Abstract: An AC-DC adapter includes a power transformer to which an AC voltage is applied, a rectifier circuit for rectifying and smoothing an AC voltage developed across the secondary side of said power transformer, and DC voltage stabilizing member for stabilizing a DC voltage outputted by said the rectifier circuit.

Abstract: Method and apparatus for providing either AC mains or DC power for an electrically powered tool having a motor designed to be powered by a removable battery pack which fits into a recess in the tool. The apparatus includes a power block capable of being powered either by AC mains or DC power. The power block includes an AC to DC convertor, a voltage input selector, a DC to DC convertor, an auto voltage selector, and a solid state current monitor which automatically sets the voltage and current to be delivered to the tool motor at the voltage and current required to produce the tool motor's full rated driving torque.

Abstract: Phase coil lead wires of a vehicle-mounted alternator with two three-phase star connections are led almost in parallel out of the armature in an axial direction, welded to lead wire connection parts of insert terminals of a circuit board, and connected in parallel to form the star connections by way of the insert terminals. The star connections are achieved in a solderless manner, without twisting or bending the phase coil lead wires. Consequently, there is no possibility of injuring the lead wires due to applications of large stress.

Abstract: The current invention provides circuitry for use in an integrated circuit controlled voltage doubler/bridge circuit such that during any period wherein a lack of AC supply voltage is detected by the circuitry and following a period of AC input voltage within a lower defined range of values, repeated triac firing pulses are provided such that the AC supply will be rectified and doubled as soon as such a supply returns, whether the supply returns with the same or opposite polarity to that which it had, just before being interrupted.

Abstract: A method and apparatus for providing a welding current 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. The welding current may be rectified and smoothed by an output inductor and an output rectifier. A controller provides control signals to the inverter and an auxiliary power controller that can receive a range of input voltages and provide a control power signal to the controller.

Abstract: An autoselecting interface for selectively connecting an input aircraft power source to one of two outputs according to a sensed voltage of the input aircraft power source comprises a pair of input terminals for connection to aircraft power sources; first and second pairs of output terminals; a first voltage sensor connected to the input terminals for producing a first trigger output when an AC aircraft voltage is present at the input terminals; a second voltage sensor connected to the input terminals for producing a second trigger output when a DC aircraft voltage is present at the input terminals; a first switch responsive to the first trigger output for electrically connecting the pair of input terminals to the first pair of output terminals; a second switch responsive to the second trigger output for electrically connecting the pair of input terminals to the second pair of output terminals; and an override circuit for disabling the second voltage sensor from producing the second trigger output when an AC

Abstract: A d.c. arc welder which can use either a high voltage power supply of a certain voltage such as 400 volts or a low voltage power supply of about a half voltage thereof such as 200 volts and is arranged to effect automatic switching between low and high voltage power supply states not only when the power supply is switched from one to the other but also when the input voltage gradually rises from zero voltage to the above-mentioned high voltage, thereby constantly providing an adequate d.c. output for welding. It is provided with a circuit breaker in a stage next to its input terminals for sensing a high voltage of the power supply to temporarily shut off the input from the power supply and closing the circuit after its initialization.

Abstract: An arc welder which can be used with either a high voltage a.c. power supply of a certain voltage or a low voltage a.c. power supply of about a half of said voltage, such as 400 or 200 volts, for example, and which is provided with a circuit configuration in which an input a.c. voltage is rectified by a rectifier and smoothed by a pair of capacitors and the resultant d c. power is converted by an invertor into a high frequency a.c. power which is reduced in voltage by an output transformer and then rectified again, and arranged to discriminate the input a.c. voltage and switchingly connect these capacitors in series or parallel between both ends of the input rectifier, thereby automatically conforming the circuit to both high and low supply voltages.

Abstract: A half-bridge inverter circuit is provided for converting a DC voltage source to an AC voltage waveform, and supplying the AC voltage waveform to a load. The half-bridge inverter includes an inverter comprising a first capacitor for supplying a positive output voltage and a second capacitor for supplying a negative output voltage during respective intervals of the output waveform. An equalizer, responsive to a control circuit, equalizes the voltage output from the first capacitor and the second capacitor in order to overcome non-symmetry of these voltages resulting from a non-symmetrical load.

Abstract: An uninterruptible power supply is disclosed which is cheaper and more adaptable to various utility service inputs than presently available power supplies. A storage capacitor is placed between a boost AC/DC converter at the input and a DC/AC inverter at the output. A storage battery for maintaining constant voltage should the utility service power be interrupted is placed at the input, before the boost converter. Thus, a small battery is required because the boost converter is capable of boosting the battery's voltage to the voltage contained on the storage capacitor. A bidirectional semiconductor switch is provided in the boost converter to allow current to flow in both directions between its switch terminals when a AC input is applied. Appropriate control circuitry is provided which monitors the voltage at specific points throughout the circuit and controls operation of the bidirectional switch.

Abstract: A microwave oven with a power supply including a transformer having primary and secondary windings, with the primary winding having a plurality of input connections and a secondary winding being coupled to a magnetron. The microwave oven includes a circuit the magnitude of a line voltage supplied to the microwave oven and, in response thereto, for coupling the line voltage to a corresponding one of the input connections to regulate the voltage provided across the secondary winding to the same voltage level regardless of the magnitude of the line voltage.

