Airfield series circuit communications lighting system and method

• US 5,926,115 A
• Filed: 06/21/1996
• Issued: 07/20/1999
• Est. Priority Date: 06/21/1996
• Status: Expired due to Term

• Current Assignee: ADB Safegate Americas LLC (ADB Safegate BVBA)
• Original Assignee: Adb-Alnaco Incorporated (Siemens AG)
• Inventors: Hyde, Shawn M., Schleder, William E.
• Primary Examiner(s): SWARTHOUT, BRENT
• Application Number:
  US08/669,261
• Time in Patent Office: 1,124 Days
• Field of Search: 340/953, 340/933, 340/642, 340/947, 340/931, 315/130, 244/114 R
• US Class Current: 340/953
• CPC Class Codes: H05B 47/185 via power line carrier transmission
• CPC Class Codes: H05B 47/235 with communication between the lamps and a central unit

Abstract

A microprocessor-controlled airfield series lighting circuit communications system and method allows bi-directional communication between the controlling microprocessor and the airfield lamps. The bi-directional communications signals are formed by using a modulated radio-frequency signal that is transmitted through a circuit containing many transformers having their primary windings connected in series. Respective secondary windings of the transformers are connected to various devices, such as lamps or sensors. A high frequency signal is imposed on the series-connected primary windings to control the lamps. The frequency of this signal is selected to be able to be detected on the secondary side of the transformer. A remote controller is connected to the secondary of each transformer to receive the control signal and selectively switch power obtained from the transformer secondary to the respective connected device. Any one of the multiple controllers can be configured as a repeater for any other one of the controller. As a repeater, the controller receives a control message addressed to a target controller and retransmits the message to the target controller.

Claims

1. A control system for a lamp in an airfield lighting system including an electrical circuit comprising a plurality of transformers, each transformer having a primary winding and a secondary winding, wherein the primary windings of the plurality of transformers are connected in series, the circuit being adapted to conduct an electrical current through the series-connected primary windings and at least one transformer of the plurality of transformers being adapted to provide operational power to the lamp, the control system comprising:

a master controller which applies an electrical control signs to the circuit;

a remote controller, connected to the secondary winding of the one transformer, said remote controller comprising;

means for receiving the electrical control signal from the secondary winding of the transformer as transmitted through the transformer from the primary winding of the transformer,

a switch, coupled to the transformer secondary winding and responsive to a switching signal, to selectively energize the lamp,

control means, responsive to the received electrical control signal, for generating the switching signal to control the lamp,

means responsive to the received electrical signal for generating an acknowledge message, and

means for applying the acknowledge message to the secondary winding of the one transformer to convey the acknowledge message to the master controller through the series-connected primary windings.

2. A control system according to claim 1, wherein:

the remote controller means further includes;

means for sensing operational failure of the lamp;

means for generating a message indicating the sensed operational failure of the lamp;

means for applying the message to the secondary winding of the one transformer; and

the master controller further includes means coupled to the circuit for receiving the message from the series-connected primary windings of the plurality of transformers.

3. A control system according to claim 2, wherein said remote controller includes means for applying a short circuit to the secondary winding of the one transformer when the lamp failure condition is detected.

4. A control system according to claim 1, wherein an other transformer of the plurality of transformers is connected to provide operational power to an aircraft detection means, and the control system further comprises

a further remote controller means further comprising:

means, coupled to the aircraft detection means for generating a message when the aircraft detection means detects an aircraft; and

means for applying the message to the secondary winding of the other transformer; and

the master controller further comprises means coupled to the circuit for receiving the message from the series-connected primary windings of the plurality of transformers.

7. A control system according to claim 1, wherein the airfield lighting system includes a tower computer which issues a command to control the lamp, and wherein:

the master controller includes;

a processor coupled to receive the command from the tower computer; and

means for modulating a carrier signal with the command to generate the electrical control signal, the carrier signal having a frequency which passes between the primary winding and the secondary winding of the transformer; and

the remote controller includes filtering means for separating signals having frequencies approximately equal to the carrier frequency from signals received at the secondary winding of the transformer to receive the electrical control signal.

11. A control system according to claim 1, wherein the switch comprises a relay having switch contacts coupled in parallel with the lamp, the relay being responsive to the control signal to selectively open the switch contacts to provide operational power to the lamp.

