MXPA99008531A - Ballast method and apparatus and coupling therefor - Google Patents

Abstract

A ballast is disclosed which can operate at an effective level of output with a number of different input voltage levels. A ballast is also disclosed that uses a ceramic (148) as a heat sink for switching transistors (144, 86, 96). A ballast is further disclosed which uses a start signal (48) for a power factor circuit (40) to boost voltage after the load for the ballast has already has a current applied to it. Furthermore, a ballast is disclosed which has a transformer (100) having a permeability which varies somewhat inversely with temperature over a given temperature range.

Description

METHOD AND BALLAST APPARATUS AND COUPLING FOR THE SAME I. BACKGROUND OF THE INVENTION A. Field of the Invention The present invention relates generally to ballasts for activating fluorescent lamps, and more specifically to methods and apparatus for activating fluorescent lamps and to methods and apparatus. to activate fluorescent lamps to connect ballasts to lamp circuits. B. Related Technology Many lighting systems, for example those using fluorescent lamps of sizes T10 and T12, use traditional coil and iron core ballasts. These types of ballasts are generally large and generate heat producing a poor energy efficiency. These ballasts tend to regulate their output poorly, especially with voltage fluctuations, often causing flickers in the light output. Improper output regulation that causes flicker reduces the quality of the lighting provided by the lighting system. When lighting systems are used in product display boxes, flickering causes lower quality lighting and generally causes irritation for people. In low temperature applications, such as in refrigerated display cases, conventional ballasts placed inside the freezer, for example, cause greater consumption of Energy. If the ballast is placed outside the freezer, the reliability of the ballast is reduced. Additionally, said conventional ballasts are commonly large in size and difficult to pack, transport and install in the limited spaces provided by said display boxes. Lighting systems generally have on-off cycles, such as between times when a store is open and when the store is closed. Commonly, the start of a lighting system applies full voltage to the lamp immediately. This fully on condition places a significant load on the cathode of the lamp, especially when the cathode is at the temperature of a refrigerated display case. This temperature can be either in a refrigerator or in a freezer, the refrigerator operates at less than 10 ° Celsius and the freezer operates at less than -10 ° Celsius. This heavy load on the cold cathode produces a significantly reduced lamp life, and therefore higher operating costs. Although some ballasts can operate at a higher activation frequency and a higher activation voltage for the lamp, said higher voltage and frequency produce significant heat and require significant heat dissipation of the ballasts. Due to the heat generated, a greater number of faults can occur if the parts wear out prematurely. Most ballasts have limited ranges of application. If a ballast is for a line configuration, such as in the United States of 220 volts and 60 Hertz, or in accordance with the European Convention of 220 volts at 50 Hertz, different ballasts are currently supplied in accordance with the required convention. Consequently, large inventories are required to accommodate variations in requirements, and the operation of any given ballast is generally affected by variations in line voltage, such as occurs during normal operation. In refrigeration boxes, fluctuations in line voltage frequently occur due to the start and stop of compressors and other equipment. These fluctuations cause flickering of the lamp or other non-uniform light output with a concurrent effect on the person. These effects resulting from the use of conventional ballasts cause shorter lamp lives, deficiencies in operation, and possibly greater ballast failure. Therefore, improvements can be made in the design and operation of ballasts. BRIEF DESCRIPTION OF THE INVENTION A ballast is provided that improves the efficiency and operation of the ballast, improves the life of the lamp and is more versatile than conventional ballasts. In one form of the invention, a ballast is provided to activate a light source having an input circuit and an output circuit for activating the light source. In one form of the invention, an operating circuit for the input circuit is provided to allow accepting Input voltages of significantly different values. For example, the ballast can operate at voltages of 1 10 and 220 volts. The ballast can also operate efficiently and provide the desired light output regardless of over voltages and other anomalies in the signal provided to the input circuit. In another preferred form of the invention, the ballast includes a transformer having a permeability value that varies as a function of temperature. Preferably, the permeability value of the transformer is higher at at least some temperatures below zero degrees Celsius, than at some temperatures above 20 ° Celsius. For example, the permeability of the transformer core