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Summary: A 2‐channel LED driver is presented herein, which possesses non‐pulsating input current and automatic current sharing. There are 4 features in the proposed LED driver. First, due to an input inductor, the input current is non‐pulsating, which makes the life of the renewable energy module or input capacitor longer. Second, each coupled inductor winding has a capacitor connected in series. Therefore, the dc magnetizing bias current is zero, and this can improve the iron core utilization, making the core loss and size reduced. Third, the number of LED channels can be extended by increasing windings. Fourth, the LED currents can be almost identical even if there are different LED numbers in LED strings. Eventually, the proposed LED driver is verified by simulation and experiment. [ABSTRACT FROM AUTHOR]

To overcome the traditional buck converter, which is difficult to achieve a high step-down gain with an appropriate duty cycle, a coupled-inductor-based step-down converter, named ultrahigh step-down converter, is proposed by Hwu et al. [11]. As compared with the buck converter, the ultrahigh step-down converter can achieve a much higher step-down gain, which can be determined by not only the duty cycle but also the turns ratio of the coupled inductor. However, the ultrahigh step-down converter is designed at a fixed input voltage of 48 V. In the telecommunication applications, the high dc bus voltage varies in a wide range, not kept at a fixed nominal voltage of 48 V. The experimental results show that as the input voltage increases, the efficiency of the ultrahigh step-down converter decreases. Therefore, in this paper, an improved ultrahigh step-down converter with a wide input voltage range is presented. According to the topology exchange, the voltage gain can be changed to a suitable one when the input voltage changes. By doing so, as compared with the ultrahigh step-down converter [11], the duty cycle of the proposed converter can be extended, and hence the efficiencies of the proposed converter can be improved. The proposed converter is verified by a wide input voltage (18–54 V), with an output voltage of 1.2 V and a rated output current of 10 A. [ABSTRACT FROM AUTHOR]

In this paper, a novel voltage-boosting converter is presented, which combines one charge pump and one coupled inductor with the turns ratio. The corresponding voltage gain is greater than that of the existing step-up converter combining KY and buck-boost converters. Since the proposed converter possesses an output inductor, the output current is nonpulsating. After some mathematical deductions, an experimental setup with 12-V input voltage, 72-V output voltage, and 60-W output power is used to verify the effectiveness of the proposed converter. [ABSTRACT FROM PUBLISHER]

A simple current sharing control technique for the switching power supply is presented herein, whose basic concept is that the control effort created from the voltage loop is finely tuned by the control effort created from the current sharing loop based on the proposed phase link so as not only to obtain the desired output voltage but also to make the load current distributed among phases as evenly as possible. Such a control method is not only without any current sharing bus as compared with the traditional current sharing methods, but also suitable for multiple phases under the condition that any one phase among multiple phases fails. Moreover, based on phase link, there is no divider used, as compared with the traditional average current method, and hence, the number of logic elements in the field-programmable gate array (FPGA) can be reduced. In this paper, the detailed basic operating principles, together with new mathematical deductions based on the superposition concept, are firstly described, and secondly some experimental results, based on the FPGA to realize the fully digitalized control of the overall system using one-comparator counter-based sampling without any analog-to-digital converter (ADC), are provided to verify the effectiveness of proposed control strategy. [ABSTRACT FROM PUBLISHER]

A high voltage-boosting converter is proposed herein, which combines one coupled inductor and one charge pump. Under a low input voltage with a high input current, the proposed converter has high voltage conversion ratio, and possesses an active voltage clamping circuit which pumps some portion of the leakage inductance energy to the output so as to increase the efficiency at light load, thereby causing the efficiency at light load to be very high. Hence, it is very suitable for the burn-in test of the buck-type converter. In this paper, the basic operating principles of the proposed converter are provided, together with some experimental results to verify its feasibility and effectiveness. [ABSTRACT FROM AUTHOR]

