US 5,479,074 A · Electronic ballast with pre-conditioner circuit

An arrangement comprising:

a pre-conditioner circuit having a pair of power input terminals connected with the AC power line voltage of an ordinary electric utility power line;
the preconditioner circuit being (i) characterized by including an intermittently conducting transistor;
(ii) operative to provide a DC supply voltage of substantially constant magnitude at a pair of DC output terminals;
and (iii) by not having a transformer winding connected across the power input terminals;
an inverter circuit having a pair of DC input terminals connected with the DC output terminals, thereby to provide the DC supply voltage across the DC input terminals;
the inverter circuit being operative to provide an AC output voltage at a pair of AC output terminals and being otherwise characterized by including:
(i) a first transistor having a first pair of transistor control terminals and a first pair of transistor output terminals;
(ii) a second transistor having a second pair of transistor control terminals and a second pair of transistor output terminals;
and (iii) a pair of intermediary terminals across which exists a voltage alternating periodically between a first voltage level and a second voltage level, spending a first part of each period at the first voltage level, a second part of each period at the second voltage level , and substantially no time at any other voltage levels;
and
a first gas discharge lamp connected across the AC output terminals by way of a first current-limiting impedance.

8 more elements

An arrangement comprising:

a pre-conditioner circuit having a pair of power input terminals adapted to be connected with the AC power line voltage of an ordinary electric utility power line;
the pre-conditioner circuit, when indeed so connected, being operative to provide a DC supply voltage of substantially constant magnitude at a pair of DC output terminals;
the pre-conditioner circuit being further characterized by providing for the magnitude of the DC supply voltage to be substantially higher during a brief period immediately following initial connection of the power input terminals with the AC power line voltage as compared with after this brief period;
an inverter circuit having a pair of DC input terminals connected with the DC output terminals, thereby to provide the DC supply voltage across the DC input terminals;
the inverter circuit being operative to provide an AC output voltage at a pair of AC output terminals and being otherwise characterized by including:
(i) a first transistor having a first pair of transistor control terminals and a first pair of transistor output terminals;
(ii) a second transistor having a second pair of transistor control terminals and a second pair of transistor output terminals;
(iii) a pair of intermediary terminals across which exists a voltage alternating periodically between a first voltage level and a second voltage level, spending a first part of each period at the first voltage level, a second part of each period at the second voltage level, and substantially no time at any other voltage levels;
and (iv) a waveshaping sub-assembly connected between the intermediary terminals and the AC output terminals and functional to cause the AC output voltage to have a substantially sinusoidal waveshape;
and
a first gas discharge lamp connected across the AC output terminals by way of a first current-limiting impedance.

8 more elements

An arrangement comprising:

a pre-conditioner circuit having a pair of power input terminals adapted to be connected with the AC power line voltage of an ordinary electric utility power line;
the pre-conditioner circuit, when indeed so connected, being operative to provide a DC supply voltage of substantially constant magnitude at a pair of DC output terminals;
the pre-conditioner circuit being further characterized by not having a transformer winding connected across the power input terminals;
an inverter circuit having a pair of DC input terminals connected with the DC output terminals, thereby to provide the DC supply voltage across the DC input terminals;
the inverter circuit being operative to provide an AC output voltage at a pair of AC output terminals and being otherwise characterized by including:
(i) a first transistor having a first pair of transistor control terminals and a first pair of transistor output terminals;
(ii) a second transistor having a second pair of transistor control terminals and a second pair of transistor output terminals;
(iii) a pair of intermediary terminals across which exists a voltage alternating periodically between a first voltage level and a second voltage level, spending a first part of each period at the first voltage level, a second part of each period at the second voltage level, and substantially no time at any other voltage levels;
and (iv) an IC having IC terminals connected in circuit with the first pair of transistor control terminals;
a first gas discharge lamp connected across the AC output terminals by way of a first current-limiting impedance.