may be greater between minus 60 and 0 ° Celsius than between 20 ° Celsius at 100 ° Celsius. This core configuration allows for more efficient and reliable operation at lower temperatures while maintaining efficient and reliable operation at other temperatures. At some temperatures, the permeability of the core can be one and a half times that at higher temperatures. In a further form of the invention, the switching transistors used in the ballast circuit are mounted on an efficient and reliable heat sink to more effectively dissipate the heat generated in the switching transistors. Preferably, the heat sink is a ceramic material having a relatively high purification, without any magnetically or iron inducible element. A heat sink of this The type allows operation at relatively high frequencies, which in some cases are more efficient for the light sources that are being used. In a further form of the invention, the transformer may be insulated for example with epoxy around the core and the windings of the transformer may have an insulation value of at least 100 ° Celsius, and preferably 200 ° Celsius. At higher frequencies, and during operation under some conditions, the heat generated in the transformer may be greater than 100 ° Celsius. Therefore, isolated windings should have insulation values capable of withstanding significantly higher temperatures. In a further form of the invention, the ballast includes a power circuit for providing a signal to the light source at a desired voltage, an activating circuit for producing an oscillatory signal for activating the light source at the voltage provided by the power circuit. energy, an output circuit for coupling the oscillatory signal to the light source, and a signal element for increasing the operating voltage after the start. In a preferred embodiment, the signal elements are configured to maintain the operating voltage at the start lower than during normal operation, while the operating voltage is subsequently increased once the lamp has been illuminated. This signal element allows a cold start by applying a relatively low voltage to the cathode of the lamp under cold conditions and subsequently increase the voltage applied to the cathode once the lamp has been illuminated. As a result, the higher operating voltage does not apply to the cathode until the moment the cathode has warmed up in some way. It is believed that this cold start operation will increase the life of the lamp, especially during operation in cold environments. In one form of the invention, the signal element takes the form of a feedback coupling of the lamp activating circuit to the energy circuit used to increase the voltage applied to the light sources. In another form of the invention, a connection configuration is provided to allow the retroactive modification of conventional ballast circuits with the new design. These and other aspects of the invention will be readily understood by considering the drawings, a brief description of which is provided below, and of the detailed description of the preferred embodiments. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view and front elevation of a refrigerated display case, which represents an application for the ballast circuit of the present invention. Figure 2 is a partial sectional view and upper plan view of part of the refrigerated display box of Figure 1 showing a part of a lighting system for illuminating product on display in shelves in the display case.

Figure 3 is a schematic block diagram of the ballast in accordance with one aspect of the present invention. Figure 4 is a schematic block diagram of an energy circuit and lamp activator circuit in accordance with an aspect of the present invention. Figure 5 is a detailed circuit diagram showing the ballast circuit in accordance with one aspect of the present invention. Figure 6 is a schematic drawing showing a heat sink and transistors mounted on a printed circuit board in accordance with an aspect of the present invention. Figure 7 is an elevational view of the ceramic and switching transistors mounted to the ceramic according to one aspect of the present invention. Figure 8 is a drawing showing the transformer for the activating circuit in accordance with an aspect of the present invention. Figure 9 is a curve showing the permeability of the transformer core of Figure 8, in accordance with one aspect of the present invention. Figure 10A-C shows connection circuits and a circuit in Figure 10C for modernizing the ballast according to the present invention in circuits using ballasts with seven (7) output connectors. DETAILED DESCRIPTION OF THE PREFERRED MODALITIES A ballast according to the present invention is described which provides a more efficient and reliable operation. The ballast can accept different input voltages and provide consistent output, for example, to activate a lighting system. The output provided is a constant signal even with variations in the input signal voltage. The ballast is more reliable even at higher operating frequencies where significant heat occurs during normal operation. The ballast also effectively operates at reduced ambient temperatures, such as can occur in refrigerated display cases, even at