In this paper, a fully digitalized current sharing strategy without any analog-to-digital converter (ADC) is presented and applied to light-emitting diode (LED) lighting. By doing so, the cost for digital control is reduced significantly due to no ADC used. Aside from this, LED dimming is easy to realize. Above all, the proposed current sharing method has the capability of resisting variations in input voltage and component parameter. Such a control topology is demonstrated by some experiments and hence is very suitable for LED street lighting. [ABSTRACT FROM AUTHOR]

A simple current-sharing control technique for the switching power supply is presented herein, which is based on the concept of the differential-mode transformer and which makes the load current evenly shared well among phases all over the line voltage and load current ranges. This current-sharing structure is very simple, and it makes the efficiency relatively high at light load, which is quite suitable for industrial applications with standby power considered. In this circuit, a synchronously rectified switch is used to further upgrade the efficiency, and the coupling output inductors in copolarity are utilized to decrease the phase current ripples. In this paper, the detailed basic operating principles, together with mathematical deductions, are first described, and second, some simulated and experimental results are provided to demonstrate the proposed control strategy. [ABSTRACT FROM AUTHOR]

A negative KY buck converter is presented herein along with its soft switching operation. This converter can transfer the positive input voltage to the negative output voltage. Above all, zero voltage switching (ZVS) and zero current switching (ZCS) are used to achieve soft switching operation. Moreover, the input current is limited to some extent. In this paper, the behavior of the proposed circuit is firstly described in detail, and secondly some simulated and experimental results are provide to demonstrate the effectiveness of the proposed topology. [ABSTRACT FROM AUTHOR]

Design and implementation of a simple current sharing control technique, based on the concept of the differential-mode choke, is presented herein, which is applied to two-phase synchronously-rectified (SR) buck converter. This current-sharing structure is quite simple. In this circuit, a synchronously-rectified (SR) switch is used to upgrade the efficiency, two phases with phase shift of 180° is employed to reduce the inductor current ripples, and coupling output inductors is utilized to further decrease the inductor current ripples. In this paper, the detailed basic operating principles, together with mathematical derivations, are firstly described, and secondly some simulated and experimental results are offered to demonstrate the proposed control strategy. [ABSTRACT FROM AUTHOR]

In this letter, a KY boost converter is presented, which is the KY converter combined with the traditional synchronously rectified (SR) boost converter. Such a converter has continuous input and output inductor currents, different from the traditional SR boost converter, and has a larger voltage conversion ratio than the traditional SR boost converter does, and hence, this converter is very suitable for low-ripple applications. A detailed description of the proposed converter is presented herein along with a mathematical deduction and some experimental results. [ABSTRACT FROM PUBLISHER]

In this paper, a simple soft switching technique, together with input current spike suppressed, is applied to the KY converter, also named 1-pluse-D converter, to upgrade the efficiency in the vicinity of the rated load and hence enhance its capability in industrial applications. The basic operating principles of the proposed soft switching scheme for the KY converter are illustrated and verified by some simulated and experimental results. [ABSTRACT FROM AUTHOR]

In this paper, a voltage-boosting converter, named KY converter (i.e., 1-plus-D converter), is presented. Unlike the traditional nonisolated boost converter, this converter possesses fast load transient responses, which is similar to the buck converter with synchronous rectification. In addition, it possesses nonpulsating output current, thereby not only decreasing the current stress on the output capacitor but also reducing the output voltage ripple. Besides, 1-plus-2D and 2-plus-D converters, derived from the KY converter, are presented based on the same structure but different pulsewidth-modulation control strategies. Above all, the main difference between the KY converter and its derivatives is that the latter ones possess higher output voltages than the former one under the same duty cycle. A detailed description of the KY converter and its derivatives is presented along with some simulated and experimental results. [ABSTRACT FROM AUTHOR]

In this paper, an input inductor current injection technique, together with the one-comparator counter-based pulse-width-modulation (PWM) control strategy, is presented herein and applied to the boost converter to upgrade its stability and transient upload response. This is easy to realize based on the field programmable gate arrays (FPGA). The detailed illustration of the proposed control strategy is provided, along with some experimental results. [ABSTRACT FROM AUTHOR]