Abstract: A hard start capacitor replacement unit has a plurality of capacitors in a container sized to fit in existing hard start capacitor space. The capacitors are metallized film capacitors wound in a single cylindrical capacitive element. The container has a common terminal and capacitors value terminals for the plurality of capacitors, which may be connected singly or in combination to provide a selected capacitance. An electronic or other relay connects the selected capacitance in parallel with a motor run capacitor. The hard start capacitor replacement unit is thereby adapted to replace a wide variety of hard start capacitors.

Abstract: A capacitor has a polymer housing and a wound metallized film capacitive element received in the housing, with leads connected to terminals on the cover of the housing through a pressure responsive interrupter assembly. An air chamber is provided in the housing, confining a compressible volume of air, and insulating fluid fills the remaining volume of the housing, substantially immersing the capacitive element. The air chamber is advantageously defined by a piston slidably mounted in the housing. Upon a high pressure condition caused by failure of the capacitive element, the volume of air is compressed to cushion the onset of the high pressure, protecting the case from rupture prior to operation of the pressure responsive interrupter assembly.

Abstract: A metallized film capacitor is provided with a polyurethane oil insulating fluid. The insulating fluid has a viscosity in the range of about 500 to 3000 poise at 25.degree. C. The polyurethane oil insulating fluid is produced by reacting an organic polyisocyanate with a primary polyol selected from the group consisting of castor oil, ricinoleic acid derivatives of castor oil and mixtures thereof. The reaction may be carried out in the presence of a secondary polyol chain extender such as a hydroxy-terminated polybutadiene diol. The reaction to produce the insulating fluid is carried out under conditions wherein the ratio of NCO groups of the organic polyisocyanate to OH groups of the primary and secondary polyols, if present, is in the range of about 0.1 to 1 to about 0.6 to 1. The ratio ensures that there is no excess of unreacted NCO groups in the insulating fluid and that the reaction produces a viscous fluid, not a substantially solid elastomer.

Abstract: A dual metallized film capacitor is provided which has improved life test characteristics in that the smaller capacitor more closely tracks the capacitance loss of the larger capacitor. This results from a reduced length of insertion of the barrier strip into the capacitor section. The result of a barrier strip of reduced width permits use of a more expensive barrier material with superior performance but without substantially increased material cost.

Abstract: The specification teaches a method for producing a wound capacitor section wherein the core of the winding is employed as an integral mechanical mount for the completed capacitor, and also the capacitor produced thereby. In one embodiment, the core is longer than the capacitor section and the excess core is threaded for use in mounting the capacitor. In another embodiment, a flexible tie strap is threaded through the hollow core and encapsulated therein.

Abstract: A metallized capacitor is formed by winding at least two thin metallized dielectric films into a cylinder, the ends of which are sprayed or metallized and connected to externally mounted terminals. A protective interrupter is provided by connecting a very thin electrically conductive strip to one of the metallized ends and running the conductive strip over the surface of the outside metallized film to one of the externally mounted terminals. The capacitor so formed is embedded in heat cured epoxy so that the strip is integrated within the rigid epoxy case. Accordingly, the strip will tear or separate on any swelling or cracking of the epoxy case due to a faulty capacitor and thereby interrupt the power supply. The conductive strip may be scored at intervals along the length thereof in order to enhance its shearing or tearing ability.

Abstract: A single encapsulated wound capacitor unit (10) is made up of a number of sub-capacitors (12, 14, 16). The sub-capacitors are connected in parallel by insulated jumpers (30, 32) which extend outwardly from the capacitor encapsulant (36). A repairman may adjust the capacitance as required by cutting one or more of the exposed jumpers (30, 32) prior to installing the capacitor.

Abstract: A multiple element, cylindrical metallized film capacitor and method of making the same are provided which facilitate the winding and making of electrical connections to a small value element of the multiple element capacitor. First and second dielectric films are metallized on one side thereof and are wound in cylindrical form with the non-metallized side of one film being in contact with the metallized side of the other. Selective portions of one or both of the metallized sides are removed in order to provide a multiple element device. In one embodiment, a metal strip having a metal tab extending therefrom is wound in an area where one of the metallized sides has been removed and an insulated strip is wound to surround the metal strip which forms one plate of a small capacitor. In another embodiment only a portion of the width of a metallized side of a film is removed providing more turns for the small capacitor to which an electrical connection can be made.

Abstract: Multiple capacitors wound from two thin metallized dielectric films on a common core are provided with electrostatic shielding therebetween. A first capacitor is wound in the usual manner using two metallized films. After the winding of the first capacitor, the metallized layers are removed from the first and second metallized films over predetermined intermediate regions of the films. A film of insulating material and a metal shielding layer are then wound between the first and second films with the insulating material and the metal shielding layer extending outwardly from one end of the cylindrical form. The film of insulating material and the metal shielding layer are wound to encircle the capacitor at least once, with the film of insulation material encircling the metal shielding layer on each side thereof. After the metal shielding layer has been wound, the winding of the first and second metallized films is completed to form a second capacitor on the first capacitor.

Abstract: A dual wound capacitor is provided in which two capacitors with a common electrode are provided or two separate capacitors are provided in a single winding operation. First and second metallized dielectric films are wound through a predetermined number of turns to a position preceding a gap in at least one of the metallized sides of the film. The gap is formed by removing or omitting metal from an intermediate portion on the dielectric film either before the capacitor is wound or during the winding process. The gap so formed may be as narrow as an eighth of an inch and, under any circumstance, is substantially less than the length of one winding of the capacitor. An insulated sheet having a length sufficient to encircle the gap is inserted and wound between first and second metallized dielectric films and extends outwardly from one side of the capacitor to form an overlapping circular barrier which separates the metallized portions on each side of the gap.

Abstract: A multiple capacitor and method for making the same. A single capacitor section is wound in the usual manner from two metallized films. After the winding has progressed through the proper number of turns for one of the capacitors, the metallized layer is removed from the surface of at least one film over a selected distance. An insulated sheet having a length sufficient to encircle the capacitor at least once is inserted between the film layers to extend beyond at least one end of the wound cylinder. The ends of two additional dielectric strips are inserted into the capacitor winding between the metallized films. Winding is then completed and each end of the wound section is metal plated. Leads are then attached to the ends of the capacitor section, resulting in a plurality of capacitors having different voltage ratings but wound within a single capacitor section.

Abstract: There is disclosed a wound capacitor which is designed to open an external circuit upon capacitor failure. This is accomplished by dividing the foil at each end of the capacitor into two regions. A lead is then connected to each region so that the completed capacitor has a total of four leads. The two leads at each end of the capacitor become a part of the external circuit. A capacitor failure thereby causes an open in the external circuit.