US 5,510,680 AGranted

Electronic ballast with special voltage waveforms

OwnerOle K. Nilsseninventor

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Abstract

An inverter-type electronic ballast for a gas discharge lamp is powered by a DC supply voltage provided from a rectifier-filter combination connected with an ordinary electric utility power line. The absolute magnitude of the DC supply voltage is higher than the peak absolute magnitude of the power line voltage. The ballast includes an inverter circuit operative to provide an inverter output voltage of special trapezoidal-like waveshape; which output voltage is applied to a series-resonant combination of an inductor and a capacitor. The gas discharge lamp is connected in parallel with the capacitor. The inverter is driven by a voltage of special waveshape and controllable frequency. By controlling the frequency, the magnitude of the current supplied to the gas discharge lamp can be adjusted, thereby correspondingly adjusting the amount of light produced by the lamp.

Claims32

Dependent claims

An arrangement comprising:

rectifier device connected with a source of power line voltage and operative to provide a DC voltage at a set of DC terminals;
a power conditioner connected with the DC terminals and operative to provide a high-frequency output voltage at a high-frequency output;
the high-frequency output voltage having a fundamental frequency substantially higher than that of the power line voltage;
the power conditioner including an inverter circuit connected between the DC terminals and the high-frequency output;
the inverter circuit being characterized by (i) including a pair of alternatingly switching transistors series-connected between the DC terminals, and (ii) producing an alternating inverter voltage of non-symmetrical waveshape across a pair of inverter terminals;
the non-symmetrical waveshape having a complete cycle period including:
(i) a positive part during which the magnitude of the inverter voltage remains at an approximately constant positive level;
(ii) a negative part during which the magnitude of the inverter voltage remains at an approximately constant negative level;
(iii) a negative-going part during which the magnitude of the inverter voltage changes rapidly from the positive level to the negative level;
and (iv) a positive-going part during which the inverter voltage changes rapidly from the negative level to the positive level;
the duration of the positive part being, at least at certain times, distinctly different from the duration of the negative part;
the alternating inverter voltage having, irrespective of the duration of the negative part as a fraction of the duration of the positive part, an average magnitude equal to zero when averaged over the complete cycle period;
and
a gas discharge lamp assembly operative to connect with the high-frequency output and to be powered by the high-frequency output voltage provided thereat.

11 more elements

An assembly comprising:

a rectifier sub-assembly having a pair of AC input terminals operable to be connected with the AC power line voltage of an ordinary electric utility power line and, when indeed so connected, to provide a DC voltage at a set of DC output terminals;
an inverter sub-assembly having a set of DC input terminals connected with the DC output terminals and operative to provide a high-frequency output voltage between a pair of high-frequency output terminals;
the high-frequency output voltage having a fundamental frequency substantially higher than that of the AC power line voltage;
the inverter sub-assembly being characterized by producing, across a pair of inverter terminals, a periodically alternating inverter voltage having a basic period consisting of:
(i) a first segment during which its magnitude remains approximately constant at a positive potential;
(ii) a second segment during which its magnitude decreases in a substantially continuous manner;
(iii) a third segment during which its magnitude remains approximately constant at a negative potential;
and (iv) a fourth segment during which its magnitude increases in a substantially continuous manner;
a gas discharge lamp connected in circuit with the high-frequency output terminals;
the gas discharge lamp having a pair of thermionic cathodes, each having a pair of cathode terminals;
and
a screw-base having a pair of base terminals;
the screw-base, the rectifier sub-assembly, the inverter sub-assembly, and the gas discharge lamp being combined so as to constitute a lamp assembly operable to be screwed into and held by an ordinary electric lamp socket, thereby to cause said AC power line voltage to be applied to the base terminals.