12. A control system according to claim 11, wherein the switch further comprises electronic switching means, coupled in parallel with the relay for providing a short circuit across the switch contacts of the relay while the relay is controlled to open or close the switch contacts.

5. A control system for a lamp in an airfield lighting system including an electrical circuit comprising a plurality of transformers, each transformer having a primary winding and a secondary winding, wherein the primary windings of the plurality of transformers are connected in series, the circuit being adapted to conduct an electrical current through the series-connected primary windings and at least one transformer of the plurality of transformers being adapted to provide operational power to the lamp, the control system comprising:

a master controller which applies an electrical control signal to the circuit;

a remote controller, connected to the secondary winding of the one transformer, said remote controller means comprising;

means for receiving the electrical control signal from the secondary winding of the transformer,

a switch, coupled to the transformer secondary winding and responsive to a switching signal, to selectively energize the lamp, and

control means, responsive to the received electrical control signal, for generating the switching signal to control the lamp;

a further remote controller, coupled to an other one of the plurality of transformers, the further remote controller comprising;

means for receiving the electrical control signal for the lamp from the secondary of the other transformer;

means for formatting the electrical control signal into a repeated electrical control signal; and

means for applying the repeated electrical control signal to the secondary winding of the other transformer to couple the repeated electrical control signal to control the lamp coupled to the one transformer.

6. A control system according to claim 5, wherein the electrical control signal includes an address value and each of the remote controller and the further remote controller has a respective address value and means for matching the address value in the electrical control signal to the address value in the remote controller before responding to the electrical control signal.

8. A control system for a lamp in an airfield lighting system including an electrical circuit comprising a plurality of transformers, each transformer having a primary winding and a secondary winding, wherein the primary windings of the plurality of transformers are connected in series, the circuit being adapted to conduct an electrical current through the series-connected primary windings and at least one transformer of the plurality of transformers being adapted to provide operational power to the lamp, the airfield lighting system further including a tower computer which issues a commands to control the lamp, the control system comprising:

a master controller which applies an electrical control signal to the circuit, comprising;

a processor coupled to receive the command from the tower computer;

means for modulating a carrier signal with the command to generate the electrical control signal, the carrier signal having a frequency which passes between the primary winding and the secondary winding of the transformer; and

a remote controller, connected to the secondary winding of the one transformer, said remote controller comprising;

means for receiving the electrical control signal from the secondary winding of the transformer;

a switch, coupled to the transformer secondary winding and responsive to a switching signal, to selectively energize the lamp;

control means, responsive to the received electrical control signal, for generating the switching signal to control the lamp;

filtering means for separating signals having frequencies approximately equal to the carrier frequency from signals received at the secondary winding of the transformer to receive the electrical control signal;

means responsive to the received electrical signal for generating an acknowledge message; and

means for applying the acknowledge message to the secondary winding of the one transformer;

wherein, the master controller further includes means coupled to the circuit for receiving the acknowledge message from the series-connected primary windings of the plurality of transformers, wherein, if the acknowledge message is not received in a predetermined time interval following the application of the electrical control signal to the circuit, the master controller applies the electrical control signal to the circuit again.

9. A control system according to claim 8, wherein the master controller includes means includes means for sending a message to the tower computer indicating that the lamp cannot be controlled if the acknowledge message is not received by the master controller after the control electrical signal has been applied to the circuit a predetermined number of times.

10. A control system according to claim 9, wherein the signal on the secondary of each of said transformers has a voltage of between approximately 2 volts RMS and approximately 75 volts RMS and the frequency of the carrier signal is approximately 125 KHz.

13. A method for controlling a lamp in an airfield lighting system which includes an electrical circuit comprising a plurality of transformers, each transformer having a primary winding and a secondary winding, wherein the primary windings of the plurality of transformers are connected in series, the circuit being adapted to conduct an electrical current through the series-connected primary windings and at least one transformer of the plurality of transformers being adapted to provide operational power to the lamp via a remote controller coupled to its secondary winding, the control method comprising the steps of:

applying an electrical control signal to the circuit;

receiving, at the remote controller, the electrical control signal from the operational power signal provided at the secondary winding of the one transformer as transmitted through the transformer from the primary winding of the one transformer;

generating a lamp control signal from the received electrical control signal to control the lamp;

switching, at the remote controller and responsive to the lamp control signal, the operational power signal provided by the secondary winding of the one transformer, to selectively energize the lamp;

generating, in the remote controller, an acknowledge message, and

applying the acknowledge message to the secondary winding of the one transformer to convey the acknowledge message to the series-connected primary windings.

