Current limited oxcillator arrangement

Claim 2

Current limiting oscillator circuitry comprising: a DC potential source; load circuit means including a transformer having an inductive reactance means connected to said DC potential source and a secondary winding coupled to a low pressure electric discharge lamp; oscillator means coupled to said DC potential source and to said inductive reactance means of said load circuit means; sampling means coupling said oscillator means connected to said inductive reactance means to a potential reference level; and switching means coupled to said sampling means and to said oscillator means and intermediate said oscillator means and said potential reference level whereby current flow exceeding a given level through said oscillator means and inductive reactance of said load circuit means as determined by said current sampling means activates said switching means which limits current flow in said oscillator means to effect development of a potential at said load circuit means in an amount greater than said DC potential source for application to said low pressure electric discharge lamp.

Claim 3

The current limiting oscillator circuit of claim 1 wherein said load circuit means includes an inductive reactance means in the form of a transformer winding on a ferromagnetic core and said switching means limits the current flow through said transformer winding to a level less than the saturation current level of said core.

Claim 4

The current limiting oscillator circuit of claim 1 wherein said sampling and switching means provides a negative feedback potential and said load circuit means provides a positive feedback potential for said oscillator means.

Claim 5

The current limiting oscillator circuit of claim 1 wherein said switching means includes a unidirectional conduction capability whereby the negative-going potential applied to said oscillator means is limited.

Claim 6

A low pressure electric discharge lamp circuit comprising: An AC potential source; rectifier means coupled to said AC potential source to provide a DC potential source; oscillator means coupled to said DC potential source; load circuit means including a transformer having a primary winding coupled to said DC potential source and to said oscillator means and a secondary winding coupled to said low pressure electric discharge lamp; current sampling means coupled to said oscillator means connected to said primary winding of said load circuit means and to a potential reference level; and switching means coupled to said current sampling means and to said oscillator means and intermediate said oscillator means and said potential reference level whereby current flow through said oscillator means and primary winding of said load circuit means above a given level as determined by said current sampling means activates said switching means which limits current flow in said oscillator means and primary winding of said load circuit means to effect development of a potential at said load circuit means in an amount greater than said DC potential source for application to said low pressure electric discharge lamp.

Claim 7

A low pressure electric discharge lamp circuit comprising: An AC potential source; rectifier means coupled to said AC potential source to provide a DC potential source; oscillator means coupled to said DC potential source; load circuit means including a transformer having a primary winding coupled to said DC potential source and to said oscillator means and a secondary winding coupled to said low pressure electric discharge lamp; current sampling means coupled to said oscillator means connected to said primary winding of said load circuit means and to a potential reference level; and switching means coupled to said current sampling means and to said oscillator means and intermediate said oscillator means and said potential reference level whereby current flow through said oscillator means and primary winding of said load circuit means above a given level as determined by said current sampling means activates said switching means which limits current flow in said oscillator means and primary winding of said load circuit means to effect development of a potential at said load circuit means in an amount greater than said DC potential source for application to said low pressure electric discharge lamp.

Claim 8

The low pressure electric discharge lamp circuit of claim 5 wherein said oscillator means is in the form of a transistor having a collector coupled to said load circuit means; an emitter coupled to said load circuit means, said current sampling means, and said switching means; and a base coupled to said switching means, said rectifier means, and said load circuit means.

Claim 9

The low pressure electric discharge lamp circuit of claim 5 wherein said transformer of said load circuit means includes a ferromagnetic core and said switching means limits the current through said transformer and oscillator means to a level less than the saturation level of said ferromagnetic core.

Claim 10

The low pressure electric discharge lamp circuit of claim 5 wherein said switching means includes a unidirectional current conduction capability for limiting the negative-going potential applied to said oscillator means from said load circuit means.

Claim 11

The low pressure electric discharge lamp circuit of claim 5 wherein a negative feedback potential from said switching means and a positive feedback potential from said load circuit means are applied to said oscillator means whereby a desired current limited oscillation is effected.

Claim 12

A ballast circuit for a flourescent lamp comprising: an AC potential source; rectifier means coupled to said AC potential source to provide a DC potential source; load circuit means including an output transformer having a ferromagnetic core with a secondary winding coupled to a flourescent lamp and a primary winding coupled to said DC potential source; oscillator means coupled to said primary winding of said transformer in said load circuit means and including a transistor coupled to said DC potential source; current sampling means coupled to said oscillator means and to a potential reference level; and switching means coupled to said current sampling means and to said oscillator means and intermediate said transistor of said oscillator means and said potential reference level, said switching means limiting current flow in said transistor of said oscillator means to effect a reduced current flow and increased potential at said load circuit means with said increased potential at said load circuit means in an amount greater than said DC potential source applied to said low pressure electric discharge lamp.

Claim 13

A ballast circuit for a flourescent lamp comprising: an AC potential source; rectifier means coupled to said AC potential source to provide a DC potential source; load circuit means including an output transformer having a ferromagnetic core with a secondary winding coupled to a flourescent lamp and a primary winding coupled to said DC potential source; oscillator means coupled to said primary winding of said transformer in said load circuit means and including a transistor coupled to said DC potential source; current sampling means coupled to said oscillator means and to a potential reference level; and switching means coupled to said current sampling means and to said oscillator means and intermediate said transistor of said oscillator means and said potential reference level, said switching means limiting current flow in said transistor of said oscillator means to effect a reduced current flow and increased potential at said load circuit means with said increased potential at said load circuit means in an amount greater than said DC potential source applied to said low pressure electric discharge lamp.

Claim 14

The ballast circuit of claim 10 wherein said sampling means and said switching means limits the current flow through said oscillator means to a level less than the saturation level of said output transformer.

Claim 15

The ballast circuit of claim 10 wherein said oscillator means operates at a frequency higher than the audio frequencies.