1627 results about "Duty cycling" patented technology

Methods and apparatus are provided for determining the duty cycle, average amperage, and/or the number of arc starts during a welding operation. The apparatus comprises first and second circuits, the first circuit being a CPU control circuit, and the second circuit being an arc time sensor circuit which is programmed to measure amperage, welding wire feed speed and preferably gas flow rates while welding. A ratio of the cumulative welding time during the audit to the total on-time provides a measurement of the efficiency of the welding arc. The welding deposition efficiency may then be calculated using the average amperage and welding duty cycle as measured and calculated by the apparatus. The number of arc starts where the arc on-time is in excess of one second may also provide a useable measurement in giving secondary information on the overall efficiency of the welding operation.

A method for reducing the harmonics contents of an input current drawn from a power line into an electrical system without sensing an input voltage, the method comprising providing an active power factor correction controller with a switch module having a main switch and a timing device, wherein the main switch has an on-time correlated with an on-duty cycle duration, and an off-time correlated with an off-duty cycle duration, and maintaining a linear relationship between the off-duty cycle duration and the input current by using the timing device; and an apparatus for active power factor correction with minimum input current distortion, comprising an active power factor correction assembly that includes a main switch and a timing device, wherein the main switch has associated therewith an on-time correlated with an on-duty cycle duration, and an off-time correlated with an off-duty cycle duration, and wherein the timing device generates the mentioned on-time and off-time, and linearization means for maintaining a linear relation between the off-duty cycle duration and the input current.

A device for heating or cooling a body of a user is provided. The device includes a thermoelectric module, a heat sink thermally coupled to the thermoelectric module, a wetting material in thermal communication with the heat sink, and a controller for cycling the thermoelectric module in accordance with a duty cycle. Additionally, a method of heating or cooling a portion of a body of a user is provided. The method includes cycling electrical power to a thermoelectric module at a duty cycle, transferring heat from the thermoelectric module to a heat sink, and evaporating a liquid from a wetting material disposed on the heat sink. The evaporated liquid enters the surrounding atmosphere.

A method is presented for enabling radio-frequency (RF) communications between an implantable medical device and an external device in a manner which reduces the power requirements of the implantable device by duty cycling its RF circuitry. A wakeup scheme for the implantable device is provided in which the external device transmits a data segment containing a repeating sequence of special wakeup characters and a device ID in order to establish a communications session with the implantable device. The wakeup scheme may be designed to operate using multiple communications channels.

A kitchen appliance for preparing yogurt, soft frozen yogurt and ice cream, hard frozen yogurt and ice cream, and cheese. The appliance includes a housing having a base and side walls defining an open top. A motor-driven paddle device is rotationally journaled with respect to the cover and base and the motor therefor is adapted to be driven either continuously or with a predetermined duty cycle, dependent upon the product being made. Also mounted on either the cover or the base is a vent hole occluder that is normally positioned to block the vent holes in the cover or base, but which shifts to a second position uncovering those vent holes when the consistency of the product being produced, as tested by the paddle motion or other apparatus reveals that a predetermined cultured state has been reached. Shifting of the occluding device from the covering position to the open position also actuates a switch to shut off the drive motor and a warming element. When a frozen yogurt product is desired, a pre-chilled freezing bowl can be placed in the housing and the paddle used to scrape the frozen yogurt from the walls of the freezing bowl.

Apparatus are provided for motor control systems and related medical devices. In one embodiment, a control system includes a motor having a rotor, a sensor to obtain a measured displacement that is influenced by rotation of the rotor, and a control module coupled to the sensor. The control module adjusts a duty cycle for a modulated voltage applied to the motor in response to a difference between an expected displacement and the measured displacement. The expected displacement is influenced by or otherwise corresponds to a commanded rotation of the rotor.