temperatures below 0 ° C. In accordance with one aspect of the present invention, the ballast can be used in a refrigerated display box 20 which commonly includes doors 22 placed in a surrounding structure 24 for housing product (not shown) displayed on shelves 26. Said display boxes are Commonly found in grocery stores, convenience markets and the like. As shown in Figure 2, the display case would include a lighting system 28 for illuminating product stored on the shelves 26 for display. Customers can access and withdraw product through the doors 22 (shown schematically in Figure 2). The lighting system commonly includes a light source 30, such as a fluorescent lamp having a cathode, an anode, and a discharge gas contained in the tube between the cathode and the anode. A ballast 32 may be placed within a shelf 34, or elsewhere in the box to activate the fluorescent lamps. The ballast may be wired in the conventional manner, or it may be upgraded to seven (7) existing wire systems, as described more fully below. The ballast according to one aspect of the present invention includes a lamp output circuit 36, a lamp activator circuit 38 and an energy circuit 40 for activating the lamp or lamps in the desired manner, as described more fully. complete below. (See Figure 3). The lamp output circuit is a conventional circuit that includes the inductors 42 and the capacitors 44, and wherein the inductors 42 are wound in such a way as to provide the desired wattage for the lighting system, given the selected value of the capacitor 46. The capacitor 46 is selected to be a relatively large capacitor, such as 0.33 for microfarads, to be used with different values of inductors 42, in accordance with the desired power output in watts. For example, if the ballast is to operate at 30 watts, the inductors 42 are configured to produce the desired power output in watts according to the selected capacitor 46. Similarly, with respect to other powers in output watts, for example 40 and 70 watts. The trigger circuit 38 produces an oscillatory signal to activate the lamps at the desired frequency, and also provides - a signal output to the power circuit 40 to indicate when the lamp or lamps have begun to be illuminated by the rest of the ballast circuit. The signal from the trigger circuit can be considered a boost signal to indicate to the power circuit 5 that the voltage level for activating the lamps can be increased to the standard operating voltage. The reinforcing signal element is shown at 48 in Figure 3. The energy circuit 40 produces a signal at the desired voltage, preferably 360 volts, to activate the output circuit of the lamp. The power circuit 40 takes a direct current voltage signal from a bridge rectifier 50 (Figure 3) which produces an output voltage based on an AC input received from a line filter 52 connected to an AC input 54 and a line protection circuit such as a fuse or a circuit breaker. (See Figure 5). The line filter 52 includes an inductor transformer T1 56 and a capacitor Cx 58 to reduce or remove any electromagnetic interference that may be present in the incoming line voltage. As shown in Figure 3, the ballast of the present invention is capable of accepting input signals of various voltages, including from 95 volts to 227 volts and provide an appropriate output to activate the lamps in the desired manner. A transformer T2 60 includes a primary winding 62 and a secondary winding 64. The transformer T2 60 is an amplifier voltage controlled by the power correction circuit 64 and by the operation of an energy switching transistor, described more fully below. The primary winding 62 for the voltage signal of the rectifier 50 to the output circuit of the lamp through the diode D2 76 and to the lamp activating circuit for lighting the lamps. After the ignition, the transformer 60 increases the voltage applied to the lamps to 360 volts as desired. The output of the diode 76 is coupled to the positive side of the capacitor C 12 78, the other side of which is coupled to ground, and to one side of the capacitor C14 80, whose other side is coupled to a leg 82 and 84 of the first and second lamp, respectively. The output of the diode 76 is also coupled to the drain of a switching transistor Q2 86 to produce an oscillating signal to activate the lamps. The voltage signal of the diode 76 is also coupled to one side of the resistor R21 88, the other side of which is connected to the input of a diode D3 90 and to earth through the resistor R22 and through a capacitor C 13 94 as shown, to start the lamp circuit, as described more fully below. The other side of the resistor 88 is also coupled to a diode 91, whose output is coupled to the drain of the power switching transistor Q3 96 and the tertiary windings 98 of the transformer T3 100. The other side of the tertiary windings 98 is coupled to the input of the inductors 42 in the lamp output circuit to activate the output circuit for the lamps. The output of diode 91 is also coupled to one side of secondary windings 102 of transformer 100. The output of diode 91 is also coupled to resistor R 1 1 104 in the reinforcing signal element 48. The other side of resistor 104 is coupled to the port Current detection I I DET of U 1 to