2313 results about "Switched-mode power supply" patented technology

A surgical device includes a radio-frequency-signal-generation assembly including a radio-frequency-signal-generation circuit operable to generate a radio-frequency signal at an output and adapted to couple to a switch-mode power supply and a surgical handle including an end effector having at least one jaw with at least one electrical contact, the end effector including at least one signal input that electrically connects to the output to provide the radio-frequency signal at the at least one electrical contact.

The invention relates to a device for supplying electrical energy to an electro-pen with an electric drive unit for driving a tool. The device comprises a console with an energy supply unit having an accumulator for supplying the electrical drive unit with electrical energy. The console may be configure to be sterilized by steam having a housing and electrical components that are sealed liquid-tight. The accumulator may include a sterile covering for sterile introduction into the console. A coupling between the console and the electro-pen carries the supply of electrical energy from the console to the electro-pen. The coupling may be an electrical contact in the form of a sterilizable connector or an inductive coupling. The console may be configured to store energy and is thus mobile, or the console may include a connection for connecting to a mains or external power supply for charging the accumulator. The console may include a switch-mode power supply for charging the accumulator. The console may include a holder for receiving and charging the electro-pen. The electro-pen includes an electrical storage device and a coupling for receiving the electrical energy supply from the accumulator. The holder may include an electrical coupling between the console and the electro-pen in which at least two electrical contacts and at least one transformer are disposed about each the holder and the electro-pen. Alternatively, the holder may include an inductive coupling in which at least one transformer having at least one coil is disposed about each the holder and the electro-pen.

An exemplary embodiment provides a current regulator for controlling variable brightness levels for solid state lighting. The current regulator is couplable to a phase-modulating switch, such as a dimmer switch, which is coupled to an AC line voltage. An exemplary current regulator includes a rectifier; a switching power supply providing a first current; an impedance matching circuit; and a controller. The impedance matching circuit is adapted to provide a second current through the phase-modulating switch when a magnitude of the first current is below a first predetermined threshold, such as a holding current of a triac of the phase-modulating switch. The controller is adapted to determine a root-mean-square (RMS) voltage level provided by the phase-modulating switch from the AC line voltage and to determine a duty cycle for pulse-width current modulation by the switching power supply in response to the comparison of the RMS voltage level to a nominal voltage level.

A novel apparatus and method of improving the power efficiency of a digital transmitter for non-constant-amplitude modulation schemes. The power efficiency improvement mechanism of the invention leverages the high efficiency of a switched-mode power supply (SMPS) that supplies the high DC current to the transmitter's power amplifier, while compensating for its limitations using predistortion. The predistortion may be achieved using any suitable technique such as digital signal processing, hardware techniques, etc. A switched mode power supply (i.e. switching regulator) is used to provide a slow form (i.e. reduced bandwidth) of envelope tracking (based on a narrower bandwidth distorted version of the envelope waveform) such that the switching regulator can use a lower switching rate corresponding to the lower bandwidth, thereby obtaining high efficiency in the switching regulator. The resulting AM-AM and AM-PM distortions in the power amplifier are compensated through predistortion of the digital amplitude modulating signal which dictates the envelope at the PA input. Similarly, the phase modulation is also compensated prior to the PA, such that once it undergoes the distortion in the PA, the end result is sufficiently close to the desired phase.

Exemplary embodiments provide an apparatus, system and method for power conversion to provide power to solid state lighting, and which may be coupled to a first switch, such as a dimmer switch. An exemplary system for power conversion comprises: a switching power supply comprising a second, power switch; solid state lighting coupled to the switching power supply; a voltage sensor; a current sensor; a memory; a first adaptive interface circuit to provide a resistive impedance to the first switch and conduct current from the first switch in a default mode; a second adaptive interface circuit to create a resonant process when the first switch turns on; and a controller to modulate the second adaptive interface circuit when the first switch turns on to provide a current path during the resonant process of the switching power supply.