Provision is made in the housing of a host to provide a socket, or sockets, to which a peripheral piece of equipment can be connected for receiving directly from the host the low voltage DC power it requires. The socket(s) are connected electrically to the outputs of a power supply (or regulator) of a host for providing the low voltage needed to power the peripheral. The power supply may be mounted on the rear face of a computer. The principal feature of the invention resides in the use of a connector for connecting the host DC power to the peripheral DC power usage device. The connector comprises pins connected to a selected resistor in the power supply. The resistor value (i.e., resistance) is selected to produce a pre-determined control voltage which is fed back to a DC to DC converter in the host's internal power supply. The converter comprises a pulse width modulation control device. The control voltage determines the duty cycle (i.e., pulse width) of the modulation to reduce the output from a maximum voltage to an appropriate voltage suitable for the particular peripheral power usage device. Thus, by simply selecting the appropriate connector (or cable) having the proper pins correlated to a selected resistor previously installed in the power supply, the voltage level for the corresponding peripheral device is automatically selected. In an alternative embodiment, the DC power distribution apparatus of the present invention comprises a stand-alone unit having one or more universal ports for receiving a cable with a connector containing the appropriate pins for a selected DC power usage device.

Exemplary systems and methods provide a transformer-isolated current-fed quadratic full-bridge converter topology. The optimal interfacing of a current source, such as a solar panel, can be implemented by using current-fed converters. The current-fed converter can operate within the whole range of a UI curve from short-circuit to open-circuit condition and its input voltage can be readily controlled. The quadratic behaviour between input and output in regard of a duty cycle allows large conversion ratios.

A duty cycle management system and method for use in a wireless device having a transmitter which transmits packets in the form of individual packets and/or packet bursts. A controller in combination with an instruction set limits the number of packets transmitted during each time period defined by one time window or adjacent time windows, on a sliding basis, so as to control the duty cycle of transmissions during successive adjacent time windows based on the transmitter's output power, to produce that average power output. The transmission of packets is thereby delayed as needed to establish sufficient idle period(s) during one time window or adjacent time windows to apply whatever duty cycle is needed to produce that average power output level limit for the transmitter.

Systems and methods are provided for compensating for variations in line voltages the power an electro-kinetic air transporter and conditioner device. The electro-kinetic air transporter and conditioner device includes a high voltage generator that provides a potential difference between at least one emitter electrode and at least one collector electrode. The high voltage generator is driven by both a DC voltage obtained from an AC voltage source, and a low voltage pulse signal. The DC voltage is stepped down to produce a voltage sense signal indicative of a level of AC voltage source. The voltage sense signal is monitored. At least one of a pulse width, duty cycle and frequency of the low voltage pulse signal is adjusted, based on the monitored voltage sense signal, in order to substantially maintain the potential difference at a desired level.

A four switch voltage converter is regulated for buck mode and boost mode under constant frequency valley-peak current mode control. Protection circuits are responsive to output voltage and regulator current to prevent excessive current that otherwise might result from abnormally low output voltage short circuit, or spurious switching abnormalities during low duty cycle operation. The regulator control circuit is responsive to the protection circuits to automatically connect a regulator inductor between a common potential and the output to limit current.

Aspects of a method and system for duty cycling a network device based on aggregate throughput of the device are provided. In this regard, a limit on aggregate ingress and egress data of a network device during a time interval may be determined. Processing of data by the network device may be duty cycled based on the determination. The device may process data at a first rate during a first portion of the time interval and process data at a second rate during a remaining portion of the time interval. In this regard, portions of the device may be slowed or powered down during the first portion of the time interval. Power consumed by the device during the first portion of the time interval may be less than power consumed by the device during the remaining portion of the time interval.

The invention provides a segmentation self-adapting hill climbing method and a system thereof applied for tracing maximum power of a photovoltaic cell. The method comprises: finding the zone of the current power by partitioning the output power of the photovoltaic cell and comparing power difference of two adjacent moments with a set value; then, adjusting duty cycle to measure the power of the next moment until the maximum power point is found. The system of the invention comprises a photovoltaic cell, a DC/DC converter and a plumbic acid storage battery which are connected by circuits in sequence, wherein, a circuit between the DC/DC converter and the plumbic acid storage battery is provided with a voltage detecting module and a current detecting module, the output ends of the voltage detecting module and the current detecting module are respectively connected with a microprocessor, and the output end of the microprocessor is connected with the DC/DC converter via an isolation/ driving circuit. The invention quickens the tracing speed of the maximum power point, improves the anti-interference performance of the system, quickens the self-optimizing process of the maximum power point of the system and decreases the oscillation of the system at the maximum power point.