indicate to the power factor circuit that current and voltage are being applied to the lamp circuit. The signal represents an indication to the energy factor circuit 64 to increase the voltage that is being applied to the lamp circuit to the optimum voltage for the lamp circuit. The delay provided between the first reception of a voltage signal from the bridge rectifier circuit and the time when a resistor signal is received from the resistor R 1 1 allows a cold start of the lamps and a voltage lower than the operating voltage. normal provided by the ballast circuit. Thus, the full operating voltage of the ballast does not apply to the lamps until such time as the cathodes of the lamps can be ignited and heated slowly, thus minimizing any undue stress on the cathode until some heating can occur. Subsequently, the full voltage can be applied to the lamp circuits. This sequence should improve the life time of the lamp. One side of the secondary 64 of the boost transformer 60 is also coupled to the detection input of the energy factor circuit 64 through a resistor R 10 108. The resistor 108 maintains the energy factor circuit operating after the Reinforcement signal is received from the activating circuit. The other side of the secondary windings 102 of the transformer 100 is coupled through the resistor R16 110 to the gate of the switching transistor 86. A zener diode D4 112 is connected through the source of the switching transistor 86 and the gate of the transistor 86. The primary windings 114 have one side connected to ground and the other side connected to the gate of the switching transistor 96 through the resistor R17 116. The resistors 110 and 116 are resistors of positive temperature coefficient used as resistors for activation of the gate of the power switching transistor. They reduce the resistance at low temperature and increase the resistance at high temperature. At low temperature, the decrease in resistance of the resistors 110 and 116 allows the lamps to produce more output, thus improving the light output. When the temperature of the lamp increases to its normal operating temperature, the resistors 110 and 116 increase their resistance by heating themselves, and the output energy of the ballast returns to its normal operating level. The switching transistor 96 has its source coupled to ground, and a zener diode D5 118 is coupled between ground and the gate of the switching transistor 96. The diode D3 90 is also coupled between the gate of the switching transistor 96 and the capacitor 94. The zener diodes 112 and 118 protect the floodgates of the power switching transistors 86 and 96 of voltage ends. The zener diodes 1 12 and 18 and the resistors 1 10 and 16 serve as a load resistor in the transformer to eliminate high-frequency parasitic oscillations and to stabilize the output waveforms at the resonant frequency of the load circuit . Part of the lamp activating circuit is a half-bridge self-resonant converter 120 (see also Figure 4) for converting the incoming voltage to an oscillatory signal, and includes power switching transistors 86 and 96. Resistors R21, R22 , 88 and 92, respectively, and capacitor C13 94 form a start charging circuit that reaches the 35 volt breakpoint of diode 90 in about half a second after the power is applied. The diode 90 starts to conduct, producing a pulse of positive ignition voltage applied to the gate of the switching transistor 96. With the switching transistor 96 on, the drain voltage of the switching transistor 96 is rapidly switched to ground, thus initiating the oscillation of the circuit. When the switching transistor 96 reaches saturation, any remaining charge on the capacitor 94 is discharged through the diode 91, thus preventing any further generation of start pulses. The polarities of the transformer 100 are selected such that any AC load applied to the half-bridge self-resonant converter 120 as an AC output will be activated by a square wave. of voltage, and the load current flowing through the primary of the energizing transformer 100 will produce the gate activation voltages for the power switching transistors 86 and 96, causing the circuit to oscillate. The transformer 100 operates as a current transformer to produce the gate activation voltages, but the resulting waveforms have relatively poor rise and fall times since they are proportional to the sinusoidal load current in the converter 120. Relatively poor rise and fall of the secondary and tertiary windings provide downtime to avoid potential damage to power switching transistors 86 and 96 that could be caused by their simultaneous operation at high frequency. The lamp activating circuit 38 produces an oscillatory signal (80kHz) to the lamp output circuit. The transformer 100, together with the inductors 42 and the capacitors 44, ensures that the output of the signals to the lamps are in phase. The diode 90 provides a trigger signal to initiate the oscillations in the lamp activating circuit, and the capacitor 94 filters low frequency signals. The diode 91 removes the operating diode 90 by passing current from the resistor 1 16 through the diode 91. Once the converter circuit 120 is started, the activating circuit takes the direct current voltage