Solar-blind ultraviolet cameras with image intensifier with CMOS detector typically use various count methodologies to measure the optical energy of an electrical corona. However, these count methodologies are non-radiometric without considering parameters such as distance, focus-, zoom-, and gain setting of a camera. An algorithm which considers the calibration and radiometric measurement of optical energy for the slow frame rate intensifier type cameras is presented. Furthermore, it is shown how these calibration data together with the flowcharts are used for the conversion from raw measured data to radiometric energy values.

PIC microcontroller has a vital role in various types of controllers and nowadays the presence of PIC microcontroller is unavoidable in most control applications. This paper describes the enhancement of soft starting of induction motors using PIC microcontroller. Soft starting is required for the induction motors with reduced applied voltages so that the peak starting current is reduced and the startup of the motor is smooth with controlled torque and reduced mechanical vibrations, reduced starting current with correspondingly reduced bus voltage drops. While many of the available schemes of soft starting offer better results in view of smooth starting process, the proposed methodology offers soft starting as well as it cares about the source current quality. In contrast to the conventional multistep starting scheme, in this work a continuously controlled starting scheme is proposed. The three phase AC voltage controller topology is used as the core controller. In each of the half cycles, instead of a single conduction period with a single delay angle, the proposed AC voltage controller is switched symmetrically in each half cycle with multiple pulses in each quarter cycle. Symmetrically placed fixed numbers of switching pulses are used. The paper also describes the various time ratio controls namely the phase angle controller, the extinction angle controller and the symmetrical angle controller. The design aspects of the proposed soft starting scheme and the validation of the proposed system in the MATLAB SIMULINK environment are presented in this paper.

Solar-blind ultraviolet cameras as part of high-voltage electrical inspections until recently have mostly been used for pure observations. These observations only imply the presence of corona discharges and not the severity thereof. A radiometric algorithm together with a calibration algorithm to perform an optical energy measurement were presented earlier. This is a guide on how to apply the algorithm to determine the total optical measurement from corona discharges, plus additional processing. This guide and additions are used to compare the electrical and optical domains with actual examples. The main objective is to illustrate how to determine the electrical and optical relation for the IEC 60720 high-voltage electrical test configurations using a standard open procedure.

The article presents precision and numerically stable method of calculation of the characteristic impedance of cylindrical multilayer waveguides used in high-precision wideband measuring instruments and standards, especially calculable thermal converters of AC voltage and precision wideband current shunts. Most of currently existing algorithms of characteristic impedance calculation of such waveguides are based upon approximations. Unfortunately, application of such methods is limited to waveguides composed of a specific, usually low number of layers. The accuracy of approximation methods as well as the number of layers is sometimes not sufficient, especially when the coaxial waveguide is a part of precision measurement equipment. The article presents the numerically stable matrix analytical formula using exponentially scaled modified Bessel functions to compute characteristic impedance and its components of the cylindrical coaxial multilayer waveguides. Results obtained with the developed method were compared with results of simulations made using the Finite Element Method (FEM) software simulations. Very good agreement between results of those two methods were achieved.