Abstract: The invention relates to a voltage switching device (23) consisting of a power rectifier (26), a boost chopper (34, 35) having at least one storage element (50, 51), a transformer (40), a switching device (59), a control device (4) and a plurality of mains leads (27 to 29), the power rectifier (26) being connected to an energy source (24) by the mains leads (27 to 29) and a consumer (25) with a secondary winding (42) of the transformer (40), a power evaluating device (32) supplied with voltage from the energy source (24) being provided, the output of which is connected to the switching device (59) or to the control device (4).

Abstract: A transformer connected to a power source, which consists of a primary coil, a secondary coil and a magnetic core, the secondary coil being configured to provide a regulated DC output voltage and/or current. The primary coil contains two portions, one portion being used to operate the transformer as a low voltage input converter and both portions being used when the transformer is used as a high voltage input converter.

Abstract: A DC power supply apparatus has two power supply input terminals between which one of 100 V level, 200 V level and 400 V level AC power supply voltages or a 575 V AC power supply voltage is applied. A rectifying unit is connected between the two power supply input terminals, and a voltage-lowering converter is connected to the rectifying unit. A thyristor is connected between the input and output of the voltage-lowering converter. A series combination of two capacitors is connected between two output terminals of the voltage-lowering converter. A switch circuit is connected between the junction of the two capacitors and one input terminal of the rectifying unit. An inverter converts a DC voltage appearing across the series combination of the capacitors into a high-frequency voltage, which, in turn, is voltage transformed by a transformer. The voltage-transformed high-frequency voltage is converted into a DC voltage in a high-frequency-to-DC converter for application to a load.

Abstract: One of commercial AC voltages is coupled to power supply terminals from one of commercial AC power supplies. The AC power supplies belong to either a first group providing higher voltages or a second group providing lower voltages. A rectifier rectifies the AC voltage applied to the power supply terminals, and a rectified voltage is developed between two rectifier output terminals. A switching unit operates to connect voltage-boosting converters selectively in series and in parallel between the rectifier output terminals. Inverters are connected in the output sides of and in association with the respective voltage-boosting converters for converting DC voltages from the associated voltage-boosting converters to high-frequency voltages. The high-frequency voltages are voltage-transformed by associated voltage-transformers, and the voltage-transformed high-frequency voltages are converted into a DC voltage by a rectifier circuit and a reactor.

Abstract: A power converter suitable for use in an uninterruptible power supply (UPS) includes first and second voltage busses, an input port having a first terminal coupled to one of the first and second voltage busses, a neutral bus and an output terminal. A first switching circuit selectively couples a second terminal of the input port to the first and second voltage busses. A second switching circuit selectively couples the first and second voltage busses to the output terminal. A third switching circuit selectively couples the first and second voltage busses to the neutral bus. Preferably, the first, second and third switching circuits are operative to produce an AC output voltage at the output terminal from a DC input voltage at the input port such that alternating ones of the first and second terminals of the first input port are referenced to the neutral bus for successive first and second half cycles of the AC output voltage.

Abstract: An improved alternator system for replacing an OEM Ford IAR alternator system. The improved alternator system includes a rectifier with increased heat dissipation qualities and decreased heat generation qualities and configured to maintain secure electrical connections. The alternator system is further configured to provide optimum electrical output by providing the rotor and the stator with additional turns or windings of heavier gauge wire whereby the alternator is capable of inducing a stabilized output current of at least about 52 amperes of current at about 1600 revolutions per minute of the rotor.

Abstract: A power supply for both alternating current (AC) and direct current (DC) which has an AC/DC converter and DC/DC converter detachably coupled with each other. The AC/DC converter is adapted to convert an AC input voltage into a DC signal, and the DC/DC converter is adapted to convert a DC input voltage into a DC signal. An output voltage selector is provided to obtain a DC output voltage appropriate to an associated device. The present power supply can be conveniently carried, supply power to an associated device regardless of AC and DC input voltages and select a level of an output DC voltage. Therefore, the present power supply can be used universally irrespective of the types of associated devices and manufacturers.

