M. Wesołowski

Laboratory tests of medium voltage switchgear isolators

This article presents results from laboratory tests of MV switchgear isolators, that were exposed to violent environmental conditions. Tests were carried out on support and bushings isolators. The problem occurred when accumulation of various active gaseous media in the interior of the MV switchgear and in contact with moisture form aggressive substances (i.e. acid). The tests setup with partial discharges detector and results from experiment were presented in the paper.

A new sensor system for measuring environmental parameters of switchgear

The corrosion process in devices and equipment of switchgears strongly depends on environmental parameters. In some cases, degradation of copper conductors and other insecure elements is impermissible intense and provides the increase of failure and exploitation costs of such devices. In the paper, an authors system for measurement and registration of chosen environmental parameters is presented. The system is dedicated for use in devices typical for electrical systems and is characterized by low prices. It can be used as a measuring device, or as a part of automatic control system where can operate like a controller that enables to run filters if it is required.

An integrated driver for quantum cascade lasers

The paper presents a construction and some investigations results of a new driver for quantum cascade (QC) lasers. The driver is designed to control pulse and CW mode QC lasers. For both laser mode operations, there is the possibility to set a laser current in the range of 0.1 A - 3 A and pulse duration of 30 ns at the frequencies to the level of 25 MHz. The stabilization of the temperature in the range of 50°C ÷ -30°C with accuracy of 1.5 K is also achieved. A full synchronization with external pulses makes the driver very useful in a construction of a free space optical transmission system and of a laser spectroscopy setup.