7 more elements

An arrangement comprising:

a pre-conditioner circuit having a pair of power input terminals adapted to be connected with the AC power line voltage of an ordinary electric utility power line;
the pre-conditioner circuit, when indeed so connected, being operative to provide a DC supply voltage of substantially constant magnitude at a pair of DC output terminals;
the pre-conditioner circuit being further characterized by not having a transformer winding connected across the power input terminals;
an inverter circuit having a pair of DC input terminals connected with the DC output terminals, thereby to provide the DC supply voltage across the DC input terminals;
the inverter circuit being operative to provide an AC output voltage at a pair of AC output terminals and being otherwise characterized by including:
(i) a first transistor having a first pair of transistor control terminals and a first pair of transistor output terminals;
(ii) a second transistor having a second pair of transistor control terminals and a second pair of transistor output terminals;
and (iii) a pair of intermediary terminals across which exists a voltage alternating periodically between a first voltage level and a second voltage level, spending a first part of each period at the first voltage level, a second part of each period at the second voltage level, and substantially no time at any other voltage levels;
the inverter circuit being further characterized by being operative:
(a) for a brief period immediately after the pre-converter circuit having been connected with the AC power line voltage, to cause the magnitude of the AC output voltage to be relatively high;
and (b) after the brief period, to cause the magnitude of the AC output voltage to be relatively low;
and
a first gas discharge lamp connected across the AC output terminals by way of a first current-limiting impedance.

10 more elements

An arrangement comprising:

a pre-conditioner circuit having a pair of power input terminals adapted to be connected with the AC power line voltage of an ordinary electric utility power line;
the pre-conditioner circuit, when indeed so connected, being operative to provide a DC supply voltage of substantially constant magnitude at a pair of DC output terminals;
the pre-conditioner circuit being further characterized by including:
(i) a pre-converter transistor;
(ii) an energy-storing inductor;
(iii) an IC connected with the pre-converter transistor and functional, but only after having been provided with an auxiliary DC supply voltage, to cause the pre-converter transistor to periodically conduct;
and (iv) an auxiliary DC power supply operative to supply said auxiliary DC supply voltage within a short period of time after the power input terminals have been connected with the AC power line voltage;
the short period of time being about equal to or shorter than the duration of a complete cycle of the AC power line voltage;
any power drawn from the auxiliary DC power supply having been supplied from the power line;
an inverter circuit having a pair of DC input terminals connected with the DC output terminals, thereby to provide the DC supply voltage across the DC input terminals;
the inverter circuit being operative to provide an AC output voltage at a pair of AC output terminals and being otherwise characterized by including:
(i) a first transistor having a first pair of transistor control terminals and a first pair of transistor output terminals;
(ii) a second transistor having a second pair of transistor control terminals and a second pair of transistor output terminals;
and (iii) a pair of intermediary terminals across which exists a voltage alternating periodically between a first voltage level and a second voltage level, spending a first part of each period at the first voltage level, a second part of each period at the second voltage level, and substantially no time at any other voltage levels;
and
a first gas discharge lamp connected across the AC output terminals by way of a first current-limiting impedance.

13 more elements

An arrangement comprising:

a pre-conditioner circuit having a pair of power input terminals adapted to be connected with the AC power line voltage of an ordinary electric utility power line;
the pre-conditioner circuit, when indeed so connected, being operative to provide a DC supply voltage of substantially constant magnitude at a pair of DC output terminals;
an inverter circuit having a pair of DC input terminals connected with the DC output terminals, thereby to provide the DC supply voltage across the DC input terminals;
the inverter circuit being operative to provide an AC output voltage at a pair of AC output terminals and being otherwise characterized by including:
(i) a first transistor having a first pair of transistor control terminals and a first pair of transistor output terminals;
(ii) a second transistor having a second pair of transistor control terminals and a second pair of transistor output terminals;
and (iii) a pair of intermediary terminals across which exists a voltage alternating periodically between a first voltage level and a second voltage level, spending a first part of each period at the first voltage level, a second part of each period at the second voltage level, and substantially no time at any other voltage levels;
the inverter circuit being further characterized by:
(a) causing the AC output voltage to be substantially sinusoidal;
(b) including a tank-inductor series-connected with a tank-capacitor to form an L-C circuit having a natural resonance frequency at or near the fundamental frequency of the AC output voltage;
(c) having a first auxiliary winding coupled with the tank-inductor, the first auxiliary winding having a first pair of auxiliary terminals across which exists a non-sinusoidal voltage of frequency equal to that of the AC output voltage;
and (d) having a first subcircuit connected between the first pair of auxiliary terminals and the first pair of transistor control terminals, the first sub-circuit being operative to provide a first control voltage to the first transistor control terminals, the first control voltage being characterized by alternating periodically between two voltage levels, spending substantially no time at any other voltage levels;
and
a first gas discharge lamp connected across the AC output terminals by way of a first current-limiting impedance.