Abstract: An adapter circuit in power supplies utilizes a selective voltage doubler which approximately doubles an input voltage with a low line connector and does not with a high line connector. The selective voltage doubler is coupled to a switcher, which in turn is coupled to a resonant circuit. The resonant circuit is coupled to a first diode and a second diode and a filter. When a low line connector is used, the input voltage is doubled and a one diode drop is used. When a high line connector is used, the input voltage is not doubled and a two diode drop is used.

Abstract: A world wide power supply apparatus which includes a full-wave rectifier circuit having a pair of AC input terminals and a pair of DC output terminals, a pair of capacitors connected in serial between a pair of DC output terminals, a relay switch connected between a common connection point of capacitors and one of said pair of AC input terminals and a relay driving circuit driving said relay switch so that the relay switch can operate in a voltage doubling mode by turning on said relay switch in case that an AC voltage supplied to a pair of AC input terminals is a low voltage, and can operate in a full-wave rectification mode by turning off said relay in case of a high voltage. The power supply apparatus switches a voltage doubling circuit by using a relay with no heat generation instead of a triac.

Abstract: A switchable power supply includes a moveable electrical plug holding member that has a first position, which places an electrical plug pair in position for use with a first voltage standard, and a second position, which places the electrical plug pair in position for use with a second voltage standard. A switch is in a first state when the moveable electrical plug holding member is in the first position and is in a second state when the moveable electrical plug holding member is in the second position. When the switch is in the first state, a voltage modifier circuit generates a first output voltage and when the switch is in the second state, the voltage modifier circuit generates a second output voltage.

Abstract: Presented is a modular uninterruptible power supply system utilizing common power modules, and providing redundant coordinated control thereof. The system and method of the instant invention provides identical control logic within each of the individual power modules, thus dispensing with the requirement for a separate control module to control and coordinate the operating modes and parameters of the UPS system. A system is presented whereby a virtual master is established through an arbitration scheme at initialization of the UPS system. The master then assigns a virtual vice master to provide the redundant back up control should the virtual master no longer be able to perform its functions. Nearly simultaneous control of operational mode and state change functions is accomplished through a coordinated communications system including a high-speed communications bus and digital control logic lines.

Abstract: A battery controller 6 is connected to a DC/DC converter 3. The battery controller 6 checks the capacities of a battery 4 and a battery 5, calculates a duty ratio between the battery 4 and the battery 5 based on the capacities to determine a switching timing in which a plurality of switching elements are to be switched, and sets the duty ratio in the DC/DC converter 3.

Abstract: AC module makers must prepare two types of AC modules for the 100-V and 200-V outputs only for domestic supply. For foreign countries, the makers must manufacture AC modules compatible with more system voltages. To solve these problems, the control circuit of an AC module controls the operation of an inverter circuit and/or the transformation ratio of a transforming circuit, and ON/OFF-controls a switch on the basis of the system voltage and connection state of an electric power system.

Abstract: The invention relates to a converter including a fly-back circuit (5). For obtaining a maximum possible adaptation to the internationally different network voltages, there is proposed to provide a first fly-back frequency range for a converter input voltage (Unet) lying in a first voltage range and a second fly-back switching frequency range for a converter input voltage (Unet) lying in a second voltage range, the first voltage range having smaller voltage values than the second voltage range and the first fly-back switching frequency range having larger frequency values than the second fly-back switching frequency range.

Abstract: A method for distributing power in an electronic system comprising of receiving power in a first domain at a connector of a peripheral device and converting the power to a second domain at the connector of the peripheral device is disclosed.

