In the poling process of PZT ceramics, the poling temperature is a critical condition. When the poling temperature is too low, no matter how high is the poling field and how long is the poling time, the planar electromechanical coupling factor kpis lower. When the poling temperature is higher enough, the kpcan reach to a saturated value with a lower poling field and short poling time. The variation of dielectric constant with the poling conditions is the same as that of planar electromechanical coupling factor. When poling with a low temperature, the dielectric constant after poling is lower than 1400. When poling with higher temperature, no matter how high is the poling field and how long is the poling time, the dielectric constant after poling is higher than 1500.
A new photovoltaic solar cell charging system with fuzzy logic control is proposed and designed. This kind of solar energy storage system is composed of a solar cell, a charger, batteries, a buck converter and a digital signal processor. It mainly applies a low-voltage level translator to control the pulse charging current of a lead-acid battery and also combines the fuzzy control method to improve the charging efficiency, suppress the abnormal temperature rise in the battery, lengthen the battery life-time, reduce the additional waste, etc..Experimental and simulated results are shown to demonstrate and compare the validity of the system and verify the effectiveness with each other.
In this study, the MITSUBISHI PLC (FX2n-32MR) is used to achieve the lead-acid battery monitoring system. The battery is by way of rater and FX-2AD used in charging state. The analog and digital data are transmitted to PLC to get the real-time monitoring and control. During charging, time and voltage keep constant to reach charging optimization condition. In addition, AD590 is used as reference measurement and battery protection in temperature control.
A robust circuit design using matching technology to design the ultrasonic welding transducer driver with zero voltage switching is proposed. The feedback output voltage is used to control the oscillator frequency to achieve the self-tracking function. Experimental results exhibit that the Class-E inverter circuit can be effectively and stably applied on the high power ultrasonic welding system.
Amorphous silicon (a:Si) recrystalized to poly-silicon (poly:Si) in different gas environments by excimer laser annealing (ELA) is studied. Variations of threshold laser power for the generation of surface ablation in pure N2 gas and the mixture of N2:98% and O2:2% environments are also investigated, respectively. From experiments, it is found the combination of N2:98% and O2:2% gas can enhance the threshold laser power from 320mJ/cm2 to 390mJ/cm2 for the suppressing of surface ablation phenomenon. In the condition of average grain over 0.25um, the process window (i.e. laser power for processing ability) is 30mJ/cm2 for pure N2 only, but is 50mJ/cm2 for the combination of N2:98% and O2:2%.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.