signal from the power circuit 40 and produces the oscillatory signal to activate the lamps. The current through the tertiary windings 98 and the transformer 100 and through the inductors 42 produces the high voltage at the output of the lamps. The current through the tertiary windings induces current in the secondary windings 102 to load the gate into the switching transistor 86, which then changes the current direction through the inductors 42 with base at the time the load was loaded. switching transistor 96. The gate for the switching transistor 96 was originally charged with the current through the diode 90 and passing through the primary 1 14. The current through the output circuit of the lamp through the capacitors 80 and 44, through the lamps and back to the inductors 42 to the tertiary windings 98, and through the drain of the switching transistor 96 to relatively ground through the source, produces the first half cycle of an activation signal. (Once started, the capacitors have little effect on the circuit). In the next half cycle, the capacitor 80 is fully charged and induces current in the secondary windings 102, also through the tertiary windings 98, and loads the gate of the switching transistor 86 through the gate activator resistor 1 10. Then , the switching transistor 86 is turned on by the current through the transistor 96, inducing current in the secondary 102, causing the capacitor 80 to discharge through the switching transistor 86 through the tertiary windings 98 and the output circuits of the lamps. Diodes 1 12 and 18 provide protection from gate for switching transistors 86 and 96. When detecting current in inductors 42 and capacitors 44, and in the lamps, the activation circuit is forced to operate with the output voltage and current in phase. Phase operation ensures optimal operation of the power switching transistors and minimizes switching losses. In the case where the alternating current load contains a resonant circuit in series with the capacitor 80 and the inductors 42 and the lamp, the waveform of the lamp voltage will be a sine wave. After the lamp starts the electric arc voltage determines the voltage - charge tuning of the capacitor. Since the Q value of the tuned circuit is greatly reduced by the lamp load, and after the lamp is started, the resonant current decreases so that in normal operation the lamp approaches an alternating voltage load of constant voltage activated by a series inductor to provide a function that limits the current. The circuit is resonant as determined by the sinusoidal voltage of the lamp. The design of the resonant ballast maintains the light output for a longer time for any given lamp life by providing additional lamp voltage to the lamps to reduce any normal wear that would commonly reduce the output of the lamp. As a result, lamp replacement is required less frequently. Considering the energy circuit 40 in more detail with respect to Figure 5, the resistor R 1 122, and the resistor R2 124 they form a voltage divider for input to an energy factor circuit U 1 126. The resistor R3 128, the capacitors C5 130 and C6 132 provide a voltage supply input to the power factor circuit 64. A primary function of the Power bank 40 is to provide correction of the power factor, and also allows operation at a number of input voltages in order to produce an output of 360 volts constantly. The voltage input signal for the power circuit 40 is filtered by the capacitor C5 130 through the resistor 128, which provides a voltage drop. Once the power circuit is turned on, the voltage of the power factor circuit is no longer provided through the resistor R3, but is received through the secondary 60 transformer 60, the switching diode D1 134 and the capacitor 130. The input voltage VI N is provided by the resistors 122 and 124 as a voltage divider network to provide a signal to the power factor circuit as a function of ballast voltage input. The secondary circuit of the transformer 60 synchronizes the waveform and phase with the supply voltage supplied to the input of the power circuit 40. The voltage divided by the resistors R5 and R6, 136 and 138, respectively, is provided at the input inverted of the energy factor circuit 40, which is an error amplifier circuit. The power factor circuit 126 monitors the voltage signal applied to the inverted input and increases the output voltage of the boost transformer if the voltage level detected in the inverted input is low, and increases it to a lesser degree if the input is greater. The voltage signals applied to the voltage input, and the inverted input, control the peak current of the inductor in the transformer T2 60 by turning off the transistor Q 1 at a minimum level. That minimum level is determined by the voltage detected in the resistor R14 140, whose voltage is provided through the resistor R13 142 to the CS input to the power circuit 40. Reaching the minimum level causes the power switching transistor Q1 144 Disconnect until the current in the transformer inductor 60 drops to zero. Subsequently, the secondary winding of the boost transformer 60 changes its voltage polarity and the transition is detected by a step of the internal comparator in the power factor circuit 126. The