Lamp failure detection system

Claim 2

Apparatus for the detection of a malfunction in the operation of a group of lamps which are arranged to flash in a periodic logical repeating sequence comprising: power means for supplying energy to flash each lamp of said group, energy storage means aSsociated with each lamp for storing a predetermined amount of energy for each lamp during periods when each lamp is not flashing, timing means for producing timing pulses which are applied to a trigger circuit associated with each lamp, to trigger each lamp into a flashing state during which time energy flows from said energy storage means into said lamp, detecting means for continuously detecting a transfer of energy from said power means to each energy storage means, timing circuit impedance altering means for altering the impedance of said timing circuit from a preset value during normal operation of said lamp to a significantly different value upon the detection of no energy transfer between said power means and said energy storage means over a predetermined period of time, timing pulse scrutinizing means for examining the shape of each timing pulse produced by said timing means to determine which of any of said timing circuits have experienced a change in impedance, indicating a malfunction in the operation of a flash lamp.

Claim 3

An airport runway approach lighting system wherein a series of lamps located in predetermined spaced relationship along a runway or extension thereof are arranged to be flashed in a repeated logical sequence comprising: power means for supplying energy to flash said lamps, storage means associated with each lamp for storing energy delivered by said power means during periods when a respective lamp is not flashing, timing means for producing timing pulses which are applied to a trigger circuit associated with each lamp in a repeated logical sequence to trigger each lamp into a flashing state, said timing means producing pulses, the shape of which are dependent upon the impedance in each trigger circuit, monitoring means for continuously monitoring the flow of energy from said power means to said energy storage means, timing circuit impedance altering means for altering the impedance of said timing circuit when said monitoring means detects no appreciable energy flow between said power means and said energy storage means for a predetermined length of time, timing pulse examination means for examining each timing pulse supplied to each trigger circuit of said system in order to determine if the impedance of each timing circuit has been altered by said timing circuit impedance altering means.

Claim 4

An airport runway approach lighting system wherein a series of lamps located in predetermined spaced relationship along a runway or extension thereof are arranged to be flashed in a repeated logical sequence comprising: power means for supplying energy to flash said lamps, storage means associated with each lamp for storing energy delivered by said power means during periods when a respective lamp is not flashing, timing means for producing timing pulses which are applied to a trigger circuit associated with each lamp in a repeated logical sequence to trigger each lamp into a flashing state, said timing means producing pulses, the shape of which are dependent upon the impedance in each trigger circuit, monitoring means for continuously monitoring the flow of energy from said power means to said energy storage means, timing circuit impedance altering means for altering the impedance of said timing circuit when said monitoring means detects no appreciable energy flow between said power means and said energy storage means for a predetermined length of time, timing pulse examination means for examining each timing pulse supplied to each trigger circuit of said system in order to determine if the impedance of each timing circuit has been altered by said timing circuit impedance altering means.