scholarly journals Power strategy in DC/DC converters to increase efficiency of electrical stimulators

2016 ◽  
Vol 26 (3) ◽  
Author(s):  
Pablo Aqueveque ◽  
Vicente Acuña ◽  
Francisco Saavedra ◽  
Adrien Debelle ◽  
Laurent Lonys ◽  
...  
Keyword(s):  
Power Efficiency ◽  
Power Transmission ◽  
Supply Voltage ◽  
Voltage Regulation ◽  
Limiting Factors ◽  
Battery Life ◽  
Output Stage ◽  
Traditional Use ◽  
Boost Converters ◽  
Hardware Designs

Power efficiency is critical for electrical stimulators. Battery life of wearable stimulators and wireless power transmission in implanted systems are common limiting factors. Boost DC/DC converters are typically needed to increase the supply voltage of the output stage. Traditionally, boost DC/DC converters are used with fast control to regulate the supply voltage of the output. However, since stimulators are acting as current sources, such voltage regulation is not needed. Banking on this, this paper presents a DC/DC conversion strategy aiming to increase power efficiency. It compares, in terms of efficiency, the traditional use of boost converters to two alternatives that could be implemented in future hardware designs.

scholarly journals Simulation of 2-Coil and 4-Coil Magnetic Resonance Wearable WPT Systems

Proceedings ◽  
2021 ◽  
Vol 68 (1) ◽  
pp. 13
Author(s):  
Yixuan Sun ◽  
Stephen Beeby
Keyword(s):  
Power Efficiency ◽  
Power Transmission ◽  
Rotation Angle ◽  
Wireless Power ◽  
Peak Efficiency ◽  
Frequency Splitting ◽  
At Resonance ◽  
Higher Power ◽  
The Impact ◽  
Proper Frequency

This paper presents the COMSOL simulations of magnetically coupled resonant wireless power transfer (WPT), using simplified coil models for embroidered planar two-coil and four-coil systems. The power transmission of both systems is studied and compared by varying the separation, rotation angle and misalignment distance at resonance (5 MHz). The frequency splitting occurs at short separations from both the two-coil and four-coil systems, resulting in lower power transmission. Therefore, the systems are driven from 4 MHz to 6 MHz to analyze the impact of frequency splitting at close separations. The results show that both systems had a peak efficiency over 90% after tuning to the proper frequency to overcome the frequency splitting phenomenon at close separations below 10 cm. The four-coil design achieved higher power efficiency at separations over 10 cm. The power efficiency of both systems decreased linearly when the axial misalignment was over 4 cm or the misalignment angle between receiver and transmitter was over 45 degrees.

scholarly journals High Step-Up Converter Based on Non-Series Energy Transfer Structure for Renewable Power Applications

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 689
Author(s):  
Luis Humberto Diaz-Saldierna ◽  
Jesus Leyva-Ramos
Keyword(s):  
Power Efficiency ◽  
Common Ground ◽  
Linear Models ◽  
Efficiency Improvement ◽  
Boost Converters ◽  
Renewable Power ◽  
Current Design ◽  
Alternative Sources ◽  
Transfer Structure ◽  
Laboratory Prototype

In this paper, a high step-up boost converter with a non-isolated configuration is proposed. This configuration has a quadratic voltage gain, suitable for processing energy from alternative sources. It consists of two boost converters, including a transfer capacitor connected in a non-series power transfer structure between input and output. High power efficiencies are achieved with this arrangement. Additionally, the converter has a common ground and non-pulsating input current. Design conditions and power efficiency analysis are developed. Bilinear and linear models are derived for control purposes. Experimental verification with a laboratory prototype of 500 W is provided. The proposed configuration and similar quadratic configurations are compared experimentally using the same number of components to demonstrate the power efficiency improvement. The resulting power efficiency of the prototype was above 95% at nominal load.

scholarly journals A 0.3 V Rail-to-Rail Ultra-Low-Power OTA with Improved Bandwidth and Slew Rate

