polarized traffic control signal (511, 603) of said combination is a “

stop”

signal.

60. The method of claim 49, wherein said inherently-polarized traffic control signal (513) of said combination is a “

stop”

signal.

61. The method of claim 38, further comprising the step of:

connecting at least one low dropout voltage diode (509, 514, 515, 601, 904, 906, 1006, 1007, 1101) in series combination with at least one high-current flow path of an interconnected system of said traffic control signals.

62. The method of claim 38, further comprising the step of:

monitoring a state of at least one of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945) using a local monitoring device (523).

63. The method of claim 62, further comprising the steps of:

monitoring said state of said at least one of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945), by monitoring at least one current characteristic selected from the current characteristic group consisting of;

value, voltage, polarity, sequencing and timing, of a power input of said at least one of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945), using said local monitoring device (523); and

providing information (522) about said monitoring to at least one local node (516, 517) and ultimately to at least one controller (302).

64. The method of claim 38, further comprising the steps of:

connecting at least one of said polarity switches (404, 405, 703, 704, 705) to an output of at least one AC-to-DC power converter (301) and to an input of at least one of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945); and

controlling said at least one of said polarity switches (404, 405, 703, 704, 705) using at least one controller (302).

65. The method of claim 38, further comprising the steps of:

connecting at least one of said polarity switches (404, 405, 703, 704, 705) to an output of at least one AC-to-DC power converter (301) and to an input of at least one of said inherently-polarized traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945);

controlling said at least one of said polarity switches (404, 405, 703, 704, 705) using at least one controller (302);

monitoring at least one current characteristic selected from the current characteristic group consisting of;

value, voltage, polarity, sequencing and timing, of a direct current output of at least one of said polarity switches (404, 405, 703, 704, 705), using at least one monitoring system (303); and

providing information (315) about said monitoring to at least one of said controllers (302).

66. The method of claim 38, further comprising the step of:

connecting at least one battery and battery charger (316) to outputs of at least one AC-to-DC power converter (301).

67. The method of claim 38, further comprising the step of:

modulating and demodulating an AC waveform over DC power lines (309, 312) interconnecting said traffic control signals to control at least one local control switch (506, 508, 510, 512, 602), using at least one in-line communication device (604, 605, 606).

68. A method of interconnecting traffic control signals to control traffic, comprising the steps of:

converting an alternating current (107, 117) to a direct current (309, 312) using at least one AC-to-DC power converter (301); and

supplying said direct current (309, 312) to power a plurality of traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945).

69. The method of claim 68, further comprising the step of:

controlling at least one switch (304, 305) connected to an output of said AC-to-DC power converter (301) and to an input of at least one of said traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945), using at least one controller (302).

70. The method of claim 68, further comprising the steps of:

connecting at least one switch (304, 305) to an output of said AC-to-DC power converter (301) and to an input of at least one of said traffic control signals (203, 204, 511, 513, 603, 706, 707, 708, 709, 922. 923, 924, 925, 942, 943, 944, 945);

controlling said at least one switch (304, 305) using at least one controller (302);

monitoring at least one current characteristic selected from the current characteristic group consisting of;

value, voltage, polarity, sequencing and timing, of a direct current output of at least one of said switches (304, 305), using at least one monitoring system (303); and

providing information (315) about said monitoring to at least one of said controllers (302).

71. The method of claim 68, further comprising the step of:

connecting at least one battery and battery charger (316) to outputs of at least one of said AC-to-DC power converters (301).

72. The method of claim 68, further comprising the step of:

modulating and demodulating an AC waveform over power lines (309, 312) of said system to control at least one local control switch (506, 508,) of said system, using at least one in-line communication device (604, 605, 606).

73. The method of claim 68, further comprising the step of:

connecting at least one local control switch (506, 508) with one of said traffic control signals (203, 204) in series combination.

74. The method of claim 68, further comprising the step of:

controlling at least one local control switch (506, 508) of said system, using at least one controller (302).