Abstract: A power transfer apparatus includes a first switch operative to couple and decouple a first AC power source to and from an AC power bus responsive to a first control signal and a second switch operative to couple and decouple a second AC power source to and from the AC power bus responsive to a second control signal. A first switch control circuit generates the first control signal responsive to a first AC source voltage produced by the first AC power source and to a first inhibit signal and generates a second inhibit signal responsive to a state of the first switch. A second switch control circuit generates the second control signal responsive to a second AC source voltage produced by the second AC power source and to the second inhibit signal and generates the first inhibit signal responsive to a state of the second switch.

Abstract: A hybrid semiconductor device comprises four identical semiconductor diode chips each having top and bottom surfaces. Each chip is mounted on a respective mounting pad all of which lie in a common plane and, for ease of assembly, the four chips are mounted in identical top to bottom orientation, e.g., bottom surface down and electrically connected to the mounting pads. In one embodiment, the mounting pads for the chips and terminals for the device are integral with leads of a single (“component”) lead frame and various electrical connectors for the chips comprise bonding wires or stamped metal jumpers added to the workpiece after the chips are mounted on the lead frame. The metal jumpers can be provided on a separate “jumper” lead frame used in cooperation with the component lead frame, or the jumpers can comprise portions of leads of the single component lead frame. Printed circuit boards embodiments are also disclosed.

Abstract: A method and apparatus for providing welding type power is disclosed. The power source is capable of receiving any input voltage over a wide range of input voltages and includes an input rectifier that rectifies the ac input into a dc signal. A dc voltage stage converts the dc signal to a desired dc voltage and an inverter inverts the dc signal into a second ac signal. An output transformer receives the second ac signal and provides a third ac signal that has a current magnitude suitable for welding, cutting or induction heating. The welding type current may be rectified and smoothed by an output inductor and an output rectifier. A controller provides control signals to the inverter and a controller power supply can also receive a range of input voltages and provide a control power signal to the controller, and a voltage independent of the input voltage.

Abstract: A power supply is provided for use in a laser system including a gas ion laser tube which requires a filament voltage provided by an output section of the power supply. The filament voltage provided should not exceed a maximum AC filament voltage specified for the laser tube. The power supply is configured to receive AC utility power using one of at least first and second AC utility power sources having different first and second intended fixed magnitudes and which utility sources vary in amplitude from the intended fixed magnitudes over corresponding first and second source voltage ranges. The power supply is configured to include a power control arrangement which automatically controls the output section to generate an auto-ranging AC filament voltage from either of the first and second utility sources to be supplied as the filament voltage.

Abstract: A dual input power supply, a method of operating the power supply and a telecommunications power plant incorporating the power supply or the method. In one embodiment, the power supply includes: (1) a single stage power converter, coupled to an input of the power supply, configured to receive primary power subject to interruption and provide therefrom DC power to a DC bus; (2) an output power stage, coupled to the DC bus, configured to condition the DC power for delivery to an output of the power supply; and (3) a backup power stage, couplable to a backup power source and having an output coupled to the DC bus, configured to provide backup power during the interruption, the single stage power converter configured to restrict a reverse flow of the backup power therethrough during the interruption.

Abstract: An input-side rectifier rectifies a commercial AC voltage from a commercial AC power supply connected to an input terminal and develops a rectified voltage between two output terminals. The rectified voltage is smoothed by a pair of capacitors. A switching arrangement connects the capacitors selectively in series and in parallel between the two output terminals. An inverter is associated with each of the capacitors. A high-frequency voltage from each of the inverters is voltage-transformed by a transformer. The high-frequency voltage from the transformer is converted into a DC voltage by a high-frequency-to DC converter for application to a load. When an AC voltage in a lower voltage group is applied to the input terminal, a switching control unit causes the switching arrangement to connect the capacitors in parallel, and when an AC voltage in a higher voltage group is applied to the input terminal, the switching arrangement is caused to connect the capacitors in series.