polarity of the windings in the transformer 60 is selected so that the Low current signals turn on the power transistor Q1 144 and maintain the operation until the process repeats. The power switching transistor Q 1 144 provides approximately 99% power factor and also a multiple voltage capability. The transistor operates with the greatest effect at lower voltages and with less effect at higher voltages. An external trip voltage is applied to the input of I DET as described herein. The energy factor circuit 126 increases the voltage approximately two to three times the input voltage. By delaying the increase in voltage until after the external trip voltage is applied, for example, after the lamp is turned on, the voltage at the cathode of the lamp will be reduced since the output voltage is reduced by more than fifteen% . The inputs to the VI N, to the inverted input, and to the input of the trigger signal to the IDET, control the power factor circuit 126. The output voltage of the power factor circuit 126, which comes from VO, is rectified by switching diode 76 and filtered by capacitor C12 78 and then supplied to the lamp output through the lamp activating circuit. Transformer 100 is provided by ISU Ceramics Co., Ltd. of Seoul, South Korea. The transformer is formed and produced with titanium and tin to increase the permeability of the core at low temperatures, and large amounts of ferrous oxide are provided to increase the permeability at low temperatures as well. The core is produced to have the permeability curve shown in Figure 9, preferably having the positive and negative inclinations as shown in Figure 9 between -60 ° and 20 ° C, but can also be flat between -60 ° C. and -30 ° C as also shown. The transformer is configured to have five turns in the primary winding, five turns in the secondary winding and one turn in the tertiary winding. All windings are at 600 volts and with 28 gauge wire insulated up to 200 ° Celsius. Low In many circumstances, the transformer may not have to be isolated, but at higher energy outputs, it is preferred to isolate the transformer with epoxy around the core and with wire insulation up to 200 °. The ballast circuit is provided on a printed circuit board 146 that includes a ceramic heat dissipation isolator 148 to which the power switching transistors 144 are mounted., 86 and 96 (Q1, Q2 and Q3) (see Figure 6). The ceramic is preferably a ceramic without iron, without any impurity, and without any magnetizable or magnetically inducible element. The power switching transistors produce significant heat that is more easily dissipated by ceramic 148. Each power switching transistor is bonded to the ceramic plate by two-point welding joints in the ceramic at joint locations coated with a layer of copper, or alternatively and preferably bonded by an epoxy thermal conductive glue 150, commonly used for heat sinks and the like. The ceramic is preferably mounted to the printed circuit board at an angle of 75 ° so that there is sufficient space between the board and the wall of the small ballast containers to flow the ceramic, minimizing the creation of voids. The circuit board and the ceramic tape or plate are inserted into a rectangular aluminum can or container 152 and encapsulated in asphalt, in the conventional manner. However, the fill can be added in increments, such as the first third, the second third and then the last third, allowing each amount to settle and possibly cool a bit before adding the next section. Asphalt helps heat dissipation. The ceramic is preferably a Kyocera substrate ribbon, material code A-473T. The size of the plate or tape can be 2.03 cm by 6.86 cm, with the transistors mounted with a center-to-center separation of 2.16 cm. Figure 10A shows a configuration for connecting the ballast of the present invention. Figure 10b shows a connection method for a pre-existing 7-wire ballast, and Figure 10C shows a method for connecting the ballast of the present invention to the boxes in which the current 7-wire ballast is connected. Figure 10C demonstrates that the ballast of the present invention can be replaced or modernized in the boxes currently designed and containing a 7-wire ballast. Specifically, one anode side of each lamp is commonly connected and coupled to an orange wire and a red wire of the ballast circuit. It should be noted that the above are preferred configurations but others are considered. The described embodiments of the invention are considered only as preferred and illustrative of the concept of the invention; the scope of the invention is not limited to said modalities. Those skilled in the art can contemplate various and numerous configurations without departing from the spirit and scope of the invention.

Claims (29)

1. REVIVAL NAMES 1. A ballast for activating a fluorescent light source, the ballast comprises: an input circuit; an exit circuit; a ceramic plate; and an activating circuit that includes transistors between the input and output circuits mounted on the ceramic plate.
2. 2. The ballast of claim 1, wherein the ceramic is a ceramic of low iron content.
3. 3. The ballast of claim 1 further comprising a container containing the ballast and pad circuit for the ballast circuit.
