US1414619A - Assiojfob - Google Patents

Description

w, C. BHTNTON, JR. MEANS FOR INCREASING THE DIVELECTRIC STRENGTH 0E CONDENSERS.y

l APPLICATION FAILED OCT. 17| 1918- 1,41 4,6 1 9 Patented May 2, 1922.

TTT-NIIIITWW will" EVLLIAM BRIITTON, JR., OF KENNETT SQUARE, PENNSYLVANIA, ASSIGNOR, BY MIESNE ASSIGNENTS, TO PHILBRIN CORPORATION, 0F KENNETT SQUARE, ENN SYLVANIA.. A CORPORATION OF DELAWARE.

I1""NS FOR NCRESING THE DIELECTRC STRENGTH OF CONDENSERS.

finiamo.

.application filed otober 17, 1918.

To (1.7i fr/.Iom- 7'2 may romena:

lle it known 'that l, WinLiAii C. BiiiNToN, Jr.. a citizen of' the United States, residing at Kennett Square. county of Chester, and f'itate ot Pennsylvania.. have invented a new and uset'ul Improvement in Means for Inf creasing the Dielectric Strength of Condensof which the following is a full, clear, and exact description. reference being had to the accoinpai fing dra-wings. which form a part oil this specification.

ln ignition systems for internal eonibustion engines, in 'wireless telegraphy, and in inany other situations. the provision ot' condeiiscrs which will resist all conditions, norinal and abnormal, tending to break the-in down.`lias seemed to present an insoluble problem. The provision of acondenser which will stand up under all normal conditions is in itselil a task of great diliculty, but even it such a condcnsei-,be provided, there are certain abnormal conditions which will break down an absolutely yperfect condenser. 'llie chief of these abnormal conditions is the breakage, accidental or deliberate, of the secondary circuit. Acciden* tal breakage ot' the secondary circuit cannot always be avoided. although careful Workniansliip niininiizes the risk. No 'well trained engineer will deliberately open `the secondary circuit: but electrically controlled apparatus is frequently operated by coinparatively ill -trained or ignorant operators; the opening of the secondary circuit alioids aconvenient means, for example, for slowing down an internal combustion engine: or it iiiay be, and frequently is, opened eXperimentally to determine how the engine Will operate under such conditions.

ln the norinal operation, for example, of an ignition system, the secondary circuitis induced by the opening of the primary circuit, the primary circuit being repeatedly rapidly opened and closed by ineans .of a vibrator or a contact maker and interrupter. The self-induction produced by the opening oi' the primary circuit raises its voltage and when the pri-mary circuit is closed, the condenser impresses its liigh voltage upon they 'primary circuit. lf the secondary circuit remains broken, the resulting mounting `voltage in the secondary coil causes the voltage of the primary circuit to rapidly increase :tar above normal, imposing a strain upon Specification of Letters Patent.

I Patented May 2, i922.,

Serial No. 253,582.

the condenser far beyond that Which it is designed to resist. Hence, even though the condenser be absolutely perfect in its construction, with a reasonable margin of safety in the Way of capacity and vdielectric strength, it breaks down under the extraordinary strain. The breaking down of the condenser paralyzes the Whole System and niay often produce the inost serious results.'

v T he danger exists to its ina-xiinum extent when the voltage rises rapidly. An eihcient condenser can stand an actually abnormal Voltage provided the increase in voltage is gradual, but not if the increase is sudden.

I have Solved the problem of building up 'the dielectric strength of a condenser so that invention presents the following characteistics. A plurality of condensersc preferably two, are arranged in the condenser circuit. They n'iust be arranged in parallel and not iiiv series. They must be of different capacities. Their total capacity need only be the saine as the calculated capacity of asinglo condenser adapted to meet normal conditions. .f

The accompanying drawing is a diagram showing the application ot the invention to the ignition system of an internal combustion engine, although it will be understood that this is only one of niany possible applications.

