Abstract: A power supply device is utilized for providing operating voltages to circuits of various processes. Said power supply device provides a direct couple path whenever the voltage supply level of a corresponding battery enters into a domain of an operating voltage of a circuit. When the voltage provided by the battery is higher than an ideal operating voltage domain of the circuit, said power supply device utilizes a conventional transformer to supply a required voltage for said circuit. However, when the voltage provided by the battery enters the ideal operating voltage region, the power supply device provides a direct couple path for enabling said battery to directly supply a required voltage for said circuit other than supplying the required voltage by transformation of said transformer. By this mechanism, power consumption generated by the conventional transformer is saved, and related voltage utilization efficiency is enhanced.

Abstract: A power equipment includes a first internal abnormality detection apparatus comprising a first antenna accommodation pipe which is connected to a first connection pipe formed in a enclosed container and which accommodates a first antenna therein, and a first signal detection circuit which is connected to a first antenna and which detects an electromagnetic wave signal emitted when any abnormality has occurred within the enclosed container.

Abstract: A device for preventing the explosion of an electric transformer equipped with a tank filled with combustible coolant fluid, includes a pressure relief element to decompress the tank, a reservoir arranged downstream of the pressure relief element and at least one stopper valve on the reservoir such that the reservoir is hermetic in order to collect a fluid that passes through the pressure relief element.

Abstract: The present disclosure provides a wildlife guard for electrical power equipment including a disc having a central opening for fitting onto the equipment. The disc includes an electrically insulating material with a conductive filler material in quantity sufficient for the disc to maintain an electrostatic charge. The disc has an insertion slot extending from an outer portion to the central opening for movement of the disc onto the equipment. The present disclosure also provides a wildlife guard for an electrical insulator bushing having an electrical conductor extending outwardly therefrom. The wildlife guard includes an electrically nonconductive cover for covering at least a portion of the electrical conductor, the cover being adapted to mount upon the bushing and a conductive panel attached to the cover.

Abstract: An iron core transformer with at least one primary winding and at least one secondary winding of which at least one of the windings are wound with aluminum wire is disclosed for use in relatively low power applications, for example 5 kVa or below. The primary and secondary windings are connected to primary and secondary terminals. In order to overcome the effects of oxidation of the aluminum wire over time which can result in compromising the connection between the aluminum wire and its corresponding terminal, the terminals are formed as insulation displacement type terminals that are configured to strip any coatings or other contaminants on the aluminum wire during insertion of the aluminum wire into the terminal. The terminals are further configured to apply a constant spring biasing force against the aluminum conductor after it has been inserted.

Abstract: A discharge tube lighting apparatus is used to drive a plurality of discharge tubes. The apparatus includes a balance coil having a winding input end and a plurality of winding output ends to which the discharge tubes are connected individually; a power section for supplying ac current to the winding input end of the balance coil; and a control section for detecting a peak value of detection voltages corresponding to voltages at the winding output ends of the balance coil and for stopping the supply of the ac current from the power section when the peak value of the detection voltages is higher than a predetermined value.

Abstract: An apparatus and methods for balancing current in multiple negative impedance gas discharge lamp loads. Embodiments advantageously include balancing transformer configurations that are relatively cost-effective, reliable, efficient, and good performing. Embodiments include configurations that are applicable to any number of gas discharge tubes, such as cold cathode fluorescent lamps. The balancing transformer configuration techniques permit a relatively small number of power inverters, such as one power inverter, to power multiple lamps in parallel. One embodiment of a balancing transformer includes a safety winding which can be used to protect the balancing transformer in the event of a lamp failure and can be used to provide an indication of a failed lamp.

Abstract: A power supply assembly for a lighting system is directly mountable onto a standard electrical junction box. The power supply circuit provides an electronically power limited output through multi-conductor power connectors. The power supply assembly is used as part of a lighting system. The power supply output is used to connect to luminaires using a multi-conductor cable having multi-conductor power connectors which mate with the multi-conductor power connectors on the power supply and luminaire. The luminaires use a circuit to interface between the power supply output and the lamp.