Exemplary embodiments provide an apparatus, system and method for power conversion to provide power to solid state lighting, and which may be coupled to a first switch, such as a dimmer switch. An exemplary system comprises: a switching power supply; solid state lighting; a first adaptive interface circuit to provide a resistive impedance to the first switch and conduct current from the first switch in a default mode; and a second adaptive interface circuit to create a resonant process. An exemplary apparatus comprises: a switching power supply; and an adaptive interface circuit comprising a resistive impedance coupled in series to a reactive impedance to conduct current from the first switch in a first current path in a default mode, and further comprising a second switch coupled to the reactive impedance to conduct current from the first switch in a second current path, with the adaptive interface circuit further damping oscillation when the first switch turns on.

A method for tuning a transmitter in order to improve impedance matching to an antenna or to intermediate radio frequency stages uses an error detector that senses a deviation of the amplitude or phase angle of a load current of a power amplifier driver or of a power amplifier. A controller calculates a correction and dynamically adjusts tunable transmitter parameters, which may include values of components in matching networks or bias voltages in the power amplifier or the power amplifier driver, so as to reduce the deviation and thereby improve the impedance matching. The load current of the power amplifier may alternatively be sensed by measuring the duty cycle of its switching mode power supply. A transmitter having a power amplifier and one or more tunable circuit elements incorporates an error detector that senses the amplitude or phase of a load current and a controller that adjusts one or more tunable parameters to reduce impedance mismatch. An integrated circuit device suitable for use in a transmitter includes a power amplifier driver circuit and a detector circuit capable of sensing a load current, and a controller circuit that can adjust tunable parameters either within or external to the integrated circuit. By eliminating directional couplers and integrating the detectors and power amplifier drivers, the size, complexity, and cost of wireless transceivers can be reduced, while efficiency and power consumption are improved through the dynamic adjustment of operating points and impedance matching.

A power supply driver circuit with low power losses and desired response characteristics with respect to changes in output and its miniaturization is provided. In a driver IC constituting a switched-mode power supply equipment controlling the switching, by pulse width modulation, of first and second power transistors passing a current in a coil, and outputting a voltage bucked or boosted from an input voltage, current sensing with desired responsiveness is enabled by providing a switching transistor between an inverted input terminal and a non-inverted input terminal of an operational amplifier, preventing, while the second power transistor is ON, the generation of a potential which is undefined when first power transistor is ON, i.e. when the second power transistor is OFF, and maintaining a node potential in a state in which the potential is well defined.

A surgical device includes a radio-frequency-signal-generation assembly including a radio-frequency-signal-generation circuit operable to generate a radio-frequency signal at an output and adapted to couple to a switch-mode power supply and a surgical handle including an end effector having at least one jaw with at least one electrical contact, the end effector including at least one signal input that electrically connects to the output to provide the radio-frequency signal at the at least one electrical contact.

Switched-mode power supplies (SMPSs) and their control methods for radio frequency (RF) power amplifiers in battery-powered wireless transmitter devices involve a Boost-type SMPS and a Buck-type SMPS in cascade connection which are controlled so that high efficiency is maintained for various loads and transmission power levels. The Boost SMPS and the Buck SMPS can be controlled based on the mode of operation of the transmitter, such as the actual battery voltage, the needed output power, the selected frequency band, the selected RF power amplifier (PA), the selected modulation method of the transmission signal, and / or the selected PA voltage control method, such as the envelope elimination and restoration (EER) technique, the envelope tracking (ET) technique, or the power-level tracking (PT) technique.

A system and method are provided for actively reducing ripple in a supply voltage provided by a switched mode power supply. In general, active ripple reduction circuitry operates to sense the ripple in the supply voltage to provide a signal indicative of the ripple. The signal indicative of the ripple is inverted and provided to the output of the switched mode power supply to substantially reduce or eliminate the ripple in the supply voltage.

A power supply including a regulation circuit that maintains an approximately constant load current with line voltage. An example circuit includes a switch including first, second and third terminals. The first terminal is coupled or decoupled to the second terminal in response to a control signal received at the third terminal. Voltage sense circuitry is included and is coupled to sense a voltage drop across the switch. The voltage drop is representative of a current in the switch during an on time of the switch. The voltage sense circuitry has a variable current limit threshold that increases between a first level and a second level during the on time of the switch. The control signal is responsive to the variable current limit threshold to regulate a power supply with an output characteristic having an approximately constant output voltage below an output current threshold and an approximately constant output current below an output voltage threshold.

