Inductive-resistive fluorescent apparatus and method

• US 6,184,622 B1
• Filed: 05/08/2000
• Issued: 02/06/2001
• Est. Priority Date: 10/16/1996
• Status: Expired due to Term

• Current Assignee: Carol A. Lovell, Estate of Walter Carl Lovell
• Original Assignee: Tapeswitch Corporation (Inductotherm Group)
• Inventors: Lovell, Walter C., Duhon, Edward, Brooks, Sheldon B., Geiger, Dana
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): Lee, Wilson
• Application Number:
  US09/566,595
• Time in Patent Office: 274 Days
• Field of Search: 315/41, 315/39, 315/46, 315/248, 315/246, 315/57, 315/58, 315/184, 315/276, 315/307
• US Class Current: 315/41
• CPC Class Codes: H01J 61/56 One or more circuit elements structurally associated with the lamp
• CPC Class Codes: H05B 41/16 in which the lamp is fed by dc or by low-frequency ac, e.g. by 50 cycles/sec ac, or with network frequencies
• CPC Class Codes: H05B 41/24 in which the lamp is fed by high frequency ac, or with separate oscillator frequencyH05B41/26 takes precedence
• CPC Class Codes: H05B 41/2821 by means of a single-switch converter or a parallel push-pull converter in the final stage H05B41/285 takes precedence

Abstract

A fluorescent illuminating apparatus includes a translucent housing with a chamber within which a fluorescent medium is supported and electrical connections configured to provide an electrical potential across the chamber. An inductive-resistive structure is fixed sufficiently proximate to the housing to induce fluorescence in the fluorescent medium when an electric current is passed through the inductive-resistive structure while an electric potential is applied across the electrical connections of the housing. Preferred inductive structures for use with the present invention include elongate tape structures having a substrate with a conductive-resistive coating. A method of inducing fluorescence comprises passing a current through an inductive structure which is adjacent a fluorescing medium in an amount sufficient to induce fluorescent in the fluorescing medium in the presence of an electrical potential imposed on the fluorescing medium. An alternating current drive circuit for illuminating the fluorescent lamp includes a source of rippled/pulsed DC voltage, a polarity-reversing circuit and a controller connected to the polaritx-reversing circuit which periodically generates a signal to reverse the polarity of the voltage applied to the lamp.

Claims

1. A fluorescent illuminating apparatus comprising:

(a) a fluorescent lightbulb including;

a translucent housing having a chamber for supporting a fluorescent medium, said housing having first and second ends;

electrical connections on said housing to provide an electrical potential across said chamber, said connetions being in the form of first and second electrical terminals;

a fluorescent medium supported in said chamber; and

first and second electrodes located respectively at said first and second ends of said translucent housing, said first and second electrodes being respectively electrically interconnected with said first and second electrical terminals;

(b) an inductive-resistive structure fixed sufficiently proximate said housing of said lightbulb to induce fluorescence in said fluorescent medium when an electric current is passed through said inductive-resistive structure while an electric potential is applied across said housing, said inductive-resistive structure having third and fourth electrical terminals thereon, said second and third electrical terminals being electrically interconnected; and

(c) a source of rippled/pulsed direct current (DC) voltage having first and second ouput terminals electrically interconnected with said first and fourth electrical terminals, said source having first and second alternating current (AC) input voltage terminals, said source including;

a first diode having its anode electrically interconnected with said second ouput terminal and its cathode electrically interconnected with said first AC input voltage terminal;

a second diode having its anode electrically interconnected with said first AC input voltage terminal and its cathode electrically interconnected with said first output terminal;

a third diode having its anode electrically interconnected with said second AC input voltage terminal and having its cathode electrically interconnected with said first output terminal;

a fourth diode having its anode electrically interconnected with said second output terminal and its cathode electrically interconnected with said second AC input voltage terminal;

a first capacitor electrically interconnected between said first output terminal and said second AC input voltage terminal; and

a second capacitor electrically interconnected between said second output terminal and said second AC input voltage terminal.

2. The fluorescent illuminating apparatus of claim 1, further comprising:

a fifth diode having its anode electrically interconnected with the cathode of said fourth diode and having its cathode electrically interconnected with said second AC input voltage terminal;

a sixth diode having its anode electrically interconnected with said second AC input voltage terminal and having its cathode electrically interconnected with the anode of said third diode;

a third capacitor electrically interconnected between said first AC input voltage terminal and said anode of said third diode; and

a fourth capacitor electrically interconnected between said first AC input voltage terminal and said anode of said fifth diode.

3. The fluorescent illuminating apparatus of claim 1, further comprising a third capacitor electrically interconnected between said second AC input voltage terminal and a node formed by the cathode of said fourth diode and the anode of said third diode.

4. The fluorescent illuminating apparatus of claim 1, wherein said inductive-resistive structure comprises:

first and second spaced conductors electrically interconnected with said third and fourth electrical terminals; and

a conductive-resistive medium electrically interconnected between said spaced conductors, said conductive-resistive medium being one of;

a non-continuous electrically conductive component suspended in a substantially non-conductive binder; and

a coating portion of a magnetic recording tape.

