# US 10,485,064 B2 · Devices, methods, and systems for alternating current circuits for airfield lighting

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- Number: US 10,485,064 B2
- Document ID: US10485064B2
- Status: Granted
- Kind: B2
- Application number: 16/352,491
- Filed: 2019-03-13
- Published: 2019-07-11
- Granted: 2019-11-19
- Earliest claimed: 2017-02-27
- Assignees: Honeywell International Inc.
- Applicants: Honeywell International Inc.
- Inventors: Nipun Kumar Chawda; Hans-Willy Schuett; Reiner Wiechert
- Web page: https://patentgrep.com/patent/US10485064B2

## CPC

- H05B 45/382: with galvanic isolation between input and output
- B64F 1/20: Arrangement of optical beacons
- H05B 47/23: of two or more light sources connected in series
- H05B 47/235: {with communication between the lamps and a central unit}
- H05B 47/26: Circuit arrangements for protecting against earth faults
- Y02B 20/30: Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]
- H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- B64F: GROUND OR AIRCRAFT-CARRIER-DECK INSTALLATIONS SPECIALLY ADAPTED FOR USE IN CONNECTION WITH AIRCRAFT; DESIGNING, MANUFACTURING, ASSEMBLING, CLEANING, MAINTAINING OR REPAIRING AIRCRAFT, NOT OTHERWISE PROVIDED FOR; HANDLING, TRANSPORTING, TESTING OR INSPECTING AIRCRAFT COMPONENTS, NOT OTHERWISE PROVIDED FOR
- Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS

## Abstract

Devices, methods, and systems for alternating current circuits for airfield lighting are described herein. One system includes a circuit comprising an isolation transformer, a protection hardware circuit coupled to the isolation transformer, wherein the protection hardware prevents a voltage between an electrical contact of the circuit and a ground contact from meeting or exceeding a threshold voltage, and a load coupled to the protection hardware circuit to receive electrical energy from the isolation transformer.

## Claims

### Claim 1

A system for alternating current circuits for airfield lighting, comprising:
a circuit comprising an isolation transformer;
a protection hardware circuit coupled to the isolation transformer, wherein the protection hardware circuit prevents a voltage between an electrical contact of the circuit and a ground contact from meeting or exceeding a threshold voltage, and wherein the protection hardware circuit includes a circulating path through a normally open (N/O) relay contact for load sensing logic, and wherein the protection hardware circuit includes a load sensor to determine when a load is decoupled from the protection hardware circuit; and
the load coupled to the protection hardware circuit to receive electrical energy from the isolation transformer.

### Claim 2 (depends on 1)

The system of claim 1, wherein the protection hardware circuit is configured to utilize the circulating path when the load is a hot pluggable load.

### Claim 3 (depends on 1)

The system of claim 1, wherein the protection hardware circuit includes circuitry configured to change from closed to open when an output of the isolation transformer meets or exceeds the threshold voltage.

### Claim 4 (depends on 3)

The system of claim 3, wherein the circuitry is configured to provide a circulating path for the load sensor when open.

### Claim 5 (depends on 1)

The system of claim 1, wherein the protection hardware circuit includes a quadruple pole double throw (4PDT) relay to change a 4PDT pole from normally closed (N/C) to normally open (N/O) when an output of the isolation transformer meets or exceeds the threshold voltage.

### Claim 6 (depends on 1)

The system of claim 1, wherein the load sensor is configured to measure a voltage, a current, and/or a frequency of electrical power provided to the load.

### Claim 7 (depends on 1)

The system of claim 1, wherein the circuit is coupled to a current regulator configured to provide electrical energy to the isolation transformer.

### Claim 8 (depends on 1)

The system of claim 1, wherein the isolation transformer and protection hardware are positioned within an enclosure configured to protect a connection between the isolation transformer and the protection hardware.

### Claim 9

An alternating current protection device, comprising:
an enclosure including an input electrically coupled to an airfield lighting circuit that includes an electrical power source, wherein the enclosure further includes:
an isolation transformer to receive electrical energy via the input from the electrical power source; and
a protection hardware circuit coupled between the isolation transformer and a load to receive electrical power from the electrical power source, wherein the protection hardware circuit is configured to prevent a voltage between an electrical contact of the airfield lighting circuit and a ground contact from meeting or exceeding a threshold voltage, and wherein the protection hardware circuit provides a circulating path through a normally open (N/O) relay contact for load sensing logic.

### Claim 10 (depends on 9)

The device of claim 9, wherein the electrical power source is coupled to a constant current regulator (CCR).

### Claim 11 (depends on 9)

The device of claim 9, wherein the electrical power source is a high voltage alternating current power source.

### Claim 12 (depends on 9)

The device of claim 9, wherein the protection hardware circuit includes a triple pole double throw (3PDT) relay configured to disconnect the isolation transformer from the load when an output voltage of the isolation transformer meets or exceeds a threshold voltage.

### Claim 13 (depends on 9)

The device of claim 9, wherein the protection hardware circuit includes a triple pole double throw (3PDT) relay configured to disconnect the isolation transformer from the load when the load is removed.

### Claim 14 (depends on 9)

The device of claim 9, wherein the protection hardware provides a safety boarder line or a safety area between the protection hardware and the load.

### Claim 15

A system for alternating current circuits for airfield lighting, comprising:
a source regulator coupled to an electrical power source;
a plurality of isolation transformers coupled in series with the source regulator;
a plurality of protection hardware devices coupled to each of the plurality of isolation transformers, wherein each of the plurality of protection hardware devices provide a circulating path through a normally open (N/O) relay contact for load sensing logic; and
a plurality of airfield lamps coupled to each of the plurality of protection hardware devices, wherein the plurality of airfield lamps are coupled to a corresponding triple double throw (3PDT) relay of a corresponding protection hardware device of the plurality of protection hardware devices.

### Claim 16 (depends on 15)

The system of claim 15, wherein the plurality of protection hardware devices each include:
a power supply coupled to a load sensor;
a relay coil coupled to the load sensor; and
the 3PDT relay coupled to the load sensor.

### Claim 17 (depends on 16)

The system of claim 16, wherein the relay coil is an electrically operated switch configured to use an electromagnet to mechanically operate a first switch and a second switch of the 3PDT relay.

### Claim 18 (depends on 16)

The system of claim 16, wherein the load sensor is configured to send a signal to the relay coil to change a state of the 3PDT relay from the normally closed (N/C) position to the normally open (N/O) position.