Gate Current in p-GaN Gate HEMTs as a Channel Temperature Sensitive Parameter: A Comparative Study between Schottky- and Ohmic-Gate GaN HEMTs

In this work, a comparison between the gate-driving requirements of p-GaN HEMTs with gate contact of Schottky and Ohmic type is presented. Furthermore, the presence of a gate current of different magnitude is experimentally verified for both types of devices. Successively, the possibility of using the gate current as a temperature-sensitive parameter and its monitoring during real circuit operation is proposed. The viability of monitoring the gate current without introducing additional complexity in the gate driver is examined through experimental measurements on commercially available p-GaN HEMTs.

Nine Channel Temperature Data Logger in Measuring the Effectiveness of the Sterilization Process of Medical Instruments with Dry Sterilization

Measuring the temperature on the dry sterilizer is very necessary because the temperature inside the dry sterilizer has the possibility that the temperature is not the same as the temperature that has been set and is displayed on the display. If the temperature in the dry sterilizer does not match the standard setting temperature for the sterilization process, then the sterilization process is said to be imperfect The purpose of this study is to record and monitor whether the distributed temperature in the sterilization chamber corresponds to the setting temperature. The workings of the temperature data logger tool is that the type K thermocouple temperature sensor will detect the temperature which then enters the analog signal conditioning circuit which then enters the ATMegga 2560 which has been given a program and processed in such a way, then the temperature will be displayed on a 4x20 character LCD. Temperature measurement data will be saved to the SD Card every 10 seconds in the form of a TXT file. This research has been used to record 2 sterilizers and compared with the Madgetech OctTemp2000 data logger. Based on data measurements and comparisons, the average error was obtained at a temperature of 50ºC with the smallest error value of 0.7% and the largest value of 3.9%. At a temperature of 100ºC, the smallest error value is 1.6% and the largest is 10.5%. Then at a temperature of 120ºC the smallest error value is 0.0% and the largest is 8.5%. This research can be used to help analyze the distribution of temperature in a room. With these measurement results, it can be said that this study still has afairly high error value at several measurement points.

Processing of Cf/SiC Composites through Two-Channel Temperature-Control CVI: I, Modeling

A two-channel temperature-control CVI scheme was proposed to fabricate thicker and denser composites. The two-channel structure helps to densify a thick preform, and a precise temperature control will guarantee a low and uniform porosity distribution. Validation simulations containing hydrodynamics, mass transfer, heat transfer and pore structure evolution were first carried out. Modeling results confirm that a two-step densification based on the new scheme can work well: At step I, all gases pass through the preform and the high-temperature bottom-preform is densified; At step II, by altering the outlet, temperature and infiltration time, part of gases are sucked into the preform and the remaining coarse preform is densified. The scheme can fabricate tick, uniform and dense composite, it can also avoid huge pump pressure thus protecting fibers from cracking. It is hoped to enlighten the CVI processing of ceramic matrix composites.

Simulation of Power RF GaN Transistors Thermal Parameters in Pulse Mode

This paper contains research results of thermal process in power GaN RF transistor in silicon substrate for pulse mode. Thermal mode research was done using computer simulation. Authors developed methodic allows significant decrease computational complexity. The dependences of maximum transistor channel temperature and thermal resistance as function of pulse width (with constant duty cycle) were done. Thermal simulation was done for power GaN RF transistor with overall gate width 2.1 mm.

FruiTemp: Design, Implementation and Analysis for an Open-Source Temperature Logger Applied to Fruit Fly Host Experimentation

FruiTemp is an open-source prototype developed to study the response of endophytic insect species such as fruit flies (Diptera: Tephrtidae) to variable temperature conditions including the controlled laboratory and fluctuating field settings. The system is a three-channel temperature sensor that consists of two precision thermistors that measure the temperature in the core and the surface of a fruit on a tree and a Harsh Environment thermistor that measures the air temperature surrounding the host at a rate of one measurement per 15 min. The sample rate can be adjusted according to the researcher’s needs. The system was successfully tested in field and laboratory experimental conditions using apples as the fruit model. The measurements on apples on trees lasted five consecutive days and produced a range of reliable data. After assessing statistical agreement and precision, the results revealed a differential bias of 0.331 °C and a proportional bias of a magnitude of 0.982. This work promotes open-source implementations allowing inexpensive solutions aiding experimentation procedures by significantly lowering operating costs.