A method is proposed for non-contact indication of the presence of operating voltage in disconnected sections of an alternating current contact network, based on the properties of liquid crystals and the effect of electrical influences. A procedure is given for selecting voltage indicator parameters when used on single-track sections of a traction network. The possibility of using sign-synthesizing liquid crystal indicators to create contactless indicators without an internal power source to indicate the presence of operating voltage in sections of the contact network is shown.

Keywords: AC contact network, single-track section, disconnected section, operating voltage, non-contact indication, liquid crystal indicator, properties, equivalent circuit, selection of parameters

The article is devoted to the study of the interaction violations of electric locomotives current collectors with a contact wire, accompanied by the appearance of an electric arc. In order to further develop the system of technical diagnostics of current collection disruptions, accompanied by arcing, it is necessary to study the nature and parameters of the processes that occur with these disruptions. The main part of the article is devoted to the determination of the geometric parameters of the heating zone of the contact wire material by a movable electric arc, followed by an analysis of the applicability of the obtained dependences and their normalization. The description of the research area, the essence of the problem and the main statements of the technical diagnosis of current collection disruptions is given. The nature of the distribution of heat in the cross-section of the contact wire is shown. Based on the nature of the process and plane geometry, the parameters of the heating zone of the contact wire material are obtained: the area of the heating zone and the depth of the heating zone. Limitations in the application of the obtained dependencies are given.

Keywords: electric transport, overhead contact system, contact wire, current collection disruption, electric arc, current collection with arcing, thermal wear, softening, diagnostics

A new device is offered for the analysis of motor oil contamination of the internal combustion engine with dispersed particles. To enhance the information content of the output data and the possibility of the continuous automated monitoring, as well as improve the accuracy, efficiency and reliability of the measurement device uses opto-electronic method of analysis of pollution of motor oils based on a method of ""spot test"".

Keywords: lubricant, optico-electronic device, the internal combustion engine, motor oil, methods for analyzing contamination, optical inspection method