US 4,730,147 A · Method and arrangement for the operation of a gas discharge lamp

Abstract

For the operation of warm start gas discharge lamps upon employment of an electronic ballast wherein the gas discharge lamp lies parallel to the effective capacitance of a series-resonant circuit and has its heater coils incorporated into this series-resonant circuit. An isolating switch is provided in series with the effective capacitance. This isolating switch interrupts the shunt to the lamp and, thus, the heater coil current as well, as soon as the lamp has ignited. It is assured in this way that the current flowing in the shunt to the lamp which otherwise represents a dissipated power is suppressed. Particular significance is accorded to this method when the effective capacitance of the series-resonant circuit is executed variably during the starting interval phase with the assistance of temperature-dependent resistors or is executed with time delayed electronic switches for the control of the lamp voltage.

Claims11

Dependent claims

A method for the operation of a gas discharge lamp provided with heater coils, particularly a fluorescent lamp, whereby a high-frequency ac voltage for operating the lamp is generated with an inverter from a dc voltage which is derived from a line ac voltage by rectification, said lamp being thereby arranged parallel to an effective capacitance of a series-resonant circuit formed of an effective capacitor and of an inductor and which includes the heater coils of the lamp, and whereby, during the heating-up operation of the heater coils (starting interval phase) between the turn-on of the power supply and the ignition of the lamp, the voltage adjacent thereto is limited to a value below the lamp's ignition voltage, said method comprising the steps of:

following the ignition of the lamp, suppressing the series-resonant circuit by interrupting a current branch having the effective capacitance and lying parallel to the lamp, said interruption affected by means of an isolating switch;
and
suppressing the series-resonant circuit as long as the lamp is in operation.

An electronic circuit for the operation of a gas discharge lamp provided with heater coils, particularly a fluorescent lamp, whereby a high-frequency ac voltage for operating the lamp is generated with an inverter from a dc voltage which is derived from a line ac voltage by rectification, said lamp being arranged parallel to an effective capacitance of a series-resonant circuit formed of an effective capacitor and of an inductor and which includes the heater coils of the lamp, and whereby, during the heating-up operation of the heater coils (starting interval phase) between the turn-on of the power supply and the ignition of the lamp, the voltage adjacent thereto is limited to a value below its ignition voltage, said electronic circuit comprising:

a current branch representing the variable, effective capacitance in series with an isolating switch, said current branch having a series connection of a first capacitor with a parallel circuit having a second capacitor and a positive-temperature-coefficient resistor;
wherein following the ignition of the lamp, the series-resonant circuit is suppressed by interrupting the current branch comprising the effective capacitance and lying parallel to the lamp, said current branch being interrupted by means of the isolating switch and remaining suppressed as long as the lamp is in operation.

a current branch representing the variable, effective capacitance in series with an isolating switch, said current branch having a parallel circuit of a series circuit of a first capacitor and a negative-temperature-coefficient resistor with a second capacitor;
wherein following the ignition of the lamp, the series-resonant circuit is suppressed by interrupting the current branch comprising the effective capacitance and lying parallel to the lamp, said current branch being interrupted by means of the isolating switch and remaining suppressed as long as the lamp is in operation.

Dependencies are inferred from the claim text.

Method and arrangement for the operation of a gas discharge lamp

Life of this patent

Method and arrangement for the operation of a gas discharge lamp

Life of this patent

Abstract

Claims11