Single Stage Active Power Factor Correction Circuit for Street LED Light with Battery Backup

This paper introduces and uses a single-phase, high-power LED driver with a battery backup. The buck–boost converter and reverse converter are both combined to achieve optimal performance. In the first part of the integrated circuit, the buck–boost converter is simply used to adjust the power when operating in the non-continuous operating mode. The reverse converter provides free voltage to the LEDs when released as a remote DC–DC converter. The battery backup cycle directly charges the battery at the same power as the LED driver required and provides charging power when there is no electricity. This paper demonstrates the functionality of the entire system and proves that it is an effective solution for new lighting applications.

Effective Error Control Scheme in Real-Time Wireless Sensor Networks

Wireless Sensor Networks (WSNs) subsist on network of huge numbers of hubs that are distributed in unfriendly environments used for habitat monitoring and to observe changes in phenomena. These hubs are susceptible to faults such as energy exhaustion, hardware glitches, communication link errors, malicious attacks, which may lead to errors in message delivery. However, these systems are typically utilized to convey vital information in remote places. Thus, efficient error identification and correction is thereby required in order to maintain the accuracy of the received message. This paper aimed at designing high speed reverse converter for effective error control codes using Redundant Residue Number System in order to enhance the accuracy of messages delivered for real-time WSNs. In order to attain a greater error correction, a reverse converter which was based on Mixed Radix Conversion was designed for the moduli set {2n+1-1, 2n, 2n-1}. In addition to this moduli, an extra redundant moduli set{2n+1+3, 22n - 3} is also designed for higher correctness. For correction and identification of corrupted values in the original data, maximum likelihood was used. The results obtained show that the suggested moduli set offers low energy utilization and consistency of the received message in real time WSNs.

An Efficient Reverse Converter for the Four Non Coprime Moduli Set {2n,2n-1,2n-2,2n-3}

In this paper, residue to binary conversion is presented for the four moduli setsharing a common factor. A new and efficient converter for the moduli set using multipliers, carry saves and modular adders is proposed based on a cyclic jump approach. A theoretical hardware implementation and comparison with a state-of- the- art scheme showed that the proposed scheme performed better. The 4- moduli set selected provides a larger dynamic range which is needed for Digital Signal Processing (DSP) applications [7].

A Multifunctional Unit For Reverse Conversion and Sign Detection Based on The 5-Moduli Set

The high dynamic range residue number system (RNS) five-moduli { 2 2n , 2 n + 1, 2 n − 1, 2 n + 3, 2 n − 3 } has been recently introduced as an arithmetically balanced five-moduli set for computation-intensive applications on wide operands such as asymmetric cryptography algorithms. The previous dedicated design of RNS components for this moduli set is just an unsigned reverse converter. In order to utilize of the moduli set { 2 2n , 2 n + 1, 2 n − 1, 2 n + 3, 2 n − 3 } in applications handling with signed numbers, two important components are needed: Sign Detector and Signed Reverse Converter. However, having both of these components results in high hardware requirements which makes RNS impractical. This paper overcomes to this problem by designing a unified unit which can perform both signed reverse conversion as well as sign detection through the reuse of hardware. To the authors knowledge, this is the first attempt to design sign detector for a moduli set including 2n±3 moduli. In order to achieve a hardware-amenable design, we first improved the performance of the previous unsigned reverse converter for the moduli set { 2 2n , 2 n + 1, 2 n − 1, 2 n + 3, 2 n − 3 }. Then, we extract a sign detection method from the structure of the reverse converter. Finally, we make the unsigned reverse converter to sign converter through the use of the extracted sign signal from the reverse converter. The experimental results shown that the proposed multifunctional unit has relatively the same performance in terms of area, delay and power-consumption than the previous unsigned reverse converter for the set { 2 2n , 2 n + 1, 2 n − 1, 2 n + 3, 2 n − 3 } while it can perform two complex signed operations.

Comparative analysis of thyristor schemes of marine DC motor control

The article considers the problem of the DC motors control that are often used in many electric drive systems. Due to the progress of industrial electronics and technology it has become possible to develop more efficient motor control circuits. The conventional speed control methods commit power losses in the system, which can be minimized by using the power electronics strategy. There is considered the thyristor control of DC motors of the ship electric drive. The DC motor control systems are described and simulation models in the MATLAB Simulink program are presented. The thyristor methods for controlling a DC motor speed are listed: single-phase semi-controlled converter (for motors with power up to 15 kW); single-phase drive with a controlled converter (available to operate in two quadrants); three-phase semi-controlled converter; three-phase controlled converter; single-phase reverse converter realized by connecting two single-phase converters (ensuring multi-mode operation); three-phase reverse converter realized as a single-phase converter. The mechanical characteristic of a DC motor was illustrated when the voltage supplied to the armature winding changed. It has been stated that control of the armature voltage is more favorable for speeds below the rated speed; flow control is preferable for speeds above the nominal speed. It has been inferred that speed control by means of power electronics devices provides large energy savings, in contrast to the traditional speed control methods, since the traditional methods experience significant energy losses.