Reverse Polarity Protection Research Articles

Design and Simulation of Cyclic Battery Tester

Abstract The paper presents an approach to the modelling of a cyclic battery tester and contains observations about lithium-ion (Li-ion) batteries, charging/discharging procedures, conditions and protections which must be observed during the testing process. The main goal was to create and simulate a schematic which will be capable of cyclically testing Li-ion battery cells. Regulation of the final schematic is based on cascade connections of operation amplifiers, which work as a voltage source with current-limiting functions. The power part is created by two MOSFETs connected as a half-bridge. This topology allows current to flow in both directions (from and to the battery). Final simulation is supplemented by protections such as reverse polarity protection, short circuit protection and overvoltage protection during charging. Proper operation of the whole connection is demonstrated by the simulation outputs in the final section.

Fully Integrated Sensor Electronics for Inductive Proximity Switches Operating up to 250 °C

Abstract In this paper we present an integrated circuit for inductive proximity switches which requires very few external components and can operate under ambient temperatures up to 250 °C. The sensor system is realized in the Fraunhofer IMS H035 technology which was specifically developed for high temperature operation. The core of the circuit is built of an oscillator which is equipped with a peak detector and readout electronics for threshold detection, references and voltage regulators to provide the necessary internal voltages as well as extensive trimming capabilities to compensate for temperature effects. The circuit can be operated from a single dc-voltage supply from 12 to 35 Volts. Calibration data can be stored in an internal EEPROM. Switching distance and hysteresis are programmable for adapting the circuit to a wide range of different detector coils and sensor geometries. Two output signals are provided that can be independently set to function as push/pull or single ended switches with programmable polarity. The only external components required are blocking capacitors for supply voltage stabilization and the LC resonator circuitry. Reverse polarity protection and special high temperature ESD and clamping structures are also fully integrated on the silicon die.

Off-grid electrification with solar home systems: An appraisal of the quality of components

Solar home systems (SHS) are seen as an attractive option for off-grid electrification in rural areas in developing countries. The combined effect of declining photovoltaic module costs and success in micro-finance has resulted in increased SHS installations in emerging economies in Asia such as Bangladesh. Majority of the SHS components are now manufactured locally with the exception of PV cells. Considering the role of component quality in SHS performance, technical quality of four key SHS components: solar panel, battery, charge controller and lamp circuit (inverter) from market-leading manufacturers were evaluated in this study in laboratory settings, against national and international standards. All of the tested components met some evaluation criteria in their respective categories but none met all. Key performance failures were found to be related to inverter efficiency, reverse polarity protection in charge controllers and battery capacity, which are critical for optimum performance of the system. Findings in this study point towards an ineffective regulatory mechanism for quality assurance and the protection of consumer rights, which needs to be rectified for maintaining public confidence and sustaining the growth of SHS based off-grid electrification.

Chemical Synthesis of O-Glycosylated Human Interleukin-2 by the Reverse Polarity Protection Strategy.

The chemical synthesis of human interleukin-2 (IL-2) , having a core 1 sugar, by a ligation method is reported. Although IL-2 is a globular glycoprotein, its C-terminal region, in particular (99-133), is extremely insoluble when synthesized by solid-phase method. To overcome this problem, the side-chain carboxylic acid of the Glu residues was protected by a picolyl ester, thus reversing its polarity from negative to positive. This reverse polarity protection significantly increased the isoelectric point of the peptide segment and made it positive under acidic conditions and facilitated the purification. An efficient method to prepare the prolyl peptide thioester required for the synthesis of the (28-65) segment was also developed. These efforts resulted in the total synthesis of the glycosylated IL-2 having full biological activity.

