1123 results about "DC-to-DC converter" patented technology

Disclosed is an energy conversion apparatus. An energy conversion apparatus may comprise a control part controlling a length of a first time duration in which input current is inputted and accumulated, a length of a second time duration in which the accumulated current is provided to a load, and a length of a third time duration in which inverse current flows; and a DC-to-DC converter including an inductor, a output capacitor, and at least one switching element, wherein the input current is accumulated during the first time duration by switching the at least one switching element according to a control of the control part so as to perform input impedance matching, and the DC-to-DC convert provides a current corresponding to a difference between the accumulated current provided during the second time duration and the inverse current flowing from the output capacitor during the third time duration to the load.

The loss of data and/or the corruption of data that may occur in flash memory when a reset signal is received during a memory write cycle is prevented by delaying reset signals sent to the flash memory for a time period sufficient for a write cycle to be completed. The loss of data and/or the corruption of data that may occur in flash memory when the power supply is interrupted during a write cycle is prevented by providing a DC-to-DC converter with one or more large capacitors in parallel with its input as the power supply to the flash memory. If the system power supply fails or is interrupted, the discharge of the capacitor(s) delays the voltage decay at the input of the DC-to-DC converter such that the output of the DC-to-DC converter remains within tolerance for a time sufficient for the flash memory to complete a write cycle.

A circuit that utilizes most of the energy stored in the bulk capacitor of an AC to DC or DC to DC converter power supply by providing an intermediate converter between a first stage boost converter and a DC-DC converter. When the bulk voltage starts to fall during the hold-up time, the intermediate converter boosts the falling voltage to maintain the regulated DC input to the DC to DC converter while reducing the operating range and increasing the operating duty cycle, so as to increase efficiency, reduce peak current and voltage stresses, reduce the size of output filter components and reduce the size of the bulk capacitance by up to half.

A solar photovoltaic plant is disclosed where a number of distributed DC-to-DC converters are used in conjunction with a central DC-to-AC converter. Each DC-to-DC converter is dedicated to a portion of the photovoltaic array and tracks the maximum power point voltage thereof. The DC-to-DC converters also boost the photovoltaic voltage and regulate a DC output current for transmission to the central DC-to-AC converter. Five distinct advantages are had over the prior art. First, efficiencies in intra-field power collection are greatly improved by transferring power at higher DC voltages. Second, the number of independent photovoltaic maximum power point trackers in the power plant can be increased, in a cost effective manner, to optimize the overall photovoltaic array energy harvest. Third, each DC-to-DC converter output “looks” like a current source at the input of the DC-to-AC converter and therefore can be easily paralleled. Fourth, the current source nature of the DC-to-DC converter outputs enables the DC-to-AC converter to operate with a minimum, fixed DC bus voltage to provide maximum DC-to-AC power conversion efficiencies. And fifth, each distributed DC-to-DC converter can isolate a faulted portion of the photovoltaic array while the remainder of the array continues producing power.

Provided is a current-source push-pull DC-DC converter using an active clamp circuit for reusing energy of leakage inductances by not only diodes on a secondary side of a transformer being zero-current switched using a series-resonant full-wave rectifier, but also the active clamp circuit on a primary side of the transformer, which provides a discharge path of the energy stored in the leakage inductances, increases power conversion efficiency even for a wide input voltage range and reduces a switch voltage stress as compared to a conventional current-source push-pull circuit by operating even for a duty ratio below 0.5 by flowing a current of an input inductor through capacitors of the active clamp circuit when both main switches are off.

A circuit for rendering an energy storage device parallelable comprised of an energy storage device connected to a power adapter that converts the potential of the energy storage device into a potential that follows a predetermined function of the state of charge of the energy storage device. When multiple assemblies are paralleled, they may be charged and discharged as a whole with individual storage devices maintaining equal states of charge. The energy storage devices can be batteries with different cell counts, configurations, and energy discharge profiles. In some cases, the power adapters are comprised of DC to DC converters and system controllers that are used to translate each battery's energy discharge profile into a user-determined energy discharge profile that is a predictable function of the battery's state of charge and independent of temperature or other external conditions.

