[NM020AAF], Technical Note, Thomas Alva Edison, April 29th, 1885


View document with UniversalViewer   → View document on Archive.org  → Re-use this digital object via a IIIF manifest


[NM020AAF], Technical Note, Thomas Alva Edison, April 29th, 1885

Editor's Notes

patent on quad for way wires see U.S. Pat. 333,291 "Dick-- I sent you diagram for another patent its on the lines of the Quadruplex one message is sent by reversing the current the other by increasing and decreasing current. To use the principle on way wires I strock a cute thing- say no reverse men are working & keys X x all along the line are open I have no battery from this apparatus= on the line there is constantly connected say 16 cells M 1/2 of these may be at one terminal & 1/2 at other or all together anywhere in line. This current is used to signal on common relay by increase & decrease by means of key & Resistance The battery S S' is exactly twice as many cells as M but always thrown to line in the opposite direction to M hence of the 32 cells 16 neutralize the 16 of the main battery put 16 on line but in opposite direction thus giving a reversal & working polarized relay but not effecting the common relay as there is always the same amount of current= You know that in Quad as in all cases the common relay at the moment of reversal loses its magnetism for an instant and this causes the relay lever to leave its front point for an instant thus mutilating signals it is very quick but still it mutiliates to obviate this in the Quadruplex the back point is used to close the sounder hence at the moment of reversal the lever jumps back nearly striking the back point & does frequently strike & give a false sound. To reduce this defect to the minimum I have struck very good thing I place a large manget N in connection with the regular magnet & shunt the latter with it But placing a condenser of large capacity in circuit with it The Resistance of this magnet is 2 or 3000 ohms or more while the regular magnet is only ordinary Relay resistance 150 ohm at the moment of reversal a powerful waves due to the discharge & recharge of the condenser takes place and this wave has its greates power at the exact moment the ordinary magnet has no magnestims the wave charges the big mag N & holds it for an instant= this wave is momentary thus you see at the moment when the regular magnet has no magnetism N has which ceases when the common magnet has-- Claim this= also number of stations on one line provided with common & polarized-- Combine throwing in out Res to work common The manner of reversing the direction of the current on the line at a number of stations This method of reversing for use in teleghy. This way station system is entirely original & you ot get some very broad claims-- The only defect is that while the common relay open can interrupt the polarized men must only close or interrupt while the sender is open this is no objection as they can hesitate every 10 words or so-- [drawings]




Folder/Volume ID


Microfilm ID


Document ID



Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University
Download CSV | JSON