14. A method for controlling first and second lamps in an airfield lighting system which includes an electrical circuit comprising a plurality of transformers, each transformer having a primary winding and a secondary winding, wherein the primary windings of the plurality of transformers are connected in series, the circuit being adapted to conduct an electrical current through the series-connected primary windings and a first transformer of the plurality of transformers being adapted to provide operational power to the first lamp via a first remote controller coupled to the secondary winding of the first transformer, and a second transformer of the plurality of transformers being adapted to provide operational power to the second lamp via a second remote controller coupled to the secondary winding of the second transformer, the control method comprising the steps of:

applying an electrical control signal including an address value and a lamp control value to the circuit;

receiving the electrical control signal, at the first remote controller, from the operational power signal provided at the secondary winding of the first transformer as transmitted through the first transformer from the primary winding of the first transformer;

comparing the address value in the received electrical control signal to an address value for the first remote controller;

generating a lamp control signal from the lamp control value of received electrical control signal if the address value of the received electrical control signal matches the address value of the first remote controller;

switching, at the first remote controller and responsive to the lamp control signal, the operational power signal provided by the secondary winding of the first transformer, to selectively energize the first lamp;

generating, in the remote controller, an acknowledge message including the address value of the first remote controller, and

applying the acknowledge message to the secondary winding of the one transformer to convey the acknowledge message through the circuit.

15. A method for controlling first and second lamps in an airfield lighting system which includes an electrical circuit comprising a plurality of transformers, each transformer having a primary winding and a secondary winding, wherein the primary windings of the plurality of transformers are connected in series, the circuit being adapted to conduct an electrical current through the series-connected primary windings and a first transformer of the plurality of transformers being adapted to provide operational power to the first lamp via a first remote controller coupled to the secondary winding of the first transformer, and a second transformer of the plurality of transformers being adapted to provide operational power to the second lamp via a second remote controller coupled to the secondary winding of the second transformer, the control method comprising the steps of:

applying an electrical control signal including an address value and a lamp control value to the circuit including the steps of;

applying a first message signal to the circuit to configure the second remote controller as a repeater for the first remote controller;

generating a second message signal, the second message signal being addressed to the second remote controller as a repeater for the first remote controller and including a message for the first remote controller to control the first lamp;

applying the second message signal to the circuit;

receiving the second message signal from the operational power signal provided by the secondary winding of the second transformer to the second remote controller;

processing the received second message signal, at the second remote controller, to generate a third message signal corresponding to the electrical control signal; and

applying the third message signal to the circuit via the secondary winding of the second transformer to control the first lamp;

receiving the electrical control signal, at the first remote controller, from the operational power signal provided at the secondary winding of the first transformer;

comparing the address value in the received electrical control signal to an address value for the first remote controller;

generating a lamp control signal from the lamp control value of received electrical control signal if the address value of the received electrical control signal matches the address value of the first remote controller; and

switching, at the remote controller and responsive to the lamp control signal, the operational power signal provided by the secondary of the first transformer, to selectively energize the first lamp.

16. Apparatus for lighting an airfield comprising:

a constant current regulator having an output terminal and a return terminal;

a plurality of transformers each having a primary winding and a secondary winding, the primary windings being connected as a series circuit such that the first primary winding in the series is coupled to the output terminal of the constant current regulator and the last primary winding in the series is connected to the return terminal of the constant current regulator;

a master controller coupled to the output terminal of the constant current regulator, the master controller including a first modem which couples a lamp control signal to the series connected transformer primary windings;

a remote controller coupled to the secondary of one transformer of the plurality of transformers including a second modem which receives the lamp control signal from the secondary winding of the one transformer as transmitted through the transformer from the primary winding of the one transformer and which provides an acknowledge message to the secondary winding of the one transformer to convey the acknowledge message through the transformer to the master controller;

a switch coupled to receive operational power from the secondary winding of the one transformer and responsive to the received control signal to apply the operational power to the lamp.

17. Apparatus for lighting an airfield according to claim 16, wherein the secondary winding of each transformer of the plurality of transformers is coupled to a respectively different one of a plurality of remote controllers, each remote controller in the plurality of remote controllers has a different address value, and each remote controller includes its address value in the acknowledge message.