4. 4. The ballast of claim 1, wherein the ceramic includes an epoxy material between the transistors and the ceramic.
5. The ballast of claim 1, wherein the ceramic includes a copper foil between the transistors and the ceramic.
6. 6. The ballast of claim 5, wherein the ceramic includes an epoxy material between the transistors and the ceramic.
7. 7. A ballast circuit for activating a fluorescent light source, the ballast comprising: an input circuit; u an output circuit; and a transformer that has a higher permeability value at a temperature below zero degrees Celsius than a permeability above twenty degrees Celsius.
8. The ballast circuit of claim 7, wherein the transformer is wound with wires having an insulation value of at least 100 degrees Celsius.
9. 9. The ballast circuit of claim 7, wherein the wires for the transformer are insulated with an insulation value of about 200 degrees Celsius.
10. 10. A ballast circuit to activate a fluorescent light source, the ballast comprises: an input circuit; an exit circuit; and means for operating at a number of different voltages greater than about 20 volts difference. eleven .
11. The ballast circuit of claim 10 wherein the operating means includes a switching transistor.
12. The ballast circuit of claim 1 wherein the switching transistor includes a power switching transistor coupled to a side of a transformer.
13. 13. The ballast circuit of claim 1 1 further comprising means for turning off the transistor at a minimum level voltage.
14. 14. A ballast circuit for activating a fluorescent light source, the ballast comprising: an input circuit; an exit circuit; Y at least three transistors to operate the ballast at voltages that include at least 1 10 volts and 220 volts.
15. 15. The ballast circuit of claim 14, wherein the transistors are power switching transistors.
16. 16. The ballast circuit of claim 14, wherein one of the transistors includes an energy switching transistor coupled to one side of the transformer.
17. 17. The ballast circuit of claim 14, further including an energy factor correction circuit.
18. The ballast circuit of claim 17, further including a trip voltage input to the power factor correction circuit for increasing the output voltage of the power factor correction circuit.
19. 19. The ballast circuit of claim 18 further comprising a transformer and turning off the transistor to provide a tripping voltage to the tripping voltage input of the power factor correction circuit as a function of an energizing circuit.
20. 20. A ballast circuit for activating a fluorescent light source, the ballast comprising: an input circuit; an exit circuit; and means for increasing the operating voltage after the start. twenty-one .
21. The ballast circuit of claim 20, which it additionally includes a power factor correction circuit and a trigger voltage input to accept a d ispair voltage.
22. 22. The ballast circuit of claim 21 additionally comprising a transformer and a transistor shutdown socket for providing the tripping voltage to the tripping voltage input of the power factor correction circuit as a function. of an activating circuit.
23. 23. The ballast circuit of claim 22 which further comprises an activating circuit for activating a lamp, wherein the ballast circuit includes an output circuit coupled between the drive circuit and the power factor correction circuit to produce a trip voltage to the power factor correction circuit.
24. 24. A ballast circuit for activating a fl uorescent light source, the ballast comprises: an input circuit; an energy circuit for providing the oscillatory signal to the light source at a desired voltage; u an activating circuit to produce an oscillatory signal to activate the light source; an output circuit for coupling the oscillatory signal to the light source; and a signal element to reduce the operating voltage at the start of the ballast and to increase the operating voltage after of the beginning.
25. 25. The ballast circuit of claim 24, wherein the signal element is a feedback coupling to the power circuit to indicate when the light sources have been illuminated.
26. 26. The ballast circuit of claim 24, wherein the signal element is a feedback coupling to the power circuit to indicate when the light sources have begun to oscillate.
27. 27. A method of activating a fluorescent light source, the method comprising the steps of: providing a voltage to an input circuit; produce an oscillatory signal for application to an output to activate the light source; produce an oscillatory signal at the output to a first voltage; and producing an oscillatory signal to activate the light source at a second voltage after producing the signal at the first voltage.
28. The method of claim 27 further comprising the step of feeding back to a power factor correction circuit a signal to produce a change in a voltage produced by the power factor correction circuit.
29. 29. The method of claim 28 further comprising the step of increasing the voltage output by the power factor correction circuit as a result of receiving the feedback.