11 more elements

An arrangement comprising:

a pre-conditioner circuit having a pair of power input terminals adapted to be connected with the AC power line voltage of an ordinary electric utility power line;
the pre-conditioner circuit, when indeed so connected, being operative to provide a DC supply voltage of substantially constant magnitude at a pair of DC output terminals;
an inverter circuit having a pair of DC input terminals connected with the DC output terminals, thereby to provide the DC supply voltage across the DC input terminals;
the inverter circuit being operative to provide an AC output voltage at a pair of AC output terminals and being otherwise characterized by including:
(i) a first transistor having a first pair of transistor control terminals and a first pair of transistor output terminals;
(ii) a second transistor having a second pair of transistor control terminals and a second pair of transistor output terminals;
and (iii) a pair of intermediary terminals across which exists a voltage alternating periodically between a first voltage level and a second voltage level, spending a first part of each period at the first voltage level, a second part of each period at the second voltage level, and substantially no time at any other voltage levels;
the inverter circuit being further characterized by:
(a) including a tank-inductor series-connected with a tank-capacitor to form an L-C circuit having a natural resonance frequency at or near the fundamental frequency of the AC output voltage;
(b) having a first auxiliary winding coupled with the tank-inductor, the first auxiliary winding having a first pair of auxiliary terminals;
(c) having a second auxiliary winding coupled with the tank-inductor, the second auxiliary winding having a second pair of auxiliary terminals;
(d) having a first sub-circuit connected between the first pair of auxiliary terminals and the first pair of transistor control terminals;
and (e) having a second sub-circuit connected between the second pair of auxiliary terminals and the second pair of transistor control terminals;
and
a first gas discharge lamp connected across the AC output terminals by way of a first current-limiting impedance.

12 more elements

An arrangement comprising:

a pre-conditioner circuit having a pair of power input terminals adapted to be connected with the AC power line voltage of an ordinary electric utility power line;
the pre-conditioner circuit, when indeed so connected, being operative to provide a DC supply voltage of substantially constant magnitude at a pair of DC output terminals;
an inverter circuit having a pair of DC input terminals connected with the DC output terminals, thereby to provide the DC supply voltage across the DC input terminals;
the inverter circuit being operative to provide an AC output voltage at a pair of AC output terminals and being otherwise characterized by including:
(i) a first transistor having a first pair of transistor control terminals and a first pair of transistor output terminals;
(ii) a second transistor having a second pair of transistor control terminals and a second pair of transistor output terminals;
and (iii) a pair of intermediary terminals across which exists a voltage alternating periodically between a first voltage level and a second voltage level, spending a first part of each period at the first voltage level, a second part of each period at the second voltage level, and substantially no time at any other voltage levels;
the inverter circuit being further characterized by:
(a) including an inductor through which an alternating inductor current is flowing;
(b) having a first auxiliary winding coupled with the inductor, the first auxiliary winding having a first pair of auxiliary terminals across which exists an alternating auxiliary voltage of frequency equal to that of the AC output voltage, the alternating auxiliary voltage having a waveshape substantially different from that of the alternating inductor current;
(c) having a first sub-circuit connected between the first pair of auxiliary terminals and the first pair of transistor control terminals, the first sub-circuit having a first pair of subterminals across which exists an alternating sub-circuit voltage having a waveshape substantially equal to that of the alternating inductor current;
and
a first gas discharge lamp connected across the AC output terminals by way of a first current-limiting impedance.