Abstract: A power supply structure is disclosed in which a base member has first and second sets of plug pin receiving openings with electrically conductive sockets behind the openings. Each first set is grouped with a second set, and the sets are provided with power from separate sources e.g. clean and contaminated power. Socket modules each of which includes electrically conductive pins can be plugged into the openings. Each socket module has plug pin receiving openings for receiving plugs on power leads. In one form each socket module is unplugged from the base member, turned through 180 degrees and plugged into the base member again to change from one type of power to another. In a further form the base member includes switches which provide power selectively to the socket behind the first and second sets of openings.

Abstract: A power supply circuit composed of a series arrangement of the primary winding of a transformer (TR), a first transistor (T.sub.1) and a current measuring resistor (R.sub.2). The first transistor (T.sub.1) is switched by means of a second transistor (T.sub.2). The second transistor is controlled by the combination of a first signal which is proportional to the intensity of the current through the current measuring resistor (R.sub.2) and a second signal which is the voltage, filtered by a low-pass filter, across the secondary winding (n.sub.2) of the transformer.

Abstract: There is disclosed an AC input free power source comprising a power transformer to receive an AC input, a rectifier to convert the AC input into a DC output, and a switching transistor so driven as to produce a stable current by the switching action thereof. In addition to the above, the present invention further includes a primary voltage detection circuit with the switching transistor used as a first switching transistor, wherein the voltage to be applied thereto is obtained substantially from the center of the secondary winding of the power transformer, while the AC input voltage is detected and a control signal is outputted in accordance with the value of the detected voltage. A switching input voltage changeover circuit having a second switching transistor and, in response to the control signal, changing the first and second switching transistors selectively for execution of the switching action.

Abstract: A solenoid operated directional control valve includes a visual position indicator assembled of rectifying bridge circuit whose DC output terminals are bridged by a series connection of a light emitting diode with a PTC resistor. In this manner, the indicator is universally applicable both for DC and AC power sources and for a wide range of supply voltages.

Abstract: A power supply which automatically configures itself to correctly respond to either a low or a high level of an A.C. supply voltage to supply a single level D.C. output voltage. The supply switches between a voltage doubler and a full wave rectifier operation dependent on the level of the A.C. supply voltage. Once the supply switches to the full wave rectifier configuration, a latch prevents the power supply from switching to the voltage doubler configuration until the A.C. supply voltage is removed from the power supply. The latch prevents damage to components by preventing the power supply from switching to a low input voltage configuration when, in fact, a high input voltage is present.

Abstract: A power converting apparatus comprising intermediate DC power which rectifies AC from a commercial power to output DC, a solar array connected in parallel to the intermediate DC power, an inverter which converts DC inputted respectively from the intermediate DC power and the solar array into AC having the variable frequency and the variable voltage, then supply its AC output to a load, and circuit networks for power regeneration which regenerates a surplus power of the solar array into the commercial power, when the generated voltage of the solar array exceeds the prescribed voltage.

Abstract: A power source capable of providing a constant DC output when supplied with one of a range of AC inputs. Converter means providing a number of outputs of differing voltages each proportional to the input voltage. A number of parallel circuit lines each connected to one of those outputs. Each parallel circuit line including a rectifier, a maximum voltage regulator and a non-return current device. The outputs from those lines being connected to a common output to give the constant DC voltage supply.

Abstract: An inverter controlling method comprising corresponding DC bus voltage after power inversion relating to commercial power supply voltage, and in a comparator, comparing both voltages, detecting the DC bus voltage at the time point when the both voltages are the same to discriminate and store the level of the commercial AC power supply voltage, and making correction of the output voltage at the next operational start of the inverter on the basis of the stored information.

Abstract: A DC power source is capable of automatically adapting to either a 120 or 240 VAC input and of providing a single regulated output range for either of the AC voltage levels provided thereto. The power source detects the AC input voltage and automatically doubles the lower voltage while allowing the higher rectified voltage to pass through. The power source includes an electronic switching arrangement responsive to the input voltage level for automatically doubling the lower AC input voltage when detected as well as timing circuitry to allow for transitory fluctuations in the input voltage level while maintaining a level DC output voltage.

Abstract: The present invention relates to supplying a load either from a direct-current source or from an alternating-current source. The power unit, according to the invention, is characterized in that it consists of a single conversion unit (CV) having unidirectional semi-conductor power components forming switches (I1, I2, I3, I4) controlled in appropriate fashion by a logic control in such a manner as to ensure the functioning of the conversion unit (CV) either in a chopper mode, or in a rectifier mode when the load functions to draw power, or to ensure energy regeneration when the load functions in a generating mode. The present invention has application particularly for supplying direct-current motors used in dual-current railroad locomotives.

