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Background: N-terminal pro-B-type natriuretic peptide (NT-proBNP) improves emergency room diagnosis and is a prognostic marker of acutely decompensated heart failure (HF) after hospitalization. We tried to assess the prognosis in heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF) using the biomarker. Methods: Patients were categorized into HFpEF (left ventricular ejection fraction [LVEF] ≥50%) (n = 102), HF with midrange EF (LVEF of 40%–49%) (n = 106), and HFrEF (LVEF ≤40%) (n = 112) as per the ESC classification of HF subtypes. Prognosis by absolute and percentage change in NT-proBNP at admission and at the 10th day of treatment was found in 3-month follow-up. Mortality after discharge was also assessed. Results: Among all HF groups, a reduction of NT-proBNP

In this study, a phase shift controlled full-bridge series resonant converter (SRC) integrated with buck converters for light-emitting diode (LED) driver application is proposed. This LED driver supplies four LED loads simultaneously. The current through LED loads is controlled by phase shift control of the SRC, and its output is added to the input voltage. Zero-voltage switching (ZVS) switching of all the switches is achieved by operating the SRC at lagging power factor for all input voltage variations. As the only part of the output power is processed through the SRC and all the switches operating with ZVS, the efficiency of the converter is 95.7%, which is high. A 142 W LED driver is designed, and its performance is tested with PSPICE simulations and experimental prototype.

This paper proposes an efficient LED lamp converter circuit incorporating dimming feature and multiple lamp independent control. The converter consists of a half-bridge resonant converter in series...

An efficient ripple-free light-emitting diode (LED) driver circuit is proposed with zero-voltage switching (ZVS) and dimming control. The proposed driver circuit utilizes a full-bridge configuratio...

In this paper output voltage modulated half-bridge series resonant converter (HBSRC) for LED driver application is proposed. In this converter HBSRC is cascaded with a buck-boost converter (BBC). The sum of output voltages of buck-boost converter and HBSRC drives the LED load. The LED current is controlled by regulating the buck-boost converter output voltage. Thus the HBSRC is working at firm frequency and duty ratio to achieve Zero voltage switching (ZVS) operation for input voltage variations. In this arrangement the BBC handles only fraction of the LED power, which doesn’t influence the overall efficiency of the converter much. The analysis of the proposed concept and a 26 Watt LED driver simulation results are presented.

An Efficient Light-emitting-Diode (LED) Driver circuit for DC-grid applications is proposed with Dimming control. The circuit consists of half bridge series resonant converter(SRC) whose input is double ended forward converter’s (DEFC) output in series with DC-grid voltage. The loss of power conversion can be decreased by processing partial amount of power for LED current regulation. The proposed driver having other advantages, including zero voltage switching of half-bridge inverter circuit, fixed switching frequency and higher efficiency. Double pulse width modulation (DPWM) is used for LED dimming control.

LEDs are the present day light sources which require suitable driver for maintaining the appropriate current in it for proper operation. If such kind of systems are powered from PV panels, the possibility of ripples in the source current are more based on the converter being used. This paper proposes a power controller to reduce the ripples in the source current with an ability of driving the LED. In the proposed circuit, a 3-phase full bridge series resonant inverter followed by a rectifier feeds the LED load. For regulating the current in the LED a small power converter is used additionally. Pulse Width Modulation (PWM) is used for dimming operation of the light source. Soft switching is used for high efficiency. The proposed converter is studied using MATLAB simulation. This configuration is also suitable for handling large power.

This paper furnish an input voltage controlled full-bridge inverter based LED driver. A Double-ended forward converter(DEFC) is used along with full-bridge inverter to regulate the input of full bridge inverter for variations in the supply voltage. Input voltage to the full bridge inverter is sum of primary DC voltage and output of DEFC. Input to DEFC is from primary source. Supply obtained for the proposed configuration can be from DC micro grid. Thus the full bridge inverter is operated with fixed frequency and fixed duty ratio to achieve ZVS over wide range of input voltage variations. Full bridge converter with interleaved operation of output inductor currents is used to achieve ripple free constant current for LED string. In this configuration, power processed by DEFC is low which doesn't influence significantly, the overall efficiency is expected to be high. The proposed circuit configuration analyzed and simulation results are presented.

This paper proposes a dual-frequency series resonant converter based LED driver which can drive two LED loads with independent control. In this converter one leg of the full bridge inverter operated at high frequency (HF) and the other leg of the inverter is operated at low frequency (LF). Two series resonant converters are connected across output of full-bridge inverter, which are tuned for HF and LF. The output voltages of LED loads are regulated independently by controlling duty cycle of respective legs of full-bridge inverter. To validate the proposed concept a 60 W (20W LF and 40 HF) LED driver is simulated in PSPICE and results are presented.

In Induction Heating (IH) cooking appliances more than one output is highly desirable. A three leg inverter is proposed for three output IH cooking application. It is operating with a constant frequency of 30.5 kHz and allows the power control in loads independently. On-off control technique in cyclic manner is used. The number of switching devices per load is two (i.e. one leg per load). Thus utilization of the switching devices is improved. It can be extended for more number of loads also. A 260 W prototype has been implemented. Experimental results have good agreement with the simulation results.

This study presents a light emitting diode driver circuit topology based on a full-bridge configuration with dimming control. It is more suitable for high power lighting loads. The proposed configuration has advantages of zero-voltage switching, reduced component count and high efficiency. It can power multiple lighting loads. Operation of the proposed circuit configuration is explained in detail and it is validated through simulated and experimental results on the 145 W experimental prototype with dimming control.