System and method for providing control for switch-mode power supply. According to an embodiment, the present invention provides a system for regulating a power converter. The system comprises a signal processing component that is configured to receive a first voltage and a second voltage, to process information associated with the first voltage and the second voltage, to determine a signal based on at least information associated with the first voltage and the second voltage, and to send the signal to a switch for a power converter. The switch is regulated based on at least information associated with the signal. The signal processing component is further configured to determine the signal to be associated a first mode, if the first voltage is higher than a first threshold.

Methods and systems are provided for LED modules that include an LED die integrated in an LED package with a submount that includes an electronic component for controlling the light emitted by the LED die. The electronic component integrated in the s submount may include drive hardware, a network interface, memory, a processor, a switch-mode power supply, a power facility, or another type of electronic component.

A battery charger that includes a primary switching-mode power supply, a secondary switching-mode power supply and a capacitor that is electrically connected to these two power supplies. In operation, this battery charger may be used to reverse the sulfation process in a battery. Also, a battery charging method that may be used to reverse the sulfation process in a battery.

In accordance with an embodiment, a method of controlling a switched-mode power includes generating a feedback signal proportional to an output of the switched-mode power supply, and operating the switched-mode power supply in a normal mode. If the feedback signal crosses a first threshold, the switched-mode power operates in a second operating mode. In the first operating mode the pulse modulated signal is adjusted to regulate a feedback signal to a first signal level, and in the second operating mode, a dead-time of the pulse modulated signal is adjusted to signal to regulate a feedback signal to a second signal level different from the first signal level. The method further includes driving a switch of the switched-mode power supply with the pulse modulated signal.

This invention generally relates to a bootstrap circuit for a switch mode power supply, a controller for a switch mode voltage converter, a switch mode flyback converter comprising the bootstrap circuit, a switch mode forward converter comprising the bootstrap circuit, and a method of bootstrapping a switch mode power converter. The bootstrap circuit comprises: a current bleed impedance (Rht1) to bleed current from an input power supply (VH+); circuitry to deliver current from the input power supply (VH+) via the current bleed impedance (Rht1) to the base of a power switch (Q1) such that the power switch (Q1) is operable to amplify the current delivered from the internal power supply; a passive circuit (Dst) to provide the amplified current to a reservoir capacitor (Cdd); and the passive circuit element (Dst) further to substantially block reverse current flow from the supply input (Vdd) to the emitter of the power switch (Q1).

The invention provides a LED arrangement including a LED string of a series arrangement of LED segments. A LED segment includes a single LED or a series arrangement of LEDs. A switching element (12, 22) is arranged in parallel with each corresponding LED segment (10, 20) of the LED string, for controlling a current (52, 62) through the LED segment (10, 20). A capacitor (13, 23) is arranged in parallel with each corresponding LED segment (10, 20) in order to prevent the occurrence of possibly harmful current spikes while switching one or more LED segments. The LED arrangement may also include a switched-mode power supply (2001). The invention further provides a LED assembly. A plurality of such LED assemblies assembles easily into a LED arrangement according to the invention.

A system and method provides virtual ripple signal generation for use in voltage regulation applications. Some switch-mode power converters or voltage regulators use output signal ripple to effect voltage regulation. A virtual ripple generator provides this type of voltage regulator with a virtual ripple signal comprising an offset component responsive to actual load voltage, but with a generated AC ripple component of arbitrary magnitude that is independent of actual output signal ripple. Unlike the actual output ripple signal, the generated AC ripple component is not dependent on implementation specifics, such as circuit board layout or output capacitor ESR, and may have its gain set independent of the offset component. The generated AC ripple component is synchronized to the inductor switching actions of the voltage regulator and thus reflects actual inductor phase switching in single and multi-phase regulation applications. Virtual ripple signal generation can include output (load) voltage droop compensation.

An over-power compensation circuit for use in a switched mode power supply having a current sense circuit for sensing a current flowing through a power transistor of the switched mode power supply. The over-power compensation circuit includes a peak detector, a sample-and-hold circuit, a current offset generator, and an offset resistor. The peak detector has an input for receiving an input voltage derived from the input line, and an output. The sample-and-hold circuit has an input connected to the output of the peak detector, and an output. The current offset generator has an input connected to the output of the sample-and-hold circuit, and an output for providing an offset current. The offset resistor has a first terminal connected to the output of the current offset generator, and a second terminal adapted to be connected to a current conducting electrode of the power transistor.