2021 ◽  
Vol 11 (2) ◽  
pp. 19
Author(s):  
Francesco Centurelli ◽  
Riccardo Della Sala ◽  
Pietro Monsurrò ◽  
Giuseppe Scotti ◽  
Alessandro Trifiletti
Keyword(s):  
Low Power ◽  
Low Voltage ◽  
Supply Voltage ◽  
Cmos Process ◽  
Slew Rate ◽  
Large Signal ◽  
Output Stage ◽  
Ultra Low Power ◽  
Input Stage ◽  
Rail To Rail

In this paper, we present a novel operational transconductance amplifier (OTA) topology based on a dual-path body-driven input stage that exploits a body-driven current mirror-active load and targets ultra-low-power (ULP) and ultra-low-voltage (ULV) applications, such as IoT or biomedical devices. The proposed OTA exhibits only one high-impedance node, and can therefore be compensated at the output stage, thus not requiring Miller compensation. The input stage ensures rail-to-rail input common-mode range, whereas the gate-driven output stage ensures both a high open-loop gain and an enhanced slew rate. The proposed amplifier was designed in an STMicroelectronics 130 nm CMOS process with a nominal supply voltage of only 0.3 V, and it achieved very good values for both the small-signal and large-signal Figures of Merit. Extensive PVT (process, supply voltage, and temperature) and mismatch simulations are reported to prove the robustness of the proposed amplifier.

Design of the variable frequency oscillator in DC-DC converter

Circuit World ◽  
2019 ◽  
Vol 45 (2) ◽  
pp. 80-85
Author(s):  
Tian Lei ◽  
Nan Gong ◽  
Li Wang ◽  
Qin Qin Li ◽  
Heng Wei Wang
Keyword(s):  
Supply Voltage ◽  
Operating Frequency ◽  
Maximum Deviation ◽  
Variable Frequency ◽  
Cmos Process ◽  
Power Supply Voltage ◽  
Output Stage ◽  
Content Type ◽  
Oscillator Frequency ◽  
Light Load

Purpose Because of the logic delay in the converter, the minimum turn on time of the switch is influenced by the constant time. When the inductor current gets to the threshold of the chip, the control signal will delay for a period. This makes the inductor current rising with the increasing of the clock and leads to the load current out of control. Thus, this paper aims to design an oscillator with a variable frequency protection function. Design/methodology/approach This paper presents an oscillator with the reducing frequency applied in the DC-DC converter. When the converter works normally, the operating frequency of the oscillator is 1.5 MHz. So the inductor current has enough time to decay and prevent the power transistor damaging. After the abnormal condition, the converter returns to the normal operating mode automatically. Findings Based on 0.5 µm CMOS process, simulated by the HSPICE, the simulation results shows that the frequency of the oscillator linearly decreases from 1.5 MHz to 380 KHz when the feedback voltage less than 0.2 V. The maximum deviation of the oscillator frequency is only 6 per cent from −50°C to 125°C within the power supply voltage of 2.7-5.5 V. Originality/value When the light load occurs at the output stage, the oscillator frequency will decrease as the load voltage drops. The test results shows that when the circuit works in the normal condition, the oscillator frequency is 1.5 MHz. When the load decreased, the operating frequency is dropped dramatically.

Power Transmission and Voltage Regulation

2013 ◽  
pp. 19-42
Author(s):  
Vahid Majidzadeh Bafar ◽  
Alexandre Schmid
Keyword(s):  
Power Transmission ◽  
Voltage Regulation

scholarly journals Quasi-resonant inverter power pulsed radar system

2015 ◽  
pp. 27-32
Author(s):  
V. N. Dolov ◽  
V. F. Strelkov ◽  
V. V. Vanyaev ◽  
A. A. Kochnev
Keyword(s):  
Output Voltage ◽  
Closed Loop ◽  
Power Transmission ◽  
Voltage Regulation ◽  
Open Loop ◽  
Radar System ◽  
Resonant Converter ◽  
Resonant Inverter ◽  
Pulse Output ◽  
External Characteristics

Presented by quasi-resonant converter of a pulse of microwave power transmission device lamp radar with pulse output voltage regulation. The features of his work are given a mathematical model, the external characteristics and some simulation results in open-loop and closed-loop output voltage system.