Abstract: A charging circuit comprises a bypassing transistor connected at the collector and base respectively to the base and emitter of a switching transistor connected to the primary winding of a transformer for inducing a charging current in the secondary winding of the transformer forming a part of a secondary battery charging path, and a current detecting resistance and constant voltage element connected between the base and emitter of the bypassing transistor so that, when the peak of a collector current of the switching transistor exceeds a predetermined level, the bypassing transistor is conducted to bypass and reduce the base current of the switching transistor, the collector current of the switching transistor is thereby reduced, and the charging current substantially constant at the average value is generated regardless of the voltage of a selective one of different power sources.

Abstract: A load control circuit having an input terminal adapted to receive any one of a number of different input voltage signals including signals of at least first and second type. These signals may be, respectively, DC and AC input signals. Control circuits are provided for operation of the load from the input voltage signal. This control circuit includes at least first part responsive only to said input voltage signal being of first type for coupling said signal of first type to the load, and a second part responsive only to the input voltage signal being of second type for coupling the signal of second type to the load.

Abstract: A power supply circuit for driving a motor includes a rectifier circuit and a converter circuit for stepping down the DC voltage from the rectifier circuit to drive a motor. The power supply circuit further includes a regulator circuit which is energized by the DC output voltage from the converter circuit to supply a constant voltage or current to the motor.

Abstract: A power controller determines which of a plurality of possible input voltages is present and configures a load to operate at that present input voltage.

Abstract: A circuit arrangement for the controlled supply of loads, in particular portable devices, for example dry razors and electronic flash devices, or also fluorescent lamps or the like, on virtually any d.c. and a.c. systems of different frequencies and voltages, without switching over. For that purpose, the arrangement uses a blocking converter (5) which is controlled by means of two controllable semiconductor switches (T1, T2) in dependence on the current (I1) flowing through the primary winding (n1) of the converter (5) and in dependence on the input voltage (U1) of the supply, in such a way that the output power supplied follows a desired characteristic curve and in particular is constant. If the load to be supplied is an accumulator (2) with a motor (1) connected in parallel, the circuit arrangement can supply either the full motor power or, when the motor is switched off, a charging current for the accumulator (2).

Abstract: A battery charger includes a transistor inverter. The transistor inverter includes an oscillation transformer and a switching transistor for controlling a current flowing through a primary coil of the oscillation transformer. This current charges the battery when the transistor is on. While the switching transistor is in an off state, charging current is supplied to the battery from a secondary coil of the oscillation transformer. The period of time where the switching transistor is in an on state is controlled depending on the amplitude of a supply voltage. Accordingly, the average value of a charging current to the rechargeable battery is automatically kept substantially constant despite variations in the amplitude of the alternating current voltage supply.

Abstract: A power supply which automatically produces approximately the same output voltage from two or more input voltages where the input voltages have substantially different magnitudes.

Abstract: A switching power supply is disclosed using a single transistor circuit which provides a constant output voltage for a range of input voltages extending from a nominal 115 volt power supply to a nominal 220/240 volt power supply without requiring a change in the circuit configuration throughout the range of input voltages. The circuit is disclosed in connection with a single transistor forward converter circuit, in which the transformer winding of the converter circuit is provided with a uni-directional clamp to prevent the transformer voltage of a given polarity from exceeding the clamping voltage magnitude. By clamping one polarity of the transformer voltage which is in series with the switching transistor, the maximum peak-to-peak voltage on the transistor is reduced from that which would be produced in the absence of clamping and enables the use of a power MOSFET transistor for the circuit.

Abstract: A D.C. to D.C. voltage converter is disclosed that operates with various applied D.C. input voltages, each having a different voltage level, to develop a desired D.C. output voltage. The D.C. to D.C. voltage converter has a saturable transformer that is sequentially excited into its positive and negative saturation conditions under control of sequentially operating first and second transistor diode combinations. The D.C. to D.C. converter has a base drive current circuit comprised of a full-wave rectifier and a multiple level current limiting circuit. The base drive current circuit is interposed between a base drive winding of the saturable transformer and the base electrodes of the transistors of first and second transistor diode combinations. The base drive circuit adapts the saturation condition of the first and second transistor diode combinations to the level of the applied D.C.

Abstract: A housing includes a removable top cover and encloses a removable electrostatic precipitating unit formed by a tandem arrangement of two cells each including parallel spaced collecting plates preceded by interspaced particle charging wires or elements. An air circulating fan is enclosed within the housing and is driven by a low voltage two speed DC motor. A first converter provides for converting a high voltage AC power supply to the low voltage DC power supply for the fan, and a second converter provides for converting the low voltage DC power to a DC power supply of several thousand volts for operating the electrostatic precipitating unit. Means are also provided for by-passing the first converter and for operating the fan and the electrostatic precipitating unit from a low voltage DC power supply.

Abstract: Four thyristors are interconnected into an AC bridge circuit. With an AC source connected across inputs to the bridge circuit, a DC motor is connected across outputs of the bridge circuit while the thyristors are operated in the phase control mode to control the power supply to the motor from the AC source. In the absence of the AC source the DC motor is serially connected to a battery across the outputs of the bridge circuit with the thyristors operated in the chopping control mode. Also, in the presence of the AC source, a rectifier bridge including thyristors and diodes can be connected across the battery to exclusively charge it from the AC source.