Abstract: A light emitting diode (LED) controller provides constant current regulation for a converter circuit providing current to an LED. The LED controller senses an inductor voltage and determines an inductor reset time from the sensed inductor voltage. Based on the determined inductor reset time, a switch on time and a switch period, the LED controller generates a control signal modifying the state of a switch coupling the converter circuit to an input voltage.

Abstract: An improved discontinuous current mode (DCM) switching power converter that compensates for the effect of dead time. The dead time of the switching power converter is measured during a switching cycle and a baseline on-time for a switch of the switching power converter is determined. The dead time and baseline on-time are used in calculating the desired on-time of the switch during a subsequent switching cycle of the power converter. The desired switch on-time regulates the output voltage to a desired voltage level. The desired switch on-time also maintains the average input current to the power converter in proportion to the input voltage, thereby improving the power factor of the switching power.

Abstract: A LED lamp that includes a LED lamp controller with delayed startup after a fault condition is detected. The type of the fault condition is used in determining a length of the startup delay, such as a number of power cycles during which the LED lamp controller is prevented from completing its configuration. Examples of different types of fault conditions include faults in a supply voltage or faults in a feedback voltage to the LED lamp controller. Fault type information can also be stored in circuitry that retains data and is not reset across the power cycles.

Abstract: A dimming controller for an LED lamp controls dimming using an adaptive filter to reduce or eliminate perceivable flickering and to provide smooth transitions during active dimming. During stable conditions, the adaptive filter operates with a relatively narrow bandwidth to filter noise that may lead to perceivable flickering. During active or startup conditions, the adaptive mapping filter operates with a high bandwidth to provide a quick response to the dimmer switch.

Abstract: An improved discontinuous current mode (DCM) switching power converter that compensates for the effect of dead time. The dead time of the switching power converter is measured during a switching cycle and a baseline on-time for a switch of the switching power converter is determined. The dead time and baseline on-time are used in calculating the desired on-time of the switch during a subsequent switching cycle of the power converter. The desired switch on-time regulates the output voltage to a desired voltage level. The desired switch on-time also maintains the average input current to the power converter in proportion to the input voltage, thereby improving the power factor of the switching power.

Abstract: A dimmable light emitting lamp configured to interface with cat-ear dimmer switches. The lamp includes one or more light emitting devices. The lamp also includes circuitry configured to receive an input voltage and provide regulated current to the one or more light emitting devices. The input voltage has a first voltage pulse that does not represent a dimming level of a dimmer switch and a second voltage pulse that represents the dimming level of the dimmer switch. The circuitry determines a first duration corresponding to a length of the first voltage pulse and a second duration corresponding to a length of the second voltage pulse responsive to first duration. The circuitry adjusts the regulated current to the light emitting devices according to the second duration to adjust output light intensity of the light emitting devices.

Abstract: The embodiments disclosed herein describe the dynamic control of a switching power converter between different operation modes of the switching power converter. In one embodiment, the operation modes of the switching power converter include a switching mode and a linear mode. The switching power converter may be included in a LED lamp system according to one embodiment.

Abstract: A power converter that controls a collector current of a bipolar junction transistor (BJT) by controlling the base current to the BJT after having determined the gain of the BJT. A gain detection block determines a gain of the BJT during a first mode. A current calculation block generates a current setting for the base current based on the gain of the BJT determined by the gain detection block during a second mode distinct from the first mode. In some embodiments, the power converter may be included in a LED lamp system.

Abstract: A switching power converter includes a controller configured to transition from a first operating mode to a second operating mode by determining the operating conditions at the transition point between the operation modes. The controller uses a point where a switch included in the power converter would have been turned on if operating under the first operating mode as a reference point to determine when to turn on the switch under the second operating mode. Using the reference point, the switching power converter determines a control period for regulating the switching period of the switch in a second operating mode.

Abstract: A low alloy steel ingot contains from 0.15 to 0.30% of C, from 0.03 to 0.2% of Si, from 0.5 to 2.0% of Mn, from 0.1 to 1.3% of Ni, from 1.5 to 3.5% of Cr, from 0.1 to 1.0% of Mo, and more than 0.15 to 0.35% of V, and optionally Ni, with a balance being Fe and unavoidable impurities. Performing quality heat treatment including a quenching step and a tempering step to the low alloy steel ingot to obtain a material, which has a grain size number of from 3 to 7 and is free from pro-eutectoid ferrite in a metallographic structure thereof, and which has a tensile strength of from 760 to 860 MPa and a fracture appearance transition temperature of not higher than 40 ° C.

Abstract: In a switching power converter, PWM mode and PFM mode are separated into two independent control sections with the control voltage range in each control section determined independently. Each of the PWM and PFM modulation modes cannot operate continuously beyond its boundaries, thereby forming a control gap between the two control sections within which no continuous operation is allowed. In order to supply a load condition within the control gap, the power supply operates at the two boundaries of the control gap. Transition between PWM and PFM modes occurs fast, with low output voltage ripple. No limitation needs to be imposed on the control voltage range in each of the PWM and PFM control sections, because the control parameters in the PWM and PFM control sections need not be matched to one another, due to separation of the PWM and PFM modes by the control gap.