Abstract: A method and means for diagnosing transformer tap changers is provided. Pressure is monitored in an insulating liquid of a tap changer for a period of time in which switching of the tap changer is carried through. Switching-related information is extracted from the pressure diagram. Quantities from pressure peaks are related to specific arcings of the switching sequence. Early error detection is achieved, whereby transformed failures may be avoided. Repeated measurements may be followed by trend evaluation. If a trend indicating tap changer problems is detected, an alarm signal is triggered. The transformer may be switched off if the pressure exceeds a predetermined emergency value. Information of the base pressure in the tap changer may be extracted and converting it to level of insulating liquid.

Abstract: The present invention relates to a high-efficiency controller of a gas-filled light producing tube; the controller can produce signals in a form of outputs of high-frequency sine wave to soft-start a gas-filled light producing tube according to the principle of modulation and oscillation of pulse (P.W.M.) so that the gas-filled tube produces light, and that service light of the gas-filled tube can be lengthened. If abnormal conditions happen, e.g. people's touching the gas-filled tube, and the tube breaking, the controller will make the transformer stop working immediately, preventing sparks from being produced to hurt people, making the gas-filled light producing tube safe to use.

Abstract: A power transformer/inductor includes at least one winding. The winding is made of a high voltage cable that includes an electric conductor, and around the electric conductor is arranged a first semiconducting layer, around the first semiconducting layer is an insulating layer, and around the insulating layer is a second semiconducting layer. The second semiconducting layer is directly earthed at both ends of the winding and furthermore at least at two points per turn of every winding such that one or more points are indirectly earthed.

Abstract: A microtransformer for a high-performance system-on-chip power supply is disclosed. Through-wafer openings in a substrate allow the primary and secondary wiring on both surfaces of the silicon substrate. An insulating silicon oxide layer is first deposited on all surfaces of the substrate. A magnetic film is further deposited on the silicon oxide layer followed by the application of another insulating layer. Coils are fabricated next by patterned deposition on both sides of the substrate and through the holes. The coils can be, e.g., single coils or primary or secondary coils of a transformer structure, with secondary having one or more output taps to supply different output voltages. For better flux closure, various magnetic layers and insulators can be deposited on top of the windings.

Abstract: A testing device is operative to sense or monitor a radiated field emitted by an igniter for heating equipment such as an oil burner and to indicate the detection corresponding to a normal operating state of the igniter.

Abstract: Disclosed is a relaying method for protecting a transformer by using a difference of current. A decision function, related to the rate of change of a primary current, a secondary current, or a differential current, is used for determining whether a detected abnormal current is due to the inrush or internal fault.

Abstract: The present invention provides magnetic structure, particularly an isolation transformer, which includes a shield to prevent radiation of electromagnetic interference (“EMI”). The magnetic structure includes a support structure, or bobbin, on which are mounted windings formed from electrical conductors. The windings are electrically connected to termination points, which provide the electrical interconnections for the magnetic structure. A magnetic core can be included in the support structure to provide optimal magnetic properties to the device. An EMI shield formed from a metallic foil such as copper is wrapped around the winding to prevent the radiation of EMI. The EMI shield is connected to a shield pin in the support structure by a conductive strap such that the shield pin is electrically connectable to a fixed potential through a safety rated capacitor to provide a low impedance path for currents induced in the EMI shield.

Abstract: An RF shielded enclosure that is configurable for a variety of testing requirements, yet still maintain proper RF isolation. User-installable modules that are specialized for the desired interface, ventilation or monitoring use can be installed on the enclosure to allow interfacing between a device under test installed inside the chamber and testing and controlling equipment outside the enclosure. The enclosure is easy to manufacture as a one or multi-chamber enclosure, allowing further flexibility for testing.

Abstract: The distribution transformer is installed in a station having N phases, at least N-1 phases being equipped on the high-voltage side of the transformer with respective current-limiting fuses capable of blowing in the event of a dead short circuit between the phases. The protection system includes: at least one fault detector for detecting faults on the basis of at least one of the following indicators: pressure in the tank, level of the dielectric, or temperature of the transformer; a short-circuiter acting on all the phases situated upstream from the high-voltage windings, said short-circuiter being capable of being triggered by said fault detector to establish a dead short circuit between the phases; and on at least N-1 phases, a detector for detecting an abnormal current upstream from the transformer, said detector being associated with a controller for controlling said short-circuiter.