Abstract: A method and apparatus for providing welding/plasma power is disclosed. The welding/plasma power source includes an input stage, an output stage, and an energy storage device such as a capacitor. The input stage is configured to receive an ac input signal and to rectify the ac input signal to provide a rectified intermediate signal. The input stage is further configured to provide a dc voltage signal across a dc bus. The output stage is disposed to receive the dc voltage signal and is configured to provide an available output power signal suitable for welding, plasma cutting and induction heating applications. The energy storage device is connected to provide sufficient stored energy to the dc bus to allow the welding/plasma power source to run off of a generator.

Abstract: Uninterrupted power supply system being connected to a power source through input terminals (11-1 and 11-2) and transforming the electric power received into a level of voltage and current appropriate for feeding a telecommunications equipment through output terminals (12-1 and 12-2). A recognising means (14) examines the electrical characteristics of the received power and, as a function of the results of the analysis, configures a determined conversion path between the input terminals (11-1 and 11-2) and the output terminals (12-1 and 12-2); to which purpose it generates a set of control signals (S1, S2, S3 and S4) which, respectively, activate a set of switching means (15-1, 15-2, 15-3 and 15-4).

Abstract: For use with a power converter having an input, first and second capacitors and first and second switches, a mode selection circuit, having selectable modes of operation, a method of configuring a power converter, and power converter employing the mode selection circuit and method are provided. In one embodiment, the mode selection circuit may function in two modes of operation. In a first mode, based upon an input voltage, the mode selection circuit is adapted to couple the first and second capacitors and the first and second switches together as a half-bridge converter. In a second mode, based upon the input voltage, the mode selection circuit is adapted to couple the first switch and the first capacitor together as a forward-flyback converter and to further couple the second capacitor and the second switch as a clamp thereto. In another embodiment, the first mode is a high voltage mode, in response to a high input voltage and the second mode is a low voltage mode, in response to a low input voltage.

Abstract: A device, used in particular in telecommunications technology to supply power to parallel-connected, electrical loads has side-by-side arranged potential lines. These are secured inside a connecting housing, with connections for supplying the operating potential. The connections supply plug-in modules for connecting individual loads, which modules are fitted against the connecting housing in longitudinal direction of the potential lines. The potential lines are configured as rigid, parallel bus bars that project on a side from the connecting housing. With the aid of passages that make contact with the bus bars, the plug-in modules are fitted side-by-side onto the bus bars, such that they fit against the connecting housing or against each other, and are frictionally secured.

Abstract: A computer monitor power supply system includes a comparator, a relay, and an inductor connected in series between the AC input and a flyback transformer circuit. The inductor includes two windings which are automatically switched between a parallel connection and a series connection upon switching between a 110 V and 220 V power input so as to reduce the amount of low frequency harmonics.

Abstract: A power supply for an emergency light includes a battery and battery charging circuit. The battery charging circuit is formed by two diodes and two resistors and possibly a capacitor.

Abstract: A dual-input, automatic-switching power supply comprises a primary power input, a secondary power input, and a power output. Included are first and second DPST mechanical relays and a third DPDT mechanical relay. A first relay input is connected to the primary power input and a corresponding first relay output is connected to a third relay input. A second relay input is connected to the secondary power input and a corresponding second relay output is connected to a different third relay input. The third relay output is connected to the power output. The relays in combination provide a relay moving contact gap spacing, source to source, of at least three millimeters. A first under voltage control module maintains the first and third relays in states causing the primary power input to be connected to the power output as long as voltage from the primary power input remains above a preestablished primary voltage dropout level.

Abstract: An AC and DC input power supply includes an AC power supply circuit and an AC input for receiving a range of AC input voltages. A rectifier circuit is connected to the AC input. An isolation output transformer has first and second primary winding terminals and a low voltage winding section for connecting to a DC voltage input that is lower than the range of the DC voltage that is rectified from the range of AC input voltages. The rectifier circuit is connected to the first primary winding terminal of the isolation output transformer. A transistor is connected to the second primary winding terminal of the isolation output transformer. The DC power supply circuit includes a DC input that is selectably connectable between the first primary winding terminal when the voltage input to the DC input connector is a nominal DC voltage that is within the range of the DC bulk voltage and the low voltage winding section when the voltage input to the DC input is lower than the range of the DC bulk voltage.

