Min-Hsuan Hung

Battery management system with dual-balancing mechanism for LiFePO 4 battery module

This paper presents a battery management system of LiFePO4 battery module with dual-balancing mechanism. First, the employed battery management can accurately capture some important parameters of the LiFePO4 battery module, including voltage, current, temperature, and providing protection functions for the battery module. Next, these obtained parameters of the battery are transmitted to the microcontroller through the inter-integrated circuit (I2C-bus). And then the microcontroller can control the pack balancing circuit according to the received battery information. The proposed dual-balancing mechanism can avoid battery unbalance so as to increase the utility rate of the battery. Finally, some experimental results are used to verify the feasibility of the complete system.

Reducing the Parasitic Capacitance Effect in LCD Panel for Backlight Module Based on Primary-Side Control and DPLL Technique

A digital-phase-locked-loop (DPLL)-based backlight module is proposed to reduce the leakage current effect in liquid crystal display (LCD). In this paper, the mathematical model of the cold cathode fluorescent lamp (CCFL) current, including the parasitic capacitance in LCD panel, is conducted to explore the influence of leakage current effect. Moreover, the primary-side control and the DPLL function are integrated to form a feedback mechanism to track the optimal operating frequency. Then, the influence of parasitic capacitance can be reduced so as to eliminate the leakage current effect. The experimental results agree with the theoretical predictions.

Eliminating the Arcing Phenomenon in Field Emission Lighting Based on the Impulse-Power Technique

An impulse-power generator, which encompasses low-cost and simple configuration, operated in discontinuous conduction mode for driving a tubular field emission lamp (TFEL) is proposed. The proposed system based on flyback topology can provide impulse-power driving to eliminate arcing phenomenon caused by traditional dc voltage driving. Therefore, both the lighting performance and lamp lifespan are improved. This paper also presents a simple feedback mechanism to capture the peak value of the impulse lamp current for stabilizing lamp luminance. Next, an equivalent model of the TFEL is constructed to exhibit its capacitive characteristics. Furthermore, the circuit configuration and mathematical models of each operation mode in a switching cycle are also derived, and detailed design considerations are presented. All the experimental results agree with the computer simulations to verify the validity of the theoretical predictions.

Series-resonant battery charger with synchronous rectifiers for LiFePO 4 battery pack

This paper presents a battery charger for LiFePO4 battery pack based on a series-resonant topology. The synchronous rectification technique is incorporated into the proposed system to improve the charging performance. Moreover, the frequency domain analysis and the equivalent circuit of each operation mode are descried and conducted. The frequency characteristics of the proposed system are also detailed from the derived mathematical models. Besides, a simple charging strategy is adopted to verify the feasibility. All the experimental results agree with the theoretical predictions.

High voltage driving circuit with negative pulse feature for tubular field emission lamp

A high voltage driving circuit having pulse mode is proposed for driving tubular field emission lamp (FEL). The employed main circuit topology, which is a flyback converter operated in discontinuous conduction mode (DCM), will not only provide a low cost negative pulse feature, but also eliminate the arcing phenomenon caused by traditional DC driving so as to improve the system efficiency and the lamp lifespan. In this paper, an equivalent model of the FEL is constructed to exhibit its capacitive characteristics. Moreover, each operation mode in a switching cycle is also described. And then a complete design considerations and mathematical model are detailed. All the experimental results agree with the computer simulations to verify the theoretical predictions.

Dual-balancing control for improving imbalance phenomenon of Lithium-ion battery packs

In this paper, a battery management system incorporating with dual-balancing mechanism applied to Lithium-ion battery module is presented. First, the employed battery management system can accurately capture some important parameters of the Lithium-ion battery module, including voltage, current, temperature, and providing protection functions for the battery module under abnormal conditions. Next, these obtained parameters of the battery are transmitted to the microcontroller through the inter-integrated circuit (I2C-bus). And then the microcontroller can control the pack-balancing circuit according to the received battery information. The proposed dual-balancing mechanism can avoid imbalance between adjacent battery packs so as to increase the utility rate of the whole battery module and to prolong the battery lifespan. Finally, some experimental results are used to verify the feasibility and validity of the proposed system.

Pulse current generator for driving tubular field emission lamp based on DCM flyback converter

This paper proposes a pulse current generator operated in discontinuous conduction mode for driving a tubular field emission lamp (TFEL). The proposed system based on flyback topology can provide pulse power driving to eliminate the temperature rise and arcing phenomenon caused by the traditional constant voltage driving. Therefore, both the lighting efficiency and lamp lifespan are improved. In this paper, an equivalent model of the TFEL is constructed to exhibit its capacitive characteristics. Moreover, the circuit configuration and each operation mode in a switching cycle are also described. And then a complete design considerations and mathematical model are discussed in detail. All the experimental results agree with the computer simulations to verify the theoretical predictions. Copyright

High voltage pulse generator with energy recovery circuit for driving CNT field emission lamp

A flyback converter incorporating an energy recovery circuit is proposed to generate high voltage pulses for driving carbon nanotube field emission lamp (CNT-FEL). The employed energy recovery circuit will not only eliminate the arcing phenomenon caused by traditional DC driving, but also recover the excess energy to DC bus so as to improve the system efficiency. In this paper, we construct an equivalent model of the CNT-FEL to exhibit its electric characteristics. Moreover, the mathematical models of each operation mode are also derived. And then a complete design considerations and mathematical model are detailed. All the experimental results agree with the computer simulations to verify the theoretical predictions.

Design of MCU-based electronic ballast for electrodeless fluorescent lamp

In this paper, A MCU-based electronic ballast for electrodeless fluorescent lamp (EFL) is implemented. The used two stage system consists of a power factor corrector and a class D resonant inverter. In addition, an 8-bit microcontroller is employed to act as the control core of the system to achieve digital control feature. Moreover, we not only discuss the lamp model, derive the frequency characteristics, but also provide design considerations to determine the resonant components and other system parameters. Finally, the experimental results are used to verify the feasibility and validity of the proposed system.

A MCU-based intelligent charger with multi-charging mode

A MCU-based charger for the LiFeO4 battery pack is implemented in this paper. The main circuit is a full-bridge phase-shift converter. The user can select the charging strategy and observe the state of charge (SOC) of the battery from the operation interface. Moreover, the proposed charger system communicates with the battery management system via the I2C interface, and generates the charging current according to the estimated SOC and the selected operation mode. In addition, the charging current is kept at preset constant value by modulating the phase-shift amount to short the charging time and improve the battery lifespan. Furthermore, there are three charging strategy for user selection. All the experimental results are also provided.