This paper presents the simulation and experimental result of class-E power amplifier. It is often used in designing a high frequency ac power source because its ability to perform the conversion efficiently even at high frequencies with significant reduction of switching losses. This paper aims to compare the transmission performance of electrical power between the air core transformer and iron core transformer which the identical input voltage of 50 VAC. Both transformers are designed to step voltage up (step up transformer) ratio of 1:4.5. The Arduino microcontroller Arduino was used to generate a pulse width modulation (PWM) with operating frequency of 3.74 kHz. IC gate drive TC4422 was used to drive the IRF510 MOSFET. Based on the simulation and experimental results the power loss in air core transformer is 75 percent while power loss in iron core transformer is 0.2 percent. The maximum distance that can transmit electric power of air core transformer is 9.3 centimeters.

The faults in a power distribution system do not only impact to power outage directly. They also cause voltage sag problem spread over the system. A single-line to ground fault is about 70% of the overhead system faults. The magnitude and duration of voltage sag causes the economic damage of the system. This paper presents an analysis of the different systems grounding to mitigate the voltage sag in a power distribution system by using the technical analysis system in case of one phase to ground fault. The objective is to minimize voltage drop for users using the simulation with single line to ground fault in distribution system voltage level at 22 kV PEA’s test system by the computer program. The results show that the grounding method can mitigate the voltage sag and reduce the damage of the economic system.

The objectives of the research were (1) to study perception of Integrated Marketing Communication (IMC) of Air Force Clubs (2) to study aspect of fans to Air Force Club’s image (3) to compare demographic characteristics with Air Force Club’s image and to study correlation of IMC of Air Force Club’s image with Air Force Club’s image. The data were collected by using questionnaire sampling from 400 members who were fans of Air Force Club. Data analysis employed frequency percentage arithmetic mean (􀝔􀒧) and standard deviation (S.D.) statistics used for hypothesis testing include t-test one-way analysis of variance and Pearson Product Moment Correlation Coefficient. The study presented the following results:Demographic Fans’Air Force Club were males (78.50%) ages between 25-34 (42.00%) government/stage enterprises occupation (42.75%) average monthly income between 20001-30000 baht (33.00%) marital status (48.30%) and lower than bachelor degree (82.50%) Demographic Air Force Club Fans from the middle class get news updates about the league from IMC social media television broadcast and radio reports. The fans are generally concerned about the league’s game results club’s news and information league’s schedule and result of drawing lots. Demographic Air Force Club Fans play a big role in bringing the image of Air Force Club in high level. The hypothesis testing showed that different occupation average monthly income and marital status of fans’ Air Force Clubhad statistically significant differences at the level of .05 on Air Force Club’s image. On the contrary difference in gender age education had no statistical significance for their Air Force Club’s image. The IMC of Air Force Club showed correlation with Air Force Club’s imageatstatistical significance .05that was three channelsincluding television broadcastingmedia radio broadcasting media and printed media.

The purpose of this research were to create and determine the efficiency of computer assisted instruction lesson on electronic circuit multimedia for secondary school students (grade 9) Triamudomsuksanomklaononthaburi school. The research sample consisted of 120 students of secondary school students (grade 9) during semester 2 in the academic year of 2012. The data were analyzed using mean standard deviation level of difficulty and discrimination power. The results found as follows : The efficiency of computer assisted instruction lesson electronic circuit multimedia for secondary school students (grade 9) is 80.15/83.35 and the students’ satisfaction with the computer assisted instruction lesson electronic circuit multimedia was at highest level ( = 4.60 S.D = 0.74)

This paper proposes the bidirectional resonant converter with duty cycle voltage control using for CCTV with solar energy. The converter designed at 20 KHz for 20 W with 92.85 % of efficiency is operated at zero voltage switch mode for reducing the losses of converter. The modes of operation divide in two modes for operating bidirectional current. The first part is buck mode which has 5 volt at the output voltage and second is boost mode which has 8 volt at the output voltage. The two operation modes of converter will be discussed in this paper.