5. The fluorescent illuminating apparatus of claim 1, further comprising a spike delay trigger having a first electrical terminal which is electrically interconnected with said second output terminal of said source of rippled/pulsed DC voltage and having a second electrical terminal which is electrically connected to said first electrical terminal of said fluorescent lightbulb.

6. The fluorescent illuminating apparatus of claim 5, wherein said spike delay trigger comprises:

a silicon controlled rectifier having its anode electrically interconnected with said first electrical terminal of said spike trigger and having its cathode electrically interconnected with said second electrical terminal of said spike trigger and having a gate; and

a piezoelectric disk having a first electrical lead electrically interconnected to said gate of said silicon controlled rectifier and a second electrical lead electrically interconnected with said first terminal of said spike trigger.

7. The fluorescent illuminating apparatus of claim 5, wherein said spike delay trigger comprises:

a triac having a first main terminal electrically interconnected with said second terminal of said spike trigger and a second main terminal electrically interconnected with said first terminal of said spike trigger and having a gate; and

a piezoelectric disk having a first electrical lead electrically interconnected with said gate and a second electrical lead electrically interconnected with said first terminal of said spike trigger.

8. The fluorescent illuminating apparatus of claim 1, wherein said inductive-resistive structure comprises a conductive-resistive medium deposited on an interior surface of said translucent housing and extending generally from said first end of said translucent housing to said second end of said translucent housing, said second electrode being electrically interconnected with said second electrical terminal through said inductive-resistive structure, with said fourth electrical terminal coinciding with said electrical terminal and said third electrical terminal electrically interfacing with said second electrode.

9. The fluorescent illuminating apparatus of claim 1, further comprising a voltage sensing trigger electrically interconnected between said source of rippled/pulsed DC voltage, said fluorescent lightbulb and said inductive-resistive structure.

10. The fluorescent illuminating apparatus of claim 9, wherein said voltage sensing trigger comprises:

a silicon controlled rectifier having its anode electrically interconnected with said fourth electrical terminal of said inductive-resistive structure and having its cathode electrically interconnected with said second ouput terminal of said source of rippled/pulsed DC voltage, and having a gate; and

at least one Zener diode having its anode electrically interconnected to said gate of said silicon controlled rectifier and having its cathode electrically interconnected to said first output terminal of said source of rippled/pulsed DC voltage and said first electrical terminal of said fluorescent lightbulb.

11. A fluorescent illuminating apparatus comprising:

(a) a fluorescent lightbulb including;

a translucent housing having a chamber for supporting a fluorescent medium, said housing having first and second ends;

electrical connections on said housing to provide an electrical potential across said chamber, said connections being in the form of first and second electrical terminals;

a fluorescent medium supported in said chamber; and

first and second electrodes located respectively at said first and second ends of said translucent housing, said first and second electrodes being respectively electrically interconnected with said first and second electrical terminals;

(b) an inductive-resistive structure fixed sufficiently proximate said housing of said lightbulb to induce fluorescence in said fluorescent medium when an electric current is passed through said inductive-resistive structure while an electric potential is applied across said housing, said inductive-resistive structure having third and fourth electrical terminals thereon; and

(c) a source of rippled/pulsed direct current (DC) voltage including;

a first transistor;

a first capacitor; and

a step-up transformer having a primary and a secondary winding, said secondary winding being electrically interconnected with said first and second electrical terminals of said fluorescent lightbulb, said primary winding being electrically interconnected with said first transistor, said first capacitor, and said inductive-resistive structure to form an oscillator, such that when a source of substantially steady direct current is electrically interconnected with said oscillator, said first capacitor charges during a first repeating time period when said first transistor is off and said first capacitor discharges during a second repeating time period when said first transistor is active, said oscillator producing a time-varying voltage waveform across said primary winding of said transformer in accordance with said charging and discharging of said first capacitor during said first and second repeating time periods, whereby a stepped-up rippled/pulsed DC voltage is produced across said secondary winding.

12. The apparatus of claim 11, further comprising a source of substantially steady direct current voltage electrically interconnected with said oscillator.

13. The apparatus of claim 12, wherein said source of substantially steady direct current voltage is a storage battery.

14. The apparatus of claim 11, wherein:

said first transistor is an npn BJT having a base, an emitter, and a collector, said emitter of said first transistor being electrically interconnected with both said third electrical terminal and a first electrical connection of said primary winding; and

said first capacitor is electrically interconnected between said base of said first transistor and a second electrical connection of said primary winding;

said apparatus further comprising;

a second transistor, said second transistor being a pnp BJT having a base, an emitter, and a collector, said base of said second transistor being electrically interconnected with said collector of said first transistor, said collector of said second transistor being electrically interconnected with said second electrical connection of said primary winding; and

a resistor electrically interconnected between said emitter of said second transistor and said base of said first transistor.