Abstract: The apparatus and methods of the invention provide conversion of a wide range of utility voltages found worldwide, to a fixed nominal voltage level. The invention therefore provides the ability to "plug in" to virtually any power source, and produce a desired nominal voltage for operation of electrical equipment either alone or in conjunction with a UPS device. The voltage selection apparatus provides standard nominal levels of electrical power to equipment while utilizing power sources of varying voltage and frequency. The device is dynamically adaptive to the input power source, and maintains its output within a nominal range even where the input source varies to a substantial degree. The voltage selection apparatus comprises an input for receiving input AC voltage from a power source, and a transformer to produce an output voltage which is coupled to the input.

Abstract: Apparatus for automatically selecting one of two or more available power supply voltages for use as a main power supply of a PCI adapter is described. In one embodiment, a power supply selector is designed such that the presence of a positive voltage at a Vaux input thereof prevents power at a Vcc input thereof from driving a main power supply input to a PCI adapter. Conversely, the absence of a positive voltage at the Vaux results in the main power supply input to the PCI adapter being derived from the Vcc input. In an alternative embodiment, jumpers are provided for enabling a user to select which power supply will be used as the "default" power supply for the adapter.

Abstract: A voltage booster device for increasing the voltage level of power received by a recreational vehicle (RV) from a separate 120-volt power source includes an electrical box, a power cord and female outlet on the box, and an encapsulated transformer within the box. The transformer (e.g., an autotransformer) is adapted to increase the actual voltage level of the separate 120-volt power source a predetermined amount. A relay is provided for switching the transformer, the power cord, and the female outlet between (i) a first circuit configuration that couples power from the power cord to the female outlet via the transformer so that the transformer increases the voltage level by the predetermined amount, and (ii) a second circuit configuration that bypasses the transformer so that the transformer does not increase the voltage level by the predetermined amount.

Abstract: A DC power supply apparatus includes a rectifier circuit which rectifies an input commercial AC voltage. The rectifier output voltage is smoothed in a smoothing capacitor. The DC voltage from the capacitor is converted to a high-frequency voltage in an inverter. The high-frequency voltage from the inverter is voltage-transformed by a transformer into a voltage-transformed, high-frequency voltage, which is then converted back into a DC voltage in a high-frequency-to-DC converter circuit. When an input commercial AC voltage is applied to the DC power supply apparatus, a pre-charging circuit pre-charges the smoothing capacitor from the input AC voltage. If a voltage having a magnitude larger than a prescribed value is applied to the DC power supply apparatus, an overvoltage protection circuit renders the rectifier circuit and the pre-charging circuit inoperative.

Abstract: An AC voltage applied among power input supply terminals is rectified by a rectifier, and the rectified voltage is adapted to be reduced in a voltage-reducing converter with a switch connected in parallel with it. A switching circuit connect smoothing capacitors in series or parallel to the voltage-reducing converter. Inverters are connected in parallel with the respective smoothing capacitors. The output voltages of the inverters are voltage-transformed by transformers. The transformed voltages from the transformers are converted to DC voltages by converters. A control unit renders the voltage-reducing converter operative and causes the switching circuit to connect the smoothing capacitors in series when a third AC voltage is applied among the power supply input terminals.

Abstract: A 5V generator circuit is disclosed that generates a reliable 5V signal for use in integrated circuits from the available VPP or VCC supplies for a wide range of VPP and VCC voltages. When VCC is greater than approximately 4V, the generator circuit generates the 5V signal directly from VCC. When VCC is less than approximately 4V and VPP is greater than approximately 4V but less than about 9V, the generator circuit generates the 5V signal directly from VPP. When VCC is less than approximately 4V and VPP is greater than approximately 9V, the generator produces the 5V signal at approximately half of the voltage level of the VPP signal. When both VCC and VPP are less than about 4V, the 5V signal is generated at the too-low VCC level.

