Three terminal inverter for electroluminescent lamps

Claim 2

An inverter for powering an electroluminescent lamp, said inverter including a supply terminal, a ground terminal, a high voltage terminal, and an inductor having a first terminal and a second terminal, wherein said inverter further comprises: a first switching circuit connected to said supply terminal and said inductor, said first switching circuit pumping electrical energy from said supply terminal to said inductor; a second switching circuit connected to said first terminal, said second terminal, and to said high voltage terminal, said second switching circuit alternately connecting said first terminal and said second terminal to said high voltage terminal.

Claim 3

The inverter as set forth in claim 1 wherein said first switching circuit includes: a first transistor connected between said first terminal and said supply terminal; and a second transistor connected between said second terminal and said ground terminal.

Claim 4

The inverter as set forth in claim 2 wherein said first switching circuit further includes: a first diode connected between said first transistor and said first terminal; and a second diode connected between Said second terminal and said second transistor.

Claim 5

The inverter as set forth in claim 1 wherein said second switching circuit comprises: a first semiconductor switch connected between said first terminal and said high voltage terminal; and a second semiconductor switch connected between said second terminal and said high voltage terminal.

Claim 6

The inverter as set forth in claim 4 wherein said first semiconductor switch and said second semiconductor switch each comprise a silicon controlled switch.

Claim 7

The inverter as set forth in claim 4 wherein said first semiconductor switch and said second semiconductor switch each comprise a complementary pair of transistors connected in SCR configuration.

Claim 8

The inverter as set forth in claim 4 wherein the said second switching circuit further includes a first diode in series with said first semiconductor switch, and a second diode in series with said second semiconductor switch.

Claim 9

A display comprising: an electroluminescent lamp having a first electrode and a second electrode; and an inverter for powering said electroluminescent lamp, said inverter including: (i) a supply terminal, (ii) an output terminal connected to said first electrode, (iii) a ground terminal connected to said second electrode, and (iv) an inductor having a first terminal and a second terminal, (v) a first switching circuit connected to said supply terminal and said inductor, said first switching circuit pumping electrical energy from said supply terminal to said inductor, and (vi) a second switching circuit connected to said first terminal, said second terminal, and to said output terminal, said second switching circuit alternately connecting said first terminal and said second terminal to said output terminal.

Claim 10

A display comprising: an electroluminescent lamp having a first electrode and a second electrode; and an inverter for powering said electroluminescent lamp, said inverter including: (i) a supply terminal, (ii) an output terminal connected to said first electrode, (iii) a ground terminal connected to said second electrode, and (iv) an inductor having a first terminal and a second terminal, (v) a first switching circuit connected to said supply terminal and said inductor, said first switching circuit pumping electrical energy from said supply terminal to said inductor, and (vi) a second switching circuit connected to said first terminal, said second terminal, and to said output terminal, said second switching circuit alternately connecting said first terminal and said second terminal to said output terminal.

Claim 11

The display as set forth in claim 8 wherein said electroluminescent lamp includes more than two electrodes.

Claim 12

An inverter for powering an electroluminescent lamp, said inverter comprising: an inductor having a first terminal and a second terminal; a first switching circuit connected to said inductor for conducting high frequency electrical pulses through said inductor; an output terminal; a second switching circuit connected to said inductor for alternately connecting said first terminal and said second terminal to said output terminal at a low frequency.

Claim 13

An inverter for powering an electroluminescent lamp, said inverter comprising: an inductor having a first terminal and a second terminal; a first switching circuit connected to said inductor for conducting high frequency electrical pulses through said inductor; an output terminal; a second switching circuit connected to said inductor for alternately connecting said first terminal and said second terminal to said output terminal at a low frequency.

Claim 14

The inverter as set forth in claim 10 wherein said first switching circuit includes a pair of diodes for re-cycling energy from said lamp back to said lamp at the beginning of each half cycle of said low frequency.

Claim 17

The method as set forth in claim 12 wherein said first and second terminals are alternately connected to said second electrode at a low frequency to produce a low frequency alternating current through said lamp.

Claim 18

The method as set forth in claim 13 wherein said direct current is intermittent at a high frequency.

Claim 19

The method as set forth in claim 12 wherein said direct current is intermittent at a high frequency.