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Miniaturization has become a prime design goal especially for airborne electronic components. Generally, this means increased electrical stresses which require both redesign of the insulation system and the introduction of improved materials. To meet these dielectric strength requirements, there has been increased reliance on epoxy embedding compounds. As in the case of any relatively new insulation...
Over the years there has been a continual increase in the rating requirements for metal-clad switchgear. Both the continuous ratings and the interrupting values have been pushed upwards in order to keep pace with the growing needs of industrial and utility electric power systems. Each rating increase has generally led to the need for better insulation for one or more of the following reasons: higher...
This paper attempts to summarize the basic molecular mechanisms which control the dielectric properties of glasses and glass-ceramic materials. An analysis of these polarizations reveals that alkali ions are the principal constituents which determine the dielectric loss properties. In glassy materials containing alkali ions in rather large quantities, these ions control the losses over most of the...
For some time, the manufacturers of electrical motors have searched for an integral insulation system to replace paper slot inserts and fiber end laminations. By way of illustration, there have been many attempts to design a suitable insulation of this type. Some of the more notable methods tried have been resinous thixotropic dip compounds, molded inserts of organic materials, spraying, and elaborate...
The development of the polyester nonwoven mat has culminated many years of searching for a high performance backing suitable for flexible electrical insulation. With the use of polyester fibers, a backing superior to cotton in moisture and thermal resistance was possible. The polyester nonwoven mat also overcame the deficiencies of glass fabric in conformability and retention of dielectric strength...
The insulation user is waiting patiently for the perfect insulation — a material that has the dielectric of synthetic films; that will withstand temperatures of mica; that is as resilient and flexible as silicone rubber; that is as tough as epoxies or polyesters. An insulation in the form of a liquid or semi-liquid with an infinite pot life, that a component can be dipped into and will air-dry in...
In the past year a new class of epoxy resins has come onto the market. These resins which go under the name of Oxiron® are epoxidized polybutadienes. In addition to having the oxirane oxygen groups, they also possess unsaturation and therefore the methods of curing them can be quite diverse. The great versatility of this resin has been discussed in previous papers(1, 2, 3, 4) as well as its application...
The demand for higher reliability in electrical and electronic components, coupled with the advent of many new magnet wire insulations and epoxy formulations, has made it advisable to look at epoxy encapsulated coils used in the electro-mechanical, electrical and electronic fields in terms of the complete systems. (The term "system" is used here to mean a specific insulated magnet wire encapsulated...
A group of insulation products based on a polyimide polymer have been introduced to the electrical industry gradually since late 1959. This group of products, sold under the trade name of "Pyre-M.L.®," includes wire enamels, coated glass fabrics, and an insulating varnish. The polyimides were selected for commercialization as the most thermally stable type of polymer yet characterized in...
The demands of the developing aerospace technology stress the need for lightweight, compact, reliable components for its various electronic systems. The encapsulated magnetic component represents one of the most reliable methods for the compact packaging of transformers and other inductive components. Encapsulation processes which are easily adapted to the fabrication of complex shapes will be demonstrated...
Because I find it difficult and almost impossible to separate the responsibilities of the distributor to the manufacturer, from those of the manufacturer to the distributor, I was tempted to change the title of this paper to "The Dynamics of the Distributor/Manufacturer Relationship" — I feel very strongly that the inter-relationship makes it almost impossible to consider them as standing...
Change is the subject of my talk — that is, change that seems to be taking place in the channels of electrical wholesale distribution; or perhaps more graphically, how the sands are shifting m the channels of electrical distribution.
Investigations originally stimulated by an interest in the passivation of silicon surfaces have culminated in a high stability capacitor with a silicon-dioxide thin film as the dielectric. This paper presents some characteristics of the silicon-dioxide thin film alone, and of a silicon/silicon-dioxide capacitor. The capacitor can exhibit either a highly stable capacitance or a capacitance which is...
The results of statistical studies on the preparation and evaluation of thin film capacitors are presented and discussed. The dielectric material used was silicon monoxide (SiO.) Data on single layer capacitors are presented followed by results and discussions of multilayered thin film capacitors. Thin films of SiO (1000 to 20,000 Angstroms) were vacuum deposited in stacked layers numbering up to...
Developments in resilient epoxy resin systems have a marked influence upon the selection and application of encapsulants for magnetic components. The designer is prone to think in terms of a resilient insulating material which accommodates the mechanical and thermal stresses arising during the performance of magnetic circuits. Resiliency in an epoxy electrical insulating material is not gained without...
As stated by the preceding speaker, Mr. Webb, it is extremely difficult to separate the responsibilities of the manufacturer to the distributor from those of the distributor to the manufacturer. Each wants a completely honest arrangement, where loyalty, integrity, sincerity, reliability and desire for creative accomplishment are watch words, not only between the participating organizations, but also...
The tantalum electrolytic capacitor can be considered as a parallel plate capacitor in which tantalum metal is one electrode, a tantalum oxide film is the dielectric, and the tantalum oxide/electrolyte boundary is the other electrode. This model is useful for many purposes, although it is obviously oversimplified and does not take into account such phenomena as the assymetry of the system with regard...
In this paper, we will confine our attention to a new method for the testing of slot cell sheet stock insulation components. However, the test procedures may be eventually extended to evaluating other forms of insulation materials.
In the last decade the electrical industry has become increasingly conscious of temperature classification of insulation. AIEE #1 "General Principles Upon Which Temperature Limits are Based in the Rating of Electrical Equipment" has recognized in recent revisions that temperature classification by chemical composition is inadequate. Therefore, AIEE #1 provides that insulation may be classified...
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