Abstract: A power supply system has a power input to receive input power from a power source, a power output to provide output power to a load, at least one battery module having a battery output that provides battery power, at least one power module coupled to the power input to receive the input power, coupled to the battery output to receive the battery power and coupled to the power output to provide the output power, a controller, coupled to the at least one power module, constructed and arranged to monitor and control the output power from the at least one power module, and a redundant controller, coupled to the at least one power module and to the controller, constructed and arranged to provide redundant monitoring and controlling of the output power from the at least one power module.

Abstract: An alternating current power supply for providing a high-voltage alternating current power output from a first low-voltage alternating current power source and a second low-voltage alternating current power source is disclosed. A first alternating current low-voltage power input is coupled to the first low-voltage alternating current power source, and a second alternating current low-voltage power input is coupled to the second low-voltage alternating current power source. A switch simultaneously couples the first low-voltage power input to a first output conductor and the second low-voltage power input to a second output conductor, thereby providing a high-voltage power output between the output conductors. A switch control activates the switch responsive to a phase difference, typically 180 degrees, between the first alternating current power source and the second alternating current power source.

Abstract: For use with a DC power supply having first and second output rectifying circuits couplable in alternative configurations to provide dual voltages at an output of the DC power supply, an adaptive voltage controller and a method of adaptively controlling the output voltage. In one embodiment, the adaptive voltage controller includes: (1) a configuration determination circuit, coupled to the output, that generates a configuration signal that is a function of a configuration of the first and second output rectifying circuits, (2) a voltage feedback circuit, coupled to the configuration determination circuit, that develops a voltage feedback signal based on the configuration signal and (3) a voltage control circuit, coupled to the voltage feedback circuit, that receives the voltage feedback signal and controls an output voltage of the DC power supply as a function thereof.

Abstract: A converter welding arrangement with a welding control for the operation on mains with different voltages, having a welding transformer which is designed for operation on a mains with the lowest voltage of different possible voltages and to which the alternating voltage which is generated by AC conversion from the rectified mains voltage is supplied directly. A saturation monitoring arrangement monitors the current in the transformer and breaks off or interrupts the current supply to the welding transformer (18) when the current (I.sub.P) flowing across the welding transformer (18) exceeds a threshold value (I.sub.

Abstract: A semiconductor memory device includes a plurality of external power supply pads P1 to P3. Connection between external power supply pads P1 to P3 and an external power supply is determined in accordance with the voltage of the external power supply to be used, and the connection is switched by bonding. External power supply of a high voltage level is connected to an external power supply pad P2 which is connected to VDC1 and VDC2. A circuit including memory cells operates using the voltage applied from VDC1 or external power supply pad P3, while a group of word line drivers operates using the voltage applied from VDC2 or external power supply pad P1. VDC1 down converts the external power supply voltage, and VDC2 down converts it in accordance with the level of the voltage of the external power supply voltage, and generates internal power supply voltages, respectively. Accordingly, a semiconductor memory device which operates adapted to different external power supplies can be obtained.

Abstract: An avionics power conversion circuit having a first input adapted to receive an AC input signal, a second input adapted to receive a DC input signal and an output at which converted signals are provided. Power conversion circuitry, coupled to each of the first and second inputs and to the output, provides boost conversion of the AC input signal when the AC input signal is applied to the first input and provides flyback conversion of the DC input signal when the DC input signal is applied to the second input. The power conversion circuitry provides the boost conversion and the flyback conversion using a single transformer coupled between the first and second inputs and the output.

Abstract: A power converter for converting shore power voltage, phase, and frequency for shipboard use includes a variable inductance input transformer that can be connected to the shore power. The primary windings of the transformer have a plurality of taps, and a respective computer-controlled switch is connected between adjacent taps to selectively establish a closed circuit or an open circuit between the taps and thereby configure the primary windings as a low or high voltage "delta" or "wye", as appropriate for the shore power voltage. The output of the input transformer is sent to a variable speed drive, then to an output transformer, and thence to the distribution bus of the ship. A voltage regulator regulates the output voltage of the output transformer. If desired, a phase selector can be provided between the shore power and input transformer to establish the phase characteristics (i.e.