Abstract: The invention relates to a planar inductive component (11) comprising at least a first and a second concentric inductor, which include a first and a second spiral pattern (12A, 12B), respectively. Both spiral patterns have a first end point (13A, 13B) and a second end point (14A, 14B), are electrically interconnected, interlaced, and interrupted at the outer side, and provided with two contacts (16A, 16B) on one side of the opening (15A, 15B) and two contacts (17A, 17B) on the other side of the opening (15A, 15B). By interconnecting the first two contacts (16A, 16B) and the second two contacts (17A, 17B), respectively, both spiral patterns are connected in parallel. The spiral patterns (12A, 12B), which are magnetically coupled, have identical electrical and magnetic properties. This leads to a reduction of eddy current losses at high frequencies. This results in a planar inductive component (11) which is suitable for high-frequency operation with a high maximum quality factor Q.

Abstract: A method for controlling a power level supplied to a load by an auxiliary output of a power source is presented. The method includes providing a power source having a user-adjustable main output and an auxiliary output. The method further includes providing a controller that is operative to control the level of the auxiliary output, the controller having at least supply and programming modes of operation. The method still further includes selecting the programming mode and adjusting the power level of the auxiliary output to a desired level while in the programming mode, thereby defining a programmed desired level. The method yet still further includes storing the programmed desired level in the controller, and then controlling the auxiliary output to the programmed desired level while operating the power source in the supply mode. The method further includes delivering power to the load in accordance with the stored desired power level.

Abstract: Device for prevention against explosion of an electrical transformer comprising an enclosure filled with combustible coolant, and a means for decompressing the enclosure of the transformer. The decompression means comprises a rupture element 1 with integrated explosion detector provided with a retention part 4 including first zones which have a reduced thickness in comparison with the rest of the retention part 4 and are capable of tearing without fragmenting when the said element 1 ruptures, and second zones which have reduced thickness in comparison with the rest of the retention part 4 and are capable of folding without tearing when the said element 1 ruptures. The said rupture element 1 is capable of breaking when the pressure inside the enclosure exceeds a predetermined ceiling. The signal from an explosion detector integrated with the rupture disc triggers a cooling system and prevents oxygen from coming into contact with the explosive gases generated by the electric arc in contact with the oil.

Abstract: A high voltage electrical device includes a removable transformer module and a receptacle attached to the high voltage electrical device for receiving the removable transformer module. The removable transformer module is configured to mate with the receptacle as the removable transformer module is plugged into the receptacle in order to connect the removable transformer module to the high voltage electrical device. The removable transformer module includes a transformer for transforming a primary input voltage into a secondary output having a voltage greater than the primary input. The removable transformer module also includes secondary contacts for connecting the secondary high voltage output of the transformer module to the high voltage electrical device when the removable transformer module is plugged into the receptacle.

Abstract: A disconnect protection structure for a rotary transformer type resolver includes insulating tube units (611, 612, 613) that house a crossover (60) connecting a rotary transformer output winding (65) and resolver excitation windings (64). A left end (611a) of the protection tube (611) and a right end 613b of the protection tube (613) are secured to the crossover (60). Ends of the insulating tube units (611, 612, 613) other than the secured ends are not secured, and a gap is provided between adjacent insulating tube units. As a result, the unsecured ends are capable of absorbing a force that would otherwise cause the crossover (60) to disconnect from the rotary transformer output winding (65) and/or the resolver excitation windings (64) when the protection tube units (611, 612, 613) and the crossover (60) thermally expand or contract.

Abstract: Devices and methods for using multiple transformers to provide a power supply to a device or system. Included are systems for using multiple transformers and multiple fuses or circuit breakers to provide a power supply. In one embodiment two transformers and two fuses or circuit breakers are used to provide a power supply. Embodiments with greater numbers of fuses and transformers are also disclosed. Also illustrated are methods and devices using thermal circuit breakers to equalize current between multiple transformer sources or to compensate for differences between multiple transformers. Also included are switched schemes for assuring proper phasing of power supply transformers.

Abstract: A microtransformer for a high-performance system-on-chip power supply is disclosed. Through-wafer openings in a substrate allow the primary and secondary wiring on both surfaces of the silicon substrate. An insulating silicon oxide layer is first deposited on all surfaces of the substrate. A magnetic film is further deposited on the silicon oxide layer followed by the application of another insulating layer. Coils are fabricated next by patterned deposition on both sides of the substrate and through the holes. The coils can be, e.g., single coils or primary or secondary coils of a transformer structure, with secondary having one or more output taps to supply different output voltages. For better flux closure, various magnetic layers and insulators can be deposited on top of the windings.

