Method and apparatus for energizing a gaseous discharge lamp using switched energy storage capacitors

Claim 1

Apparatus for flashing a gaseous discharge lamp having a gaseous interior, anode and cathode terminals, a trigger electrode, a minimum anode voltage and a minimum holding voltage, comprising: a. trigger means for applying a series of spaced apart trigger voltage pulses to said trigger electrode where each trigger voltage pulse initiates first stage ionization of the gas in said lamp; b. capacitor means including a boost storage capacitor rated to operate at a first voltage having a magnitude less than the magnitude of the trigger voltage pulses and an electrolytic energy storage capacitor rated to operate at a second voltage lower than the minimum anode voltage but higher than the minimum holding voltage for storing a defined quantum of energy, said energy storage capacitor having an equivalent series resistance substantially lower than the equivalent series resistance of a high voltage electrolytic capacitor rated to operate at a voltage above the minimum anode voltage and capable of storing the defined quantum of energy at an operating voltage above the minimum anode voltage, the capacitance rating of said energy storage capacitor substantially exceeding the capacitance rating of said high voltage capacitor and the capacitance rating of said boost storage capacitor; c. a DC to DC converter power supply coupled to said capacitor means for charging said boost storage capacitor to the first voltage and for charging said energy storage capacitor to the second voltage, wherein the sum of the first and second voltages exceeds the minimum anode voltage, said power supply including i. a coupled inductor having a primary winding and a secondary winding; ii. a switching transistor having collector and emitter terminals coupled in series with said primary winding for switching between conductive and non-conductive states to control the flow of current through said primary winding; iii. said secondary winding of said coupled inductor including a first winding section coupled to direct a charging current into said boost storage capacitor when the voltage on said first winding section exceeds the voltage on said boost storage capacitor and a second winding section coupled to direct a charging current into said energy storage capacitor when the voltage on said second winding section exceeds the voltage on said energy storage capacitor, wherein said boost storage capacitor and said energy storage capacitor are recharged simultaneously during a part of each time interval between sequential trigger voltage pulses; and d. voltage controlled capacitor switching means having input terminals coupled across said boost storage capacitor and across said energy storage capacitor and output terminals coupled to the anode and cathode terminals of said lamp for operating in a first state to apply a boost voltage exceeding the minimum anode voltage to the anode and cathode terminals of said lamp to allow energy to flow into said lamp after the first stage ionization of the gas in said lamp has been achieved by said trigger means to initiate second stage ionization of the gas in said lamp and for switching into a second state after the boost voltage falls below the minimum anode voltage but before the boost voltage falls below the minimum holding voltage to couple said energy storage capacitor across the anode and cathode terminals of said lamp to enable said energy storage capacitor to discharge additional energy into said lamp; whereby said energy storage capacitor dissipates substantially less heat in its equivalent series resistance and operates at a lower temperature than the high voltage, higher equivalent series resistance electrolytic capacitor.

Claim 23

A method for flashing a gas discharge lamp having a gas interior, anode and cathode terminals, a trigger electrode, a minimum anode voltage and a minimum holding voltage, comprising: a. providing a trigger voltage source coupled to said trigger electrode to accomplish first stage ionization of the gas in said lamp; b. providing a boost storage capacitor and an electrolytic energy storage capacitor, wherein the capacitance rating of said energy storage capacitor is substantially greater than the capacitance rating of said boost storage capacitor; c. charging said boost storage capacitor to a first voltage; d. charging said energy storage capacitor to a second voltage having a magnitude greater than the minimum holding voltage but less than minimum anode voltage, wherein the sum of the first and second voltages exceeds the minimum anode voltage of said lamp; e. operating said trigger voltage source to initiate first stage ionization of the gas in said lamp; f. configuring said boost storage capacitor and said energy storage capacitor into a series-connected first state to apply a boost voltage having a magnitude greater than the minimum anode voltage across the anode and cathode terminals of said lamp to allow energy to flow into said lamp after initiation of first stage ionization of the gas in said lamp to initiate second stage ionization of said lamp; and g. configuring said boost storage capacitor and said energy storage capacitor into a second state after the boost voltage falls below the minimum anode voltage but before the boost voltage falls below the minimum holding voltage to couple said energy storage capacitor across the anode and cathode terminals of said lamp to enable said energy storage capacitor to discharge additional energy into said lamp.

Claim 24

A method for flashing a gas discharge lamp having a gas interior, anode and cathode terminals, a trigger electrode, a minimum anode voltage and a minimum holding voltage, comprising: a. providing a trigger voltage source coupled to said trigger electrode to accomplish first stage ionization of the gas in said lamp; b. providing a boost storage capacitor and an electrolytic energy storage capacitor, wherein the capacitance rating of said energy storage capacitor is substantially greater than the capacitance rating of said boost storage capacitor; c. charging said boost storage capacitor to a first voltage; d. charging said energy storage capacitor to a second voltage having a magnitude greater than the minimum holding voltage but less than minimum anode voltage, wherein the sum of the first and second voltages exceeds the minimum anode voltage of said lamp; e. operating said trigger voltage source to initiate first stage ionization of the gas in said lamp; f. configuring said boost storage capacitor and said energy storage capacitor into a series-connected first state to apply a boost voltage having a magnitude greater than the minimum anode voltage across the anode and cathode terminals of said lamp to allow energy to flow into said lamp after initiation of first stage ionization of the gas in said lamp to initiate second stage ionization of said lamp; and g. configuring said boost storage capacitor and said energy storage capacitor into a second state after the boost voltage falls below the minimum anode voltage but before the boost voltage falls below the minimum holding voltage to couple said energy storage capacitor across the anode and cathode terminals of said lamp to enable said energy storage capacitor to discharge additional energy into said lamp.