scholarly journals Analysis of Fixed-Frequency Voltage Regulating and Fixed- Frequency Duty Cycle in Magnetic Induction Wireless Charging

2021 ◽  
Vol 632 ◽  
pp. 032034
Author(s):  
Wei Sun ◽  
Weimin Li
Keyword(s):  
Duty Cycle ◽  
Magnetic Induction ◽  
Wireless Charging ◽  
Fixed Frequency

Analysis of the Influence and Number of Turns on the Smartphone Wireless Charger on the Output Power of the Wireless Charger

2020 ◽  
Vol 10 (1) ◽  
pp. 20-25
Author(s):  
Donny Firmansyah
Keyword(s):  
Output Power ◽  
Magnetic Induction ◽  
Secondary Coil ◽  
Wireless Charging ◽  
Transmitted Power ◽  
Primary Coil ◽  
Power Test ◽  
Transmission Distance ◽  
Coil Diameter

Charging the smartphone battery can be done via powerbank or default charger from the smartphone still using the cable for charging the electricity. Charging using a cable certainly limits the use of the smartphone when it is charging. Smartphone users can not be far from the electric socket which of course is troublesome if this happens in the middle of a room that has a few electrical sockets. To solve this problem, now many wireless charging smartphones or smartphones have been developed wireless charger. Behind the benefits obtained from a wireless charger, it also has disadvantages, namely the transmission distance is short, even there is no distance and the transmitted power is unstable. Wireless chargers are based on the principle of magnetic induction in which electricity is transferred between two objects through a coil. Wireless charger consists of the primary coil as a charger (usually in the form of a thin board or cylinder), and the secondary coil is located on the back of the cellphone. Based on the results, the output power is obtained. The largest wireless charger is 0.027W with a coil diameter of 8cm in all the number of primary coils, namely 40 turns, 50 turns, and 60 turns at a primary and secondary coil distance of 0cm to 1cm. The farthest distance from the wireless charger output power test is 6cm as well as the 8cm coil diameter for all the number of primary coil turns, namely 40 turns, 50 turns, and 60 turns.

scholarly journals ZVS-Operation of LLC Resonant Inverter with Phase Limit Control for Induction furnace

2019 ◽  
Vol 13 (1) ◽  
pp. 29-36
Author(s):  
Piyasak Kranprakon ◽  
Anawach Sangswang ◽  
Sumate Naetiladdanon
Keyword(s):  
Computer Simulation ◽  
Duty Cycle ◽  
Room Temperature ◽  
Induction Furnace ◽  
Heating Process ◽  
Fixed Frequency ◽  
Zero Voltage Switching ◽  
Resonant Inverter ◽  
Zero Voltage ◽  
Voltage Switching

This paper presents an LLC resonant inverter with phase limit control to guarantee zero voltage switching (ZVS) operation and protect switching devices from spike current during the heating process. The output power is controlled by using the asymmetrical duty cycle (ADC) modulation. With phase limit control, the non-ZVS operation and spike current caused by a change of duty cycle with fixed frequency and load Curie’s temperature can be eliminated. The proposed method is confirmed through computer simulation and hardware experiment. The experimental results are provided with the heating of a 300 g of Tin from room temperature until melting at 232 ˚C.

The Development of the LOT-Bekesy Test for Nonorganic Hearing Loss

1971 ◽  
Vol 14 (3) ◽  
pp. 605-617 ◽  
Author(s):  
Karl W. Hattler
Keyword(s):  
Duty Cycle ◽  
Screening Tests ◽  
Correct Identification ◽  
Test Results ◽  
Fixed Frequency ◽  
Continuous Tone ◽  
Identification Threshold ◽  
Type V ◽  
Off Time ◽  
Normal Adults

During Experiment 1, 10 normal adults maintained the loudness of 1 kHz tones at 50 and 80 dB SPL via the Bekesy audiometer. Loudness memory tracings were compared for one continuous and six pulsed conditions in an attempt to define the temporal parameters which are related to the Type V Bekesy pattern. At both intensities tracking levels increased in SPL with a decrease in the duty cycle of pulsed signals. Within Experiment 2, the lengthened off-time (LOT) test employed a 20% duty cycle pulsed tone for comparison with the 100% continuous tone tracing. LOT test results were compared to conventional fixed-frequency Bekesy results which employs a 50% pulsed tone. LOT signals yielded significantly more Type V separation of pulsed and continuous tracings among the nonorganic patients than conventional Bekesy signals thus yielding a higher rate of correct identification. Threshold tracings for organic patients were unaffected by lengthening the off time from the conventional 200 to 800 msec. For Experiment 3 the LOT-Bekesy test was administered to 340 unselected patients in a clinical setting. The test correctly identified 95% of the nonorganic patients and 99.6% of the organic group for an overall efficiency of 98.3%. The LOT test appears to have some advantages over established screening tests for nonorganicity.

The Type V Bekesy Pattern: The Effects of Loudness Memory

1968 ◽  
Vol 11 (3) ◽  
pp. 567-575 ◽  
Author(s):  
Karl W. Hattler
Keyword(s):  
Young Adults ◽  
Duty Cycle ◽  
Test Signal ◽  
Preliminary Training ◽  
Learning Effects ◽  
Fixed Frequency ◽  
Temporal Parameters ◽  
Pure Tones ◽  
Loudness Adaptation ◽  
Type V

Ten trained, audiometrically normal young adults heard a 1K-Hz reference tone at 50-dB or 80-dB SPL. They were instructed to maintain the reference loudness throughout a three-minute 1K-Hz fixed-frequency run. Seven test signals, consisting of one sustained and six differentially interrupted pure tones, were employed for loudness-memory tracking. Preliminary training eliminated learning effects. Thirty-second pretracking adaptation periods produced loudness adaptation which was complete to asymptote for each test signal. The tracking levels were inversely related to the signal’s duty cycle and were independent of other temporal parameters such as on-duration and interruption rate. The occurrence of the Type V Bekesy audiogram is attributed to the differential effects of memory upon the loudness of sustained and interrupted pure tones.

scholarly journals An Open-Loop Start-up Method for LLC Resonant Converter with Fixed Frequency and Variable Duty Cycle

2021 ◽  
Vol 2022 (1) ◽  
pp. 012012
Author(s):  
Fei Xue ◽  
Yong Ren ◽  
Yuqi Yang ◽  
Lei Zhou ◽  
Hengshan Xu ◽  
...  
Keyword(s):  
Duty Cycle ◽  
Open Loop ◽  
Resonant Converter ◽  
Fixed Frequency ◽  
Start Up ◽  
Llc Resonant Converter

Two-photon excitation microscopy in cellular biophysics

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.

Sign in / Sign up

Export Citation Format

Share Document