Abstract: A DC power supply device which includes a housing, an AC plug moved in and out of the housing and adapted to obtain AC power supply from a city power supply outlet, a DC plug moved in and out of the housing and adapted to obtain DC power supply from a socket for cigarette lighter of a car, a circuit board mounted inside the housing and adapted to process AC power supply obtained from the AC plug or DC power supply obtained from the DC plug into desired-DC power supply, and a DC output connector connected to the circuit board for DC output.

Abstract: An improved power supply apparatus for controlling electrical elements of a vehicle which is used for a vehicle using 12 volts as well as a vehicle using 24 volts. The apparatus includes a mode selection switching unit which is selectively switched in accordance with a voltage level inputted from a battery, a first voltage transformation unit, which is not operable when the mode selection switching unit is in the turned-on mode and is operable when the mode selection switching is in the turned-of mode, for dropping an input voltage from the battery to a predetermined level, and a second voltage transformation unit for dropping a voltage from the battery when the mode selection switching unit is in the turned-on mode and dropping an output voltage from the first voltage transformation unit to a predetermined level when the mode selection switching unit in the turned-off mode.

Abstract: A dual power battery charger for charging a rechargeable battery having power input terminals.

Abstract: An inverter power supply for use with various voltage inputs is provided. The inverter power supply generally receives 208 VAC single-phase, 208 VAC three-phase, 230 VAC three-phase, 230 VAC single-phase, 460 VAC single-phase, or 460 VAC three-phase power and provides a DC output current for welding, heating or cutting applications. The power inverter circuit includes a first tank circuit and a second tank circuit which are configured in serial or parallel according to a particular voltage input. Dual contactor switches respond to control signals from an AC sense circuit in order to configure the inverter power supply for the appropriate voltage input. The dual contactors may be mechanically interlocked and driven off the DC power for the control board.

Abstract: A circuit for controlling multiple input voltages to produce a given output voltage using only a single DC-to-DC converter. Sensing of the input voltages supplied to the circuit effect automatic switching to route the applied voltages between input terminals and output terminals, and configure the feedback network selecting the output voltage of the DC-to-DC converter. The DC-to-DC converter thus configured provides required output voltages not appearing in the input supply.

Abstract: A circuit connecting device is used to switch a characteristic of a circuit among a plurality of operating conditions. The circuit connecting device has a set of source terminals, a plurality of sets of receptor terminals and a selector for selectively connecting the set of source terminals to one set of the plurality of sets of receptor terminals. The selector simultaneously connects every terminal of the set of source terminals to a corresponding terminal of the selected set of receptor terminals. This results in the operating condition of the characteristic of the circuit being determined in accordance with the set of receptor terminals which is selected by the selector.

Abstract: A universal input dimming circuit for coupling an isolated external control signal into a variable output power supply, particularly those used for driving fluorescent lamps. Circuitry is incorporated which allows to discriminate between a DC control voltage or a relatively low-frequency pulsewidth-modulated signal using the same pair of input leads. By appropriate conditioning and waveshaping, the circuit produces a pulsewidth-modulated output which is then coupled across an isolation boundary and then demodulated to provide a command signal to the dimming ballast.

Abstract: A power conditioning circuit for use in a power supply includes a power input and a power output. The circuit also includes a series connected RFI-EMI filter, rectifier, and SCR between the power input and the power output. The SCR has a control input for switching the SCR on and off, thereby interrupting current flow between the power input and the power output. An energy storage circuit is connected across the power output. Furthermore, the circuit includes a control circuit coupled to the control input of the SCR for switching the SCR on and off to maintain a regulated voltage at said power output in response to an AC input. A conditioned DC output is produced in response to a DC input.