[N197077], Patent Caveat, Thomas Alva Edison, June 1882
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Title
[N197077], Patent Caveat, Thomas Alva Edison, June 1882
Editor's Notes
SELECT THIS DRAFT CAVEAT. LONG BUT IMPORTANT; SUMMARIZES TAE'S SPRING/EARLY SUMMER RESEARCH ON LAMP MFG, DYNANO REGULATION, BATTERIES: "The object of this caveat is to set forth various devices and inventions which I have perfected for use in my system of electric lighting, but which require the inventions and arrangement for economical manufacture etc that they may be used commercially. In Electric Lamps when very high candle power and emf is used the sealing in of the wire through the lamps shouldbe very perfect" [discusses leading wires, sealing, and using mixture of Pt and ground glass in the wires] "To keep water from being absorbed by the carbon filaments after carbonization I dip them when they are taken out of the mould in a solution containing a disolveed solid the menstrum having no water parafine disolved in a hydrocarbon liquid will caus the carbon when dippedto be covered with a skin of parafine. Beeswax, resins, gums, tar, etc may be used all but the broadened ends are so dipped" [describes process of treating, drying, mounting the carbons & exhausting lamp] A small ball of charcoal filled with phosphorus anyhdide of other drying agent might be used within the lamps" [etc] Then "a good method of regulating the EMF of the lamp circuit automatically from the dynamo or rather magneto electric machin, is to use separate brushes on the commutator to work the field and so place these brushes that when the load increases by putting in lamps advantage will be taken of the shifting neutral point on the commutator due to lead to give a greater emf across these two brushes employed to give the field magnet as current, when the two brushes are placed at right angles to the brushes that form the lamp circuit the field forming the bridge wire of a wheatstone balance this is when the load is very light hence to obtain sufficient emg to energize the few lamps that are on the brushes must be set off of the exact neutral point. Now if the load is increased by addiing lamps the neutral point will shirt & while this causes the emf of the mainline brushes to drop the emf between the field brushes increases hence the drop in emf on one is nearly compensated by the rise in the other" etc "Another method of regulating is to use a small electric engine for rotating brushes around a commutatoe & have the commutator connected to a portion only of the wire around the field" etc. Then describes mercury regulator, other regulation schemes. Then c. 2 pages describing battery construction. Then describes hydrocarbon filament coating experiments. Ends p. 121 with discussion of providiing even reisstance of multiple filaments in a lamp.
Supplied year and month
Author
Date
1882-06-00
Type
Subject
Folder/Volume ID
N197-F
Microfilm ID
40:371
Document ID
N197077
Publisher
Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University