10 more elements

An arrangement comprising:

a pre-conditioner circuit having a pair of power input terminals adapted to be connected with the AC power line voltage of an ordinary electric utility power line;
the pre-conditioner circuit, when indeed so connected, being operative to provide a DC supply voltage of substantially constant magnitude at a pair of DC output terminals;
an inverter circuit having a pair of DC input terminals connected with the DC output terminals, thereby to provide the DC supply voltage across the DC input terminals;
the inverter circuit being operative to provide an AC output voltage at a pair of AC output terminals and being otherwise characterized by including:
(i) a first transistor having a first pair of transistor control terminals and a first pair of transistor output terminals;
(ii) a second transistor having a second pair of transistor control terminals and a second pair of transistor output terminals;
and (iii) a pair of intermediary terminals across which exists a voltage alternating periodically between a first voltage level and a second voltage level, spending a first part of each period at the first voltage level, a second part of each period at the second voltage level, and substantially no time at any other voltage levels;
the inverter circuit being further characterized by:
(a) including an inductor through which flows an alternating inductor current, each complete cycle of the inductor current having a substantially sinusoidal waveform starting at zero degrees and ending at 360 degrees, with zero degrees, 180 degrees, 360 degrees, etc. representing zero-crossings of the substantially sinusoidal current waveform;
(b) having a first control circuit operative to cause the first transistor to conduct current between its output terminals during each period extending between zero degrees and X degrees, where X is a number smaller than 180;
and (c) having a second control circuit operative to cause the second transistor to conduct current between its output terminals during each period extending between 180 degrees and Y degrees, where Y is a number larger than 180 but smaller than 360;
and
a first gas discharge lamp connected across the AC output terminals by way of a first current-limiting impedance.

10 more elements

An arrangement comprising:

a pre-conditioner circuit having a pair of power input terminals adapted to be connected with the AC power line voltage of an ordinary electric utility power line;
the pre-conditioner circuit, when indeed so connected, being operative to provide a DC supply voltage of substantially constant magnitude at a pair of DC output terminals;
an inverter circuit having a pair of DC input terminals connected with the DC output terminals, thereby to provide the DC supply voltage across the DC input terminals;
the inverter circuit being operative to provide an AC output voltage at a pair of AC output terminals and being otherwise characterized by including:
(i) a first transistor having a first pair of transistor control terminals and a first pair of transistor output terminals;
(ii) a second transistor having a second pair of transistor control terminals and a second pair of transistor output terminals;
and (iii) a pair of intermediary terminals across which exists a voltage alternating periodically between a first voltage level and a second voltage level, spending a first part of each period at the first voltage level, a second part of each period at the second voltage level, and substantially no time at any other voltage levels;
under at least under one stable operating condition, the inverter circuit being further characterized by:
(a) having an inverter output terminal connected with one of the first pair of transistor output terminals as well as with one of the second pair of transistor output terminals;
(b) being operative to cause a periodically alternating current to flow from the inverter output terminal;
the periodically alternating current having an instantaneous magnitude and a fundamental period;
each fundamental period being represented by a waveform divided into 360 equal time divisions;
the periodically alternating current flowing either between the first pair of transistor output terminals or between the second pair of transistor output terminals;
and (c) having a control circuit connected with the first pair of transistor control terminals as well as with the second pair of transistor control terminals;
the control circuit being operative such that, once during each complete fundamental period:
(i) at a first point in time, as the periodically alternating current is flowing between the first pair of transistor output terminals and has a first instantaneous magnitude, to cause abrupt cessation of flow of the periodically alternating current between the first pair of transistor output terminals, thereby to cause the periodically alternating current to be diverted so as to flow instead between the second pair of transistor output terminals, and (ii) at a second point in time, as the periodically alternating current is flowing between the second pair of transistor output terminals and has a second instantaneous magnitude, to cause abrupt cessation of flow of the periodically alternating current between the second pair of transistor output terminals, thereby to cause the periodically alternating current to be diverted so as to flow instead between the first pair of transistor output terminals;
the first instantaneous magnitude being substantially different from the second instantaneous magnitude;
and
a first gas discharge lamp connected across the AC output terminals by way of a first current-limiting impedance.