A source of current supply, a, which may be assumed to be a storage joattery, is grounded at one side, While its other side is connected to the primary winding b of an induction coil: rl`he Winding b connects with a contact maker and interruptor c actuated roin an engine-driven shaft (l. The secondary winding c' of the induction coil .is grounded. at one side, ivlliile its other side is connected to a. distributor f, the rotating blade g of Which (driven from shaft closes the secondary through the spark plugs or' a plurality of. engine cylinders, one cylinder h and spark plug being shown. I prefer that the contact maker and interruptor shall have the specific construction shown in the Brown and Brinton Patent No. 1,234,278, issued July 24, 1917. The distributor may be constructed in accordance with Brinton Patent, No. 1,227,109, issued May 22, 1917.

in the primary circuit, in shunt with the contactmaker and interruptor, are two conolensers m and n, arranged in parallel. llhese condensers are shown as of different size as a diagrammatic Way of illustrating their different capacities. lf the two condensers are of precisely the same. capacity, they are apparently no improvement over a single condenser. I have not determined, with absolute accuracy, what percentage of variation in capacity is a prerequisite to' success, but I have tried condensers Whose respective capacities Vary as little as two per cent. and have found that they broke down,

under conditions` y producingv a sudden mounting of voltage, about as quickly as a single condenser, while if the variation in capacity is increased to eight per cent the condensers vwill stand upnnder conditions which are invariabl fatal where a single condenser, or itsequ1valents-a plurality ot condensers in series or a plurality 'of condensers of the same capacity in parallclare used.

The observed phenomena in the case of a sudden increase in voltage With the use of a single condenser is, first, violent sparking and then, or perhaps simultaneouslyLthe burning of the condenser, thus destroying,g` its properties. Where my invention is einn ployed, there is no sparking, and the condensers are not deleteriously affected, but take care of the highest voltage which can be created by the deliberate breaking of the secondary circuit. As above stated, l have i'ound it unnecessary to increase the 'totalcapacity ofthe ltwo condenser beyoiid that which is required for. a single condenser that ,is designed for normal working' conditions.

The condensers that l have successfully employed are constructed in accordance with the Brinton Patent No. 1,237,015, issued .August 14, 1917; and also embody the specific improvements set forth in my appliI cations, Serial No. 181.735. filcd July 20.' 1917, and Serial No. 206.900, ilcd December My theory of the electrical action that accounts for the abilit \v oi' a pair of parallel unlmlanccd condenscrs to withstand a tar greater and more sudden increase ot' voltage than a single condenser ot' greater capacity is that there occurs a surging` oi' the current back and Jorth from one condenser to another. eaclli condenser momentarily taking up the shock while the dielectric strength of' the other is buildingr up. l do not feel warranted, however. in advancing too con iidently any scientific theory to account for the observed result. The prccise action may be too obscure to be with certainty discoverable. However, this exact knowledge is unnecessary to the practice ot' the invention, it being only necessary to follow the simple instructions herein contained to avoid the breaking,r doivn'heretotore deemed to be an inevitable consequence of a sudden marked increased in voltage.

Havingr now fullydcscrihed my invention, what I claim and desire to protect by lietters Patent is:

l. rlhe combination of a primary and a secondary circuit having' an induction coil connected thereto, a malte and break device, and a lurality et' condensers ot dili'erent capacities connected in multiple to each other in the primary circuit.

2. An ignition system Jtor internal ecmbustion engines having an induction coil, a primary circuit-connected in series ivith'a source ot electrical energy, `the Aprimary winding of the induction coil and an interrupter, a secondary circuit connecting the secondary Windiin;1 of the induction coil, a

distributor and asparlr plug: in series, and

a condenser having a plurality of units oi? substantially difercnt capacities connected in parallel with eachother and shunting the interruptor.

3. An ignition system 'for combustion. engines comprising an indue-tion coil having a primary winding and a secondary Winding. a source of electric energy` an interruptw, a plurality oic condcnscrs ot diiiicrcut capacities, a distributor, a spark plug. a secondary circuit connecting),r the secondary winding ot the induction coil, the distributor and spark plug in series with each other. anda priu mary circuit connecting'the condensclrs and intcrrupter in multiple with each other and in scrics with thc primary winding' of 'the induction coil and the. source ci energy.

ln testimony of which invention, l have hcrcunto set my hand` at Kennett Square, la., on this eleventh day oi October, 1918.

Vif'LLIAll/i (l. BlllNTON, die.

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