Abstract: A high frequency power supply device has an inverter circuit and an output circuit connected thereto. The inverter circuit includes a diode and a capacitor being connected in parallel to an output side of a switching transistor. A drive input voltage of the switching transistor has a dead time during which a collector voltage thereof is inverted by resonance between the capacitor and a circuit inductance of the device. The switching transistor is turned on when the diode is turned on, thereby reducing the switching loss of the switching transistor. The output circuit includes a ferroresonant circuit or a magnetic amplifier circuit which has a saturable inductor.

Abstract: A circuit for maximizing power transfer from a station to an interactive memory card via a capacitive interface. A reader system in the station generates an ac signal which provides operating power that is transferred to the card through the capacitive interface formed when the card is placed against a window on the station. The ac signal from the station is directed through a series resonant circuit to the card. The capacitive interface between the station and card make up the capacitive element of the resonance circuit while the series combination of the secondary of a transformer and an electrically variable inductor form the inductive element. Use of the variable inductor allows the station to tune the circuit to resonance and cancel the capacitive element, thereby maintaining maximum power transfer to the card.

Abstract: The outputs of a plurality of modules or generators of electrical energy, such as fuel cells, chemical storage batteries, solar cells, MHD generators and the like, whose outputs are different are consolidated efficiently. The modules supply a power distribution system through an inverter. The efficiency is achieved by interconnecting the modules with an alternating voltage supply and electronic valves so controlled that the alternating-voltage supply absorbs power from modules whose output voltage is greater than the voltage at which the inverter operates and supplies this power as a booster to modules whose output voltage is less than the voltage at which the inverter operates.

Abstract: Apparatus is disclosed for controlling the regulating inductance of a power supply by applying across a control winding mounted on the same core a voltage having a volt-second product proportional to the difference between a desired output voltage and the actual output voltage so that the frequency of response is the same under all operating conditions. In a preferred form, the apparatus is incorporated in a power supply having a source of DC pulses that are rectified to produce the output voltage and the volt-second product of the voltage applied across the control winding is proportional to the difference between the detected value of said pulses and a control voltage that is related to the difference between the actual output voltage and the desired value.

Abstract: A variable inductance is placed in series with the diode rectifiers of the auxiliary outputs of a dc-to-dc converter. Increasing or decreasing the value of this inductance affects only the permeance of leakage flux paths which link the transformer winding peculiar to that auxiliary output. Such changes in the permeance of the leakage flux involve only the self-inductance of the transformer winding associated with that auxiliary output. When the permeance of the variable inductor is increased, the voltage to which the auxiliary output can rise increases as well. Conversely the steady state value to which the output voltage can rise may be reduced by reducing the permeance of the variable inductor. An error amplifier across the terminals of the auxiliary output detects and deviation in the output voltage from a predetermined, selected level. The error detector causes the value of the variable inductance to change so as to compensate for deviations in the output voltage from the predetermined selected levels.

Abstract: A multiple-output DC-DC converter has an electronically controllable reactor (64,66) connected in series with each output circuit. In response to variations in voltage of the output circuits (80,82), control signals are fed back to vary the permeance of the electronically controllable reactor (64,66) in each output circuit. The voltage in any output circuit is thereby made independent of input voltage variations and load fluctuations in any other output circuit.

Abstract: A linear power supply is preregulated to compensate for variations in load and power line voltage. The inductance on the primary side of the power supply step down transformer is varied by a current controlled inductor to efficiently maintain the desired power supply output voltage. A variable current is supplied to the inductor by a d.c. power source under control of an integrator which monitors output voltage fluctuations. In one embodiment of the invention, a voltage selector is included for use with power supplies which provide more than one output voltage. This selector automatically selects the most heavily loaded output voltage for control of the inductor.

Abstract: A switching regulated power supply operates over a broad range of input voltage and frequency, and outputs direct current power for computer equipment and the like. The power supply can be paralleled with identical power supplies, thereby satisfying any predetermined power requirement. A charge pump bulk voltage balancing circuit balances voltage on capacitors in an input rectifier and filter circuit. A flux sensing circuit senses magnetizing current in the secondary of a power transformer and the integrated signal is incorporated into pulse duration modulation to achieve dynamic flux balancing of the power transformer through a feedback loop. Output voltage of the power supply connects to a control supply of the power supply, providing power feedback to the control supply to maintain the operating parameters of the power supply as long as the output voltage does not fall below a predetermined level.