[D8818ACN], Letter from Charles Batchelor to Edison Machine Works, February 2nd, 1888


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


[D8818ACN], Letter from Charles Batchelor to Edison Machine Works, February 2nd, 1888

Editor's Notes

I sent you the drawings for the Edison-Simms torpedo motor; along with them I sent you drawings for the new motor, which is the general size for the motor to run in Mr. Simms' new boat. The conditions for this motor are 1500 volts at the dynamo, the resistance of the line 3 1/2 ohms, and the amperes passing through the cable should not exceed about 25. The speed of the motor is 1600 and it is geared down to 700 on the propellor; the armature is made to give back a contra E.M.F. of 350 volts; about 25 ohms of extra resistance is to be in the line at the transmitting end, on order to keep the heat down in the armature and also to give the operator a chance to put more current through the armature if he likes at any particular part of the run. I have figured this out to be not heavier than the old motor; in fact, I think it will be a little lighter and give about 18 to 20 horse power on the propeller. Please have these sizes as shown on the drawing kept to, if possible, and let Mr. Walters figure out a motor having about those sizes that with 1500 volts at the dynamo and will deliver about 20 horse power at the propeller. It would allow at least 25% more heat units on the armature than we allowed on the old machine.





Folder/Volume ID


Microfilm ID


Document ID



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