Chemical Synthesis of O‐Glycosylated Human Interleukin‐2 by the Reverse Polarity Protection Strategy

AbstractThe chemical synthesis of human interleukin‐2 (IL‐2) , having a core 1 sugar, by a ligation method is reported. Although IL‐2 is a globular glycoprotein, its C‐terminal region, in particular (99‐133), is extremely insoluble when synthesized by solid‐phase method. To overcome this problem, the side‐chain carboxylic acid of the Glu residues was protected by a picolyl ester, thus reversing its polarity from negative to positive. This reverse polarity protection significantly increased the isoelectric point of the peptide segment and made it positive under acidic conditions and facilitated the purification. An efficient method to prepare the prolyl peptide thioester required for the synthesis of the (28‐65) segment was also developed. These efforts resulted in the total synthesis of the glycosylated IL‐2 having full biological activity.

HV-CMOS Design and Characterization of a Smart Rotor Coil Driver for Automotive Alternators

The work presents a single-chip integrated rotor coil driver (RCD) that can be used in automotive alternators. It integrates the power switch with the control circuitry and the diagnostics; with respect to the state of the art, new functionalities are integrated such as full reverse polarity protection and programmable output slope control against in-rush currents and current spike transients. The paper will discuss the driver IC design from the choice of the architecture to the real silicon implementation. The proposed innovative RCD has been implemented in a 0.35 μm HV-CMOS technology and has been embedded in a mechatronic brush-holder regulator system-on-chip for an automotive alternator. The simulation results and experimental measurements prove the effectiveness of the proposed RCD facing the harshest automotive conditions.

The New Voltage Level 48 V for Vehicle Power Supply

Some presumptions had to be made to define the voltage range and were constituted in the following assumptions, ❸: : For DC voltages below 60 V a shock protection is not required. This is valid up to ripples of maximum 10% rms. : For AC voltages the requirements of ISO 6469-3 have to be considered. Up to AC voltages Ueff ≤ 30 V a shock protection is not required. : Generating or regenerating components must not cause a transition into the overvoltage range. : During regular operation of the 48 V power supply any voltages above the shock protection limit must not occur. : There is a common ground for 12 V and 48 V. The contacts have to be locally separated. : Ground for 12 V and 48 V control units have to implemented separately. : Loss of ground of a 48 V component must not cause a disturbance or a destruction of the communication networks and the electrical networks : All data for voltages and currents are related to the I/Os of the component and do not include any voltage drops caused by the wiring harnesses in the vehicle. : The base is existing Li-ion accumulator technology (like LiFePO4, LiNiMnCo und Li-titanium). The voltage range shall be valid for further and new technology developments. : There will not be a reverse polarity protection at 48 V. Adequate measures have to be applied in order to exclude any reverse polarity. A jump start at 48 V is not scheduled. : A single failure must not cause a short circuit between 48 V and 12 V (or 24 V) systems. Open image in new window ❸ Definition of the voltage ranges

A hybrid study on self-generators based on system for high-efficiency

This study incorporates a welder and a generator as needed while using the generator to be used as a welder is to configure the system. As such, in order to offer an integrated system to prevent the rapid charging process to manage the power state information, system configuration is the most important. Ideall y, the random controls the flow of charge is ideal for that. When charging is good as long as possible, less current. However, In this study, the most ideal fusion welder and generator as required by the generator or welder can be used as a system is proposed. Specifically, the damage can be caused by carelessness, so short-circuit protection, overload protection, reverse polarity protection, automatic charging system is all about, including the ability to adjust.

Design, qualification and production of integrated sensor interface circuits for high-quality automotive applications

The product development of integrated sensor interface circuits for automotive applications requires various additional features accounting for the harsh environment in automotive applications. Unlike in a pure prototype development yield is key to achieve the required automotive quality targets of zero ppm. The paper first describes the general automotive requirements like electro-static discharge (ESD) and reverse polarity protection. Then the design flow from specification until start of production for an industrial product development is outlined. Finally, the requirements for automotive circuits qualification based upon the international standard AEC Q-100 are described. Furthermore, the automotive test requirement and additional measures such as the dynamic part average testing and statistical bin analysis are discussed to achieve at zero ppm quality. The paper includes a real product example of ZMD.