A battery controller for charging and discharging a plurality of batteries is disclosed. The battery controller has a plurality of direct current to direct current (DC to DC) converters connected to each other in series. Each battery of a plurality of batteries is electrically connectable to a respective DC to DC converter. A co-ordinator connected to each of the plurality of DC to DC converters controls charging and discharging of the battery electrically connected to the respective converter. The co-ordinator can also control charging and discharging of any one of the batteries to ensure that the battery retains sufficient electrical capacity, and, to increase the longevity of the respective batteries. Because each battery is electrically connected to a respective DC to DC converter, the energy from one battery can be used to charge another battery in order to monitor battery characteristics including energy capacity of each battery. Each of the DC to DC converters is selected to operate preferably below 30 volts while the total voltage of the entire battery system can be much more than 30 volts depending on the number of DC to DC converters placed in series.

Embodiments of the invention can provide systems, methods, and an apparatus for converting direct current (DC) power to alternating current (AC) power. According to one embodiment, a system for converting DC power to AC power can be provided. The system can include a DC power source electrically coupled to a DC-to-DC converter. The DC power source can be associated with a first ground, and the DC-to-DC converter can be operable to isolate the power provided by the DC power source from the first ground. The DC-to-DC converter can be further operable to condition the DC power and to provide the conditioned DC power to an inverter. The inverter can receive the conditioned DC power and can convert the conditioned DC power to AC power. The AC power can be associated with a second ground and can be provided to at least one load electrically coupled to the inverter.

A DC power source conversion module is provided, including a DC power source module and a DC to DC conversion module. The DC to DC conversion module includes a DC to DC converter and a control module. The DC to DC converter is powered by the DC power source module to generate an output signal. The control module senses a responding signal of the DC to DC conversion module and controls the DC to DC converter according to the sensed responding signal, such that the DC power source conversion module is operated at a predetermined output power, in which the responding signal responds to the output signal of the DC to DC converter.

Methods and apparatus for control of DC-DC converters. The DC-DC converter is operable so that the low side supply switch may be inhibited from turning on in a cycle following the high side supply switch turning off. Turn on of the low side switch is inhibited if the time between turn off of the high side switch and the inductor (L) current reaching zero is less than a predetermined duration. Inhibiting the low side switch from turning on can prevent the inductor current from going negative, which would reduce the efficiency of the converter. When turn on of the low side switch is inhibited the inductor current flows through a parallel path, such as a parasitic body diode associated with the low side switch, which allows current flow in one direction only.

A DC-to-DC converter having a transformer with a primary and a tapped secondary, two serial output filter inductors connected parallel with the secondary, a center output filter inductor connected between the secondary tap and serial output inductors, two serially connected switches connected in parallel with the two output inductors for receiving a signal to control operation of the switches during steady state and an output load connected between the serial connection of the serial output inductors and serial switching devices. The transformer primary side connected with double-ended primary-side topologies. The transformer secondary and output filers configured to form a current tripler rectifier, current quadtupler rectifier or current N-tuper rectifier. The output filter inductors evenly share output current resulting in reduction of current and thermal stress during high current application and the rectification topology has simple driving for synchronous rectifier application without increasing complexity of control and operation of primary-side topologies.

A propulsion energy storage control system and method of control interspersed between a heavy duty hybrid-electric drive system and its propulsion energy storage. The control system having an energy storage DC bus, electrical interfaces to the drive system and a plurality of propulsion energy storage subsystems, DC-to-DC converters at each interface, and a controller configured to operate each DC-to-DC converter independently such that power flow may charge, discharge, and shuttle between the plurality of propulsion energy storage subsystems.

A three stage power source for an electric arc welding process comprising an input stage having an AC input and a first DC output signal; a second stage in the form of an unregulated DC to DC converter having an input connected to the first DC output signal, a network of switches switched at a high frequency with a given duty cycle to convert the input into a first internal AC signal, an isolation transformer with a primary winding driven by the first internal high frequency AC signal and a secondary winding for creating a second internal high frequency AC signal and a rectifier to convert the second internal AC signal into a second DC output signal of the second stage, with a magnitude related to the duty cycle of the switches; and, a third stage to convert the second DC output signal to a welding output for welding wherein the input stage has a regulated DC to DC converter with a boost power switch having an active soft switching circuit.