10 more elements

An assembly comprising:

a first sub-assembly connected with the AC power line voltage of an ordinary electric utility power line and operative to provide a DC voltage at a pair of DC output terminals;
a second sub-assembly having a first DC input terminal and a second DC input terminal, both connected with the DC output terminals;
the second sub-assembly including a first transistor connected between the first DC input terminal and a center terminal, and a second transistor connected between the center terminal and the second DC input terminal;
the second sub-assembly being further characterized in that it provides a periodically alternating output voltage across a pair of AC output terminals, one of which AC output terminals being the center terminal;
the periodically alternating output voltage having a waveshape with a complete cycle period consisting of:
(i) a positive part during which its instantaneous magnitude remains at an essentially constant positive level;
(ii) a negative part during which its instantaneous magnitude remains at an essentially constant negative level;
(iii) a negative-going part during which its instantaneous magnitude changes rapidly from the positive level to the negative level;
and (iv) a positive-going part during which its instantaneous magnitude changes rapidly from the negative level to the positive level;
the duration of the positive part being, at least under some conditions, significantly different from the duration of the negative part;
and
a third sub-assembly connected with the AC output terminals and including a light-emitting gas discharge lamp.

9 more elements

An assembly comprising:

a rectifier sub-assembly having a pair of AC input terminals operable to be connected with the AC power line voltage of an ordinary electric utility power line and, when indeed so connected, to provide a DC voltage at a set of DC output terminals;
an inverter sub-assembly having a set of DC input terminals connected with the DC output terminals and operative to provide a high-frequency output voltage between a pair of high-frequency output terminals;
the high-frequency output voltage having a fundamental frequency substantially higher than that of the AC power line voltage;
the inverter sub-assembly including a transistor having a pair of transistor terminals between which flows a periodic transistor current and across which exists a periodic transistor voltage;
the inverter sub-assembly including circuitry operative to prevent transistor current from flowing except when the absolute magnitude of the transistor voltage is substantially lower than that of the DC voltage;
the inverter sub-assembly being also characterized by producing, across a pair of inverter terminals, a periodically alternating inverter voltage having a basic period consisting of:
(i) a first segment during which its magnitude remains approximately constant at a positive potential;
(ii) a second segment during which its magnitude decreases in a substantially continuous manner;
(iii) a third segment during which its magnitude remains approximately constant at a negative potential;
and (iv) a fourth segment during which its magnitude increases in a substantially continuous manner;
and
a gas discharge lamp connected in circuit with the high-frequency output terminals.

9 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/993,628Filed 21 Dec 1992 · continuation
Priority: 20 Mar 1978
Granted: 23 Apr 1996
Term ends: Not estimatedThe source records don’t support an estimate.

Classification17 codes

H02M 7/53862
Control circuits: using transistor type converters
H02M 7/53832
In a self-oscillating arrangement: in a push-pull arrangement
H02M 7/53835
In a push-pull arrangement: of the parallel type
H02M 7/53846
In a self-oscillating arrangement: control circuits

Family

Serial890,586Parent of this continuation-in-part · filed 20 Mar 1978
Serial973,741Parent of this continuation · filed 28 Dec 1978
Serial23,849Parent of this continuation-in-part · filed 26 Mar 1979
Serial178,107Parent of this continuation · filed 14 Aug 1980
Serial330,599Parent of this continuation-in-part · filed 14 Dec 1981
Serial555,426Parent of this continuation · filed 23 Nov 1983
Serial644,155Parent of this continuation · filed 27 Aug 1984
Serial787,692Parent of this continuation · filed 15 Oct 1985
Serial787,962Parent of this continuation-in-part · filed 16 Oct 1985
Serial546,267Parent of this continuation · filed 29 Jun 1990
Serial636,246Parent of this continuation · filed 31 Dec 1990
Serial717,860Parent of this continuation-in-part · filed 19 Jun 1991
Serial751,587Parent of this continuation · filed 22 Aug 1991
US 4,700,625 AParent of this continuation-in-part
US 5,166,578 AParent of this continuation-in-part
US 4,441,087 AParent of this continuation-in-part
US 4,184,128 AParent of this continuation-in-part
US 4,279,011 AParent of this continuation-in-part
US 5,510,680 AThis patent

From the US filing history. Foreign family members aren’t listed.