Patent application number | Description | Published |
20120212258 | TRIAC Dimmer Detection - Methods, circuits, and systems for determining the presence of a chopped input signal are disclosed. A digital signal generator can produce multiple digital signals when an alternating current (AC) signal input reaches multiple threshold voltages. The times at which the threshold voltages are reached can be determined by looking at the times at which the digital signals go high and low. The differences between the times at which the digital signals go high and low are used to determine if the AC signal input is a leading or trailing edge chopped signal. The AC input signal is a leading edge chopped signal when the difference between the times at which the digital signals go high is less than a predetermined time threshold, and is a trailing edge chopped signal when the difference between the times at which the digital signals go low is less than a predetermined time threshold. | 08-23-2012 |
20120230065 | Two-Peak Current Control for Flyback Voltage Converters - A system including a switch configured to supply power to a load. A first comparator is configured to compare a first current through the switch to a first threshold. A second comparator is configured to compare the first current through the switch to a second threshold. The second threshold is greater than the first threshold. A current control module is configured to turn off the switch (i) for a first duration in response to the first current through the switch being greater than or equal to the first threshold and (ii) for a second duration in response to the first current through the switch being greater than or equal to the second threshold. The current control module is configured to adjust the second duration based on a difference between an estimated current through the load and a desired current through the load. | 09-13-2012 |
20130134905 | COLOR MIXING SYSTEM WITH BUCK-BOOST AND FLYBACK TOPOLOGIES - A system includes a first solid-state lamp that generates a first illuminated output having a first color. A second solid-state lamp generates a second illuminated output having a second color. The second illuminated output is mixed with the first illuminated output to generate a third illuminated output having a third color. An inductor or a transformer includes a primary coil and a bias coil. A first circuit includes the primary coil and a first switch. The first circuit supplies power to the first solid-state lamp. A second circuit includes the bias coil and a second switch. The second circuit supplies power to the second solid-state lamp. A control module alters the third color including controlling (i) a state of the first switch to adjust current supplied to the first solid-state lamp, and (ii) a state of the second switch to adjust current supplied to the second solid-state lamp. | 05-30-2013 |
20130242622 | METHOD AND APPARATUS FOR STARTING UP - Aspects of the disclosure provide a method. The method includes receiving an input voltage rectified from an alternating current (AC) power supply, detecting a time duration that the input voltage is between a first threshold voltage and a second threshold voltage, determining a line voltage of the AC power supply based on the time duration, and regulating a time for turning on a switch to transfer energy via a transformer based on the detected line voltage. | 09-19-2013 |
20140063857 | METHOD AND APPARATUS FOR CONTROLLING A LIGHTING DEVICE - Aspects of the disclosure provide a method. The method includes determining a power adjustment to a load, determining whether a switching frequency of a pulse width modulation (PWM) signal is within a specific range, and adjusting the switching frequency of the PWM signal based on the power adjustment to control power transfer to the load. The switching frequency is adjusted to remain in the specific range. | 03-06-2014 |
20140112035 | METHOD AND APPARATUS TO REDUCE OVERCURRENT DURING THE STARTUP OF A SWITCHING REGULATOR - A power supply apparatus includes an inductor to store and discharge energy and a circuit to charge the inductor using a plurality of charging pulses. The circuit skips a charging pulse of the plurality of charging pulses to reduce overcurrent associated with the inductor. | 04-24-2014 |
20140217916 | METHOD AND APPARATUS FOR ALTERING A COLOR OF A MIXTURE OF LIGHT PROVIDED BY MIXING OUTPUTS OF LIGHT FROM MULTIPLE LAMPS - A system including first and second lamps, one of an inductor or a transformer, first and second switches, and a control module. The first lamp generates a first output of light having a first color. The second lamp generates a second output of light having a second color. The first and second outputs of light are mixed to provide a mixture of light having a third color. The transformer includes first and second coils. The first and second coils supply power respectively to the first and second lamps. The first and second switches are connected respectively to the first and second coils. The control module alters the third color by controlling (i) a state of the first switch to adjust a first amount of current supplied to the first lamp, and (ii) a state of the second switch to adjust a second amount of current supplied to the second lamp. | 08-07-2014 |
20140239825 | REDUCED NOISE POWER CONVERTER USING NOVEL SHIELD - Power converters that produce less noise are disclosed. For example, in an embodiment, power converter can include a first inductor magnetically coupled to a second inductor, wherein a first end of the second inductor is electrically open and a second end of the second inductor is electrically coupled to ground via a second capacitor, a transistor electrically connected to the first inductor, and control circuitry to control switching of the transistor, wherein when the transistor is repeatedly switched on and off by the control circuitry, a current loop is formed through the transistor, the second capacitor, the first inductor and the second inductor, the current loop causing a reduced amount of switching noise to be generated by the power converter. | 08-28-2014 |
20140327372 | METHOD AND APPARATUS FOR DIMMABLE LED DRIVER - Aspects of the disclosure provide a method for driving dimmable load. The method includes detecting a dimming characteristic in an energy source from which a load draws a first energy according to the dimming characteristic. The dimming characteristic requires a second energy in addition to the first energy to be drawn from the energy source to sustain an operation of the energy source. The method further includes biasing a switch to consume the second energy. The second energy and the first energy are drawn from the energy source to sustain the operation of the energy source. | 11-06-2014 |
20150070946 | METHOD AND APPARATUS FOR POWER DRIVING - Aspects of the disclosure provide a power circuit to provide electric energy with control and protection for driving a load, such as a light emitting diode (LED) array, and the like. The power circuit includes a converter, a voltage feedback module, a current feedback module and a controller. The converter is configured to receive electric energy from an energy source and to deliver the electric energy for driving the load. The voltage feedback module is configured to generate a first feedback signal based on a voltage of the delivered electric energy. The current feedback module is configured to generate a second feedback signal based on a current of the delivered electric energy. The controller is configured to receive the first feedback signal and the second feedback signal, and to control the converter to receive and deliver the electric energy based on the first feedback signal and the second feedback signal. | 03-12-2015 |
20150077090 | LINE VOLTAGE DETECTION CIRCUIT - A first filter outputs a first signal in response to receiving an input signal. The first signal has a first state in response to the input signal reaching a first threshold voltage on a leading edge of the input signal, and a second state in response to the input signal reaching the first threshold voltage on a trailing edge of the input signal. A second filter outputs a second signal in response to receiving the input signal. The second signal has the first state in response to the input signal reaching a second threshold voltage on the leading edge of the input signal, and the second state in response to the input signal reaching the second threshold voltage on the trailing edge of the input signal. A detection circuit determines, based on times when the first and second thresholds are reached, whether the input signal is received from a triac. | 03-19-2015 |