High Efficiency Alternating Current Driver for Capacitive Loads Using a Current-Balance Transformer

Abstract

This paper proposes a new alternating current driving method for highly capacitive loads such as plasma display panels or piezoelectric actuators, etc. In the proposed scheme, a current balance transformer, which has two windings with the same turnratio, provides not only a resonance inductance for energy recovery but also a current balance among all of the switching devices of the driver for current stress reduction. The smaller conduction loss than conventional circuits occurs due to the dual conduction paths which are parallel each other in the current balance transformer. Also, the leakage inductances of the transformer are utilized as resonant inductors for energy recovery by the series resonance to the capacitive load. Furthermore, the resonance contributes to the small switching losses of the switching devices by soft-switching operation. To confirm the validity of the proposed circuit, prototype hardware with a 12-inch mercury-free flat fluorescent lamp is implemented. The experimental results are compared with a conventional energy-recovery circuit from the perspective of luminance performances.

Low-Cost High-Efficiency PDP Sustaining Driver with a Resonance Bias Level Shift

“…Although the Weber and Wood circuit has been employed by many PDP makers, it still has some undesirable drawbacks. When charging and discharging the PDP, parasitic components, such as equivalent series resistor (ESR) and diode forward voltage drop, prevent the panel from being fully charged to V S and discharged to 0 V [10]- [12]. This scenario results in hard switching operation in all H-bridge inverter switches, excessive surge current, serious power dissipation, EMI noise, and undesirable voltage oscillation across the PDP.…”