16 more elements

An arrangement comprising:

a pre-conditioner circuit having a pair of power input terminals adapted to be connected with the AC power line voltage of an ordinary electric utility power line;
the pre-conditioner circuit, when indeed so connected, being operative to provide a DC supply voltage of substantially constant magnitude at a pair of DC output terminals;
an inverter circuit having a pair of DC input terminals connected with the DC output terminals, thereby to provide the DC supply voltage across the DC input terminals;
the inverter circuit being operative to provide an AC output voltage at a pair of AC output terminals and being otherwise characterized by including:
(i) a first transistor having a first pair of transistor control terminals and a first pair of transistor output terminals;
(ii) a second transistor having a second pair of transistor control terminals and a second pair of transistor output terminals;
and (iii) a pair of intermediary terminals across which exists a voltage alternating periodically between a first voltage level and a second voltage level, spending a first part of each period at the first voltage level, a second part of each period at the second voltage level, and substantially no time at any other voltage levels;
under at least one steady-state operating condition, the inverter circuit being further characterized by:
(a) having an inverter output terminal connected with one of the first pair of transistor output terminals as well as with one of the second pair of transistor output terminals;
(b) being operative to cause a periodically alternating current to flow from the inverter output terminal;
the periodically alternating current having an absolute instantaneous magnitude and a fundamental period;
the alternating current flowing either between the first pair of transistor output terminals or between the second pair of transistor output terminals;
and (c) having a control circuit connected with the first pair of transistor control terminals as well as with the second pair of transistor control terminals;
the control circuit being operative such that, once during each complete fundamental period:
(i) at a first point in time, as the alternating current is flowing between the first pair of transistor output terminals and has a first instantaneous magnitude, to cause abrupt cessation of flow of the alternating current between the first pair of transistor output terminals, thereby to cause the alternating current to be diverted so as to flow instead between the second pair of transistor output terminals, and (ii) at a second point in time, as the alternating current is flowing between the second pair of transistor output terminals and has a second instantaneous magnitude, to cause abrupt cessation of flow of the alternating current between the second pair of transistor output terminals, thereby to cause the alternating current to be diverted so as to flow instead between the first pair of transistor output terminals;
the first instantaneous magnitude being substantially different from the second instantaneous magnitude;
and
a first gas discharge lamp connected across the AC output terminals by way of a first current-limiting impedance.

15 more elements

An arrangement comprising:

a pre-conditioner circuit having a pair of power input terminals adapted to be connected with the AC power line voltage of an ordinary electric utility power line;
the pre-conditioner circuit, when indeed so connected, being operative to provide a DC supply voltage of substantially constant magnitude at a pair of DC output terminals;
the pre-conditioner circuit being further characterized in that, for a brief period immediately following initial power up, the magnitude of the DC supply voltage is substantially higher than it is subsequent to said brief period;
the pre-conditioner circuit also being characterized by not having a transformer winding connected across the power input terminals;
an inverter circuit having a pair of DC input terminals connected with the DC output terminals, thereby to provide the DC supply voltage across the DC input terminals;
the inverter circuit being operative to provide an AC output voltage at a pair of AC output terminals and being otherwise characterized by including:
(i) a first transistor having a first pair of transistor control terminals and a first pair of transistor output terminals;
(ii) a second transistor having a second pair of transistor control terminals and a second pair of transistor output terminals;
and (iii) a pair of intermediary terminals across which exists a voltage alternating periodically between a first voltage level and a second voltage level, spending a first part of each period at the first voltage level, a second part of each period at the second voltage level, and substantially no time at any other voltage levels;
and
a first gas discharge lamp connected across the AC output terminals by way of a first current-limiting impedance.

8 more elements

Electronic ballast with pre-conditioner circuit

Life of this patent

Electronic ballast with pre-conditioner circuit

Life of this patent

Abstract

Claims39