Electronic Protection Devices Research Articles

Rancang Bangun Elektronik Motor Relay sebagai Proteksi Berbagai Gangguan Motor Listrik

The protection system against disturbances in induction motors has an important role in industry. In general, protection in electrical installations only uses MCB (Miniature Circuit Breaker) and fuses which can only protect against overcurrent and short circuits and there are still many kinds of important protection that have not been covered in it even though along with technological developments many electronic protection devices have been created. The purpose of this final project is to plan and manufacture electronic motor relays against over load, phase loss, phase reverse, phase unbalance, short circuit, ground fault, and locked rotor disturbances. The AVR microcontroller is used as a controller for all systems in detecting disturbances. Where the current setting range and trip time are programmed using the C language which is operated with a keypad and displayed on the LCD. As current and voltage sensing using current transformers and voltage transformers. As for sensing phase reverse, it takes the signal from the differential amplifier and forwards it to zero crossing, trigger and X-or. Testing the accuracy of the electronic motor relay is carried out in each fault. The data obtained shows that the microcontroller can be used as a precision analog voltage controller. This is because the AVR microcontroller has good features and is supported by adequate processor speed for use in this kind of application.

A Predictive Model on the Intention to Accept Taekwondo Electronic Protection Devices

This study’s purpose was to establish a predictive model of the intention to accept Taekwondo electronic protector devices through the application of the technology acceptance model. Two hundred and twenty collegiate Taekwondo practitioners affiliated with the Korea Taekwondo Association participated in a survey that included 28 questions (4 relating to demographic characteristics, 12 to precursor variables, and 12 to the technology acceptance model). Correlation and structural equation modeling analyses were applied and a significance level of 0.05 was used. The results were as follows. Perceived quality had a significant influence on perceived ease of use (β = 0.380, t = 3.481, p < 0.001) and perceived usefulness (β = 0.544, t = 5.098, p < 0.001). Visual attractiveness had no significant influence on either perceived ease of use (β = 0.159, t = 1.798, p = 0.072) or perceived usefulness (β = −0.010, t = −0.131, p = 0.896). Wearability had a significant influence on perceived ease of use (β = 0.234, t = 2.867, p < 0.01), but a significantly negative influence on perceived usefulness (β = −0.218, t = −2.932, p < 0.01). Functionality had no significant influence on either perceived ease of use (β = 0.116, t = 1.031, p = 0.302) or perceived usefulness (β = 0.107, t = 1.093, p = 0.274). Perceived ease of use had a significant influence on perceived usefulness (β = 0.418, t = 4.361, p < 0.001) and acceptance intention (β = 0.361, t = 4.031, p < 0.001). Perceived usefulness had a significant influence on acceptance intention (β = 0.525, t = 5.758, p < 0.001). These results suggest that improving the perceived quality and wearability of the devices will enhance their acceptance. We believe that this study provides an appropriate verification model for the intention to accept Taekwondo electronic protection devices.

Microstructure and Electrical Properties of Low-Voltage Barium Titanate Doped Zinc Oxide Varistor Ceramics

In the present, varistor ceramics through the combination of zinc oxide (ZnO) with a perovskite material have become widespread because of their unique properties for a wide range of applications in electronic protection devices. Low-voltage zinc oxide (ZnO) varistors with fast response and highly nonlinear electrical properties for overvoltage protection in an integrated circuit are increasingly significant in the application of low-voltage electronics. The present study highlights the interaction between barium titanate (BaTiO3) and ZnO varistors through the employment of solid-state reaction method in the production of low-voltage varistors. The effects of BaTiO3 on the microstructure of ZnO varistors were analyzed through scanning electron microscopy (SEM), energy dispersive X-ray analysis spectroscopy (EDS) and X-ray diffraction (XRD). The EDS analysis and XRD measurements suggest the presence of ZnO and BaTiO3 phases. The electrical properties of BaTiO3-doped ZnO varistors were examined based on the current density-electric field (J-E) characteristics measurement. The varistor properties showed the nonlinear coefficient (α) from 1.8 to 4.8 with the barrier height (φB) ranged from 0.70 to 0.88 eV. The used of BaTiO3 additive in ZnO varistors produced varistor voltages of 4.7 to 14.1 V/mm with the voltage per grain boundary (Vgb) was measured in the ranges 0.03 to 0.05 V. The lowest leakage current density was 348 μA/cm2, obtained at the samples containing 12 wt.% BaTiO3 with high barrier height. The reduction in barrier height with increasing BaTiO3 content was associated with the excessive amount of BaTiO3 phase, hence cause the deterioration of active grain boundary due to the variation of oxygen (O) vacancies in the grain boundary.

The design of electric drives with electronic protection devices

The possibility of designing an electronic device for protection and diagnostics of electric drives with improved characteristics is considered. The technique and algorithm of design of similar devices, the structural scheme of the device constructed on their basis are offered. To improve the characteristics of the device of protection and diagnostics of electric drives in the work it is proposed to provide for the use of measuring transducers with linear dependencies of the output values on the controlled ones. The latter is possible as a result of the use of measuring circuits in measuring transducers with linearized dependencies of the output values on the input and the use of intelligent sensors. As a measuring circuit for the construction of measuring transducers is considered the measuring circuit of Kenigsberg, which is characterized by a linear dependence of the output active value of the passive measured (controlled physical quantities). At the same time, the intelligent sensors are additionally assigned the function of linearization of the output dependence of a «simple» sensor on the controlled physical quantity.

Advanced hearing protection and auditory awareness in individuals with hearing loss

In-ear and earmuff-type electronic protection devices are rapidly being introduced into the marketplace and deployed in noisy industrial workplaces and military settings. In these environments, workers must be sufficiently protected from noise while being able to maintain good communication abilities and situational awareness. Features such as level-dependent attenuation or amplification, user-adjustable talk-through circuitry, noise reduction, and remote communication capabilities are commonly found in advanced devices. The benefits of these features depend on their complex interaction with the signal and noise characteristics, the hearing status and language proficiency of the workers, and the nature of the auditory task. Yet, detailed electro-acoustical specifications are rarely reported by manufacturers. Measurement standards are also lacking, though the advent of ANSI/ASA S12.42 should in part address this situation. In this paper, the characteristics of two advanced devices are reported over a test battery including measurements of the passive sound attenuation, level-dependent talk-through sound transmission, and speech recognition in noise for listeners with a wide range of hearing profiles. Electronic level-dependent attenuation provided superior speech recognition performance than passive attenuation for all groups of listeners, and often exceeded unprotected speech recognition performance.