| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 363090000 | With inductive control means in the line circuit | 6 |
| 20080285319 | Method and apparatus achieving a high power factor with a flyback transformer - Common household power transformers (e.g., “wall warts”) typically exhibit poor power factors, which, in turn, cause energy losses to power grids and adversely affect current waveforms in the power grids. AC-to-DC power conversion with good power factor is achieved using a transformer, power switch coupled in series with the primary side of the transformer, and switching controller. The switching controller measures current through the primary side of the transformer, via a current sense element, and controls the power switch to enable and disable current through the primary side of the transformer. The switching controller generates a power switch control signal at a frequency with a duty factor that changes non-linearly as a function of an instantaneous current through the primary side of the transformer. As a result, a power factor of greater than 90% or even 95% can be achieved. | 11-20-2008 |
| 20090175061 | INSTANTANEOUS LOAD CURRENT CONTROL SCHEME FOR VOLTAGE FED DC TO AC INVERTER SUPPLYING RESISTIVE-INDUCTIVE LOAD - A control system is provided for controlling varying alternating current (AC) to a load with varying resistance and inductance. A plurality of nested control loops may employ cascaded proportional controllers to provide desired control of a pulse width modulation (PWM) block to control an inverter that supplies AC power to the load. An AC feedback signal may be supplied to each proportional controller. An AC feed forward signal may be added to outputs of the proportional controllers. | 07-09-2009 |
| 20100002480 | Constant current and voltage controller in a three-pin package operating in critical conduction mode - A self-oscillating flyback converter includes a controller integrated circuit housed in a 3-pin package. A switch control terminal is coupled to the base of an inductor switch that controls the current through a primary inductor of the converter. The controller IC adjusts the on time of the switch such that output current remains constant in constant current mode and output voltage remains constant in constant voltage mode. A signal received on a switch control terminal turns the switch off and provides an indication of the output current when the switch is on. A signal received on a feedback terminal powers the controller IC and provides an indication of the output voltage when the switch is off. The controller IC is grounded through a ground terminal. The flyback converter transitions from critical conduction mode to discontinuous conduction mode at light loads to prevent its efficiency from deteriorating at high switching frequencies. | 01-07-2010 |
| 20100118572 | LED DRIVER WITH LOW HARMONIC DISTORTION OF INPUT AC CURRENT AND METHODS OF CONTROLLING THE SAME - A power supply circuit for powering a load at constant current has a rectifier stage for receiving an AC voltage input and for producing a first substantially DC voltage. A first capacitor is attached to the load. A charge-pump is attached to an output of the rectifier stage and to the load for providing power factor correction and for converting the first substantially DC voltage to a second substantially DC voltage at the first capacitor. The charge pump is prevented from conducting energy back into the output of the rectifier stage. The charge pump delivers energy to a charge pump output, the energy being delivered directly instead of being stored. A converter stage is attached to the load and the first capacitor. The converter stage is used for converting voltages at the first capacitor and the charge pump to an output DC current. The converter stage has a switch for periodically connecting a first series-coupled circuit of the charge pump to the output of the rectifier stage. | 05-13-2010 |
| 20130194845 | CONTROL DEVICE OF A SWITCHING POWER SUPPLY - A control device of a switching converter controls the closing and opening of a switch of the converter that regulates the operation of an inductor. The control device includes a ramp voltage generator, a switch control circuit configured to close the switch based on a comparison of the ramp voltage with a first signal and a generator control circuit configured to control the ramp voltage generator based on a value of a second signal representative of a current flowing through the inductor of the converter, in comparison with the value of a third signal. | 08-01-2013 |
| 20150016166 | Line Current Reference Generator - The invention generally relates to the field of power factor correction and specifically to generation of a reference waveform which is proportional to line voltage and is controllable in amplitude. | 01-15-2015 |