A single phase power supply module for electric arc welders and plasma arc cutters comprising: a single phase input stage; positive and negative output terminals; a full wave rectifier connected to the input stage for rectifying the single phase voltage at the input stage; a buck converter type power factor correcting circuit for controlling current flow from the input stage to the rectifier, which buck converter has an output capacitor regulated to an intermediate voltage in the range of 100-150 volts; and, a high speed DC to DC converter having an internal transformer coupling applying voltage across the output terminals and means for regulating the applied voltage to an output voltage in the range of 0-113 volts. The module is universal and several can be connected in parallel, in series or to switch networks to construct several welders or cutters.

A power factor corrected (pfc) ac-dc converter has a modified boost input and a modified buck output. Unlike the prior art boost input, the boost switch returns to the output, not to ground. Unlike the prior art buck output stage, a third switch connects to the input. This allows much of the input current to pass through the converter to the output. There is no input current measurement, but nearly ideal power factor correction is achieved through “natural modulation.” A preferred pfc ac-dc converter uses a variable dc-dc transformer on its output, as a post regulator, to provide dielectric isolation and to provide voltage level shifting. The output of the pfc ac-dc converter has the control characteristics of a buck converter, so it is a natural mate for the variable dc-dc transformer. An ac-dc buck converter is most efficient at its maximum duty cycle. It cannot regulate for a lower input voltage, but it can reduce its duty-cycle to control for higher input voltages. A variable dc-dc transformer is most efficient at its maximum ratio. It cannot regulate for a higher input voltage, but it can reduce its effective turns ratio to control for a lower input voltage. With a small overlap in their control ranges, both parts of the power system can operate at maximum efficiency. The variable dc-dc transformer controls the output voltage for nominal and low input voltage. The ac-dc buck converter limits over-voltage transients.

The present invention discloses a PFC-PWM controller having interleaved switching. A PFC stage generates a PFC signal for switching a PFC boost converter of a power converter. A PWM stage generates a PWM signal for switching a DC-to-DC converter of the power converter. The PFC-PWM controller includes a power manager for generating a discharge current and a burst-signal. Under light-load conditions, the discharge current decreases in proportion to a load of the power converter. The burst signal is utilized to disable the PFC signal in a suspended condition for power saving. A pulse width of the pulse-signal ensures a dead time to spread switching signals, such as the PFC and PWM signals, and reduces switching noise. When the discharge current decreases, the pulse width of the pulse-signal will increase and a frequency of the pulse-signal will decrease correspondingly. This further reduces power consumption under light-load and zero-load conditions.

A two- (or multi) stage power amplifier receives a variable RF input signal, and outputs an optimized. RF output signal from, for example, a mobile handset. The output power level from the handset is predetermined, as known in the art, by the received control signal from a base station. The first power amplifier stage amplifies the variable RF input signal and outputs an RF signal, Vin, to a power detector circuit and an RF signal to the second or next amplifier stage. The power detect circuit amplifies the Vin signal and rectifies that signal with a linearly biased diode and provides a detect signal to a DC to DC converter. The converter responds by providing an optimum voltage bias, which is linearly related to the DC voltage detect signal from the power detector, to the output stage, and, if desired, to the first and/or other stages of the power amplifier that optimizes the output power level while meeting the required linearity specification. The battery current consumption is optimized through this automatic, dynamically control of the supply voltage for the power amplifier at each output power level through the DC to DC converter.

A three stage power source for an electric arc welding process comprising an input stage having an AC input and a first DC output signal; a second stage in the form of an unregulated DC to DC converter having an input connected to the first DC output signal, a network of switches switched at a high frequency with a given duty cycle to convert the input into a first internal AC signal, an isolation transformer with a primary winding driven by the first internal high frequency AC signal and a secondary winding for creating a second internal high frequency AC signal and a rectifier to convert the second internal AC signal into a second DC output signal of the second stage; with a magnitude related to the duty cycle of the switches and, a third stage to convert the second DC output signal to a welding output for welding wherein the input stage and the second stage are assembled into a first module and the third stage is assembled into a second module connectable to the first module.

A bi-directional DC-DC converter has a transformer for connecting a voltage type full bridge circuit connected to a first power source and a current type switching circuit connected to a second power source. A voltage clamping circuit constructed by switching elements and a clamping capacitor is connected to the current type switching circuit. The converter has a control circuit for cooperatively making switching elements operative so as to control a current flowing in a resonance reactor.