A Novel Intelligent Load Control Switch Based on Dynamic Compensation Method for Current Zero-Crossing Point

2012 ◽  
Vol 433-440 ◽  
pp. 4717-4724 ◽  
Author(s):  
Gui Lin Zheng ◽  
Zhi Fu Zhang
Keyword(s):  
Load Control ◽  
Electric Load ◽  
Dynamic Compensation ◽  
Zero Crossing ◽  
Term Operation ◽  
Control Switch ◽  
Ac Current ◽  
New Type ◽  
Current Zero ◽  
Crossing Point

A new-type of intelligent electric load control switch composed of three separate magnetic latching relays is presented. A method of AC current and voltage sampling and root mean square (RMS) calculation is employed to ensure reliable operation of the electric load. The method possesses such features as less hardware requirements, good real-time performance, high frequency interference eliminating. Current zero-crossing break is the most outstanding advantage of the switch. In order to guarantee the magnetic latching relay shut off at current zero-crossing point accurately in long term operation, a dynamic compensation for delay time is proposed based on all-around research of the properties of magnetic latching relay actuation time. Finally, an application of the switch in the electric load control system constructed via CAN bus and ZigBee network is well brought forth.

Temperature and Humidity Controller Based on P89LPC920FDH

2014 ◽  
Vol 539 ◽  
pp. 577-580
Author(s):  
Dong He Xi ◽  
Juan Du
Keyword(s):  
Time Delay ◽  
Control Circuit ◽  
Circuit Board ◽  
Trigger Pulse ◽  
Zero Crossing ◽  
The Core ◽  
Temperature And Humidity ◽  
Current Zero ◽  
Crossing Point ◽  
Ac Conduction

This paper describes the design of a temperature and humidity controller, the controller takes P89LPC920FDH SCM as the core. P89LPC920FDH micro-controller integrated with internal comparator, watchdog timer, and reset circuit modules. The main control circuit board uses comparator to detect alternating current zero crossing point, uses the timer after a time delay to thyristor trigger pulse to control the hair AC conduction angle, thereby heating power control circuit to control the temperature and humidity of the environment, the purpose of.

scholarly journals Research on fast solid state DC breaker based on a natural current zero-crossing point

2014 ◽  
Vol 2 (1) ◽  
pp. 30-38 ◽  
Author(s):  
Wang Xiang ◽  
Yu Hua ◽  
Jinyu Wen ◽  
Meiqi Yao ◽  
Naihu Li
Keyword(s):  
Solid State ◽  
Zero Crossing ◽  
Dc Breaker ◽  
Current Zero ◽  
Crossing Point

Development and Validation of Derivative Spectroscopic Method for Simultaneous Estimation of Cefadroxil and Probenecid

2014 ◽  
Vol 7 (1) ◽  
pp. 2350-2355
Author(s):  
Pratik S Mehta ◽  
Pratik R. Patel ◽  
Rajesh R Parmar ◽  
M M K Modasiya ◽  
Dushyant A Shah
Keyword(s):  
Spectroscopic Method ◽  
Spectral Interference ◽  
Synthetic Mixture ◽  
Simultaneous Estimation ◽  
Zero Crossing ◽  
First Order ◽  
Derivative Spectroscopy ◽  
Development And Validation ◽  
Crossing Point

A novel, simple, accurate, sensitive, precise and economical derivative spectroscopic method was developed and validated for the determination of cefadroxil and probenecid in synthetic mixture. First order derivative spectroscopy method was adopted to eliminate spectral interference. The method obeys Beer’s Law in concentration ranges of 4-36 μg/ml for cefadroxil and of 5-25 μg/ml of probenecid. The zero crossing point for cefadroxil and probenecid was 260 nm and 237.8 nm respectively in 0.1N HCl. The method was validated in terms of accuracy, precision, linearity, limits of detection, limits of quantitation. This method has been successively applied to synthetic mixture and no interference from the synthetic mixture’s excipients was found.   

Optimized Non-Dead-Time Control of Inverter with Two-Phase Modulated SVPWM

2012 ◽  
Vol 562-564 ◽  
pp. 1531-1536
Author(s):  
Ming Xing Zhu ◽  
Jing Bo Shi
Keyword(s):  
Control Strategy ◽  
Pulse Width Modulation ◽  
Dead Time ◽  
Control Method ◽  
Short Circuit ◽  
Two Phase ◽  
Zero Crossing ◽  
Time Control ◽  
Bus Voltage ◽  
Current Zero

In the inverter control system, two-phase modulated space vector pulse width modulation (SVPWM) algorithm has the advantages of minimum switch loss and higher utilization of direct current (DC) bus voltage. Non-dead-time control strategy can eliminate the problems of the dead time effects. But the traditional non-dead-time control strategy heavily depends on the current zero-crossing detection, which may cause the output voltage distortion or even a short circuit. Based on the analysis of the reason for the distortion, a new optimized non-dead-time control method is proposed. Two methods for the detection of the overlapping area are enumerated. The conclusions are confirmed by the simulation results with MATLAB/ SIMULINK.

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