scholarly journals Equivalent circuit modeling in GaN wireless power transmission including stray inductance and capacitance by measuring radiated emission

2022 ◽  
Author(s):  
Toshihide IDE ◽  
Mitsuaki Shimizu ◽  
Noriyuki TAKADA
Keyword(s):  
Power Transmission ◽  
Supply Voltage ◽  
Peak Shift ◽  
Stray Capacitance ◽  
Resonance Model ◽  
Series Resonance ◽  
Equivalent Circuit Modeling ◽  
Destructive Measurement ◽  
Output Capacitance ◽  
Radiated Emission

Abstract We establish the method for estimating the stray elements of the GaN-WPT circuit by measuring the radiated emission around the GaN switching device. By controlling the circuit supply voltage, the spectrum peak shift due to the output capacitance of the GaN-HEMT is observed. It is found that these peak shift characteristics include the influence of both the stray wire inductance and stray capacitance. By the fitting using the series resonance model, the value of the stray inductance and stray capacitance can be estimated in the non-destructive measurement in the GaN-WPT circuit.

scholarly journals Analysis On Power Gating Circuits Based Low Power VLSI Circuits (BCD Adder)

2021 ◽  
Vol 2089 (1) ◽  
pp. 012080
Author(s):  
M. Srinivas ◽  
K.V. Daya Sagar
Keyword(s):  
Energy Consumption ◽  
Low Power ◽  
Power Dissipation ◽  
Supply Voltage ◽  
Oxide Thickness ◽  
Cmos Technology ◽  
Digital Circuit ◽  
Leakage Power ◽  
Vlsi Circuits ◽  
Battery Life

Abstract Currently, energy consumption in the digital circuit is a key design parameter for emerging mobile products. The principal cause of the power dissipation during idle mode is leakage currents, which are rising dramatically. Sub-threshold leakage is increased by the scaling of threshold voltage when gate current leakage increases because oxide thickness is scaled. With rising demands for mobile devices, leakage energy consumption has received even greater attention. Since a mobile device spends most of its time in standby mode, leakage power savings need to prolong the battery life. That is why low power has become a significant factor in CMOS circuit design. The required design and simulation of an AND gate with the BSIM4 MOS parameter model at 27 0C, supply voltage of 0,70V with CMOS technology of 65nm are the validation of the suitability of the proposed circuit technology. AND simulation. The performance parameters for the two AND input gate are compared with the current MTCMOS and SCCMOS techniques, such as sub-threshold leakage power dissipations in active and standby modes, the dynamic dissipation, and propagation period. The proposed hybrid super cutoff complete stack technique compared to the current MTCMOS technology shows a reduction in sub-threshold dissipation power dissipation by 3. 50x and 1.15x in standby modes and active modes respectively. The hybrid surface-cutting technique also shows savings of 2,50 and 1,04 in power dissipation at the sub-threshold in standby modes and active modes compared with the existing SCCMOS Technique.

Optimal Design of Energy-Saving Induction Cooker Power Controller Based on Fuzzy Technology

2014 ◽  
Vol 678 ◽  
pp. 423-428
Author(s):  
Pin Qi Zheng ◽  
Qing Sheng Yu
Keyword(s):  
Fuzzy Control ◽  
Output Power ◽  
Power Supply ◽  
Supply Voltage ◽  
Operating Temperature ◽  
Voltage Regulation ◽  
Soft Switching ◽  
Switch Mode ◽  
Output Efficiency ◽  
Switch Voltage

Application of Soft-switching technique and fuzzy control is discussed to optimize traditional induction cooker controller. Soft-switching technique is used to improve output efficiency of induction cooker. Switch voltage regulation by fuzzy control are used to adjust output power of induction cooker. Soft-switching inverter consists of resonant DC link and LC resonant network. Resonant DC link is used to realize ZVS, and resonant network is used to eliminate harmonics. Fuzzy control based on look-up table is adopted to adjust duty cycle of switch mode regulated power supply, which changes the DC supply voltage, so that amplitude of AC signal inverted by induction cooker is changed to adjust output power of induction cooker according to the requirement, , ensuring the operating temperature aligned with the target temperature.

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