Abstract: The present invention relates to a relaying method using the ratio of induced voltages or the ratio of flux linkage increments. The protective relaying method for power transformers with one or more phases includes the first step of obtaining primary and secondary voltages and currents of the transformer; the second step of calculating induced voltages, induced voltage differences, ratio of primary and secondary induced voltages, or ratio of primary and secondary induced voltage differences from the currents and the voltages; the third step of calculating at least one predetermined decision parameter derived from at least one predetermined equation; the fourth step of deciding whether an internal winding fault occurs by comparing the decision parameter to the induced voltages, the induced voltage differences, the ratio of primary and secondary induced voltages, or the ratio of primary and secondary induced voltage differences.

Abstract: A protection device for a transformer, particularly for supplying power to lamps, the transformer including a primary electric circuit that interacting with at least one secondary electric circuit, comprising an electronic control unit that detects the intensity of the electric current that circulates in the primary circuit as a function of the secondary circuit and compares it with a previously stored threshold value, the control unit deactivating the transformer after a preset number of readings of the electric current intensity that are incompatible with the threshold.

Abstract: A microtransformer for a high-performance system-on-chip power supply is disclosed. Through-wafer openings in a substrate allow the primary and secondary wiring on both surfaces of the silicon substrate. An insulating silicon oxide layer is first deposited on all surfaces of the substrate. A magnetic film is further deposited on the silicon oxide layer followed by the application of another insulating layer. Coils are fabricated next by patterned deposition on both sides of the substrate and through the holes. The coils can be, e.g., single coils or primary or secondary coils of a transformer structure, with secondary having one or more output taps to supply different output voltages. For better flux closure, various magnetic layers and insulators can be deposited on top of the windings.

Abstract: The invention relates to a thyristor tap changer that comprises a mechanical tap selector and a diverter switch with thyristors as the switching means. The inventive tap changer is further characterized in that only the tap selector is mounted in the oil-filled transformer tank while the diverter switch is externally mounted in a laterally attached separate housing.

Abstract: Disclosed is a relaying method for protecting a transformer by using a difference of current. A decision function, related to the difference of a primary current, a secondary current, or a differential current is used for determining whether a detected abnormal current is due to the inrush or internal fault.

Abstract: A control method and arrangement is provided that monitors the condition and operating parameters of a power electronic system having power electronic devices to optimize operation of the power electronic system. Further, electrically isolated power supplies to individual control stages for high-voltage, series-connected switch devices/power electronic devices.

Abstract: A high voltage electrical device includes a removable transformer module and a receptacle attached to the high voltage electrical device for receiving the removable transformer module. The removable transformer module is configured to mate with the receptacle as the removable transformer module is plugged into the receptacle in order to connect the removable transformer module to the high voltage electrical device. The removable transformer module includes a transformer for transforming a primary input voltage into a secondary output having a voltage greater than the primary input. The removable transformer module also includes secondary contacts for connecting the secondary high voltage output of the transformer module to the high voltage electrical device when the removable transformer module is plugged into the receptacle.

Abstract: The present invention relates to a vacuum arc discharge power supply. The power supply may be a high frequency resonant AC supply or it may be rectified to give resonant DC. The power supply of the present invention may be used in x-ray production, vacuum arc deposition equipment, vacuum metal refining, ion implantation devices, or other applications that perform vacuum arc discharge.

Abstract: A neon sign includes a removable transformer module and a receptacle attached to the neon sign for receiving the removable transformer module. The removable transformer module is configured to mate with the receptacle as the removable transformer module is plugged into the receptacle in order to connect the removable transformer module to the neon sign. The removable transformer module includes a transformer for transforming a primary input voltage into a secondary output having a voltage greater than the primary input. The removable transformer module also includes secondary contacts for connecting the secondary high voltage output of the transformer module to the neon sign when the removable transformer module is plugged into the receptacle.

Abstract: An electrical protection device which protects an electrical power distribution system supplying voltage from a secondary winding of a transformer through an electrically conductive path to the protection device includes an impedance detector which measures the impedance of the path. When the impedance of the path exceeds a pre-determined threshold, the protection device produces a signal which is used to indicate a problem or interrupt the circuit. In a system approach, an overcurrent protection device is installed at an origin of a branch circuit for interrupting current when an overcurrent condition is present, while a fault protection device is installed at an outlet in the branch circuit. The fault protection device includes circuitry for measuring an impedance in the branch circuit and circuitry for producing a signal when the measured impedance exceeds a predetermined value. Such a system affords series fault and parallel arc fault protection to the branch circuit.

