The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Packaging of military electronic equipment frequently utilizes etched circuit boards. The need for insulating, or protective, coatings on etched hoards is recognized, particularly if the circuit boards are to he used in even moderately severe environments. Protective coatings must maintain a high resistance between conductive paths on circuit boards, must maintain cleanliness, prevent corrosion, and...
In this session we are limiting our discussions to the usual, day-by-day problems encountered in the use of glass epoxy laminates in making printed wiring assemblies; we will eschew the esoteric problems of ultra high temperatures, exotic materials and the like. We have as much as we can handle with what has to be done right now; we'll let someone else solve tomorrow's problems.
The following account of European testing practice and methods of testing electrical insulating materials is best appreciated if it is preceded by a brief resume of the volume of production of the West-European electrical industry and of the distribution of the total production among the individual countries.
In this brief discussion, the general natures of the molecular structures of insulating materials will be presented and some relationships between structure and physical properties and thermal and oxidative stability will be pointed out.
Electronics is the branch of electricity that deals with the behavior of electrons and especially the way they behave in space when they move inside vacuum or gas filled tubes. The word “electronics” is now universally applied to types of equipment such as Radio, Radars, Television, etc. and they are all examples of the use of electronics and electron tubes.
For the insulation of high-voltage windings of electrical apparatus two fundamental insulation systems and manufacturing methods have been in use during many years. In the U. S., a continuous hand wound mica tape insulation was preferred on the slot and coil end portion, which was impregnated with asphalt in vacuum in several operational steps. In Europe, to the contrary, many manufacturers insulated...
Net too long see the range of insulating manuals for d.c. rotating machines was limited to organic fabrics, paper, mica asbestos and a few simple natural resins and compounds. These materials are sound and in many places are still serving then purpose well. In the last decade the number and variety of insulation materials available have increased many fold. The synthetic resins, the fibre glasses,...
In the last three decades many new synthetic organic resins have come from the research laboratories of our chemical industry. When these are applied as an insulating film on a copper wire, and subjected to the many evaluation tests of the magnet wire industry, we can learn much about their fundamental properties. An insulated magnet wire to be used successfully for winding electrical equipment —...
Since 1955 the Rogers Corporation has been engaged in research and development in the field of synthetic fiber papers. For the past 3 years this work has been aimed primarily at the development of flexible, paperlike structures suitable for use as electrical insulation in rotating machinery. This paper is intended to serve as a progress report on the work done to date.
A great many statements have been made by various business and economic experts about opportunities expected to materialize during the decade — now hopefully being referred to as “The Soaring Sixties”. A number of these statements have proven — at least for the present — to have been overly optimistic. However, one prediction about this decade — which incidentally went almost unnoticed — is continually...
A great deal of importance has been placed on electronics during the age of automation and the ever increasing requirement for high reliability of electronic packages. Numerous problems have been encountered in assuring the successful and continuous operation of electronics in different environments. Temperature variations both high and low, humidity changes, shock and vibration are some of the major...
To many engineers not directly concerned with the more basic theories of dielectrics behavior, and, it must be recognized, even to some persons having a good knowledge of the electrical properties of individual insulating materials, it is often difficult to understand the detailed behavior of any particular insulation system. In other papers of this tutorial session, eminent speakers, well versed...
For centuries, matter has been understood by man largely in terms of its gross, macroscopic properties. To the electrical engineer this has usually meant such properties as resistivity, permeability, permittivity, and dielectric strength. Engineering design calculations have traditionally been based on tables of experimentally-derived “average” values of such properties. The limitations of the materials...
At last year's Insulation Conference there were four papers presented at the Marketer's Meeting. They were: "What the Purchasers Expect from the Marketers of Electrical Insulation" "What the Manufacturer Expects from the Marketers of Electrical Insulation" "What the Design Engineer Expects from the Marketers of Electrical Insulation" and finally Ned Phelan of Prehler...
Electrical insulation used in circuit breakers and various switching devices may be subjected to periodic arcing in the vicinity of moving contacts. Other insulating components are frequently under voltage stress and become susceptible to surface tracking when surface contaminants are present. It has been necessary for the insulation engineer to develop test methods for evaluating the arc and track...
This class of materials has become of greater importance during the past years for both military and non-military applications. It might be well to briefly elaborate on the title as it applies to this session.
Mica is surely no stranger to the manufacturer of rotating electrical machinery; it is as old as the industry. Within the last three to five years or so, a quiet revolution has begun in the mica industry. New synthetic binders have come into general usage, new forms of mica have become standard products. Mica papers, in tapes and in sheets, have given industry products which are so unlike the old...
The rapid advances being made in the airborne instrument field necessitates the use of higher temperature electrical insulating materials which will withstand severe thermal ageing and cycling, humidity, salt spray, fungus, vibration and MIL-L-7808 diester type oils.
Excellent thermal stability and electric performance combined with scalability were the chief properties which caused the electrical insulation design engineer to take note of silicone rubber. Several years of successful operating experience in rotating equipment and cable applications have shown that the interest was well founded. This paper discusses the application of silicone rubber tapes with...
It has been recognized for many years that a high potential test at the service frequency is a reliable indicator of the suitability of an insulation system for the service period. However, because a high capacitance apparatus requires large charging KVA at the test voltages and service frequency, it is often not convenient nor possible to apply the service frequency high potential test at field installations...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.