15. The apparatus of claim 14, further comprising a source of substantially steady direct current voltage electrically interconnected between said emitter of said second transistor and said fourth electrical terminal.

16. The apparatus of claim 15, wherein second source of substantially steady direct current voltage is a storage battery.

17. The apparatus of claim 11, wherein:

said first transistor is an npn BJT having a base, an emitter, and a collector;

said first capacitor is electrically interconnected between said emitter of said first transistor and said fourth electrical terminal; and

said primary winding of said step-up transformer is split into a first portion electrically interconnected between said third electrical terminal and said collector of said first transistor and a second portion electrically interconnected between said base of said first transistor and said fourth electrical terminal;

said apparatus further comprising a second capacitor electrically interconnected between said third electrical terminal and said emitter of said first transistor.

18. The apparatus of claim 17, further comprising a source of substantially steady direct current voltage electrically interconnected between said emitter of said first transistor and said third electrical terminal.

19. The apparatus of claim 18, wherein said source of substantially steady direct current voltage is a storage battery.

20. The apparatus of claim 11, wherein said inductive-resistive structure comprises an elongate layer of conductive-resistive material deposited on an inside portion of said translucent housing and extending generally between said first and second ends of said translucent housing.

21. A fluorescent illuminating apparatus comprising:

a translucent housing having a chamber for supporting a fluorescent medium and having electrical connections thereon to provide an electrical potential across said chamber, said housing generally having the size and shape of an ordinary incandescent lightbulb, said electrical connect ions being in the form of first and second electrical terminals adapted to mount into an ordinary light socket;

a fluorescent medium supported in said chamber;

first and second spaced electrodes located within said chamber;

a first inductive-resistive structure located within said chamber; and

a source of rippled/pulsed DC voltage, said source having first and second AC input voltage terminals electrically interconnected with said first and second electrical terminals, said source having first and second output terminals, said first electrode being electrically interconnected with said second output terminal, said second electrode being electrically interconnected with said first output terminal through said first inductive-resistive structure.

22. The fluorescent illuminating apparatus of claim 21, further comprising a second structure located within said chamber, wherein:

said first electrode is electrically interconnected with said second output terminal through said second structure; and

said first inductive-resistive structure comprises;

a rod-like substrate formed of an electrically insulating material; and

a solid emulsion comprising an electrically conductive discrete phase dispersed within a substantially non-conductive continuous phase, said emulsion being applied to said rod-like substrate.

23. The fluorescent illuminating apparatus of claim 21, wherein said first inductive-resistive structure is formed as a coating on an inner surface of said translucent housing, said coating having a width and thickness selected to produce a desired direct current (DC) resistance value with minimal occlusion of light emitted from said apparatus, said coating being a solid emulsion comprising an electrically conductive discrete phase dispersed within a substantially non-conductive continuous phase.

24. The fluorescent illuminating apparatus of claim 21, wherein said first inductive-resistive structure comprises:

a solid-like substrate formed of an electrically insulating material; and

a solid emulsion comprising an electrically conductive discrete phase dispersed within a substantially non-conductive continuous phase, said emulsion being applied to said rod-like substrate.

25. The fluorescent illuminating apparatus of claim 21, further comprising a spike delay trigger having a first electrical terminal electrically interconnected with said second output terminal and a second electrical terminal electrically interconnected with said first electrode.

26. The fluorescent illuminating apparatus of claim 25, wherein said spike delay trigger comprises:

a silicon controlled rectifier having its anode electrically interconnected with said first electrical terminal of said spike trigger and having its cathode electrically interconnected with said second electrical terminal of said spike trigger and having a gate; and

a piezoelectric disk having a first electrical lead electrically interconnected with said gate of said silicon controlled rectifier and a second electrical lead electrically interconnected with said first terminal of said spike trigger.

27. The fluorescent illuminating apparatus of claim 25, wherein said spike delay trigger comprises:

a triac having a first main terminal electrically interconnected with said second terminal of said spike trigger and a second main terminal electrically interconnected with said first terminal of said spike trigger and having a gate; and

a piezoelectric disk having a first electrical lead electrically interconnected with said gate and a second electrical lead electrically interconnected with said first terminal of said spike trigger.

28. The fluorescent illuminating apparatus of claim 21, further comprising a voltage sensing trigger electrically interconnected with said source of rippled/pulsed DC voltage, said first and second spaced electrodes and said first inductive-resistive structure.

29. The fluorescent illuminating apparatus of claim 28, wherein said voltage sensing trigger comprises:

a silicon controlled rectifier having its anode electrically interconnected with said inductive-resistive structure and having its cathode electrically interconnected with said second output terminal of said source of rippled/pulsed DC voltage and having a gate; and

at least one Zener diode having its anode electrically interconnected to said gate of said silicon controlled rectifier and having its cathode electrically interconnected to said first output terminal of said source of rippled/pulsed DC voltage.