Abstract: A power splitter that has a small package size and low cross-talk noise. The power splitter includes a low temperature co-fired ceramic (LTTC) substrate with several layers. Electrical components such as transmission lines and resistors are integrated onto and within the LTCC substrate. The power splitter provides impedance matching and dividing functions. The LTCC substrate has counter rotating spiral shaped circuit lines and electrically conductive vias extending therethrough. The vias are used to connect the power splitter to an external printed circuit board. The vias are also used to make electrical connections between the layers of the LTCC substrate. The counter rotating circuit lines allow the power splitter to have a small package size and low cross-talk noise.

Abstract: A (vibration) stopper protection circuit of an electronic ballast for fluorescent lamps. The electronic ballast has an inverter to convert a direct current source into a square-wave source, and to provide the square-wave source to multiple lamp tubes. The stopper protection circuit has several harmonic oscillating capacitors, a sampling transformer, a protection signal processing circuit and a stopper circuit. The sampling transformer samples a normal sampling signal and an error sampling signal when the lamp tubes are normal or out of order, respectively. The protection signal processing circuit outputs an error signal while receiving the error signal. While receiving the error signal, the stopper circuit outputs a stop signal to the inverter, so that the inverter stops operating.

Abstract: A invention relates to a transformer having a primary coil and a secondary coil, with a ferromagnetic core inserted in a coil former. The alternating current resistance of the primary coil (3) drops on reaching a triggering temperature (TC) which lies above the operating temperature but below the softening temperature (TW) of the coil former (6) and/or insulation of coil winding (3, 4). The coil core (5) may consist at least partially of a material with a magnetic permeability which drops when the triggering temperature (TC) is exceeded.

Abstract: A neon transformer includes secondary windings 16 and 17, and a junction 20 therebetween is connected through a voltage detection circuit 41 to a ground terminal 18 of the transformer. A resistive element 54 is connected in shunt with the voltage detection circuit 41. The voltage detection circuit 41 may comprise a series circuit of a Zener diode 52 and a light emitting element 53L of a photocoupler, for example. When a ground fault occurs on the secondary side of the transformer, the location of the ground fault assumes a reference potential, whereby the potential of the junction 20 rises to cause a current flow through the Zener diode 52 and the light emitting element 53L, which renders a light receiving element 53P conductive to pass an energizing current through a relay drive coil 34, thus throwing a relay contact switch 13 from NC to NO, thus interrupting the supply of the a.c. power.

Abstract: A phase control switch apparatus incorporating a phase-based break/make controller (80A, 80B, 80C) for protecting a reactive load such as a transformer (10) from transient surge phenomena taking place upon power-supply breaking/making operation.

Abstract: Transformer winding movement is detected by providing an input sensor inside the transformer on an input winding lead and providing an output sensor inside the transformer on an output winding lead. This eliminates the frequency limitation imposed by the lead lengths required for prior art external measurement, making it possible to obtain useful measurements at much higher frequencies (20 MHz) than with the prior art techniques.

Abstract: A multi-winding transformer with a short ring includes an electrically conductive discharge path connected to the short ring for discharging the short ring and/or the transformer. Discharging the short ring suppresses or eliminates electrostatic interference caused by the structure and operation of the transformer.

Abstract: Induced voltages of two tertiary coils magnetically coupled with two secondary coils, respectively, are detected separately by two voltage detector circuits, and the detected voltages V1 and V2 are compared by two comparators with a reference voltage VS. When wiring connected to either one of the two secondary coils or a neon tube is grounded, the induced voltage of the corresponding tertiary coil decreases, then the output from the corresponding comparator is reduced down to zero volt, then a light emitting element emits light, and a phototriac is turned ON to actuate a relay to turn OFF its contact switch, shutting off the supply of AC power.

Abstract: The current transformer comprises a magnetic circuit associated to a primary conductor and a secondary winding connected to a trip relay. The magnetic circuit comprises a mobile part and a fixed part. The mobile part goes from an open position to a closed position when a primary current flowing in the primary conductor exceeds a preset value. The change of position of the mobile part makes the magnetic flux in the magnetic circuit vary which induces a secondary current in the secondary winding to actuate the trip relay. Application, notably to trip devices and circuit breakers.