Abstract: A switching power converter detects low load conditions based on the ratio of a first peak current value for peak current switching in constant voltage regulation mode to a second peak current value for peak current switching in constant current regulation mode. The power supply load is considered to have a low load if the ratio is lower than a predetermined threshold. Once a low load condition is detected, the switching frequency of the switching power converter is reduced to a level that minimizes switching loss in the power converter. In addition, the switching power converter also adjusts the switching frequency according to the sensed input line voltage. An offset is added to the switching period to reduce the switching frequency of the switching power converter, as the input line voltage is increased.

Abstract: The invention relates to a gate driving device for Thin Film Transistor liquid crystal display comprising: a plurality of shift registers directly deposited on an array substrate, said shift registers being composed of effect transistors and a capacitor, obtaining a gate driving signal voltage by controlling an input signal. Said shift register can be realized by 5-layer mask process or 4-layer mask process, by arranging the field effect transistors on the margin part outside the active region on the substrate or at the edge of the substrate, and then directly depositing them on an array substrate. The invention obtains a gate driving signal voltage by the shift registers directly deposited on the substrate, thus overcoming the shortage of the need of driving chips and film layers in the prior art, substantially reducing the production cost for LCD.

Abstract: A computer having a BIOS recovery function includes a baseboard management controller (BMC) circuit, a main control circuit, a switching module and a BIOS chip. The switching module is connected to the BMC circuit and the main control circuit. The BIOS chip stores BIOS programs for the computer and is selectively connected to the BMC circuit and main control circuit by the switching module. When the BIOS programs are corrupted, the switching module selects the BMC circuit to communicate with the BIOS chip. New BIOS programs can be sent to the BIOS chip to update the corrupted BIOS programs.

Abstract: In a switching power converter, PWM mode and PFM mode are separated into two independent control sections with the control voltage range in each control section determined independently. Each of the PWM and PFM modulation modes cannot operate continuously beyond its boundaries, thereby forming a control gap between the two control sections within which no continuous operation is allowed. In order to supply a load condition within the control gap, the power supply operates at the two boundaries of the control gap. Transition between PWM and PFM modes occurs fast, with low output voltage ripple. No limitation needs to be imposed on the control voltage range in each of the PWM and PFM control sections, because the control parameters in the PWM and PFM control sections need not be matched to one another, due to separation of the PWM and PFM modes by the control gap.

Abstract: Adaptive multi-mode digital control schemes that improve the light-load efficiency (and thus the overall average efficiency) in switch-mode power converters without causing performance issues such as audible noises or excessive voltage ripples. Embodiments include a switch-mode power converter that reduces current in the power converter using a second pulse-width-modulation (PWM) mode before reaching switching frequencies that generate audible noises. As the load across the output of the power converter is reduced, the power converter transitions from a first PWM mode in high load conditions to a first pulse-frequency-modulation (PFM) mode, then to a second PWM mode, and finally to a second PFM mode. During the second PFM mode, the switching frequency is dropped to audible frequency levels. Current in the power converter, however, is reduced in the second PWM mode before transitioning to the second PFM mode.

Abstract: In a switching power converter, PWM mode and PFM mode are separated into two independent control sections with the control voltage range in each control section determined independently. Each of the PWM and PFM modulation modes cannot operate continuously beyond its boundaries, thereby forming a control gap between the two control sections within which no continuous operation is allowed. In order to supply a load condition within the control gap, the power supply operates at the two boundaries of the control gap. Transition between PWM and PFM modes occurs fast, with low output voltage ripple. No limitation needs to be imposed on the control voltage range in each of the PWM and PFM control sections, because the control parameters in the PWM and PFM control sections need not be matched to one another, due to separation of the PWM and PFM modes by the control gap.

Abstract: A hybrid constant current control system that uses both pulse width modulation (PWM) and pulse frequency modulation (PFM) control. When transitioning from constant voltage mode to constant current mode the present invention can continue to control using PWM. Thereafter, when the voltage has dropped, the present invention smoothly transitions to PFM mode. The point of transition is based upon the switching frequency and the lowest rated voltage of operation. The system and method avoids very short (narrow) Ton times which ensures accurate constant current (CC) control with bipolar junction transistor (BJT) devices. The present invention also avoids acoustic noise because the switching frequency is maintained at a high enough level to avoid such acoustic noise even when the energy transferred through the transformer is still substantial and the output voltage is not too low.

Abstract: A transmitter identification information (TII) signal detection circuit is suitable for an orthogonal frequency division modulation system. A TII signal detection circuit receives a TII signal and conducts a cross-correlation calculation on the TII signal and a phase reference symbol (PRS) so as to obtain a present cross-correlation result, and then, sums the cross-correlation results obtained by conducting cross-correlations on AVE_TF_NUM-1 pieces of TII signals and the PRS and the present cross-correlation result so as to obtain an accumulated cross-correlation result. After that, a plurality of indices corresponding to a plurality of maximal values in the accumulated cross-correlation result is found out according to the accumulated cross-correlation result.

Abstract: In a switching power converter, PWM mode and PFM mode are separated into two independent control sections with the control voltage range in each control section determined independently. Each of the PWM and PFM modulation modes cannot operate continuously beyond its boundaries, thereby forming a control gap between the two control sections within which no continuous operation is allowed. In order to supply a load condition within the control gap, the power supply operates at the two boundaries of the control gap. Transition between PWM and PFM modes occurs fast, with low output voltage ripple. No limitation needs to be imposed on the control voltage range in each of the PWM and PFM control sections, because the control parameters in the PWM and PFM control sections need not be matched to one another, due to separation of the PWM and PFM modes by the control gap.