A single stage switch mode power converter receives a supply line voltage and a supply line current from a power supply line, and provides one or more regulated output voltages for a load, such as an amplifier. The power converter is operable to regulate the output voltage(s) using a controller that includes a voltage controlled current loop. The controller can enable substantially constant supply line current to be drawn from the power supply line by selectively allowing conduction of the supply line current through the power converter. A power factor of the supply line voltage and the supply line current may be optimized by the controller at medium to high power levels thereby maximizing the power provided to the switch mode power converter from the power supply line. Due to the adaptive nature of the controller, the power converter can operate over a wide range of supply line voltage.

A primary side controlled power converter having a voltage sensing means coupled to a transformer of the power converter and configured to provide a voltage feedback waveform representative of an output of the transformer is provided. A primary switching circuit operates to control energy storage of a primary side of the transformer. The primary switching circuit is operable during an on time and inoperable during an off time. The on and off time is switched at a system frequency. A feedback amplifier generates an error signal indicative of a difference between the voltage feedback waveform and a reference voltage. A sample and hold circuit samples the error signal at a periodic frequency during the off time. An error signal amplifier is configured to provide the sampled value to the primary switching circuit wherein the primary switching circuit controls the transformer and thereby regulates an output of the power converter.

A power converter includes a transformer, a primary switch, an auxiliary switch, first and second resonance capacitors, and a secondary side rectification means. A switch mode power supply is formed to use reflected voltage and parasitic capacitance as an energy source for a transformer resonance. The auxiliary switch effectively exchanges energy between the primary inductance of the transformer and the first and second resonant capacitors. The auxiliary switch effectively switches the transformer resonance between two distinct frequencies. In one embodiment of the invention, the power converter can be, but is not limited to, a flyback converter and further includes a comparator and a driver. The comparator is for detecting the voltage across the second resonance capacitor and the driver is configured to drive the auxiliary switch based on the output state of the comparator. The resonant nature of the converter provides zero voltage (ZVS) for the primary switch as well as for the auxiliary switch.

The present invention relates to a switch mode power supply and a driving method for reducing switching loss and audible noise in the burst mode. The switch mode power supply includes a main switch, a power supply, an output unit, and a switch controller. The power supply includes a transformer having a primary coil connected to the main switch, and supplies power to a secondary coil of the transformer according to the operation of the main switch. The output unit is connected to the secondary coil of the transformer and outputs power supplied to the secondary coil of the transformer. The switch controller receives a feedback signal corresponding to the output voltage of the output unit, a sense signal corresponding to the current flowing to the main switch, and a sync signal corresponding to the voltage difference at the main switch, controls the on / off of the main switch, and determines whether to start the burst mode by using the feedback signal, and maintains the switching operation forcibly off period in the burst mode so that the reference frequency of burst switching may be less than a predetermined value.

An integrated circuit comprises a radio frequency (RF) power amplifier (PA) output stage; at least one amplifier stage prior to the RF PA output stage; a linear amplifier comprising a voltage feedback wherein the linear amplifier is operably coupled to a low frequency supply module such that the linear amplifier and low frequency supply module provide a combined first power supply to the RF PA output stage; and a switched mode power supply module arranged to provide a second power supply to the linear amplifier and to the at least one amplifier stage prior to the RF PA output stage.

Switch-mode power conversion system and method thereof. The switch-mode power conversion system includes a primary winding configured to receive an input voltage, and a secondary winding coupled to the primary winding and configured to, with one or more other components, generate an output signal. Additionally, the switch-mode power conversion system includes a feedback component configured to receive the output signal and generate a feedback signal based on at least information associated with the output signal, and a voltage detector configured to receive the input voltage and output a detection signal. Moreover, the switch-mode power conversion system includes a mode controller configured to receive the detection signal and the feedback signal and generate a switch signal based on at least information associated with the detection signal and the feedback signal, and a switch configured to receive the switch signal and affect a first current flowing through the primary winding.