Abstract: In an example embodiment, there is disclosed herein an airfield lighting system that employs an IR emitter. The IR emitter can be located within an airfield lighting fixture or external to the lighting fixture. Activating the IR emitter can enable an Enhanced Flight Vision System (“EFVS”) to determine the location of lighting fixtures which may be undetectable by the EFVS, such as Light Emitting Diode (“LED”) fixtures.

Abstract: In accordance with an example embodiment, there is disclosed herein a LED PAPI (10) with condensation protection. The condensation protection may suitably comprise passive components, such as gaskets and seals (26, 36) and a desiccant (48), and/or active components, such as a defroster (39) and/or a heater (50).

Abstract: A system and method that contemplates operating an LED at its characterized current (e.g. 400 mA) for any luminous intensity. A Direct Current Pulse Width Modulation (PWM) signal is employed, wherein the pulse width of the pulse width modulated signal is used to control the luminous intensity of the LED. Optionally, the LED can be biased to reduce the intensity of the pulses used to operate the LED.

Abstract: Disclosed herein is a power supply suitable for use with an airfield lighting device. In accordance with an example embodiment, there is disclosed herein, a rectifier that converts a signal from an alternating current (AC) current source to a direct current (DC) voltage. The circuit comprises a current sensor, a controller, and a half active bridge rectifier. The controller receives a signal from the current sensor and controls the operation of the half active bridge rectifier to produce a light emitting diode (LED) current based on the current sensed by the current sensor.

Abstract: Described herein is a LED PAPI having an array of light emitting diodes (LEDs), the array of LEDs comprising a first set of LEDs emitting a first color and a second set of LEDs emitting a second color. Light from the array of LEDs passes through a pair of apertures separated by a precision ground blade. The precision ground blade has a first edge that is closest to the array of LEDs and a second edge opposite the first edge. The first and second edges have different thicknesses. After passing through the apertures, the light passes through a first lens and a second lens.

Abstract: Described in an example embodiment is an airfield light where the optical system can be easily removed, e.g., no tools. This allows maintenance of the optical system to be performed elsewhere, reducing the amount of time that airfield maintenance crews have to be spend on the field.

Abstract: A system and method that contemplates operating an LED at its characterized current (e.g. 400 mA) for any luminous intensity. A Pulse Width Modulation (PWM) is employed, wherein the pulse width of the pulse width modulated signal is used to control the luminous intensity of the LED. Optionally, the LED can be biased to reduce the intensity of the pulses used to operate the LED.

Abstract: A system and method for producing a flash of a desired intensity and duration utilizing devices of a lower intensity, such as light emitting diodes (LED's). The on period of the LED is lengthened so that the product of the LED's intensity and the on period is approximately equal to the product of the desired intensity and duration of the flash. A parameter for determining intensity, such as operating current or voltage, can be measured and the on period can be adjusted accordingly. The device can be turned on responsive to an external trigger signal, and a timer can be utilized to turn the device on if the external trigger signal is not received within a predetermined time.