Small-signal switching-stage gain of duty-cycle controlled dc-to-dc chopper regulators

This paper introduces a novel topology of the proposed converter that has these merits: (i) the topology of the converter is based on conventional boost and buck-boost converters, which has caused its simplicity; (ii) the voltage gain of the converter has provided higher values by the lower value of the duty cycle; (iii) due to the use of high-efficiency conventional topologies in its structure, the efficiency of the converter keeps its high value for a great interval of duty cycle; (iv) besides the increase of the voltage gain, the current/voltage stresses of the semiconductors have been kept low; (v) the continuous input current of this converter reduces the current stress of the capacitor in the input filter. It is worth noting that the proposed converter has been discussed in both ideal and non-ideal modes. Moreover, the operation of the converter has been discussed in both continuous/discontinuous current modes. The advantages of the converter have been compared with recently suggested converters. In addition, the different features of the converter have been discussed for different conditions. In the small-signal analysis, the appropriate compensator has been designed. Finally, the simulation and experimental results have been reported for 90 W output power, 90 V output voltage, 3-times voltage gain, and 100 kHz switching frequency.

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Small-signal duty cycle to inductor current transfer function for boost PWM DC-DC converter in continuous conduction mode

2004 IEEE International Symposium on Circuits and Systems (IEEE Cat. No.04CH37512) ◽

10.1109/iscas.2004.1329943 ◽

2004 ◽

Cited By ~ 16

Author(s):

B. Bryant ◽

M.K. Kazimierczuk

Keyword(s):

Transfer Function ◽

Duty Cycle ◽

Small Signal ◽

Current Transfer ◽

Conduction Mode ◽

Continuous Conduction Mode

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Two-photon excitation microscopy in cellular biophysics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100136684 ◽

1995 ◽

Vol 53 ◽

pp. 62-63

Author(s):

David W. Piston ◽

Brian D. Bennett ◽

Robert G. Summers

Keyword(s):

Confocal Microscopy ◽

Laser Beam ◽

Duty Cycle ◽

Excited Electronic State ◽

Input Power ◽

Two Photon ◽

Simultaneous Absorption ◽

Photon Excitation ◽

Very High ◽

Two Photon Excitation

Two-photon excitation microscopy (TPEM) provides attractive advantages over confocal microscopy for three-dimensionally resolved fluorescence imaging and photochemistry. Two-photon excitation arises from the simultaneous absorption of two photons in a single quantitized event whose probability is proportional to the square of the instantaneous intensity. For example, two red photons can cause the transition to an excited electronic state normally reached by absorption in the ultraviolet. In practice, two-photon excitation is made possible by the very high local instantaneous intensity provided by a combination of diffraction-limited focusing of a single laser beam in the microscope and the temporal concentration of 100 femtosecond pulses generated by a mode-locked laser. Resultant peak excitation intensities are 106 times greater than the CW intensities used in confocal microscopy, but the pulse duty cycle of 10-5 maintains the average input power on the order of 10 mW, only slightly greater than the power normally used in confocal microscopy.

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Acoustic-Reflex Dynamics for Pulsed Signals

Journal of Speech and Hearing Research ◽

10.1044/jshr.2102.295 ◽

1978 ◽

Vol 21 (2) ◽

pp. 295-308

Author(s):

Terry L. Wiley ◽

Raymond S. Karlovich

Keyword(s):

Duty Cycle ◽

Acoustic Impedance ◽

Normal Hearing ◽

Broadband Noise ◽

Threshold Shift ◽

Temporary Threshold Shift ◽

Acoustic Reflex ◽

Stapedius Muscle ◽

Duty Cycles

Contralateral acoustic-reflex measurements were taken for 10 normal-hearing subjects using a pulsed broadband noise as the reflex-activating signal. Acoustic impedance was measured at selected times during the on (response maximum) and off (response minimum) portions of the pulsed activator over a 2-min interval as a function of activator period and duty cycle. Major findings were that response maxima increased as a function of time for longer duty cycles and that response minima increased as a function of time for all duty cycles. It is hypothesized that these findings are attributable to the recovery characteristics of the stapedius muscle. An explanation of portions of the results from previous temporary threshold shift experiments on the basis of acoustic-reflex dynamics is proposed.

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