Abstract: An earth cooled distribution transformer system and a method of cooling same and distributing electrical power to a plurality of consumer loads (31) is described. A distribution transformer (10 is provided with the primary (16) and secondary (17) windings encapsulated in a solid insulating material. The steel magnetic core (13) remains exposed and the transformer is buried in ground at a predetermined depth with the core (13) exposed whereby heat generated by the windings is dissipated into the earth through the exposed magnetic core. The high voltage supply cable (20) may be a buried cable or is at least partly buried as well as the power distribution cable (21), which feeds power to one or more consumer loads. The power distribution transformer (10) may be buried adjacent a manhole enclosure (12) with the primary and secondary winding power cables being connected to terminals (22-25) accessible in the manhole.

Abstract: A transformer over-voltage protection circuit shuts down a resonant inverter when high voltages occur at the output of a transformer. The high voltages can be caused by a broken or removed display tube. The system is designed to be used in display system, such as, an active matrix liquid crystal display (AMLCD). The system senses the voltage at the output of the transformer by utilizing a tickler or a tertiary winding. The signal from the tertiary winding is rectified and compared to a threshold. If the signal from the tertiary winding is greater than the threshold, the inverter is shut down for a period of time.

Abstract: An electrical transformer which is filled with a combustible coolant may experience a break in the electrical insulation within the transformer. This break in the electrical insulation may lead to an explosion or fire. A pressure sensor and a vapor sensor are preferably coupled to the enclosure to monitor the pressure and vapor content of the enclosure. An increase in pressure of the enclosure may indicate that an insulation breakdown has occurred. When an increase in pressure is detected, the coolant is partially drained from the enclosure. After draining some of the coolant, an inert gas may be injected into the bottom of the enclosure to stir the remaining coolant.

Abstract: A protection system for a three-phase distribution transformer immersed in a liquid dielectric contained in a tank, at least two of the three phases being equipped on the high voltage side of the transformer with respective current-limiting fuses. On each of the two phases equipped with current-limiting fuses, a protective micro-fuse is also connected in series with the current-limiting fuses and which operates faster than the current-limiting fuse. In addition, each micro-fuse is associated with a striker which, in turn, is connected to a mechanical trigger system which causes a three-phase short-circuiting device connected across the three phases to close in the event of a micro-fuse operating. Furthermore, the system includes at least one fault detector detecting one of pressure in the tank or the level of the dielectric. In particular, the three-phase short-circuiting device is situated on the high voltage side of the transformer between the current-limiting fuses and the high voltage windings.

Abstract: A voltage surge suppression system for the protection of electronic equipment from damage from voltage surges and voltage transients has at least one metal oxide varistor electrically connected to a primary power source; a transformer; at least one second metal oxide varistor electronically connected between said transmission interceptor and a power circuit board; and a circuit opener electronically connected between the a transformer and power circuit board; wherein the a transformer is connected between the primary power source and second metal oxide varistor. The circuit opener is a resettable breaker for protecting the transformer from surges greater than the rated value of the second metal oxide varistor by opening in order to close off current flow.

Abstract: A fault protection device incorporated in a transformer having a primary winding and at least two secondary windings connected to ground, and having a sensing coil to sense the fluxes generated by each of the secondary windings and generating a flux signal when an imbalance in the fluxes in the secondaries is detected and in which the sensing coil is in the form of at least two sensing coil portions, the sensing coil portions being positioned near but spaced from the sides of the secondary windings, the flux signal being constituted by a voltage induced in the sensing coil by fluxes produced by the secondary windings, and a switch connected to the sensing coil and connected in series with a power supply and at least one terminal of the primary winding, the switch being conditioned to an open condition in response to the flux signal to isolate the primary winding from the power supply.

Abstract: A low cost power supply with enhanced safety protection for neon lamps connected in a midpoint commoned lamp configuration. The power supply has a return path which is isolated from the earth ground so that a fault current does not flow from the output terminals to the earth ground. The windings are phased in a series opposing configuration such that the voltages between the output terminals sum to zero. This power supply of mid-point connected secondary coil design is capable of operating lamp lengths that typically require 15,000 volts of open circuit voltage while not exceeding 7500 volts to ground when any one output terminal is grounded.