Abstract: A Style B PAPI system comprises a plurality of identical lamp housing assemblies, each with one or more lamps and each housing assembly including: an electronic bypass circuit with first and second oppositely poled SCRs coupled across the terminals of each lamp; a zener diode; and a diode bridge for developing a first trigger voltage across the zener diode in the event of failure of a lamp. The first trigger voltage causes alternate conduction in the first and second SCRs from the AC voltage developed across the failed lamp. A lamp control circuit includes a third SCR that is coupled across the zener diode for developing a second trigger voltage for similarly driving the SCRs. The lamp control circuit is operated by a microcontroller-controlled common lamp control circuit that activates all of the lamp control circuits and disable all of the lamps in response to a tilt condition for the lamp housing assembly.

Abstract: An airport strobe lighting system includes a BCD source of pulses generating trigger voltages for a plurality of strobe lamps and a sensor circuit for comparing confirmation signals with the trigger pulses and generating corresponding return pulses indicative of the operation of the strobe lamps. A microcontroller is supplied with conditioned 5 bit address inputs from the BCD source of pulses and conditioned confirmation signal outputs from the sensor circuit and compares each confirmation signal with the 5 bit address of the corresponding strobe lamp. The microcontroller controls the illumination of dedicated LEDs to indicate the status of each of the strobe lamps.

Abstract: A strobe lamp switching system includes first, second and third capacitors of different value for simultaneously storing energy from a DC power supply. The strobe lamp is connected across the power supply and periodically fired by energizing an ignition electrode. The number of capacitors are permitted to discharge through the strobe lamp determines the intensity of its light output. An intensity control energizes a pair of relay operated switches that complete discharge paths for the second and third capacitors. A diode parallels each of the relay operated switches so that the second and third capacitors are charged whenever the power supply is on. A discharge resistor is coupled across the power supply for discharging energy in all of the capacitors when the power supply is off.

Abstract: A runway approach lighting system with fault monitor includes an oscillator which develops clock pulses which are accumulated by a counter. The output of the counter is used to develop trigger signals which control the sequential energization of runway alignment indicator lights. The operation of each light is sensed and is compared with the oscillator pulses, and a fault signal is generated each time a light fails to operate in response to a trigger signal. The number of fault signals generated in an energization cycle is accumulated, and a fault indication is generated once a predetermined number of faults has occurred.